An engine to consider for large planes, the LA .65

[Andrew Borgogna]

A few years back I acquired a Top Flite Score and a ST 51.  This was suppose to be the combination that was best for the plane.  Well the ST 51 was just not enough for my Score.  I emphasize MY Score because I have seen some that fly on a O/S .46.  The weight difference from plane to plane must be great.  Anyway to make a long story short I decided to buy an O/S LA 65 and give it a try.  I made some minor changes to the engine, I replaced the muffler with a MAC mini pipe muffler.  Removed the R/C carburetor and installed a venturi form an Evo .36 and installed a spigot type NVA into the venturi and use an APC 13 x4 prop.  The results were quite supprising.  This engine seems to run quite well for stunt application.  It has strong power and just purrs along at around 9K RPM.  When I pull the nose up there is a slight break that remains through the maneuver, it settles back to it's cruise speed when the plane goes level.  The LA .65 has shown no tendency to run away and in general has been a very user friendly package. 

Now the down side, it is heavy and it consumes lots of fuel.  I currently use 8 ounces of fuel per flight and that gets me through the pattern with just a three or four laps left.  My lap times are around 4.8 seconds, I would like to slow it down just a fraction, but there just is not enough room in the Score for a larger tank.

What the LA .65 does do well is fly the Score with complete authority and it does for around a $130, that's hard to beat.

[FLOYD CARTER]

Andrew.  4.8 sec. laps isn't too fast.  However, if you want to improve fuel consumption, go to a smaller venturi- and the easiest trick is to fit a piece of aluminum tubing into the existing venturi.  That will reduce power, but you seem to indicate you have plenty of power as is.

Floyd

[Tim Wescott]

I'm with Floyd on this -- I think if you reduce the venturi a bit you should get enough better mileage to make up for an increased flight time.

[proparc]

Big motor, small venturi-you get all ducks lined up your way.

[Wynn Robins]

had one of those  big ol' Donks a few years ago - couldn't bring myself to use it as it was too heavy - and a non bearing engine.....for the price (at the time) the ST 51 was far better value for money - but the LAs just go and go and go...........glad to hear someone is using one for stunt tho!!

[Andrew Borgogna]

A couple of things I forgot to mention the all of weight of the Score with the LA 65 is (sit down and brace yourself) 4 lbs. 15 ounces.  I believe that adds up to 79 ounces.  Regarding the venturi, the first set up had the large Evo .36 venturi with the stock spigot and using the O/S remote needle valve.  This work OK for a while until the remote NVA started giving me trouble.  I removed it and changed the venturi to the medium size Evo 36 venturi and the spigot type NVA.  I could go to the small venturi, but I am happy with the current setup.  The fuel I use is RSM 11x11x10.  I tried some all Castor 10x28 and the engine didn't seem to like it.  Can't say for sure the fuel was the problem because I did a number of things before I flew it again, but I do intend to retry the 10x28 sometime in the future.  I would also like to try some 5% nitro fuel, that's what I always ran in my big engines when I flew R/C and they seem to like it.

I am not for one second say this is a replacement for a RO-Jett 65 or 70, but if you don't fly expert and want to fly a big airplane this is a very real substitute for the more expensive engines.  I am giving some consideration to buying a T-Rex and using the LA .65 in it.  It has the power!
Andy

[Brian Massey]

I am not for one second say this is a replacement for a RO-Jett 65 or 70, but if you don't fly expert and want to fly a big airplane this is a very real substitute for the more expensive engines.  I am giving some consideration to buying a T-Rex and using the LA .65 in it.  It has the power!
Andy

Andy; there are 3 T-Rex's in our club and I have to say that a .65 just might be overkill. The plane is light and very manuverable. All three are now being flown on E-power.

Brian

[Brett Buck]

Andrew.  4.8 sec. laps isn't too fast.  However, if you want to improve fuel consumption, go to a smaller venturi- and the easiest trick is to fit a piece of aluminum tubing into the existing venturi.  That will reduce power, but you seem to indicate you have plenty of power as is.

