ccrobins wrote:
>
> Gotta real problem with some of this, no knock to you guys, everyone
> has his way of doing things successfuly; no one way is the "only" way,
> in my experience.
Agreed, there is a lot of mysticism and hocus pocus
about building engines, but some of it is based in fact.
Breaking in the cam is important. The important mating
surfaces that you are bedding is the interface between
the cam lobes and the lifters.
Remember that, like engine valves, the lifters are supposed
to rotate in their bores very slightly with each contact with
the cam lobes. The means that the contact area and wearing point
between the lobe and the lifter is always changing, and
service life is greatly extended.
When bedding in a new cam and/or new lifters, the first
few minutes of running is when the surfaces wear to each
other. It's important that the engine is running quickly
enough so that the lifters spin. This is why the general
consensus is to use moly lubes and rev the engine up
for the first few minutes.
If the revs are low when the cam is first run, the lifters
won't spin and the cam and lifters will wear only on one
spot. If you are unlucky, the initial wear pattern will
cause the lifter to not turn even in normal service, and wear
will be greatly accelerated since the wear that is normally
distributed all over the face of the lifter will be focused
on one spot.
As for the other "engine assembly lubes", they are useful
if you spend a month or two building an engine, then
drop it into a restoration project that doesn't run for
six months. The assembly lubes will be still there when
you eventually fire it up, where plain oil might have
long dripped away.
--
Trevor Boicey, P. Eng.
Ottawa, Canada, tboicey@brit.ca
ICQ #17432933 http://www.brit.ca/~tboicey/
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