NoOneFlysAtMyClub

My Feedback: (32)

Which one is better the OS FP or the OS LA?

And why.

Planning a budget multi engine.

Thanks, Tony

RCPAUL

My Feedback: (1)

I think the FP is the better engine because of the chromed liner - but- it is no longer available.

Paul

mike109

G'day

And don't forget the Thunder Tiger GP42. It is very similar to the OS FP and they run really well. A friend uses one on a trainer. It goes well and is very quiet. Tower have them for about $85.

Cheers

Mike in Oz

controlliner

The TT GP .42 is the way to go, Thunder Tiger has a thicker nickle plating on the liner than OS. The FP's never had a chromed liner, it was the Tower Hobbies .40 that did. You may have trouble getting parts for the FP .40. The TT 42 has a ready supply of present day parts available.

Hobbsy

My Feedback: (102)

If you want to hear from someone who has actual OS LA experience, I have four of them. an LA .10, two blue .46s and one blue .65. They are stone reliable, smooth running, and you won't wear one out for a really long time. They are great engines and will run fine on 5% fuel and are not glow plug fussy.

mike109

G'day

I also have had a couple (three actually) LA 46s. The first two were in trainers and were perfect. Reliable, easy to start and just nice engines to use. The third came to me very second hand and had a big hole in the chrome plating on the liner. I suspect it had been fed a "high silicon diet" as it was very scored. Its bottom end was still perfect so I put a new piston and liner in it and gave it away. They are good engines. A bloke I am teaching has one in a Kadet LT-40. It flies it perfectly. We did have some fun getting it to run the first time but once it had a couple of tanks of fuel it became easy to start and very consistent. He really likes it.

This is a bit off the topic but a friend has an LA 46 with a diesel head of his own construction on it. It really runs well as a diesel. I believe Hobbsy has some too and I know he likes his diesel conversions. The LA series do seem to make good diesels.

I always run more castor in my plain bearing engines. They seem to like it.

I also like the Thunder Tiger GP 42 as I mentioned above and I have one which needs a carby. Perhaps one day .....

I did have a Thunder Tiger GP 40 many years ago. It was in my son's first trainer and ran well enough though no amount of opening the air bleed would stop it running rich at idle. A friend had one also with the same problem. He slightly drilled out the air bleed and it fixed his problem. I just lived with the slightly spluttery idle. It never caused me any problems.

You have many choices. Enjoy choosing. And tell us more about your "multi".

Cheers

Mike in Oz

Hobbsy

My Feedback: (102)

Thanks Mike, yes one of my .46s is a Diesel conversion and the .65 is now, as is the .10. Many folks slam the LAs for their lack of ball bearings, this should not be the case. The bushing engines cranks run on a film of oil that is every bit as slick as a ball bearing. Nearly all TurboChargers run on two films of oil one inside a sleeve bearing and one outside a sleeve bearing and they turn in the 50,000 to 110,000 rpm range, not a misprint. I suspect castor creates about as tough a film as you'll find. Just a little sermon and its free.

Sport_Pilot

I think most FP's were ringed or cast iron. Maybe there were some ABC versions right before the LA came out, not sure.

IMO you would be better with a ball bearing engine and someting more reliable than an LA with its bleed air carb. I would go with either a Fox 40deluxe ABCor TT Pro 40 if you are after a 40 size. I just wouldn't mess with a cheap engine like the FP or TT GP.

KW_Counter

In my opinion there is nothing more reliable than on OS LA.
The only trouble I have ever had with any of mine was when I moved from
below sea lever to the mountains, I had to switch from 10% to 15% nitro.

Yes, a bearinged engine will spin faster than a bushed, but the bushed
engines are reliable and strong enough to do most jobs and easy for
a beginner to learn on.

I have no actual experience with the FP or TT.

Good Luck,
KW_Counter

jaka

Hi!
Both FP and LA is and has been ABN engines. No ring.

airraptor

My Feedback: (66)

To the OP the LA engines run very well not very strong but not meant to be. they are meant for beginners and with that they are meant to be easy to start and easy to run. they will out last a ball bearing engine. Go with the LA 46 engine!!

Bax

My Feedback: (11)

When the O.S. Max FP series of engines first came out, they had a steel piston running in a steel liner. They would usually take at least an hour's worth of running very rich on the bench before you could reliably fly them. We had many returned by customers who tried to lean them too early, which would cause them to quit almost immediately because they'd overheat. However, just restarting and running richer would cure any problem.

The long breakin requirement was considered a detriment by many customers, and so O.S. changed to the ABN system that's evolved into the ABL system they use today. Those original FP engines would last "nearly forever" if properly run with a good-quality fuel containing mostly castor oil as the lubricant and 0%-10% nitro content.