   4.8 seconds on a maybe 75-80 oz airplane *pulls really hard*!  If mine gets down around 5.0 it's beginning to be a problem.

     Brett

[proparc]

  4.8 seconds on a maybe 75-80 oz airplane *pulls really hard*!  If mine gets down around 5.0 it's beginning to be a problem.

     Brett

Strongly agreed.
Under 5 seconds per lap with a 5 pounder is a tough row to how. The late Bob Baron talked about "practice fatigue". That much strain makes it significantly harder to practice more, and PRACTICE is what gets the job done.

Also, and this is what I have personally found out, a heavy ship moving fast, makes it a bitch to accurately AND consistently place your moves. You are physically and psychologically focused on keeping your ship from going into the ground.

The other major factor is lift. When you have a plane like a TopFlite Score, which does not have the wing to carry that much weight, (a Patternmaster can) you REALLY start to compound the problem because, you have to fly even faster still.

In short, the ship is dictating affairs to you, instead of you dictating affairs to it. 

[Andrew Borgogna]

Yep the first time I flew this combination I went home with a sore back.  But I am now quite use to the pull and the plane tracks very well.  It just does not seem fast to me, I would like to try some 70 foot lines I am on 65' lines currently.  I agree with everybody that is to my advantage to slow it down just a bit.  With respect to the Score not being able to carry that much weight, well others have commented it fly quite well.  I am an intermediate flier and as I have said this is a combination that will let me get better.  For one thing is flies consistently, I am not fighting to get a decent engine run.  I know what to expect and for me that a good thing, to quote Martha.

Thanks for the heads up on the T-Rex maybe electric is the way to go.  I plan to put electric in my next project an RSM Continental.
Andy

[proparc]

Andrew, like a lot  of people, I had considered the LA .65 as a perfect large profile engine. And, as companion to the LA 46. But, I lost access to a lathe and that was the end of that. Sticking an expensive Saito on the nose of a profile still doesn't sit well with me, so I will mostly revisit the LA 65 again.

You know, till this day, I don't know why OS never put a venturi on the thing. They seemed to put it motors nobody was using, but not on the motor a lot of people would have liked to try.

[MrSteve09]

Andrew,...

I applaud your effort in developing an INEXPENSIVE, readily available, 60 size engine.  It seems that a of of the guys who have been in this hobby for a number of years are using Super Tigre 60's and have an abundant supply of spare parts and extra engines.  However for guys like me who are just getting started in this end of the hobby, I'm at a loss for "off the shelf" readily available 60 size stunt engines.

Like you, I am an Intermediate flyer, just looking for a consistent engine run on a decent flying plane.  I'll keep an eye out for 65LA on ebay and give it a try on a larger stunt ship.

Thanks for sharing your experience with the LA65.

Sincerely,
Steve T.

[phil c]

.....
Now the down side, it is heavy and it consumes lots of fuel.  I currently use 8 ounces of fuel per flight and that gets me through the pattern with just a three or four laps left.  My lap times are around 4.8 seconds, I would like to slow it down just a fraction, but there just is not enough room in the Score for a larger tank.

What the LA .65 does do well is fly the Score with complete authority and it does for around a $130, that's hard to beat.

That's the big issue with the 65.  It weighs about 4 oz. more than comparable power 60-75 engines.  16 oz. is a lot for a 60 size engine. If you swap one into a a Score you have to add another ounce or so to the tail for balance.  In the right plane, say a semi-scale FW-190A3 with a short nose it would work very well.  The shorter nose saves a couple ounces and you need the engine weight to balance the longer tail.

