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Engine basics => Engine set up tips => Topic started by: Bill Little on April 03, 2011, 12:57:37 AM
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Run Style: (4-2-4, wet 2, solid 4)
Venturi:
NVA:
Prop
Make:
Diameter and Pitch:
Fuel
Brand:
Nitro%:
Oil% and "Blend":
Quantity used:
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Bill,
Hope you get good feedback here. I've got an OS .46 LA that I just completed a light break in( 20 ounces of 5% Nitro, 20% castor ). I got rid of the remote NVA , plastic backplate and stock venturi. Using the NVA and venturi from the OS 25LA with an additional headshim.
I did the break-in using an 11-4 Zinger and plan to start with an 11-5 XOAR in the air. After a half dozen or so flights, I'll be going to 10% nitro and a 20% synthetic/ castor blend. Using a tongue muffler.
The aircraft is a Nobler and it will possibly be over-powered, so I'll likely run it 4-2 if it'll cooperate.
Just waiting for the weather and field ground conditions to improve.
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Bill...I'd suggest adding "muffler type & brand" to the questionaire. It can make a lot of difference on the rest of the setup, and 'specially on fuel mileage. Might ask about muffler pressure or not, also.
I used my .46LA (Tower .40 backplate, .285" venturi, .156" spraybar, 10-22 Powermaster and 11.5 x 4 APC) on a Humongus, and it worked well for that plane with a MACS Muffler, launching at 10.2k or so. Slightly wet 2 stroke. Great fuel economy, easy to setup, start, and fly.
I eventually tried a Big Art tube muffler with a 12-5 APC, everything else the same except launch rpm. Liked the run a lot, but it wasn't fast enough for the Humongus, and the fuel economy was not nearly as good. Sounded like a 4-2-4, but maybe just bogged down. I still think it would have worked nicely on a Profile Cardinal or a classic.
I put that engine into Don McClave's old white Skylark with a Randy CNC Tube muffler on muffler pressure. It worked ok with the 11.5 x 4 APC, but I had to reduce the venturi to .272" to work with the existing fuel tank, and the Bolly CF LG was marginal with the 11.5" prop. The model still exists, but it never had much line tension up high. I do have some ideas to make it work better. I tried a 10.5 x 4.5 "Magic" prop with poor results, and some Bolly 12 x 4.25 3-bladers clipped to 11", with nothing good happening. I'd like to try the 12.25 x 3.75, 12-4, and 12-5 APCs, or at least a 12-4 Xoar. The LE of the fin is kinda blunt, and I'm thinking that maybe it's a problem. I'll re-shape the fin LE sometime soon. H^^ Steve
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I have three Brodak Cardinal profiles that are powered by OS LA .46 engines. The set up that seems to work best for me is:
*APC 12-4 prop.
*Mac's muffler.
*Muffler pressure.
*.285 venturi.
*Randy Smith NVA.
*Aluminum back plate.
*Brodak 10%-11-11 fuel.
*5 oz. Sullivan clunk tank.
I have not been able to get a true 2-4 engine break with these motors. Perhaps another combination of the above would allow this but I'm quite happy with the wet 2 stroke run that it produces. I might add that I am not an expert flyer. Mostly week end sport flying so that might be taken into consideration. I have tried a good number of combinations with this engine/plane and as I mentioned, so far, this particular set up works best- for me.
Joe
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I have not been able to get a true 2-4 engine break with these motors.
It can be done (seen several that way), but there's no reason to, it provides much better performance when run the way it is intended.
Brett
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My purpose is to gather information in one thread so that fliers (like Frank has already contributed) can see what different people are doing and have a "clue" when they start to use theirs. The OS .46LA is very popular (as it should be ;D ) but not many people actually ever say "how" they have set theirs up or how they "run" them. Just, "I put an OS .46LA in the Nobler............"
Prop, fuel, venturi, NVA, muffler (yes, Steve, I should have included that ;D ), type of run, etc., used will give people a start point. Too often we are guilty of just saying "use a LA .46" which leaves questions in some minds. Putting these set ups in a single thread will save time, IMHO, for those who have not used the .46LA yet.
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Bill
with all due respect, I have listed my setup ( Pat Johnstons actually ) many times, in fact most every time the subject of the LA46 comes up online,,
but fwiw,,
.272 venturi
ST needle assembly ( or Randy)
Powermaster 10 22 GMA fuel
good thourough break in!!!!
and the key,, an APC 12.25 x 34.75 prop
Ground setting is typically right around 9800 rpm
we tried to run them with 11x4, 11x5, 11.5 x 5 and all kinds of stuff, including the 12x4, with all the other setups, the engine had a tendancy to go over rich, or lean with small variations in needle settings, specifically a few hundred rpm could make a HUGE difference in flight times. Once we set upon the 12.25x3.75, ran them wet two stroke, those issues all went away.
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good thourough break in!!!!
How much bench time do you consider a "good thourough break in" ?
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Allan,
on the LA engines, I read a lot of people that run a couple tanks through them, I think I ran most of mine about 25 minutes combined before I flew them. They will fly sooner, but you end up messing with minor inconsistencies in flight and I don't need any help being inconsistent!
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Bill
with all due respect, I have listed my setup ( Pat Johnstons actually ) many times, in fact most every time the subject of the LA46 comes up online,,
but fwiw,,
.272 venturi
ST needle assembly ( or Randy)
Powermaster 10 22 GMA fuel
good thourough break in!!!!
and the key,, an APC 12.25 x 34.75 prop
Ground setting is typically right around 9800 rpm
we tried to run them with 11x4, 11x5, 11.5 x 5 and all kinds of stuff, including the 12x4, with all the other setups, the engine had a tendancy to go over rich, or lean with small variations in needle settings, specifically a few hundred rpm could make a HUGE difference in flight times. Once we set upon the 12.25x3.75, ran them wet two stroke, those issues all went away.
Gee Mark, a 12.25 X 34.75 prop, not figuring for slippage, and assuming the engine has enough ponies to spin that prop that fast, I figure level lap, flight speed of over 322 mph. S?P LL~ LL~ LL~
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well John, my flying skill has improved so I can keep up now,, and I figure at that speed the judges cant find the errors in my pattern,,
yuck yuck,,
yeah ok so how about 12.25 x 3.75
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Bill I am running my LA 46 with the head squish band reduced to about 50% of the original, to expand a little the band is about, and I mean about, 3/16" and I had "Rube Goldberg" AKA Curtis Ship reduce the s/band to about 3/32", this lowers the compression some, but the needle setting is very steady.
I am using a 46/60 Super Tiger needle valve assy, 10/22 Powermaster fuel, long reach T/Bolt idle bar plug, running a 12x5 APC prop, and it breaks 2-4-2 somewhat, not at all like the Fox 35, but it does break, it is using 5oz of fuel per flight and I am very satisified with it.
I sent Curtis a cylinder head that Charley Melancon had some for a lot of us prior to his untimley demise, oh the venturi is a .275 that I got from Jim Lee.
