LA46

[Richard Hutlet]

 Evening. Sort of a 2 part question. Based on the opinions I've read I'm going to try
the LA46 in the Vector 40 I've ordered. My question is are there any parts that SHOULD be
swapped out immediately or will the engine fly ok out of the box for a mid talent flyer.
The last part is I've heard that engine may be a tad large for the Brodak Vector40.
Is there anything wrong with a Brodak 40? Or can anyone recommend another product
line to look at? If any of you have built the Vector with the LA46 is it being tight an issue??

Thanks

[Geoff Goodworth]

Richard, nothing wrong with the Brodak 40—it's possibly the best match for the Vector 40—if you can get one.

I was going to follow up on my post yesterday by saying that the rear needle setup on the stock LA will probably take up space that simply isn't available. I bought two FP 40 backplates when Tower was phasing them out—just in case I went to LA 46s, and I've bought two of them. So when my engines arrived, I replaced the backplates and the cross head screws in the head and the backplate with socket heads.

Somebody is making replacement aluminium backplates so I would consider them.

Otherwise, I was surprised that the screws retaining the plastic backplates are not super tight—just tight enough to ensure a seal. I'm confident that the problems with leaking backplates is caused by over tightening the screws and distorting the backplate. If I buy anymore LA 46s, I will remove the rear needle setup and replace the screws in the head and backplate. I will put washers under the backplate screws and note carefully the force required to remove the standard screws so that I can repeat it when tightening the cap screws. If that doesn't work, I will either canibalise a couple of FP or Thunder Tiger GP 40s to replace the backplates or buy aftermarket replacements.

The issues with the LA 46 ans the Vector 40 are not insurmountable and, in fact, a few years ago, Novice at the NSW state championships was won by an ARF Vector 40 with LA 46 power.

[Tim Wescott]

I can't comment on the Brodak 40 -- I have one, but I've never fired it up.

It's very easy to tone down an LA 46, so it shouldn't be too powerful for that plane.  I can't comment on weight. 

If you get the 46S it should be plug & play, however you'll probably want to swap in a "real" needle valve and either put in a metal backplate, or whack off the needle valve body from the plastic one.  If you have an RC one then get a venturi with needle and go to it.  Do not overtighten the plastic backplate screws -- I can't say I've done this, but I can say that I have a bone-stock LA 46 (RC carb & everything) that has been trouble-free for me, with the plastic backplate and remote needle.

Dunno who all has needles for it, but I'm nearly sure that Randy Smith does, and Lee Machine is probably worth a call, too.

[Geoff Goodworth]

Tim, I use the OS factory part, 22311000 which carries Tower stock code LXCR49.

[Keith Miller]

Fly it as-is! Stock muffler, stock venturi, stock needle.
Tried mine with a tongue muffler - no good.  Went back to the stock tube muffler - runs like a champ.

[Gerald Arana]

Richard,

I had a vector with an LA 46 until I flew it into the ground inverted. Duh!  

AFAIC it was the perfect combination for a beginner to advanced flyer as well as some experts.  

Cheers and good luck with it. Jerry

PS: Mine was all red. Still have the cowl.

[Randy Cuberly]

As Geoff stated above the Brodak 40 is an excellent choice for the Vector 40 if you can find one.  They are practically "unobtanium".

Another excellent choice that is also hard to find now is a Aerotiger made by Randy Smith.  It's actually the best choice in terms of performance but is out of production and fairly expensive.  In fact you can buy two LA46's with the extras etc for what they cost!

Another potential excellent candidate for the Vector is a RO Jett 40 Barstock Engine...side exhaust or rear exhaust.  The penalty there is also Cost!  They are very light and powerful and would be an excellent fit for the Vector.

Now that that's all out of the way, it really wont be much of a problem to put an LA46 into a Vector 40...a slight setback of about 1/4 inch on the engine position which requires moving the firewall (or simply not using one in front) and building a crutch to take the slightly larger LA46 mounting.

The photos below are with a much larger engine, a RO Jett 67 being built into a crutch of 3/8 X 1/2 maple with 1/16" aluminum for engine mount facing, but the same principle could easily be used to build a crutch for the LA46 and install it into the Vector 40 fuselage using the same methods as shown in the other photo showing this one going into my Collossus.