[dennis lipsett]

That's the big issue with the 65.  It weighs about 4 oz. more than comparable power 60-75 engines.  16 oz. is a lot for a 60 size engine. If you swap one into a a Score you have to add another ounce or so to the tail for balance.  In the right plane, say a semi-scale FW-190A3 with a short nose it would work very well.  The shorter nose saves a couple ounces and you need the engine weight to balance the longer tail.
[/quot

I'm not going to dispute fuel consumption as I don't know how this particular engine is set up. But I am tired of the weight thing being thrown up at every opportunity. there are no light 4 cycles being used a Saito 62 is 16 oz or 17.6 oz with the muffler the Saite 72 is 17.6 and the 82 is slightly more. You you can justify using the 4 cycle based on fuel allotment but please spare us the missused statement about engine weight that is not the whole story.Any engine can be made to be more fuel efficient. Granted it might be more effort then it is worth.
Which leads me to another problem. How long are we going to have light 60 sized engines available to the c/L community. Those that are well equipped for now are set for the forseeable future but availability of these types of engines is liable to become iffy in the future.I'm curious if the pA model of the future will evolve to accomodate a heavier I.C. engine or simply give up and go electric. Which seems to make more sense to me then any other option.
Since I don't fly competatively and do not use 60's it's all just retorical to me.
Dennis

[phil c]

Hey Dennis, I'm not trying to argue here.  It's just that dropping a 16 oz motor into a plane designed around a 12 oz. motor will likely cause some problems.  Fortunately Andy had good results with his, but it is not a drop in replacement.  The whole LA series is pretty conservatively timed for an RC engine, which makes them, on the whole, very tractable and easy to get to run well in CL.

[dennis lipsett]

Phil,
I wouldn't take any remark as an argument. I'm just curious why no opposition to a heavy 4 cycle and a lot to a heavy 2 cycle. The end result is a heavy motor any way you slice it. Less fuel for the 4 cycle really is not a viable contrast to the weight of the engine.
Perhaps that is why the 4 cycle bloom is fading. For those that like them I say enjoy them but I can't see much to recommend them, Oh and I have run 4 cycles since 1976 with the First Anemic OS 60.
So when is the first 11 oz 72 4 cycle going to be produced.
Dennis

[Randy Cuberly]

Phil,
I wouldn't take any remark as an argument. I'm just curious why no opposition to a heavy 4 cycle and a lot to a heavy 2 cycle. The end result is a heavy motor any way you slice it. Less fuel for the 4 cycle really is not a viable contrast to the weight of the engine.
Perhaps that is why the 4 cycle bloom is fading. For those that like them I say enjoy them but I can't see much to recommend them, Oh and I have run 4 cycles since 1976 with the First Anemic OS 60.
So when is the first 11 oz 72 4 cycle going to be produced.
Dennis

Well...
First of all there is some opposition to a "big" four cycle and it's weight.  However there are a couple of things that mitigate the four cycles weight if you build for it.  First of all it uses considerably less fuel...maybe 1/2 to 2/3 as much and that equates to less weight up front...it also means a shorter smaller tank which equates to a shorter nose to make it easier to get a reasonable CG location without adding a lot of  UUUgggg...tail weight.  It also seems that most of the serious competitors have pretty much given up on four strokes...maybe the weight problem had something to do with that.

Randy Cuberly

[Tom Niebuhr]

Randy,
Been trying to contact you.
Please send me an email.

[Andrew Borgogna]

My original intent for this project was to come up with low cost engine for large airplanes.  If you can afford a 4-C 70 you most likely can afford a Ro-Jett engine.  Also you are most likely an Advance or Expert flyer.  I still think it is a reasonable engine for large planes and a good alternative for intermediate flyers like me.  It is cheap, it is powerful and the modifications are simple and stright forward.  Above all it performs quite well in our environment.  Anyway thanks to all who commented on this post.  The project is continuing, I am waiting for a venturi from a friend.  We have been working with him off line and I will let you know how things work out.
Andy

[john e. holliday]

Andy, isn't tat what this is all about,  HAVING FUN?    I am glad to hear there is another almost big engine out there to be played with.   Not all of us are Expert/Open flyers and fly for the fun.  Keep up the good work/play.

PS:Remember every one has an opinion.  Some I like, some I don't like,  can't hate em as the pastor used to say.  jeh