Hope that this helps, if I can help any more just let me know... I also add about 2 oz of castor to the fuel, and a tongue muffler that has 10 4-40 holes in it and I have three of them blocked. Your milage may vary.. LOL
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Teosawki LA 46 Setup
Stock Engine
Stock Muffler
.288 Venturi ( FP )
ST NVA
Powermaster 10 22 1/2 syn 1/2 castor
5 ounce Brodak Tank Uniflow vent,Vents forward
No Muffler Pressure
12 4 to 12 3.75 C/F prop, Eather.. Bolly or Equal .
Run very fast 2 stroke . No 2 4 break
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stock muffler or tonque 280 venturie o.s or tigre needle valve 8800 to 9000 rpm 11x5 zinger prop 5% nitro 50/50 oil pressure or not it is work for me
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Bill
with all due respect, I have listed my setup ( Pat Johnstons actually ) many times, in fact most every time the subject of the LA46 comes up online,,
but fwiw,,
.272 venturi
ST needle assembly ( or Randy)
Powermaster 10 22 GMA fuel
good thourough break in!!!!
and the key,, an APC 12.25 x 34.75 prop
Ground setting is typically right around 9800 rpm
we tried to run them with 11x4, 11x5, 11.5 x 5 and all kinds of stuff, including the 12x4, with all the other setups, the engine had a tendancy to go over rich, or lean with small variations in needle settings, specifically a few hundred rpm could make a HUGE difference in flight times. Once we set upon the 12.25x3.75, ran them wet two stroke, those issues all went away.
Thanks, Mark. With all due respect, the problem is, a lot of people are very impatient and do not like to dig through a bunch of search results. I know I hate that, I want the answer when I want the answer, not 30 mi. later after going through a couple hundred posts which do not list the "set up", only a reference to "OS .46LA". ;D This will get pinned at the top since the .46LA is so popular.
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Granted, agreed, and acknowledged,,
I know I have been "guilty " of the same thing,, not searching before asking a question,, lol,,
having a pinned topic is a great idea,,,
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Before its demise a few weeks ago, the LA46 I had was running in a 2-4-2 break, It was mounted on a TUTOR II- gross wt. 50oz. The head had been hemi'd to a deep spherical chamber almost to the glow threads. The squish band was less than 3/32" wide. Similar to the bootlegger's head, but a little deeper into the head. I was still using the OS NVA, venturi I.D. was .282", still had the plastic backplate. Ran engine on pressure w/ Dubro 6-oz. plastic clunk tank . 5-1/2 oz. fuel gave 7 min. run. Fuel was POWERMASTER- 10/22- half syn./castor. Randy Smith tongue muffler. Prop- 12-5 APC. 62' lines. This motor was very very strong, plenty line tension on the verticals, even though it had a soft break in the right places. These motors do well with virtually no mods running lower pitched props as has been stated in this thread, but most of us in the Baton Rouge Bi-Liners like to get them softened up a little. The late Charlie Melancon started this trend on the LA46 WITH THE DEEP HEMI, they ran so well we have continued the mod. We have found the best prop for the LA46 with these mods. to be an APC 12-5, Rev-UP 12-5 wood, TF-EW 12-5 wood.
Doug
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Take the motor out of the box and bolt it on the plane after cutting off (or not mounting on the newer ones) the rear needle valve. Run a regular OS CL needle valve through the venturi. I use a .256 venturi and the stock muffler. 10/4 APC prop. 10/11/11 fuel. Sullivan SS-6 tank with uniflow. Takes off at about 12,000 rpm in a lean 4 cycle until the last couple of laps..
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I need to make a correction.Just noticed I previously mistakenly stated that I ran the LA46 with a tongue muffler.I meant to say I use a Randy Smith Tube muffler. In the future, I will install the metal back plate and ST NVA's on my other LA46'S. I would have made these mods to the first one, but pilot error and concrete saw otherwise.
Doug P
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Stock .46 in a Tutor ARF,
Tounge muffler, long wedge hard tank, muffler pressure, capped vent for fueling
RSW 11X6 (5 ?) prop, 10 -22 ( 50/50 mix), needle is ST, set just past fat into a solid 2 stroke held level,
Tried the APC 11 X 3.75 but it just didn't cut it @ 5K feet in ABQ. Jim from CLC suggested the RSW- it works great.
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Metal FP backplate
ST NVA (from a ST 51)
OS venturi (7mm inside diameter I believe)
Stock muffler
Plastic clunk tank on muffler pressure.
Sig 5/20 fuel (half castor and half synthetic) plus 2oz on Sig castor added to a new gallon.
APC 12.25 X 3.75 prop (stock-not cut down)
Fox long plug
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I flew three patterns on Wednesday and was able to get down to 3.25 oz of fuel per pattern. This engine is just amazing.
Rick
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We will have our own .46LA going pretty soon in Aaron's new Trophy Trainer. Going to go with the 12.25X3.75 APC, small .40FP venturi (6mm??) and still have to decide on muffler. Looks like the model will come out nose heavy so a light tongue will probably be used.
Big Bear
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Bill,
I have had mixed results with a toungue muffler , in some situations its not very happy with it. wants to heat to much I guess.
I used a Randy Smith CNC tube muffler, at just around an ounce its not much heavier than a tongue muffler and I would rather carry 1/4 ounce tail weight than deal with questionable runs.
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Bill,
I have had mixed results with a toungue muffler , in some situations its not very happy with it. wants to heat to much I guess.
I used a Randy Smith CNC tube muffler, at just around an ounce its not much heavier than a tongue muffler and I would rather carry 1/4 ounce tail weight than deal with questionable runs.
Thanks, Mark. I *might* have one of Randy's liteweight tube mufflers around here that will fit. Forgot all about that, the mind is semi mush right now. ;D
Bill
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I have a os la 46 and the break is to strong,it comes on @8 and stays on until level again? suggestions on how to 4/cycle more. Thank you. Ron. here is the setup.
11.5x4 apc -T.bolt plug. metal backplate.
10/22 powermaster 1/2-1/2.
.282 venturi and ST.nva and 1-head gasket.
scott dinger muffler with no pressure.
B.line air filter with green screen.
6.oz uniflo tank.
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I took one right out of the box and bolted on Ryan's Tutor II. Ran two tanks of fuel through it and went flying. Set it between 9600-10200 depending on the weather conditions. We run Lou's brew 10/22 on muffler pressure on a clunk tank swinging a TT 11.5x4.5 One flip starts every time.
I also have one with a standard OS front mounted NVA metel backplate. Standard muffler running pressure to a clunk tank. APC prop 11x4 same fuel and rpm as above.
Set it and forget about it.
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I have a os la 46 and the break is to strong,it comes on @8 and stays on until level again? suggestions on how to 4/cycle more. Thank you. Ron. here is the setup.
11.5x4 apc -T.bolt plug. metal backplate.
10/22 powermaster 1/2-1/2.
