Cipolla Master 4cc (.24ci) engine questions

[CosmicWind]

Hi All,

I ran a Cipolla Master 4cc (0.24ci) RC engine on the bench. It started and ran nicely but fuel was flying out between the case and the prop driver. There is roughly a 1/16" gap between the two.

Is fuel loss in that area normal? Is the spacing normal?

Also, it came with only one muffler bolt. I cannot find a similar bolt in my collection of bolts.

Thank you for any assistance or advice you may render.

Tom

[GERALD WIMMER]

Hello Tom

Fuel coming out between the case and prop driver is not normal but not unusual and some seepage indicates a loose fit between the crankshaft and case.
Unless fuel is squirting out or you have a big air /vacuum leak we normally live with it.
Being an Italian engine I presume threads for the muffler will be metric but you need a thread/pitch gage to check the size to order from a bolt specialist.

Regards Gerald

[Motorman]

That wet nose problem will reduce your fuel economy sometimes dramatically. Also gets allot of fuel all over your plane. To fix it you'll need to replace the front bearing with one that has a rubber seal. The spacing between the case and drive washer is normal and necessary.

MM

[CosmicWind]

Thank you Motorman and Gerald.
It may have been a while since the motor was run. Might the bearing seal up with more running? I'll attempt to measure the bolt and thread count.
Tom

[Steve Helmick]

If the bolt fits both holes in the exhaust stack, I'd take it down to the local hardware store and look for a socket head machine screw (SHMS) that fits and is the right length. But I find it peculiar that the current sample has a hex head, and have to ask if there is some reason that a hex head would be needed, instead of a socket head? I'd prefer the latter. 

I would also pull the front bearing and take it to the local bearing supply store and select a sealed bearing. From all my experience, it will be sealed on both sides, and the seal on one side (inboard) should be removed. I'm not sure how long that seal will help reduce the fuel exodus, but I don't view that as a permanent fix. I think the proper fix would involve boring the front of the case, pressing in an aluminum, bronze or oilite bushing, and boring that to be a tighter fit on the crank. Getting it straight and concentric (Uncle Jimby would approve) is the problem. Could be done on a Bridgeport mill or similar. Not for the faint of heart!    Steve

[Motorman]

Might the bearing seal up with more running?

I'm afraid it will not but, it won't hurt the engine to run it like that.   

[M Spencer]

As its a ball race engine ( we hope ) ( pictured , I  hope  ) a SEALED front Bearing will lick it . Womble supplied SHIELDED  , which is NOT the same thing , by any means .
So if its to be got , I hope yours is more reliable . 

This being SEALED . Scalple / knife end to start - Lift ONE , Seal to front , remove rear for lube .




This being SHIELDED .  Same Trick , remove one . Common in FSR OS , perhaps . Maybe someones been at them , May help , but its not a SEAL . its a walrus . 

[Gerald Arana]

Hi All,

I ran a Cipolla Master 4cc (0.24ci) RC engine on the bench. It started and ran nicely but fuel was flying out between the case and the prop driver. There is roughly a 1/16" gap between the two.

Is fuel loss in that area normal? Is the spacing normal?

Also, it came with only one muffler bolt. I cannot find a similar bolt in my collection of bolts.

Thank you for any assistance or advice you may render.

Tom

Tom, Take it apart, call Boca Bearings and inquire about it. They have several grades, will match it and send you a new one of whatever grade you want.

Good luck, Jerry

[david smith]

Tom, Take it apart, call Boca Bearings and inquire about it. They have several grades, will match it and send you a new one of whatever grade you want.

Good luck, Jerry

And The bearing plus shipping will cost an arm and a leg I would use boca to find out the bearing part number(or just measure it with some calipers) then search amazon for it. More than likely it will be significantly cheaper.

David

[CosmicWind]

Thanks everyone.
Tom

[Robert Zambelli]

I’ve found every bearing I needed from Amazon.

Bob Z.

By the way. That Cipolla is a great little engine!

[CosmicWind]

Thanks All,
After messing around in my collection, I found metric bolts that fit the exhaust stack nicely.
Next step is to take this medium feller apart and replace the bearings.
Then, mount it to an airplane and let it fly again.
What would you recommend as a compatible airplane for sport (my son) and intermediate (me) pattern flying?
Fly on, Friends, and feel the pull!
Tom

[Motorman]

Shark 402 is a nice flying plane. Have you changed beaings before?

[CosmicWind]

No, I have not. What would you recommend (e.g. don't, or maybe a service (Randy or other)?).
@:-)

[Gerald Arana]

No, I have not. What would you recommend (e.g. don't, or maybe a service (Randy or other)?).
@:-)

Put it in the oven at 350 for 15 minutes on the backplate side and the main bearing will fall out. Then the front bearing can be pushed out with a wooden dowel that just fits the main CC. 

If they don't come out, up the temperature.

Good luck, Jerry

[Motorman]

No, I have not. What would you recommend (e.g. don't, or maybe a service (Randy or other)?).
@:-)

Well it could be an easy job or a very hard job depending on many things. If you want to send it through the mail I have the tools and experience and can do it for free

[CosmicWind]

Sounds like fun. Maybe I'll give it a try.

[M Spencer]

Havnt Readit , but . theyrell be a million more there . Try a few for comparison .

[CosmicWind]

Thank you, fellow fliers.
Let me work on it. Hopefully I'll have an update for you this winter during build season (after flying season ends with snow here in Minnesota).
Fly on Friends!
Feeling the pull.