Quote:
Originally Posted by Jay S
Butler’s composite gaskets crush to around .042”. to .044” thick.
Blue Fel-Pro crush to about .045”, most cheaper head gaskets crush to .045” also.
I assume the cam is still using the comp 9-way timing set using full advance 4th key yet, as reported earlier. Could be just a miscommunication on my end. I will reiterate it though, the 4th key should be 8* advanced, each key changes the advance 2*. Using the extreme 4th key ends up at roughly 105.5* if it started at 113.5*.
Like Cliff said, If Head to Block Quench is marginal, too bad. If the cam is advanced too far, you'll wish you never touched the cam timing. If you're convinced that all is good though, carry on.
There is plenty of valve to piston clearance using the SPC-8 cam, that is the "041" Cam, with the 1.5 rocker arms. No reason to bother checking that. The clearance should be good, unless the installation was improperly done.
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Let me go over the math with you, I think we both made an error in our calculations: You are measuring in Crank degrees and I am measuring at Cam degrees to start.
You go 113.5 - 8 degrees at the Crank = 105.5 advanced at the Crank.
Measuring the way, you are, I beg to differ, here is why, 113.5 = 8 + 1.5 degrees (built into the Cam) = 9.5
113.5 - 9.5 = 104 advanced at the Crank.
Mike is measuring via the Cam degrees: 4 advanced degrees + 1.5 (built into the Cam) = 5.5
113.5 - 5.5 = 108, A little more advanced than my 109 target, but I have read people advancing their race timing to between 108-109.
If I am wrong or I have advanced this Engine too far, please correct me now, before it is too late.
P.S You said: " Butler’s composite gaskets crush to around .042”. to .044” thick.
Thus, we add Piston TDC to Deck clearance @ .023" +.042” crush = .065 Quench, in my case approx.? Still a safe place to be for now?
By the way the Piston to cyl. walls are smooth to begin with and the Piston clearance is between .005" - .010", in addition the Cam Bearings looked so good that we used them when we installed the new "041" Cam. For this very reason we deduced that the Crank Bearings would have held up as well. The lower part of this Engine has been dependable so far, never a noise anomaly until the Trans. disinegration.
I firmly believe that accident caused the majority of the issues today, especially the Thrust impact through the Trans. thrusting toward the Crank and lastly arriving at the Harmonic Balancer. The Head is a time related issue and stands alone, this is my view, and I am sticking to it. Nothing happens from nothing here it all happened at once, too bad I am still repairing this Engine from the accident I had, running over a root beneath an asphalt driveway.