engine leaking oil

Stuka Stunt Main Forum · 10 of 10 known posts recovered

stephen · May 07, 2006 10:08 PM

engine leaking oil#0 source

I have a question what causes the bearing to leak on a bearing engine. I have a Ro-Jett .40 and after every flight the front of the plane has oil on it and when I remove the cowl it also has oil on it. I have checked the pipe connections and I can not find a leak but from what I can tell is its comming from the front of the plane. If the bearing is indeed leaking is it hard to fix?

Thanks for the help

ama21835 · May 08, 2006 05:59 AM

RE: engine leaking oil#1 source

Progress is our most important problem

I've never seen a RoJett.

But, in general, the front of the crankcase is the issue, not the bearing. If they leak, get a new crankcase.

This was chronic problem on the Cox Conquest 15. Machinists around here started cutting a left-hand spiral groove on the inside of the crankcase, between the two bearings. It effecively pumped the leakage back into the case and completely solved the problem.

The real problem was the volume of lost fuel.
It kept us from running the full 5 minutes in a match. With "the groove", run time was consistantly longer.

scooterjay · May 08, 2006 08:13 AM

RE: engine leaking oil#2 source

is the front bearing sealed on one side? never seen a ro-jett but i know some engines come with the front bearing sealed on one side, and the rear bearing shielded. nose first crash? you could have an egged bearing housing.

"i ain't got it! really, i ain't got it!!!"

Steve Scott · May 08, 2006 03:56 PM

RE: engine leaking oil#4 source

>Machinists around here started cutting a left-hand spiral
>groove on the inside of the crankcase, between the two
>bearings. It effecively pumped the leakage back into the
>case and completely solved the problem.

Anyone who has ever worked on the old aircooled VW engines knows there was NO oil seal on the pulley (belt) end of the crankshaft. Merely a spiral groove which flung oil (well, some of it) back into the engine.

captcurt · May 08, 2006 04:39 PM

RE: engine leaking oil#5 source

Paul, the ROJett 40 is a ball bearing engine.

Curt

norvaldo · May 08, 2006 03:50 PM

RE: engine leaking oil#3 source

Well , I have an RO-Jett 40 (RE) mounted in a profile Cardinal.
(Not ARF)
I was out flying it yesterday about 10 flights.
I have not noticed as much as a drop of oil leaking from the front.
I use the alu spinner and the mount that comes with it.
Running this one on 10 Nitro and 18% pure synth..

So ...Better ask Maverick..

Norvald Olsvold

LAkre · May 08, 2006 04:45 PM

RE: engine leaking oil#6 source

You can partially fix it by drilling a hole in the crancase paralell to the hole that the crankshaft rides in. You drill it from the front bearing housing through so that it comes out inside the venturi boss (right between the window area). The vacum created during running helps keep the fuel from seeping out of the front bearing. Most all of the current glow racing engines now incorporate ths mod right from the factory.

Les

Dr Spark · May 08, 2006 07:48 PM

RE: engine leaking oil#7 source

I have an RO-Jett 61, which has no problems, except for having too much power! I think you should send the engine back to Rich Oliver and he will surely fix it.

Duke Fox used to say "if oil doesn't come out the front, it isn't getting enough lube."

Floyd

stephen · May 08, 2006 08:45 PM

RE: engine leaking oil#8 source

My engine runs great this is my second one I just don't want the oil soaking under the finish. No complaints at all Richard has been great I know he will take care of it. thanks for your post guys

RCPAUL · May 09, 2006 05:56 AM

RE: engine leaking oil#9 source

>You can partially fix it by drilling a hole in the crancase
>paralell to the hole that the crankshaft rides in. You drill
>it from the front bearing housing through so that it comes
>out inside the venturi boss (right between the window area).
>The vacum created during running helps keep the fuel from
>seeping out of the front bearing. Most all of the current
>glow racing engines now incorporate ths mod right from the
>factory.
>
>Les

The only engines I know that incorporate this is FOX (anyone know any others?)- and it is not one of his better ideas! What is created is an air leak that varies with modulation of the air by the front bearing and the returning oil. This can make tuning impossible.

Paul