This isn't hard to do, it just requires measuring from the front of the fuselage on the plans back to where the rear of the engine needs to be when the LA46 thrust washer lines up with the nose ring...allow at least 1/32 inch clearance in front of the nose ring for the spinner etc.  measure back to the front of the mounts and mark the fuselage sides (doublers actually) at that position.  That's where the front of the crutch will be.  measure for the necessary length of the crutch based on a 4.5 to 5.0 oz tank...that's where the end of the ctutch will be.  make the crutch according to those dimensions.  Prepare the maple mounts with the aluminum facing and mark and drill each one for the engine.  Bolt the engine into the maple/aluminum mounts with blind nuts and then cut the balsa filler to fit between the mounts.  Epoxy the balsa to the mounts with the whole thing clamped at the rear and held in place by the engine at the front and weighted down on a piece of waxed paper as shown in the photo.

Viola, Stress free engine crutch to mount between the fuselage sides.  Light weight and last "forever".  well a long time anyway!

These photos show a larger airplane and a rear exhaust engine (RO Jett 67) but the principle is the same.

Randy Cuberly

[Tim Wescott]

Boy, the head on that ROJETT sure faded fast -- didja leave it out in the sun or something?

[Don Chandler]

I hve an LA 40 in my Vector and it flies the plane very well. The moter was re-done by Tom Dixon and works great.

Don

[Steve Fitton]

I would hesitate to put a big bucks engine in the Vector 40 ARF or ARC, after watching one fold a wing and sent a PA-40 smashing into the pavement.

I have, however, seen a number of LA-46 powered Vector 40s and they all flew very well on that motor...

[Randy Cuberly]

Boy, the head on that ROJETT sure faded fast -- didja leave it out in the sun or something?

No Tim...No sun!  The one with the black head is a 76BSE RE and the one shown in the airplane is a 61 BSE RE...

The 61 is actually for the Collossus that's pictured.  The other engine mount with the 76 is for the Trivial pursuit I'm building now.

You should have known that!    I also have a 67 BSE RE that's slated for a Minato Blue Max Eternal!

I also have two 65 BSE RE engines that don't have a home yet...The 65's have been discontinued...supposedly too difficult to manufacture due to the thinner aluminum sleeve.

I had one of the 65's in a Trivial Pursuit and at the time I decided it was the best running stunt engine I'd ever had...

I think Ted Fancher liked his also...He won the Nat's with it!  Right now I'm flying a Whitely Shoestring with a PA65 on a pipe and it's the easiest engine to deal with I've ever had...to many choices not enough time to build!  The PA seems to be a little more flexible for fuel, pipes, etc.  It is very forgiving and powerful.  Truly a lazy fliers engine!  

There are a lot of good choices in IC engines...but they are unfortunately becoming fewer!
 
Randy Cuberly

[Dwayne]

The LA 46 is a dynamite engine for the money. Add a head gasket seal the plastic back plate with silicone (or replace it) and get rid of the remote needle, I'm running a 11X5 Zinger  launching at around 9850, rock solid 

[Bill Little]

The LA .46 is an excellentr choice for a newer pilot and the Vector 40.  It is almost too easy to run.  I do differ with some as I replace the backplate with an aluminum one before i go flying.  I HAVE seen the plastic one leak and once they leak it seems u cannot get them to stop.  I have precious little flying time so I don't want a backplate cutting into my practice or competition flying.  Aluminum backplates are available from Curtis Shipp, a member here and they fit perfect.  Why have a highly potential problem when it can be easily cured?

HAVE FUN!

BIG Bear
RNMM/AMM

[Neil Rogers]

Hi Richard

The LA46 and Brodak 40 are both good engines.  The Brodak is a great engine for classic airplanes designed for a Fox 35.  I describe it as a Fox 35 that works.  I've used one in an ARF Oriental for 3 years now and it is the perfect engine for that airplane.  I use 10% Power Master, a Randy Smith tongue muffler and an APC 10x5.

I flew a Vector 40 ARF with an LA46 for a couple of years.  It was a great flying airplane and the LA was a nice match.  I used 5% Sig, an RSM tongue muffler, and an 11x5 APC prop.  The lines were 63 ft. eyelet to eyelet to get desired lap times.  I like it enough that I am now building a kit Vector 40 to use the same power plant.

