I was feeling cranky:-) Here is a little more....
>The proper way to remove a bearing is with a bearing puller. And the proper
>way to insert the bearing is with a bearing press.
>You think the factory puts bearings in the oven?
This is just plain wrong.... While the factory may or may not heat the case
to install the bearings I (and anyone else I've raced with in 30+ years)
always reinstall the bearings on all my performance engines by heating the
case. Bearings are a sweat fit in the case and should be perfectly aligned
with the case/crank bore. The easiest way to do this is to heat the case
and use the crank itself as an alignment "tool".
>Take a look at what Clarence Lee has to say on this very subject.
>He states that heat should be used when needed if the bearing will not come
>out easily when using just a puller alone. UNLESS the factory instructions
>specifically indicate that you should apply heat.
>The bearing is held in place on the crankshaft by an interference fit. It
is also held in the actual engine case by this very same interference fit.
Clarence was a great engine man and still very knowledgeable if not somewhat
dated. He is now (and has been for years) a very respected engine collector.
He was also very involved in the development of the K&B/Veco line of engines
30+years ago and to my knowledge K&B's were the only engine that the bearing
was not a slip fit on the crank. They were press fit.
Bearings should NOT be held in place on the crankshaft by an interference
fit! They were in some K&B's and it was a nightmare. On K&B's where the
main bearing was press fit on the crank I would remove the crank and stuck
bearing from the engine, chuck the bearing in a vise and hammer the end of
the crank until the bearing slipped off. That of course destroyed the
bearing. I would then polish the crank until the bearing was a tight slip
fit and put in a new bearing. I own 300+ engines from Nelsons to Nova
Rossi's, 40+ K&B's to OS and Fitzpatricks and with the exception of some
older K&B's, the bearings are NOT and should NOT be a press fit on the
Now to answer the original question. "What are the implications now (of cold
pressing the bearings in place)?" In all likelihood nothing. Just run the
thing. I've seen folks run engines orange with rust and while I don't
recommend it and performance and life may suffer, it will be fine. If you
are running your engine in the 30,000 rpm range it would matter but for the
average OS, TT, GMS, ASP... turning 12,000 rpm and making 1.2ish horsepower
it just doesn't matter. Any possible damage to the balls or races (if the
cage is damage, that matter!), or any misalignment will not be a factor in
sport flying. VERY few model engines are flown enough to find the service
life of the bearings even if poorly installed and misaligned. Look back at
the years of SPORT flying at your club...when was the last time you saw a
My guess is that we will disagree but that is OK...
> Could you be a little more vague?
> > Careful here John,
> > There is some really bum gouge in this thread....
> > Bill Vail