.282 venturi and ST.nva and 1-head gasket.
scott dinger muffler with no pressure.
B.line air filter with green screen.
6.oz uniflo tank.
HI ROn,
Sorry for being late, but I just haven't felt much like spending time on the computer for a few days. Chemo starts tomorrow........
Anyway, the LA.46 is generally run in a "wet 2" mode since that is what the stock timing likes to do. Props in the 11-1/2 to 12-1/4 diameter and pitch from 3-3/4 to 4-1/2. One excellent set up is the APC 12-1/4 X 3-3/4 prop ans set just off peak rpm for launch. To get a real 4-2 run you will probably have to lower the blowdown which will cause some loss of power. Derek Pickard gave a run down on this in a Stunt News (??) article a while back. He raised the top edges of the intake ports in the cylinder. He also talked about cutting grooves in the top of the piston to achieve the same basic result.
It doesn't appear to be the case where too many are getting a true 4-2 run on the stock .46LA.
Big Bear
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Here is an alternate setup that probably doesn't fit your template guidelines! Enjoy.
http://www.davisdieseldevelopment.com/diesel_conversion_0S46LA.php
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My purpose is to gather information in one thread so that fliers (like Frank has already contributed) can see what different people are doing and have a "clue" when they start to use theirs. The OS .46LA is very popular (as it should be ;D ) but not many people actually ever say "how" they have set theirs up or how they "run" them. Just, "I put an OS .46LA in the Nobler............"
Prop, fuel, venturi, NVA, muffler (yes, Steve, I should have included that ;D ), type of run, etc., used will give people a start point. Too often we are guilty of just saying "use a LA .46" which leaves questions in some minds. Putting these set ups in a single thread will save time, IMHO, for those who have not used the .46LA yet.
Mr. Little, perhaps the posts on the LA 46 engine a bit lower in this forum could be transferred here?
Also, I think it would be useful when people specify the glow plug they use. See my discussion on the use of the Enya 3 plug?
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Hi Guys,
This is my first post. I have a few LA .46 engines. I am a beginner. (retread) I fly profile Twisters , Cardinals , and I have an arf Brodak Pathfinder. All with the LA .46. I use a Curtis Shipp backplate, 7mm Stuka Stunt delrin venturi, (longer) and Randy Smith style NV from same. I like the rubber gasket to keep the needle setting rather than the "collet " style of the Super Tiger NV. I haven't taken the head off. I do use a bru-line green air filter , and a Sig GP003 plug with idle bar. I use the Admissin tongue muffler from SS. It seems to run hotter. I have used muffler pressure. I like the way it runs with the pressure. I have used normal vent and uniflo vent I like the uniflo better. I use 11-5 , APC. All my engines are converted from RC , if it makes any difference. I mix 3 gal of Wildcat 15% premium and one gal of Fox Superfuel. It comes out to abouit 12% Nitro and 22% oil - mostly castor. Yeah my planes get oily! I launch 9800-10000 on 60' lines for about 4.8 second laps. They start right up , speed up the last lap or two. Wet 2 stroke the whole run. It works well for me. So that is my 2 cents worth. Thank you all for your posts that help me. #^
Scott Pahlow
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Because I got a new LA .46 coming in the mail in a few days I started looking here for more info on this engine. Then I remembered some time ago I got a PM from Pat Johnson with some very good information.
Here is his PM.
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Paul,
This is one of my favorite subjects as the LA46 is one of the best engines I have ever owned. Here is the Top Secret setup!:::
Starting with a ST style NVA through the body in the usual place, I use anywhere from a .257" (stock LA25) venturi up to a .275" venturi. With 5% nitro and 24% oil, this produces fuel consumption anywhere from 2 3/4 ounces up to 3 3/4 ounces. Starting Props are 11.5 X 4W APC and the 12 1/4 X 3 3/4W APC. These props are very good but a little heavy. A modify 12" props to approximate the lap times. The wood props weigh 1/3 the weight of the APC props and reduce GP by that much. A "Rabe" rudder helps negate the effects of the wood props.
Other minor mods to consider: Install a metal backplate. They are supposed to make for a more consistent seal. The second is to decompress the head a little. I open the chamber a little with a ball shaped stone in my drill press. Primitive, but it works. Opening up the combustion chamber is better than shims as the plug stays a consistent distance away from the face of the piston. The decompressed head does not seem to make all that much difference and is just an option to play with.
Hope that helps.
Pat
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Some good info from Pat.
And for those of us to don't know.... what is a squash band? I saw that in a few post here.
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Hope that helps.
Pat
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Some good info from Pat.
And for those of us to don't know.... what is a squash band? I saw that in a few post here.
Squash band or Squish band- If you take off the head you see a more or less flat circle with a dimple in it so the glow plug shows. That leaves a band around the face of the head, the squish band. Usually it has a slight angle in it, maybe 2-3 degrees. It's purpose is to squeeze the charge into the dimple with a lot of turbulence so it burns cleaner. To do that it needs to be about .010-.015 away from the piston at Top Dead Center. Since higher compression is needed to run at higher rpms, Pat's method of opening up the plug cavity lowers compression so it matches stunt rpms and still lets the squish band work. Let's you run bigger props without overheating.
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Good article on squish bands here -
http://web.me.com/flyingkiw1/Model_Aircraft_Stuff/The_Secret_Life_of_Squish.html
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I'm still running the same setup I developed over 12 years ago when I first comverted an RC LA46 to Stunt use (The CL versions weren't available yet) in a Scarinzi Blue Angel for VSC (Too far back to remember which one). It still works very well here in Tucson (2200 ft alt) or in CA at sea level.
Run Style: solid 4, Breaks a little toward end of flight on overheads.
Venturi: .280
NVA: ST (.156 dia valve body)
Prop
Make: APC
Diameter and Pitch: 11.5 X 4, 9600 RPM Launch, on 66 ft lines (center to center)
Fuel
Brand: Brand has changed several times over the years bu mix has remained constant. Used Power Master GMA 10-22 half and half for last several years.
Nitro%: 10%, except in summer here in Tucson switch to 15% when temp goes over 100 degrees. Have on occassion used 20% but only effect is about 10% more fuel usage.
Oil% and "Blend": always 22% half castor half synthetic.
Quantity used: Varies a little from one engine to the next but typically about 4.5 oz some have used as much as 5 oz (3.8 to 4 oz with port mods listed below).
I've modified the transfer ports to re direct the intake flow toward the rear of the cylinder on a lot of LA46's and it does improve fuel consumption a little and seems to broaden the torque curve...although this is subjective but does make sense dynamically. Less of the incoming charge in the cylinder lost out the exhaust port.
It works and is worth while however I would caution anyone who tries it that the crank case is very thin in the area that needs to be modified and it's easy to break through to the outside world. I did a "how to" thread on the other stunt forum many years ago on the redirect machining required. Note that this is not a port timing change the engine timing is not changed. I have tried modified timing changes but most did nothing really noticible at best and some were decidedly not good. I also tried different head chamber shapes and squish band areas. Not much improvement for a lot of work. I did most of this work when the engines first came on the market with the intention of marketing some replacement parts but other than the redirected ports decided that the engine ran just fine for most folks without modification and that marketing parts would likely not be a very enterprising business. I also got more responsibilities at Raytheon about that time and couldn't keep up with continuing to do engines.
