MECOA's Model Engine Forum & Swap Shop

[jocondor]

Hi to everyone, i need the help of real experts, i just bought on the bay this motor NIB, i know that BB means Ball Bearings but what about ABC?
I have more than one .099SR but no BB ones, and even if they are airplane engines i use them on my vintage buggies, they are very popular on small nitro buggies in the 80s.

Any info or tech sheet would be appreciated.

Thanks a lot for your help

jc

[ron bennett]

ABC is an Aluminum piston running is a Bronze (or in the case of high performance engines, Beryllium), Chrome-plated liner. AAC is an Aluminum piston rinning in a Aluminum Chromed-plated liner. The idea is to more closely match the expansions at running temperature. The aluminum liner saves about an ounce in weight.

Ron Bennett
Monouth, OR

[chiefss]

Not quite correct. ABC is an aluminum piston running in a chromed BRASS cylinder. Not bronze or beryllium.

[dennis]

[chiefss]

Yup, that's why Dumas quit making boat propellers out of the stuff.

[ron bennett]

If you contact engine makers, you will hear that brass alloys are way to soft for liners and most all makers used a bronze alloy, not brass. And, like I posted, high performance engines like Cyclon and Profi et.al., use beryllium liners on their better engines.

[chiefss]

You better check your manufacturers again. None use bronze and beryllium is a no no now as it is a known carcinogen. Has been for years. Dumas quit using in in boat props 25 years ago.

No one has ever used beryllium in engine cylinders. I think if it was used guys like Clarence Lee, Dave Gierke, and the other engine guys might have mentioned it. They would have also mentioned it if bronze was used. Brass is the metal of choice becuase of its coefficient of expansion.

Brone and brass are two completely different alloys. Bronze is copper and tin, Brass is copper and zinc.

I have two Profi engines and neither one uses beryllium.

[jocondor]

Thanks a lot for your replies!

Can someone suggest me the best mix % methanol, % oil (what kind, Castor, Syntetic...) , and % nitro methane, to run this small engines? Consider that i don't use them to fly, but on vintage rc cars that were made for them.

[chiefss]

Small engines like higher nitro as they give their heat of faster. I would use at least 15% nitro. That said, the engine you are using never was meant to be used as a car engine so I would not get weird with the nitro content. I would use at least 20% oil and I use 100% castor in all my engines. 2 or 4 cycle.

[Frank Klenk]

Good advice Chief, easy on the nitro and use good ole 20% castor.
_________________
MAAC 32001
IMAC 3698
MECA 4762
SAM 5032
We have enough youth, how about a fountain of smart?