One of our flyers here in Edmonton flew his Vector 40 ARF with a Brodak 40 and it seemed to fly well.  My preference is to use the LA.

Neil Rogers
Edmonton, Alberta

[Dennis Moritz]

Many LA46/Vector combos. A typical match. Get an FP40/FP25 needle valve from Tower. Remove the remote needle. Fit the FP needle. Yep. I saw Matt Colan's Vector 40 ARF, powered by PA, fold a wing at Huntersville. Best Vector patterns I ever saw, before the wing broke. Looking it over, the mainspars appeared light and  soft. Welcome to the world of ARFs. Only Vector, by the bye, I ever saw fold a wing. I have seen a hundred different Vectors, seems to me, doing the pattern. The LA46/Vector 40 is the most popular match out there. I'd use a .272 venturi and fit a 5 ounce tank. The .283 might burn too much fuel. I used an LA46 on a Tanager type profile. It used every bit of 6 ounces for the pattern. That plane/engine combo worked very well with the engine dripping wet rich. Brodak makes a 5 ounce that will fit in a stock Vector ARF. Swapping out the motor mounts takes some hacking or grinding. If the mounts feel hard, I'd heat gun epoxy into the mounts and the joints. Do it through the top hatch as well as from the bottom. And use them. It's an ARF. Don't over think an ARF. Assemble, do some this and that, put a reasonably priced engine in the thing. Go FLY. Cheap engines are also OK. I've come to prefer FP40s and Tower40s, stock engines. The lazy LA46 blubber and break started to get on my nerves. FPs and Towers are more high strung and tempermental. Often real cheap. In my current state of Karmic Illusion, they feel like thoroughbreads.

[Leester]

Were do you get socket head screws for the back plate ? what thread are they as 4-40 don't want to start.

[Wayne J. Buran]

LA 46 screws are metric. Probably M3. Thats why the 4-40's will not work.  OS part number 23313000 is a screw set for 35-40 FP using socket head construction. Which may help you in finding backplate screws for sure. Has to be old stock black packages for sure. You will mess up the threads. Someone you know have any experience with screw threads. I am sure something will show up on this forum.
Wayne

[Jim Svitko]

I found 3mm socket head screws from Du Bro at a local hobby shop.  The LA 46 head and backplate screws are 3mm but different length.

[Wayne J. Buran]

If they are to short you still have a problem. If they are longer you can carefully trim and chamfer them with a thin Dremel cutoff blade.  Have you tried to see if they screw in easily? Hope this helps.
Wayne

[Don Jenkins]

I built a Vector 40 (50 ounces) with the LA46 and it is a great combination.  I rid of the remote needle valve and replaced it with one from Randy Smith as well as replacing the back plate with a CNC piece from Curtis Shipp.  I use a 12.25 X 3.75 APC prop at 9500 RPM with a little over 4 ounces of 10/22 fuel to fly the pattern.  I also replaced the stock landing gear with a ".60 size" from Randy Smith, otherwise you can't swing a prop much larger that 10.5 inches or so, and you need a larger, low pitch prop for this set up.

Don

[Peter Grabenstein]

My Brodak ARF Vector 40 - OS LA 46 Combo
fly's like this:
Replaced all (head and backplate) screws into M3 metric stainless steel socket head screws,
OS NVA up front with OS LA 25 venturi, Curtis Shipp backplate,many thanks Curtis,
Enya No.3 glow plug, APC prop 12.25 x 3.75, stock landing gear with 2 1/2 Inch "light foam" wheels,
4oz 5/20 all Castor fuel, excellent perfect shiny Tongue muffler with slightly enlarged holes from
Greg Hart/Scott Riese, SORRY, don't remember who made it,
35 grams (which is 1 oz + a few hairs) at the very last end of the fuse
to meet the perfect C.G.  ....and
it works "GREAT" for my Vector 40 and me.
Forget about the (heavy as brick) stock muffler.
I was thinking about
sending them (3 mufflers) back to the factory to mold new LA 46 crankcases.
BTW, there are lots of OS LA 46 hints on the "Engine set up" section in this "GREAT Forum", thanks a lot Sparky.
Coming season I will try second headgasket just for curiosity to know how it shifts then 4-2-4.

