318 Connecting Rods and Crankshaft

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I just meant that stock chambers are always larger than the number found in the service manual or the NHRA minimum spec- which is usually the same thing
as you just found out
so you can do your calcs and eliminate the "about"
9.5 is good unless you are a motorhome
sorry about your loss
just get rid of any sharp spots then if not unshrouding
however unshrouding with a SERDI or other valve cutter is sorta a freebee
 
A Serdi is a valve and guide machine that uses cutters instead of stones
you have different cutters that can cut multiple angles and widths at the same time including a top and bottom cut which you can then easily hand blend in for quickie "bowl blend"- there are other vendors
(you can also use multiple cutters for uncommon jobs)
you can have the top cut round into a unshrouding of the valves
more area around the periphery of the valve can give more flow
Too much and the flow then hits the top of the cylinder and the sharp ridge causes turbulence and shear
that's why sometimes you need to relieve/ bevel/ break the edge of the top of the cylinder (but stay above the location of top ring travel)
That's why I suggested comparing the bore to the chamber with a dykem and scribe

are you following this thread
302 casting on a set of 318 heads
good luck with your build
everyone here is here to help
 
Wyrmrider said:
A Serdi is a valve and guide machine that uses cutters instead of stones
you have different cutters that can cut multiple angles and widths at the same time including a top and bottom cut which you can then easily hand blend in for quickie "bowl blend"- there are other vendors
(you can also use multiple cutters for uncommon jobs)
you can have the top cut round into a unshrouding of the valves
more area around the periphery of the valve can give more flow
Too much and the flow then hits the top of the cylinder and the sharp ridge causes turbulence and shear
that's why sometimes you need to relieve/ bevel/ break the edge of the top of the cylinder (but stay above the location of top ring travel)
That's why I suggested comparing the bore to the chamber with a dykem and scribe

are you following this thread
302 casting on a set of 318 heads
good luck with your build
everyone here is here to help
Click to expand...
Yes, I have been following that thread.
Thanks for the explanation. I'm not really after all that much with this motor. I just want a simple, easy to maintain and tune, strong cruiser type 318.
 
I can vouch for the Serdi type machine work. I have the additional cuts along with some extra cuts in the port bowl to open things up in a set of 675's with stock size valves. It really brings a set of eighteen heads into a whole new realm, but 10:1 static compression doesn't hurt anything either.
 
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