Well after I boiled my Webra 50 in antifreeze I'm having problems. It's probably my fault so don't think this cleaning method is wrong. After I finished doing the crock pot thing for about 20 hours I took it out and blew it off with air. Then I put after run oil on the bearings. I put it all back together and everything was fine. Then after putting the prop on I turned it over and it sounded funny. Anyway I think the front bearing went bad. Any comments would be appreciated.

Thanks,

Mike

well thats what you get for doing someting diffrent
just kidding hope you get that solved.

Hi Jerkey. Not sure what the funny sound is that you're getting, but my Webra 50 will sound like it has a very slight front bearing noise until I prime it a few time before starting. (just dried out?) After a little fuel gets into the carb, it seems to quiet down...

Hi Mike...I'm assuming it doesn't feel or sound as smooth as it did before you cleaned it? It's possable you dis-lodged some crud, and it got into the bearing. FWIW, I have a brand new Speed .50, and the bearings feel and sound a little rough and noisy. I haven't run it yet, but I'm hoping they'll wear-in a little and smoothen out some. We'll see...(there's no symbol for crossed fingers on my keyboard )

Hi Proptop,

I purchased a Webra 50 Speed two weeks ago. Brand new, I couldn't realize this scratchy sound of the bearings because it was too difficult to turn the engine by hand (piston tolerance). After running 1.5L FAI Fuel (20% Castor, 80% Methanol) through it this weekend, the engine seems to be on the way to run in as it should, but when I turn the engine by hand between both "compression points", now I realize that sound in the bearings. When the engine is running, everything seems/ sounds OK. I decided to continue running in until either sound disappers (good luck) or it gets really bad (shi..)

This engine has huge compression. Seems not to need Nitro at all. Engine vibrates in transition with glow plug hotter than Novarossi 5 at the moment.

AlexSpeed,

That "scratchy" sound results from the ABN Webra, as well as all other ABN/ABC/Plasma ceramic engines' cylinder bores being tapered. The internal diameter of the sleeve is slightly smaller at the top, than at the bottom.

When the engine reaches operating temperature, this taper is "canceled out" by the differential heating of the sleeve.
This, since the top heats and expands much more than the bottom.

This is why such engines must be broken-in at operating temperature, unlike ringed engines that need a very rich and lukewarm initial break-in.

You can search the pages of old RCU for the "break-in in tapered bore engines" thread.

When cold, your Webra must still have a slight "pinch" at TDC. If an ABN/ABC/Plasma ceramic engine is broken in four-cycling, slobbery, dribbly rich, this "pinch" will be gone and the engine will be ready for an overhaul...

Not broken-in - just broken...

Dar,

Your advise is very helpful. Thanks a lot! (I also did my homework and I've read the old postings you mentioned related to this). Really worth to read!!!

Kind regards

Alex Birk

Barcelona (Spain)

Thank you, Alex.

That is what the forum is for, to give and get some good advice and ideas.

Although I did publish ABC/ABN break-in instructions in a local R/C web site, I ran into some people that are reluctant to accept the idea that they may be doing it wrong.
They will go on doing it wrong and then they say their engine was worn out after 10-15 hours... instead of lasting over 100.

Well, I've since run it in a WM Dago Red. The bearings are crap! Brand new engine, w/ sh*# bearings! They get noisier each time it's run, and when hot, the crank's loose and clunkin' around! I'll run it for while like this, frankly, I don't give a rats ass if it blows... I don't think they make Webras as good as they used to. Had to send a brand new, not run, Speed .61 back, because of a ton of slop in the lower rod bushing/crank-pin. I'm getting 13,500 on 10% w/ an 11x6 APC and Ultra Thrust muffler, but it was 1000 less w/ the stock muffler, which is un-impressive in my book. $200.00 for 13,500 aint that great, I don't care what anybody says...My TT .46 gives me close to that, and for $80.00 too...

Update:

Don't really know what the funny noise was but it runs just like new now. Maybe the bearings just needed a little more lube. anyway every thing is fine and it also looks just like new.

Thanks,

Mike

I'm guessing it was just a dry engine you were hearing. Engines retain a very thin coating of oil on the parts after running. You cleaned all that off and were hearing metal to metal contact....cylinder to piston, bearings to race, con-rod to wrist pin and crank. There were lots of places for the noise to come from....probably a little noise came from all of them.

Wiz