Andy wrote,
>Hoping to drop my ser V alloy head in for some overhaul work.
>The guy recommends a skim.
>It's already got 10 thou skimmed off
>(I think this 'cause theres a [0.010] stamped on the head face.)
>So what's the usual minimum you can take off during a head skim?
>If it's another 10 thou, is this going to
>cause high compression ratio problems (or worse)?
I doubt that the .010 could be very valuable info. Most machinists
wouldnt stamp the info, so if its been skimmed more than once, and
it likely has, the info is meaningless.
The alpine head had wear bars cast into the head.
I think they start at about .060, and you can gauge the approximate
number of skims left by what is left.
An added .010 skim wouldnt make a big deal in compression.
I calculate a loss of .75 ccs per .010 skim, so at .020 you would
be at 35.5ccs instead of 37ccs for a virgin head.
This would give a net compression of about 9.5/1 from 9.2/1.
The alpine head can be skimmed all the way to .100, but the chamber
volume would be somewhat low, and you would have to open the chambers
to compensate. Also as the head is skimmed too far, the holes in
the side cover dont line up anymore, and the pushrod lengths
become too long for the adjustments to work properly.
Jarrid Gross
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