All the best and "HAPPY NEW YEAR 2015"
    Peter G.

 

[john e. holliday]

Hey guys,  when I need screws for my engines that aren't 4-40, I take the engine to my local "Ace Hardware Store" and visit the screw section.   Get some strange looks when I show them what the screws are for.   

[Peter Grabenstein]

ooops

[Gerald Arana]

Leester,

Go to "www.microfasteners.com" and get whatever you want. I buy mine there by the bag full. It's good to have spares, never know when I'll drop one and can't find it!

To find the exact size you are looking for go to the Tower Hobbies web site and read the parts list section for LA engines.

Happy New Year, Jerry

[Peter Grabenstein]

second time ooops

[Gerald Arana]

In the instruction manual they are listed as:
Head= (4) M3X12               
Cheers, Jerry

PS: Through Microfasteners they are:

Head = Package of 20 = $2.00
Backplate         "   "  " =  1.90

Enough for five engines

[Mike Scholtes]

The specific question is whether the LA46 is too tight a fit in the Vector. Not sure if this is going to be a kit-built or an ARF/ARC. I built the Vector kit (excellent quality) with an LA46, and it fit fine. This assumes use of a venturi mounted NVA, otherwise I think it may be a problem plumbing the fuel lines with the rear NVA. I used a Randy Smith NVA, generally regarded as the best available. This requires drilling out the spraybar hole in the case and the venturi slightly. I have 2 other LA46s with OS front NVAs that also run just fine, less expensive than the Randy NVA and a drop-in fit. My Vector LA has a metal backplate but the plastic one also seems to be no problem once the NVA boss is whacked off. I think it is a Curtiss Shipp product, mentioned above. Randy Smith also makes an excellent lightweight tube muffler for the LA, which I use on the Vector LA. Seems to work better than a tongue muffler and a lot quieter. Regardless of motor choice the Vector needs some serious trimming and grinding around the spraybar inlet end to allow the plumbing to fit without kinking. Unless you are seeking contest appearance points, grind away. The LA does require some ground clearance adjustments since it wants an 11.5 or 12.25 dia prop. I think I bent the dural gear enough to clear but just barely. Longer gear would be better, but the cost of this project is adding up. I have not adjusted the needle in about 5 years on this sweet setup. It just runs like a watch.

[john e. holliday]

If the LA 46 is a tight fit how come mine drop right in where I have had an LA 40.    I always thought they used the same case with a different liner and piston..

[Matt Colan]

I ran an LA 46 for a couple years in an ARF Vector and it worked well before it met it's demise meeting a paved runway.  The LA 46 has plenty of power and I think it's a good match for the Vector.  I was running a Majic 12.25-4.25 prop and an ST needle valve.  My second ARF Vector had a PA 40UL and pipe in it and that combination was incredible compared to the LA.  There's nothing wrong with the LA, but I thought the PA was more competitive in expert, especially when the conditions deteriorated.

[Steve Helmick]

If the LA 46 is a tight fit how come mine drop right in where I have had an LA 40.    I always thought they used the same case with a different liner and piston..

Same crank, but the headbolt pattern is bigger on the .46, because the cylinder flange is a bunch bigger diameter. I'd have made the .40LA the same as the .46, but I'm not an OS engineer. The crankcase is actually different, because the meat around the headbolts is way different.

Did you have to shave the engine bearers to put the .40LA in the Vector? Was it a kit, or ARF/ARC? Still flying it?  Steve

[Geoff Goodworth]

Doc, the FP 35/4o and the LA 40/46 fit—no argument.

However, the crankshaft length on the FP/LA engines is about 7/16" longer than the Brodak 40.

In Oz, I've seen ARFs with with FP/LA engines jammed hard against the first former with no spinner or an acorn nut and the really ugly fix is a 1/8" lite ply spacer stuck to the front of the ARF fuselage with no attempt to fill and fair it and the spinner to the fuselage.

Another fix is to use Dubro spinners. The gap is still excessive in my opinion but maybe acceptable

With the regular kit, you can shorten the spacer in the engine crutch to move the first fuselage former back enough, or add about 1/8" to the nose of the model and fair the spinner in properly.

I guess it all depends on what you consider acceptable aesthetically.