This, in my humble opinion is the best stunt engine available for under $250.00.
Randy Cuberly
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Your milage may very but this works most days. Stock LA46s- plastic back plate were resealed with RTV, 2 of them have the metal back plates that have been sealed with RTV also- Ven is 265 w/ stock OS nva listed for 20 through 40 LAs - APC 10.5 X 4.5 RPM 11,200 for flying in the wind - APC 11 X 3 RPM 10,800 to 11,100 this is a wet 2 - APC 11 X 4 9,800 - Top Flite, Zinger, Brodak narrow and wide blade in 11 X 5 and 11 X 6 with RPM range 8,400 to 9,000 will give a nice break as long as the outside temp in below 85* with less than 70% hum. Made sure to check the balance on all props! Thunder Blot idler bar long - Power Master 5%- 22% half and half - Big Art tube muffler, to fine tune use one of those flexable extentions and cut the length to what ever works the best for you. Tank is a clunk 6oz(on muf pressure) with fuel used between 3 3/4 to 4 1/4. Out side temp, hum, and nitro does change this here. Lap time on my Cardinal (44oz) with 62' - .015 lines run 5:05 to 5:40. Landing time is always less than 7 1/2 min. Back when we could get away with running a tongue muffler getting a good 2-4-2 run wasn't that hard with most any 11 X 6 wood prop and on good days an APC 11 X 6 could be made to work. The hole size and number of holes in the tongue muffler make a big difference too. I think we're 1,000 above sea level here in Akron Ohio. All these numbers come from 4 different LA46s, one has 6 hard years of crash and burn, two had 15 or 20 flights when I bought them 5 years ago and one was new 3 years ago. My flight book and I got really wet the last time out and some of these numbers are hard to read, but the LA46 will do anything you want it to do once you get the right set up. Roger Strickler and Gary Tultz helped me work out different things to try and the one thing that surprised me is the different weight in props. One bag of T.F. 11 X 6 wood props can very as much as 3 grams from prop to prop. Here's the difference is some others APC 10 X 6 is about 31.5 grams - Master Air Screw 22.7 - Xoar wood 17.2 Merry Christmas and a Safe New Year - Ray
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""This, in my humble opinion is the best stunt engine available for under $250.00.
Randy Cuberly"""
Hmmmmmm I would put up an Aero Tiger against it any day of the week, will far outperform the LA 46 and last about 3 times or more longer
Randy
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""This, in my humble opinion is the best stunt engine available for under $250.00.
Randy Cuberly"""
Hmmmmmm I would put up an Aero Tiger against it any day of the week, will far outperform the LA 46 and last about 3 times or more longer
Randy
So....He should have said "under $239" ? VD~
All kidding aside; do you have any new ones in stock?
Merry Christmas
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So....He should have said "under $239" ? VD~
All kidding aside; do you have any new ones in stock?
Merry Christmas
Yes they are in stock , and are 239.00 ... so maybe try 238.00 ... nO that would not work either, there are other motors :-_
Randy
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LA 46, stock venturi, Super Tigre NVA, aluminum backplate, 1 extra head gasket. Fuel, home brew 5% nitro, 15% castor, 5% klotz, 3 to 4 oz. Prop, XOAR 12 X 4, Tower 40 muffler. Pulls my Fronkensteen 4 with authority. Setting, wet 2.
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Yes they are in stock , and are 239.00 ... so maybe try 238.00 ... nO that would not work either, there are other motors :-_
Randy
Well Randy I'm afraid I have to disagree with you. I have two Aerotigers and they are great engines but definitely will not handle the prop or the airplane weight that the LA46 will...
Believe what you will, I've tried many times to fly a larger airplane with an aerotiger and it doesn't work well!
So "Sorry Charlie" but it just ain't so!!!
The advantage of the Aerotiger of course is that it's smaller and lighter but put it in a 650 SQ in 57 oz airplane and it will suffer. The LA46 with more displacement is just a different animal and will fly a bigger airplane easily.
In a Nobler size airplane at 45 to 47 oz. the Aerotiger shines.
In my opinion you're comparing apples and oranges!
Randy Cuberly
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Well Randy I'm afraid I have to disagree with you. I have two Aerotigers and they are great engines but definitely will not handle the prop or the airplane weight that the LA46 will...
Believe what you will, I've tried many times to fly a larger airplane with an aerotiger and it doesn't work well!
So "Sorry Charlie" but it just ain't so!!!
The advantage of the Aerotiger of course is that it's smaller and lighter but put it in a 650 SQ in 57 oz airplane and it will suffer. The LA46 with more displacement is just a different animal and will fly a bigger airplane easily.
In a Nobler size airplane at 45 to 47 oz. the Aerotiger shines.
In my opinion you're comparing apples and oranges!
Randy Cuberly
There is a guy in cal. flying a 60 ounce TP, Ted Fancher design, Aero Tiger powered 60 size ship, with authority, PTG was stunned when he saw it.
so that blows your theory that it has not enough power. sorry
It also knocked many of Bill Werwages ST 46s out of several of his airplanes, and It will pull a USA-1 which is about 750 sq in..........
The Aero Tiger will also turn the same prop that Walker used on his Impact running a VF 40... with authority.
They will also last many times longer than the LA will.
regards
Randy
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My two cents worth. This is flown on
modified .40 sized Cardinals with 62'
lines.
- Standard OS venturi and NVA. (Not remote NVA)
- metal back plate
- Gently cut back squish band.
- APC 12.5 x 3.75 prop
- Omega 5% fuel with 5oz of castor added.
- Idle bar plug
This set up 2-4's beautifully and seems to
work well in the wind. The added castor does
turn everything brown but it gives me
more consistent runs.
I own 6 LA .46's but, (and this is my point)
the oldest one with many hundreds of flights
is also the best. It's getting a little sloppy in
the bearings but I know it will start and it's
very consistent. I would fly an LA straight
out of the box, but they seem to improve
over time.
The LA.46 isn't as good as my PA.40 or my
Ro-Jett but it's almost as good.
Cheers! - Goozgog
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Great thread on the LA 46 setups, just one minor thing a lot of the guys are not specifying what type & brand of plugs they use in their setups ?? ???
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Now it's been flown by a few people who like it, here's my LA 46 setup:
Model—my Shoestring 40, designed with Bob Reeves around the Brodak P-40 wing (see Control Line World Jan 2011) which weighs a porky 59 oz
Engine—stock with an FP 40 backplate (I bought a couple before they all disappeared)
Venturi—stock (the large 7.1mm/0.280" dia from when FP 35/40 was supplied with two venturis)
NVA—stock OS through-the-venturi part
Plug—OS No6 supplied with the engine
Muffler—Standard factory E-3030 with the outlet drilled out to the diameter of the outlet tip, i.e. the casting draft removed (5/16" dia).