The FP and LA engines have never had piston rings in any of them.

Sport_Pilot

Oh come on! It has an air bleed carb!That means that any small amount of dirt getting into the oriface will change the mixture. Any twin needle carb will be more reliable, OS makes some fine carbs. However the same cannot be said about their ABC liners. ThelaterLA liners are better than the older liners and likely the FP. However for the most reliable I would go elsewhere, I have seen many air bleed carbs give trouble because of dirt in the orifice.

Hobbsy

My Feedback: (102)

You must have really dirty air in Ga. I have Fox airbleed carbs, Enya airbleed carbs, OS airbleed carbs and have never seen that happen. One would be hard pressed to beat the LA for day in and day out reliability.

Sport_Pilot

Oh, they are relatively reliable, just not as reliable as a twin needle carb. Ok, you can get trash in the fuel and end up with the same problem, but with anair bleeed you can get trash in both air and fuel and end up with a dead stick. Not that it happens that often, but trash in the orifice of an air bleed does happen and it can cause the engine to quit. Ihave seen it happen at least a couple of times, both right after take off.

049flyer

My Feedback: (18)

I prefer the FP series because of the metal backplate and traditional needle valve. The LA series have a plastic backplate and remote needle valve assembly. As far as reliability I would say they are equal. Parts are easier to get for the current production LA.

No problems in Texas with air bleed carbs and bushed engines. Use the right fuel and the engine will last for years plus no worries about rusted bearings!

Never experienced dirt in the air bleed oriface that was not caused a mishap.

Never can understand why people think that bearings make an engine more powerful. I'm thinking that there is more to it than just the bearings.

Sport_Pilot

The ball bearings do have less friction, however that is small. The main thing is that the bushing engines are simply set up for low power and simple carbs.

airraptor

My Feedback: (66)

just because you couldnt get one to run doesnt mean everyone else cant. Air bleeds dont off the best transition but i think they are more reliable than two needle carbs. for the OP the LA 46 or GP 42 engines will do just fine. i have around 20-22 engines with air bleeds and they all run just fine. for a multiengine project like this LA engines are the way to go.

hsukaria

A question to the OP, does the fact that you are using these engines in a budget multi-engine application dictate that it has to be air-bleed carb and bushing engined? Or is the choice of engines based on availability used from somebody?
This thread went off on airbleed vs. twin needles and ball-bearing vs. plain-bearing (still interesting to me btw). But what does each criteria have to do with multi-engine and budget? There are cheaper engines that are ball-bearing/twin-needle than the OS LA. But those engines might be heavier. (power vs. weight vs. budget).

Sport_Pilot

Never had a problem with getting any engine running. That is any engine that has compression or fuel. Orifices do indeed occasionly or sometimes rarely plug up. Even if rare it still makes it less reliable than a twin needle carb.

1QwkSport2.5r

Personally, I wouldn't use either engine that was listed by the OP because I don't care for OS, so I too would recommend a Thunder Tiger for a budget engine. For a little more money, An Enya or Fox would be good candidates as they will run nearly forever with the proper treatment and parts are readily available for them. In regard to airbleed carbs, I think there is a distinct difference between a normal airbleed carb and a metered airbleed carb. I would prefer an Enya airbleed carb over any other airbleed carb on the market. My experience is limited, but in what experience I do have, I would pay more for an engine that will last longer and not have a liner peel than an engine that may need a liner replaced due to the plating flaking off. Fox has a trade-in program where a clunker engine of ANY make can be traded in for a Fox for half the retail price. I'd consider that a bargain. K&B Sportsters are good budget engines as well, and throttle well, but require a substantial break-in before they're flight-ready.

Just my opinion, though.

aspeed

I would make the choice on where you want the needle valve sticking out, front or back.  They are both siimilar. Maybe the LA could get parts easier, but they will likely stay on the plane and not wear out for a while. The carbs are very small to make them easy to tune and get good suction and give ok but not spectacular performance.  Just what you want for a multi engine plane.

turbo.gst

My Feedback: (8)

The quality of the LA series is down from the FP IMO. The TT.42 is another very good option.

airraptor

My Feedback: (66)

This is dead on for a multi engine plane of this size.

For you guys that think the liners still peel on the newwer OS engines they are not like the older engines. Yes enya engines are great but not as available as the OS engines.

The fox engines run well also.

If it was me it is a no brainer LA 46 engines 15% fuel and 10x6 props

jeffie8696

I prefer the OS40FP engines , they seem to be made much better than the LA series. But Ilike the TT GP42 best.
Ihave 2 GP42s, one LA65 an LA46 and one 40FP. All run well , some just better than others. Ilike air bleed carbs just fine. Iwould rather have a good air bleed carb than a bad (cheap junk) twin needle carb.