Well between Charley and Charles, I get the point of why there are
bearings. But I have to agree with Charley. If there is no wear in the
journals, then why bother. On the engine I am rebuilding the cam journals
look very good. It was the lobe that is worn. Now I just got off the
phone with TSI (Ted Schumacher's outfit) and while they do not have a
1500 cam in stock :-( the do not recommend boring for bearings, unless
going for a full race spec, or if there is evidence of excessive wear in
the journal area.
Larry
At this exact moment in time 10/8/00 10:45 PM, ccrobins@ktc.com made the
profound statement:
>Larry, et al,
>
> Hmm, I think thing need to be put into perspective here. Most
>engines have separate "cam bearings" (sleeves) installed into the block
>for the cam to spin within. Some don't. The Spridget 1500CC engine is
>a case in point; its cam spins within machined bores in the block. If
>the cam bores in the block get worn out of tolerance, the oil pressure
>could indeed suffer. Also, if the bores wear too much, the cam will
>flex under the valve spring pressure. The cam can break because of
>this, but the most frequent sign of this is that the valve lash won't be
>constant. I had a Fiat 128 Spyder DOHC engine that manifested worn cam
>bores in this way. The fix is, reputedly, to bore out the cam bores for
>bearings and run an XXX cam. Take your pick; I've been told of several
>different to use.
>
> My thought is that I'd have to see signs of real probs in the cam
>bearing area before I'd bother. By signs, I mean a real good going-over
>of the cam bearing journals on the cam for signs of loss of alignment,
>out-of-round, etc.
>
> Hope this clears it up a bit,
>
>
> CR
Larry B. Macy, Ph.D.
macy@bblmail.psycha.upenn.edu
System Administrator/Manager
Neuropsychiatry Section
Department of Psychiatry
University of Pennsylvania
3400 Spruce St. - 1015 Gates
Philadelphia, PA 19104
Ask a question and you're a fool for three minutes; do not ask a
question and you're a fool for the rest of your life.
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