Propeller—APC 12.25 x 3.75. I had been using a Bolly Clubman 11.5 x 5 until I crashed last year and broke it so I'm saving the remaining Bollys until I can fly better.
Tank—3 1/2 oz Brodak deep profile uniflow, no muffler pressure—currently gives about 8 minutes flight time
Fuel—22% oil, 50/50 blue Coolpower and castor, no nitro
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Fronkensteen 4 (heavy), OS LA 46, Tower 40 muffler (large exhaust), XOAR 12 X 4 prop, Fuel-5% nitro, 15% castor, 5% Klotz. 3.75 oz gets a pattern.
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Stock nva, 11x 5 zinger prop, Brodak tank on a 58oz. rebuild of a Tutor II(STUNT PIG). Actually all that was left of the plane was the wing. Don't know what lap times or for that matter fuel(doctored up some r/c fuel). I do know it is thoroughly broken in(2nd airframe) and runs great right out of the box.
Steve
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Here's my LA 46 set up on a 53 ounce Trophy Trainer;
NVA: Stock
Venturi: Stock
Back Plate: Stock
Muffler: Scott Dinger
Head shims; Added 2 (3 total)
Fuel Tank: 6 oz round Sullivan cluck tank on pressure
Prop: Brian Eather 12.5 x 4.5 reworked to 12.25 x 4.2
Fuel: GMA 10/22 (50/50)
Glow Plug: Stock
Fuel Consumption: About 125cc's for a 7 minute run.
I fly at an elevation of 250 feet above sea level, in a mostly dry climate.
I've done a lot of experimenting with this setup, and I can get a 4-2 break with the right tweaking, but it seems easier to set to run the wet 2 stroke. When I get the 4/2, it does it very well with the right power when you want it. When running the wet 2 stoke, the 4/2 break never seems far away.
Brian
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Can you run the 46 out of the box stock?
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Adam, that is pretty much the best way,, the only exception being some like a smaller venturi,,
personally,, I use a .270 venturi,, with 10% nitro,, etc etc,, see above,,
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How much does it cost to modify a 46?
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0$ in my book,, its pretty solid out of the box,,,
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Is a 46 to much for a vector ?
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Adam,
I think the LA .46 is one of the most popular engines for the Vector . I'm using one in my new Vector. Short of an Aerotiger .36 the LA should be as good as anything .
If you get out to the Balsabeavers field or down here in Dresden (Bean Field) you can most likely find someone with a Vector . They do fly nice .
Brad LaPointe
MAAC 5418L
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This set-up might of special interest for UK fliers.
Wet 2 Stroke.
Venturi: 7mm
NVA: Super Tigre large
Prop
Make:APC
Diameter and Pitch:12,25 X 3,75
Fuel
Brand: Formula Irvine
Nitro%:10%
Oil% and "Blend": Klotz Techniplate (18%). Add 80ml of the same oil to 1L of ready made fuel. That will rise the oil content to 24%.
Quantity used:135cc. I have substituted the plastic back plate for aluminium one from FP .40, and used FP .40 CL muffler with exhaust opening enlarged to 8mm diameter. However that set-up used to give me the revs in region of 9800 which resulted in fast 4,8" lap time. When I changed to regular RC muffler with silent cone things went more normal to 9400-9600 and lap time of 5,2" - 5,4". Give it a try, if you model is less then 1400g then you should have no problem with power / line tension on 19,5m lines.
Best of luck,
Theo H^^
[/quote]
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I know this might sound dumb, but where do you folks get the metal back plates
for the 46?
I have googled just about every where I can think of.
Thanks much..
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It's not a dumb question Laurence. The backplate from the FP 35/40 fits the LA 40/46 and I bought a couple of OS parts when Tower was running out their FP parts stock. There is, however, a member of this forum who runs an NC machine shop. He supplies new backplates. Somebody here will tell you who it is.
The first thing I did when I received my LA 46s was replace the cross-head screws with cap heads and, of course, replace the backplates.
I was quite surprised at how easy it was to undo the backplate screws. They are tight enough but nowhere near as tight as those on a metal backplate. I suspect that so long as you do not tighten the screws so tight that you distort the plastic backplate, you should be OK. Flat washers under the M3 screws might help as well.
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Thanks much.
Will deffinately replace the stock screws with metric allen screws first.
Will wait for a responce on the back plate from some one.
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I have appreciated seeing all of this information, but a previous comment about the glow-plug used is correct, it would fill in the picture more. I've just ordered a pair of 46LA-S' and will check what plugs they arrive with, but OS seem to recommend their No6/A3 Hot or OS8 Medium - do people use use these?
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I just swapped out my only recently run in OS .40fp on my Banshee for a well used LA46, a blue one converted from rc.
Has the small .40FP venturi and a standard OS needle valve, rc clunk tank made uniflow.
Zinger 11x5 wood. Merlin hot plug.
Fuel, 18% castor, 5% nitro, 77% methanol.
I couldn't be happier, this thing 4/2 breaks beautifully and has just the perfect amount of power for my Banshee. Which has been modified, 53 inch span, shorter nose longer tail etc, also increased tail area by about 30%.
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For the LA 46, I use a fuel mix of 5% N, 15% C and 5% KL-200. Stock venturi, 1 extra head shim, and XOAR 12 x 4 prop. Also a Tower 40 muffler, stock stunt tank and muffler pressure. Uses 3 3/4 oz per pattern. Tank back angled out slightly.
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I have appreciated seeing all of this information, but a previous comment about the glow-plug used is correct, it would fill in the picture more. I've just ordered a pair of 46LA-S' and will check what plugs they arrive with, but OS seem to recommend their No6/A3 Hot or OS8 Medium - do people use use these?
When I had the head off my 46, the recommended plug came up short. I put an american plug in and it fit perfectly. I like the OS 4 stroke plug too.
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We don't use the metal backplates. We use what they come with and just cut off the stem for the rear needle valve/venturi mount. Dick Houser does a "clean-up" on these engines and just uses an anerobic sealer (made for auto use) as a gasket for the plastic backplate and is careful not to over-tighten the machine screws. Works great and we have had no problems. Our LA-46s are extremely reliable.
Now the one problem we have had is with tanks. To the point that I make my own as do other club members. Once building season starts, Dick and I are going to do a workshop for NVCL on tank making.
