> ->. Some of the tappets are badly pitted too. Can I just replace the
> ->pitted ones?
NO. Tappets are not re-usable parts. I've heard it said that the
most common cause of premature wear, engine failure after rebuilds,
and rough running on an otherwise new engine come from reusing the
tappets. Only re-using rod bolts will wreck a rebuild faster.
Cams and tappets develop a wear pattern to each other, and it's
important not to install a worn tappet on a new cam lobe. (A new
tappet on a worn cam isn't as big a problem but is sort of a "why
would anyone actually *do* this?" question.)
You should also be aware of start-up and break-in technique for
new cams. You want to run the engine at about 2000-2500 RPM and
NO LOWER for 15 to 30 minutes after reassembly to ensure proper
seating of the cams and tappets. Of course, you also want to use
enough of the right kind of assembly prelube. The German STP stuff
that we used on the race motor worked well enough, but Redline makes
a specially formulated prelube that is just slightly less goopy than
bearing grease and is formulated specifically for use on the cam
surfaces of a rebuilt engine. (Actually, now that I recall, we used
graphite on the cam surfaces to help avoid metal-to-metal contact
while cranking to get oil pressure. Molybdenum disulfide is a good
thing to use for the same purpose.)
Assuming you've used enough lubricant, you then want to keep the
engine turning fast enough for at least 15 minutes. The reasoning
here is, again, getting the right kind of seating and wear patterns
on the lifters and cam lobes. The problem is that if the engine
runs too slowly or without sufficient lubrication, metal can actually
be transferred from the lobe to the tappet or vice versa, which then
wears everything out that much faster and can cause pieces of either
the cam or the tappet to break off and fall into the engine. Not a
good thing. And recall that the cam is running at half engine speed,
which is why you need to keep the speed up. At 1000+ cam RPM it will
glide over the tappets. At 500 cam RPM or less, it will just act like
a slow lathe.
>I'm not interested in inferior parts to save a just few $$$ as
>I really don't want to rebuild the engine again any time soon.
Remember this every time you turn the torque wrench or pick up the
phone. It's a lot less painful to spend a little more now than it
will be to do this all again in six months.
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