Patxipt

Guys, what manufacturers have plain bearing engines still available?

I can think of OS and TT with their LA and GP series. Anyone else?

huck1199

MECOA has K&B Sportsters in .20, .28, .45, .65 sizes.

martenson

The new COX company in Canada

tiffitech

Don't forget Enya!

Regards,

Holm

huck1199

Magnum

controlliner

Fox

MinnFlyer

My Feedback: (4)

What you are referring to is a "bushing" engine

Hobbsy

My Feedback: (102)

Bronze sleeve bearing in lieu of ball bearings, add OS LA series and certain PAW Diesels to that list.

Sport_Pilot

I didn't know the bearing had to be bonze.  I thought the aluminum bearings in Cox engines and others were also plain bushing.

Hobbsy

My Feedback: (102)

Bronze is the most common, K&B used to run the crank in bare aluminum but as of late they have a non aluminum sleeve bearing. I have a couple of Fox .36x' and Fox .15s that are plain bearing but I don't know what.

earlwb

If I remember correctly, the K&B Sportsters use aluminum bushing bearings no bronze bearing sleeve. With good oil lubrication there is no real reason the aluminum bushing would not last as long as the bronze bushing. But bronze bearing material tends to soak up oil like a sponge making it more resistant to inadvertent lean runs, etc. sort of self lubricating. OOps, someone already meantioned that K&B now has a non-aluminum bushing in there current Sportster engnes.

The venerable FOX .35 Stunt is a bushing engine too. The rest of the Fox engines though all have ball bearing supported cranks.

Some of the smaller Enya engines still use bronze bushings.

Now I haven't seen a current Magnum engine with a bushing crank. I think all the current ones are using ball bearings.
But years ago they copied the OS FP series and there might be a considerable number of engines still floating around.

Patxipt

So the list of plain bearing / crank bushing models manufacturers is as follows:

OS
Thunder Tiger
Enya
K&B
Fox
PAW

Thanks guys [8D]

spaceworm

K&B Sportsters were originally hi silicon aluminum cases that were intended to not need additional bearing material for the crankshaft. However, K&B apparently re-thought the issue (probably after replacing a lot of crankcases with worn shaft "bushings"), and offered bronze bushed crankcases free in exchange for the original non-bushed cases to the original purchaser. I have an original 65 Sportster with a quite worn shaft "bearing" that still runs well, but spits a little fuel out the front end.

Sincerely, Richard

qazimoto

My Feedback: (1)

Only in the USA. Everywhere else in the world people call it a plain bearing (PB).

Norvel (now called NV) produce many good PB engines.

See: http://www.nvengines.com/

pe reivers

If you write it the way you pronounce it, it would be a plane bearing

In the old days of low power engines that needed a lot of nitro to run well, those plain bearings slowly would acquire a tonneau shape that allowed the crankshaft to rock rattle and roll. In that shape, they ran surprisingly well, albeit with some oil expelled out of the front part. Without the spill oil, the shaft would be lacking lubrication.
Modern engines, and modern philosophy no longer has room for this kind of design thought. People complain about the OS LA type of engine, because they will not run well. They need castor oil to run well, and yes, after a while they do leak a lot of oil, but run quite good. Having said that, full ball race bearing engines run a lot better.

cutaway

The .36X came in two flavors (dull cases), needle bearing rear main, and ball bearing rear main, both used the aluminum case as a bearing in the front of the crank.

There was a somewhat cheaper plain bearing Fox .36 (shiny cases) that came out in the 70's that used the same P/L as the 36X.

All the early Fox .15's, plain/15X/15XX were plain bearing. The current model schnurle .15 was available with plain or ball bearings when it came out.

earlwb

You know that early Fox .15 Schnuerle with the bronze bushing for the crank was one of my favorite engines. It tended to last forever baring a nasty crash or something. it didn't lose that many RPMs over the ball bearing version either. After it was really well worn in, it probably came out about nearly equal in RPMs. I used to use a Fox 15X with the special rod and lightweight piston for Quarter Midget racing in the early days. That little guy could turn over 20,000 RPMs at the time.

The Fox .40 and .45 big case bushing engines were also great engines too.

willig10

G.E. See attached. This is a plain bearing turbine engine.

willig10

here is a couple more pictures of a plain bearing turbine. I know, I know not RC related but you asked.

Glenn Williams

dieselbloke

Plain/Plane are two words that are pronounced to sound exactly the same in standard English.

You're information is way out of date

The modern OS LA series of engines run very well in c/l Stunt with 5% nitro and 20% oil made up of half castor , half synthetic. The LA 25 makes a very hot Classic B team race engine despite being Plain Bearing. The Brodak 25 PB stunt engine can be modified to make a very hot team race engine as well. Same with the Norvel 25 PB engine and the Enya 25SS PB..

These engine are much lighter than the Twin Ball Race equivalents which is a big advantage.

Really Pe you should get your facts straight before you comment.

Hobbsy

My Feedback: (102)

When all other factors are equal, for example when a ball bearinged engine and a bushing engine have the same bore and stroke, same compression ratio, same port timing they will have exactly the same amount of power. The ball bearings do not give the engine an edge. The bushed engines crank runs on a film of oil that is as slick as any ball bearing only the bushing will last much longer. Most TurboChargers have sleeve bearings and the shaft runs on a film of oil, two actually as there is a film of oil inside and outside the sleeve, the sleeve bearing in TurboChargers require oil flow not oil pressure so are fed oil through a small orifice.

earlwb

Years ago Fox had .40 and .45 large frame engines sold as both plain bearing and ball bearing versions. The plain bearing versions ran about 300 rpms less than the ball bearing versions. But it could have been more equal though as he had a little bit more porting done on the ball bearing versions.

But Pe Reivers is correct that on some plain bearing engines the rear of the bushing next to the crankweb would tend to get more oval in shape due to the engine's power strokes. But you had to rack up quite a few hours on the engines though to get it that way. Plus not all plain bearing engine designs exhibited the problem. The most classic example goes way back to around 1947 with the early plain bearing Drone diesel engines. The next year they had a single rear ball bearing on the newer engines to correct the problem.

spaceworm

Of course almost all automobile engines are plain bearings, bushed with babbit or other alloys.

Sincerely, Richard

Sport_Pilot

Actually if you force oil into the bearing area it is called a journal bearing, a type of plain bearing.  Our model engines use bushed bearings another type of plain bearing.  But its really sematics as I suppose the terminology gets swapped around in other countries.

http://en.wikipedia.org/wiki/Plain_bearing

spaceworm

Bottom line: Some cranks have balls, or rollers, and some don't

Sincerely, Richard