Scott
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My $0.02
No expertise, never run an OS 46 LA, with some slight modification I have converted 2 used R/C LA 46s for C/L. I am cheap (why waste fuel @ $25/gal) & soon will have planes ready to fly them on. After reading these posts it appears, if I assembled ten 46 LA users in a room I could easily obtain 13 different opinions on how to set up & run an OS 46 LA. ~^
Searching past posts these were the most helpful; understanding the different setups & what they can do, in somewhat order of value: : ???
http://stunthanger.com/smf/index.php/topic,18819.0.html
http://stunthanger.com/smf/index.php/topic,6285.msg51626.html#msg51626
http://www.leemachineshop.com/Catalog.pdf
http://stunthanger.com/smf/index.php/topic,13738.0.html
http://stunthanger.com/smf/index.php/topic,21431.0.html
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I have found a sweet set up...tried most of the ones mentioned above and they were all great but muffler and prop certainly make a huge difference. Replace back plate with metal one from FP40, ST needle, .272 venturi, no added shims, Eather 11.5 x 5.5 repitched to 4.25, old E762 muffler with stinger cut off (came with old FP40S engines) launch at 9800 (calm) 10,000 (windy). Solid 2 stroke. No sagging and no speed up...even in high winds. And here's the biggest kicker of all...3.5 ozs with 8-10 laps to spare!! Just runs like a clock. Easy starts and plenty of predictable power. Went from 62 to 65 foot lines with this set up and everything just slowed down a bit where i can practice shapes instead of just "completeing" the pattern.
Truly is an amazing engine for $85. Got 3 total and they all act a little different...funny huh?...but all good. This set up has 100s of flights...literally hundreds.
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Probably the reason so many people can find success with this engine running so many (slightly) different set-ups is that it is just a good stunt engine. What we are seeing is not so much getting it set up for stunt, but the individual flyer's preferences in engine run...
Scott
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I agree...I just had better luck when i stopped trying to get it to break...solid 2 is the trick...i know it still "breaks".... just all that trying to get it to come on and off was just time wasting. Solid 2 and low pitch and just fly!! great motor...and never seem to wear out. I added up this summers flights...over 120 and I was using the same motor last year for more than that..incredible..in my opinion.
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46LA
tongue muffler from RSM
OS venturi - small, from a 25LA-S (.250 i believe?!?)
OS NVA from the FP series.
12.25 x 3.75 apc prop.
10-11-11 excalibur fuel.
LA series are definitely my favorite. there are better engines, but these are cheap, easy to run, and easy to find parts.
and I'm with Chris on the run. just a solid 2 low pitch and experiment with line length. once its tuned and broke in, one flip starts forever!
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By the way, I made a uni-flow tank with the uni-flow positioned per Paul Walker's recent reply in another topic (uniflow vent goes from inner side of tank towards outer side, actual vent faces forward and is positioned halfway back instead of at rear of tank.) It is giving me an even better run with my LA-46.
Scott
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1st 46LA Primary Force
stock motor with stock head clearance.
7mm venturi with Enya NVA
10% Nitro with 11/11 oil
APC 12/4 prop
Uniflo tank on muffler pressure.
2nd 46LA Brodak Smoothy Kit
stock motor with stock head clearance.
7mm venturi with Enya NVA
10% Nitro with 11/11 oil
Xoar 12/4 prop
Uniflo tank on muffler pressure
both motors run on a wet 2 cycle and solid running thru out the flight.
oh, both motors have the stock plasticback plates that I have seal with the black anarobic sealer from Auto zone. no leakage problems at all.
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Note that there is no good reason to replace the cross-head screws with Allen heads (or "socket cap screws" before one of my stalkers corrects me again). A #2 JIS screwdriver (from Hozan or Vessel) fits perfectly and you will break the head off before the screwdriver slips. It's *far* more secure than the small 2.5 MM Allen driver on the replacement screws.
Brett
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I used to wallow out the heads of my muffler bolts on OS engines before I realized that they were Japanese Industrial Standard (JIS) and not Phillips. There is a significant difference between the two and JIS is much better. Years ago I ordered a set of JIS screwdrivers from Central Hobbies in Billings MT. I've been very happy with them.
Scott
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Note that there is no good reason to replace the cross-head screws with Allen heads (or "socket cap screws" before one of my stalkers corrects me again). A #2 JIS screwdriver (from Hozan or Vessel) fits perfectly and you will break the head off before the screwdriver slips. It's *far* more secure than the small 2.5 MM Allen driver on the replacement screws.
Brett
Hmmm, the 'good' reason that I like Allen heads is that it is painfully obvious as to which size key must be used, they either do not fit the head at all or spin uselessly if you get the wrong one - not so with a tapered star head as you can bludgeon either system into use with the inevitable 'camming out' issues.
And it gets worse with a good coating of castor and grit to identify between JIS and Philips.
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since im still a beginner im just going to run everything stock and what the instructions tell me. im building a brodak profile oriental for this engine. anybody have the same combo? im going with a brodak uniflow tank what size would be recommended four or five ounce, and how long of lines?
thanks in advance !
adam.
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since im still a beginner im just going to run everything stock and what the instructions tell me. im building a brodak profile oriental for this engine. anybody have the same combo? im going with a brodak uniflow tank what size would be recommended four or five ounce, and how long of lines?
thanks in advance !
adam.
Adam my Cardinal with a stock LA 46 starts burping out of gas in the clover with the 4.5 oz tank unless I run it leaner than I prefer with 10/22 fuel and a 12x4 APC prop. I could possibly get by with going to 5% nitro, or a larger tank. There's plenty of extra tank room, so that's what I'll probably do. Mainly because all my other planes use 10/22 fuel and I don't want to buy 5% for just one plane. It could run leaner and still be safe, but I prefer it a bit on the wet side, and it seems happy that way, and will last longer too. I do not try to get a real 4-2 break, because as designed, it's a really sweet 2 stroker. Your fuel economy may also be different depending on your location, that is temperature, altitude, barometric pressure, etc.
As for lines, I use 62' .015" 7-strand lines. If you don't like wrapping your own terminations, buy the Tom Morris lines from Stunthangar Hobby. They are as well made as you can buy. Just place the order with a note as to the length you want him to make. I also highly recommend his unbiased cable handles too. Just shape the final details to fit your hand, wipe on a coat of polyurethane and it's good to go.
Also being a beginner, you'll find that if you bust that Oriental, a full fuse plane is a pain in the ass to repair, if it can be repaired. My Oriental with an FP.40 and my Cardinal weigh about the same and fly very similarly. The profile Cardinal can be fixed in one or two shop sessions, whereas the full fuse model repair is much more frustrating. Ask me how I know.
Rusty
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I am converting a NIB engine for use on a profile Oriental that is on it's way from Brodak's sale. I'm planning on using the 7 mm OS Venturi with a ST NVA, but stock otherwise.
I have seen many references to using the APC 12.25 x 3.75 prop, but when I calculate the airspeed I come up with very low numbers. So does anyone know just how much this engine prop combination unloads? I mean if you launch at 10K, you would need to unload to at least 14K to reach 50 mph. Of course prop pitch is never as simple as a number would indicate.
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I have seen many references to using the APC 12.25 x 3.75 prop, but when I calculate the airspeed I come up with very low numbers. So does anyone know just how much this engine prop combination unloads?
Enough, although I can't give you numbers. It doesn't sound like it unloads any more than with a TT 11x4.5, and those only run up to 10,600 or so (I've measured). That prop has a fairly thick airfoil, so if the pitch is measured on the flat side then it's got more effective pitch than stated.
