MrSteve09

Just a question regarding which engines are better for control line stunt; the older style OS FP versions or the newer OS LA's?? In other words, if I had the opportunity to pick up a used FP on ebay would that be better than purchasing a new LA from the hobby shop??

Thanks for all your help and advice.

Sincerely,
Steve T.
Monson, Massachusetts

gcb

Here are some of the differences: FP has six head bolts, LA has four. FP has full sleeve bearing, LA has partial bearings. FP has booster port, LA does not. FP has needle assembly in venturi, LA has remote.

I only have one LA (.15 FP-S) but it seems to run well. I have several FP's that all run well.

Some were concerned about only four head bolts. Others were concerned about the partial bearing. I have not read of either being a problem.

For the RPM that most run for stunt, the booster port adds nothing. As a matter of fact, some engine reworkers would seal-off the booster port in the FP to help scavenging at stunt RPMs.

Some do not like the remote needle and replace it with the FP version. The remote needle runs well but is slower at responding to changes in needle (tweaking).

Oh yes, one more thing. Some replace the LA's plastic backplate with a metal one (FP).

Some also run the LA right out of the box. Most OS engines are good for plug-and-play.

To answer your question, before bidding on one on *bay I would ask the seller if there is anything wrong with it. Nothing like being able to fondle it and look it over at the LHS.

These are just opinions, I'm sure folks who run both a lot will chime in with some better answers.

George

MrSteve09

Thank you George!! That gives me a lot to think about. Sounds like the FP engine are better made while the LA engines had some "corners cut"; however like you said, for the rpms we are running in stunt, that doesn't seem to make a difference.

Thanks again for the information.

Sincerely,
Steve T.
Monson, Massachusetts

308jockey

Steve having run many of both, they are both pretty good engines. The FP's are built using some older mfg. methods and they seem more 'solid' if you know what I mean. Still, the LA's seem to run just fine in every application I've used them. Neither series are high performance but the FP's will run for decades and I'm betting the LA series will as well. I just finished a Primary Force ARF I got for Christmas and put an FP .25 in it. Haven't flown it yet (maybe tomorrow or Monday) but the engine has been in quite a few planes and always runs.

Rick H.

Motorboy

OOOpps, there are a very bit mistake, the newer and the older 10 FP has 4 bolts, but not placed as same as newer 10 FP.
The older 10 FP has 2 bolts fore and aft, 2 other in left and right while the newer 10 FP 2 bolts front and 2 other aft.

From 15 FP to bigger FP series has 6 bolts..

Jens Eirik

PipeMajor

My Feedback: (1)

The consensus is that the LA engines (particularly the 46) are more stunt friendly out of the box than were the FP engines. I have an LA 46 in a Top Flight Tutor II ARF and am quite pleased with it. I plan on mounting an LA 40 in a modified Twister soon.

I also acquired the Sig Primary Force ARF and initially had an FP 25 in it. It really did seem underpowered. I swapped it out for a Brodak 40 and now seems much more solid through the maneuvers. I fly a Ukey-40 with the FP 25 and it does very well. Ditto for my TF Flite Streak ARF with FP 20.

ghost123uk

I have been asking this on the Barton C/L clubs forum ( see http://tinyurl.com/ym7598 )

There is one big difference that is very important especially if you are building an old design stunter or even more so if you are buying an ARTF and that is weight.

I do not know how much the LA 40's weigh ( anyone got that info out there please ? ) but I do know it is quite a bit heavier than the 8 ounces the 40 MAX FP weighs.

It also is common practice, with our guys, to use the smaller 25 size silencer, as it is lighter and helps prevent the runaway ( "winding up" ) revs the boost port can cause.

jimcork1

My Feedback: (4)

I agree on the La .46 being ready out of the box,, but don't mount it inverted. I have 2 great La. .46's that run vertical or horizontal but won't idle and throttle up inverted. Jim