bushing?
 

Whats a "bushing?" and how is it not as good as a bearing? Thanks

RE: bushing?
 

Hello!
The crankshaft on engines are supported by either a brass "tube" (brass kind of material at least) ...or by one or two ball bearings.
Ball bearing....if they are good (are of C3 quality) ...gives much less friction than a comparable bushing, this because of larger friction surface aganst the crankshaft using a bushing).
Using a bushed crankshaft is also cheaper too manufacture so only cheaper engines ( I did not say they are bad in any way) use "bushings" .
Horse power is first gained by minimizing the friction inside the engine...thus ballbearings are used in more high-powered-type engines.
Both engine types last decades if treated well. Ball bearings must be changed after a couple of years if you are serious about having good power. A bushed engine does not require as much maintenance but usually deliver less power.
Regards!
Jan K

RE: bushing?
 

Additional opinions:
I think most bushings are bronze, although equally good ones use hard-anodized aluminum (such as the "good" Cox engines).
GENERALLY, bushed engines require a little larger oil content in the fuel.
Bushings are less likely to accumulate rust than BBs.
Bushings tend to be more affected by unbalanced props (wear).
BB engines tend to be just a little heavier per displacement.
I like both.

George