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I've had very good performance out of a Zinger Pro 12-4. Note that this is NOT the standard Zinger. Make sure it is the Pro. Also: find yourself an OS-35S muffler and cut off the stinger.
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I'm going to disagree with Scott: The E-3030 muffler works great if you need nose weight. If you don't, see if you can find a muffler for a Tower 40. It's about the same size as an E-3030 but half the weight or less.
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Airplane #1: "Sister Jenny", a modified Twister that weighs in at 54 ounces.
- Engine appears stock, but came to me used
- What appears to be a stock venturi with a ST-style needle, and a couple of layers of panty-hose style netting to effectively neck it down a bit
- Powermaster GMA 10% nitro, 11% castor 11% synthetic oil, with two ounces of Coleman lantern fuel so that it'll fly the pattern on 4 ounces
- 4 ounce Hayes tank running on muffler pressure
- Tower muffler
- Thunder Tiger 11x4.5 prop unmodified but for balancing
- Launch at about 9600 RPM in a wet 2-stroke -- a good launch flies in a wet 2 throughout, if I get it a hair rich it'll hover around a 4-stroke but still fly the pattern
Airplane #2: "Atlantis", Paul Walker's 1988 WC ship. About 700 squares and 64 ounces. Paul told me to put the 46LA in it -- I didn't believe him, but it works, with a nice solid feel throughout and about 5.2 second laps on 65' lines eyelet-to-eyelet.
- Engine appears stock, it came to me used from Mark Scarborough who was using it for RC so I suspect no mods.
- RC carburetor with remote needle (I'm doing some weirdo experimentation). It's roughly the equivalent area of the usual venturi setup.
- Powermaster GMA 10% nitro, 11% castor 11% synthetic oil, with a couple of ounces of Coleman lantern fuel so that my other plane will fly the pattern on 4 ounces
- 6 ounce uniflow clunk tank running on atmospheric pressure.
- Tower muffler
- APC 11.5x4 prop, cut down to 11.25x4. This wasn't intentional -- it was a dinged and repaired prop that I was using for fitting things up, which I forgot and left on the plane for the first flights. It's worked so well I haven't taken it off.
- Launch at about 9600 RPM in a solid 4-stroke -- I don't know the exact RPM. The plane has a nice 4-2 transition right where you want it
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Tim, I'm assuming you're adding 2 oz. of Coleman fuel to a gallon, right? I have not tried that.
Mine is an old blackened blue LA that Will Davis gave me for my 51.5 oz. Cardinal.
- I measured the venturi and promptly forgot what it was, so I'll edit it in later. ST needle valve and no panty choke.
- Powermaster GMA 10/22 fuel.
- Enya #3 glow plug
- APC 12x4 prop with slightly rounded tips. Recently I buzzed 3/8" off each tip on takeoff and I couldn't tell any difference, but I put a new 12x4 on it for now.
- 6 oz. Sullivan clunk tank, standard vented, with pressure from an RSM tongue muffler with extra holes. It uses 5 oz. for the pattern.
- I needle by ear for a slightly wet 2 stroke that goes to full 2 when nose-up and stays in a steady 2 throughout the flight.
- It flies a little fast since it's always windy here, about 5 sec., on 62' eye-to-eye. It climbs straight up in the horsepower maneuvers with very good authority.
- It shuts off with little or no warning about 5-10 laps after the pattern
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Yes, two ounces.
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I'm flying the La 46 in my 45 ounce Sig Akrobat. (Mike Stott design ,similar to Chipmunk)
Here's my set up:
6oz Round Sullivan Clunk Tank set up with muffler pressure,on tongue muffler
Thunderbolt Plug
7mm venturi with ST NVA
Fuel "Home Brew" 5% Nitro 23% oil 50% Castor 50% Klotz Techniplate
Prop APC 12.25 x 3.75.....works great!
65' x.015 lines center of handle to center of plane
Lap times 5.1to 5.3
Engine is stock and gives terrific 4x2x4 break
I hope this info can help some other folks....PhillySkip
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I hadn't heard of adding 2 ounces per gallon of Coleman fuel. What's it do?
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Those that use it say it increases fuel efficiency. Could be true, but I haven't tested it. If you have no room left for an adequately larger tank, then it might be worth experimenting with. If Tim says it works, I'm inclined to believe it. But fuel usage is so dependent on environmental details, I'd try to squeeze that extra pattern time out with the traditional engine tuning methods first.
Rusty
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I have an OS LA46 on a Cardinal, .300 venturi, ST NVA, 10% fuel, 22% 50/50 oil, 4 1/2 oz Brodak uniflow oval profile tank. Runs great however it does not cut off clean at the end of flight. It will burp on and off for probably 5 laps before it quits. Any suggestion out there in control line world?
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Hi Jimmy,
I had an old metal 4.5 oz. tank on my Cardinal ARF. Also with an ST nva, but I'm not sure of the venturi size. It wasn't enough fuel for the pattern, and burped for a couple of laps. So now I have a 6 oz. Sullivan clunk on pressure from the tongue muffler. With 5 oz. in it it runs all the way up to shutoff with no warning except a slight speed up that you almost don't notice for a half lap... two laps after the Clover. But I can still add a little to it. I haven't flown it in the cold cold winter yet, and it's soon to be my #3 backup.
It could be that the tubes aren't soldered exactly in the right place, and if not secured to the side of the tank, one or both could be ringing like a tuning fork or cracked.
Rusty
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I have an OS LA46 on a Cardinal, .300 venturi, ST NVA, 10% fuel, 22% 50/50 oil, 4 1/2 oz Brodak uniflow oval profile tank. Runs great however it does not cut off clean at the end of flight. It will burp on and off for probably 5 laps before it quits. Any suggestion out there in control line world?
firs thing I would try is to cant the back end of the tank oubtboard slightly, like an 1/8"
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Unfortunately, we've seen a lot of bad tanks out there. And they result in bad engine runs. Poor soldering, mis-aligned pick-up tubes, unsoldered pick-up or uni-flow tubes, various pieces of "crap" floating around in the tank, etc. Hint: if you can hear noises when you shake your tank you know you've got problems.
Last winter our club, NVCL, did a shop session dedicated to making tanks. Sometimes its what ya gotta do.
Buy a tank "kit" from Brodaks and make your own or if you want to scratch build, buy K&S .008 tin sheet, 1/8th inch copper tubing, and look up the posting by Paul Walker describing the tank he was using just before going electric.
Good luck!
Scott
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Paul Walker's Atlantis from 1988. 700 square inches of wing, 64 ounces dry.
Run Style: solid 4, "beeping" into 2 at the tops of maneuvers.
Venturi: Home-made, with the spraybar off to the side (so you look down and see a "D" shaped hole). Same area as a 0.265" venturi with a stock OS needle, but with some nylon mesh over it to tune the run.
