How much does it cost to modify a 46?

Is a 46 to much for a vector ?

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   
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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.

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?

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.

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

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.

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.

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

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

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.

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

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.

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.

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

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

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

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

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

Very good prop for 46LA:
https://www.amainhobbies.com/gemfan-wood-12x4-normal-rotation-propeller-gfn-1240-wood/p297474

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

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.

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 .

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