propjobbill

OS LA-40 compared to OS FP-40

What is the difference between the LA-40 and FP-40? With a 10-6 prop can you expect the FP to have more rpm, and how much more power. Thanks

bigchap

all the la's i've used are finicky beasts,the fp's are absolute gems,i have a few that i've had a long time and they're totally dependable,the la was a step backwards in my opinion.as to power differences in my experience the fp has a slight edge.

DavidAgar

My Feedback: (108)

The FP engines were first and then came the LA and the FP engines went bye bye. The FP engines were without a doubt the best non bearing engines made. I have a couple of LA engines and they do run okay when they are adjusted corrrectly, however they do not hold a candle to the FP. The FP engines that I am still flying have more power and are alot more dependable. If you have a choice, go with the FP. Good Luck, Dave

broke_n_bummin

answer: .73 ounces and the location of the needle valve. The LA is the predacessor to the FP. I have both and don't notice any difference in power or RPM The LA is slightly lighter. That might give it a slight edge, but as far as power, they both pull my SPADs the same. If you use 15%, most of the carb problems will go away.

RCVFR

My Feedback: (7)

Well, almost: the FP is the predecessor to the LA. The LA is the successor to the FP.

broke_n_bummin

Yeah ... what he said....

rcdude7

My Feedback: (264)

The FP has a few things going for it that are missing from the LA. Metal backplate, full length crankshaft bushing on the fp, the LA makes due with a two short bushings to cut mfg costs. I also prefer the six bolt head and needle assy. on the carb instead of backplate.

bigchap

i just got a b.n.i.b. 35 fp,you can keep those horrible la's!

jaka

Hi!
Horrible...???
Most be a missunderstanding! The OS LA line of engines are as good as the FP.
Same power, same increadable good idle and throttle characteristics.
A perfect engine for newbies as well as for adwanced flires who want a dead sure engine for their twin engine airplane, where outmost reliability is required.
Bad?....Must be joke!

A 10x6 prop is no good for these .40 or .46 engines if used in a high winged trainer like the Kyosho Calmato trainer. Instead use a 11x5 or a 11x6 , preferable APC or RAM.

propjobbill

I've never tried an 11x6 prop, I thought that would be to much. I will be going to the hobby shop later this week. Do you have any idea what rpm's an 11x6 apc will turn with 15% nitro?

HighPlains

My Feedback: (1)

The OS FP was a very nice sport motor. A good replacement is the TT GP42, though you will have to put up with slightly lighter weight and more power.

jaka

Hi!
well ..around 9000-10000 rpm! Just a guess.
It doesn't really matter what the rews are as long as the engine can handle the load.
Why! 15% nitro????
The OS runs perfectly on just 5% nitro.

bigchap

i've run a 40fp on straight fuel no probs at all,there seems to be a lot of people on this site convinced that high nitro is the answer to all ills,i've seen posts where 20% nitro is used in super tigre engines which are actually designed to use no nitro.

jaka

Hi!
Yeah! The Yanks seem to favor lots of nitro (15%).

propjobbill

I JUST GOT AN 11X5 APC PROP. IT TURNED AT 11,500 = 12,300 FOR STATIC TEST ON MY LA-40. ACCORDING TO THRUSTHP IT SHOULD GIVE ME 6.64 POUNDS OF THRUST AT OVER 58 MPH AT 12,300. I WILL TRY AN OS 40-FP TOMORROW. BUT THAT SOUNDS LIKE WHAT I AM LOOKING FOR. THIS IS A DIFFERENT ENGINE FROM THE ONE ON THE TRAINER, IT'S RUNS 11,300 WITH A 10-6 MASTER AIRSCREW PROP. THRUSTHP SAYS IT ONLY HAS 3.83 POUNDS OF THRUST AT 64 MPH. I CAN'T WAITE TO GET TO THE FIELD AND SEE HOW IT FLYS WITH THE 11-5 APC.

AND THAT WAS ON 10% NITRO.