NVA: Bone stock OS remote needle (!) with a spraybar. Don't ask. It's weird, but sensible for the mission of the plane (I'm doing some experimentation).
Prop
Make: APC
Diameter and Pitch: 11.5 x 4, cut down to 11.25 x 4.
Fuel
Brand: VP Racing GMA "10/22"
Nitro%: 10%
Oil% and "Blend": 11/11 castor/synthetic
Doctored up with 2oz of Coleman lantern fuel for more mileage with undersized tanks.
Quantity used: 6 ounces. Probably 6-1/2 if I didn't use the Coleman fuel.
I would not have even attempted this engine in this plane, except that Paul suggested it as an alternative to a (too heavy, in his view) Magnum 52. It may not be Nats-winning material, but the plane flies way better than I do.
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Very good prop for 46LA:
https://www.amainhobbies.com/gemfan-wood-12x4-normal-rotation-propeller-gfn-1240-wood/p297474
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Sig Twister Slightly Modified
38oz Pre-Crash
40oz Post Crash
.46LA R/C Converted
Aluminum Backplate
Venturi: factory stock
NVA: PA NVA
Prop
Make: Thunder Tiger 11 x 4.5
Tank: RSM SnubNose GRW Uniflow 5.25oz
Fuel
Brand: PowerMaster 10/22
4.5 oz does pattern. Slightly more than needed but keeps pattern within limited time
Sent from my SAMSUNG-SM-G891A using Tapatalk
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I'm going to disagree with Scott: The E-3030 muffler works great if you need nose weight. If you don't, see if you can find a muffler for a Tower 40. It's about the same size as an E-3030 but half the weight or less.
Thunder Tiger 36 - 39 muffler works as well as the OS and is lighter, I have them for 15.00 ot tongues for 19.99
Randy
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Er ,
anyone tried fitting a MAGNUM GP 44 Crank into a LA 46 ?
Should fall straight in , bit the groove for big end clearance might split it in two . :(
Maybe ? need the groove .8 mm deeper ?
Unfortunately strokeing ' quickens ' the sleeve timing.
That Said it'd take it out to .51 Cu.In. or 8.3 c.c ,.
So itd be pretty light & compact for that displacement .
The 35 , 40 & 46 OS are 18.4 mm stroke . The GP 44 is 20 . LA .46 Bore is 23 . Now , if you got 23 x 23 . . . . :-X :!
Maybe the LA liner into the GP 44 case'd be less hassle . :-\
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One thing in all these engine/prop/fuel/plane comparisons is density altitude. Ground altitude, +, +. +, temperature, and humidity combine to make big differences. That explains why one combo will work for one flyer, but not so well for another flyer in another place, or why one engine to can do fine with a particular plane some place and not others.
On the other hand, there is not arguing that a properly developed engine with ball bearings, AAC or ABC piston and liner, and top quality machining will, for a price, outperform a relatively inexpensive mass- produced engine on some instances.
One big advantage of the LA series has been relatively good performance in right-sized planes for very competitive prices. They also adapt easily many different sizes of planes. OS quality, even on it's budget engines, is way above what we all accepted from Fox years ago.
Unfortunately we're all looking for something else since OS isn't building them anymore.
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I don't understand why anyone would want to "hop up" the OS 46LA. They are strong, reliable engines that will work with a variety of fuels, props, glo plugs, etc. If the model is correctly sized for the stock OS, there is no reason to look for more "performance".
I have several of those engines. All box-stock and all perform well.
One example is mounted in this Cub stunter. Yes, it is a stunter. Patterned after the plans from Don Hutchinson, only with a few scale details added.
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Stroking lowers the port timing.
Id check that , the only time the cranks more advanced is inside obtuse around T D C .
dragged a pair to pieces . Looking at LA , max drop'd be 0.7 mm , which'd lower timing one whole degree .Before S P I obviously a Woftam .
Looks like the LA liners 25 od & 44 GP 24 mm od . so no go there . Tho GP 44 & FSR 45 look interchangeable - head bolt pattern too .
For what its worth . :(, and maybe the LA 46 Liners with the SF 46 OS . :( So maybe a blocked boost or a Gardner LA 46 P/L in a SF 46
could make something of it .
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Hi guys , new to replying ,been reading and absorbing for sometime now, thanks for all the great information.I'm trying to get back into pattern flying again with my new 1972 JVL modified chipmunk ,copying my dads version/plans of the JVL from the 70's . Any way getting down to stats, my model weighs 50 oz's, OS LA46 up front with a 4.5 oz uniflow tank ( I use tank pressure), tong muffler, APC 12.25 x 3.75, fuel 10%nitro x 23% Klotz x 67% methanol ,running 4 - 2 stroke giving just under 6 minute flights , 5.1 second laps , 65Ft lines center fuse to center handle... I usually end with engine cuts 3-4 laps after clover ...
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I know this might sound dumb, but where do you folks get the metal back plates
for the 46?
I have googled just about every where I can think of.
Thanks much..
I have them in stock
Randy 678 407 9376 Randyaero@msn.com
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Hi
This may sound even dumber. What is the advantage of the metal backplate as a replacement for the stock item?
Cheers
Mike
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Hi
This may sound even dumber. What is the advantage of the metal backplate as a replacement for the stock item?
Cheers
Mike
It's lighter, it doesn't cold flow and it's shiny. Someone was making them with O-ring seal so you don't have to mess with RTV.
Motorman 8)
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It's lighter, it doesn't cold flow and it's shiny. Someone was making them with O-ring seal so you don't have to mess with RTV.
Motorman 8)
Lol, so what’s a cold flow?
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Cold flow is a type of material deformation that is defined as the tendency of a solid material to slowly move or deform under the influence of mechanical stress.
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Hi
This may sound even dumber. What is the advantage of the metal backplate as a replacement for the stock item?
Cheers
Mike
[/quote
For most people, the only advantage is that you can change to socket head screws and then crank the crap out of them and not break corners out. In general use, not much of advantage really. If you use truss head screws like those it came with and don't over torque them, or use flat washers under socket head screws, there is absolutely nothing wrong with the stock back plates. There used to be several guys making and selling metal replacements but most have dropped out or are no longer with us. Availability of the metal part is the biggest problem. I only keep a few metal units on hand in case I pickup an engine with a screwed plastic back plate and I don't have any plastic ones to replace it with.
Type at you later,
Dan McEntee
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Came across this kinda late. I built a Smoothie, pretty much stock with an LA46 with stock 30-30 muffler.T he venturi was changed to a 1.24in high straight stack and a 0.260 id. Stock needle valve. 10%nitro, 12.5% synthetic, 12.5% Castor. After some fiddling, I ended up with a 11/7 3 blade Master Airscrew.
One minor modification- the kit came with slightly long sticks for the stab leading edge and trailing edge. I like a plane with a "solid feel" so the stab came out a bit oversize, 24in. span, 7.25 root, 4.5in tip = 141 sq.in.
Turned out to a good flying plane with no bad habits.
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Removed