540 take 3
So hopefully 3rd times the charm. I ran the 540 all last summer and after the final cam change it ran pretty good. Sometime last fall I noticed a popping sound in the exhaust and sounded like a valve issue so I ran a compression test and #6 had 0 psi. Pulled the head and found a burned exhaust valve and loose valve guides. The exhaust guides were way loose and the intakes were starting to get loose. So trying to be thorough I put the head back on with checking springs to recheck the rocker arm geometry. The intake checked out right on (using the Foxwell video) with the contact pattern right at .060. The exhaust was off center toward the exhaust port and the pattern was a bit wide. But the length came out the same as when I set it up a year ago. So even though the pushrod is the right length, the pattern on the tip of the valve is wide and off center. My understanding is as long as the pattern is in the center 1/3rd of the valve it's ok so if that's the case I just need to narrow up the pattern. I tried going about .050 shorter and longer on the pushrod to see if it would narrow up the sweep but it made no difference. It seems like some use different (setback) rocker arms. But I would think that would just center the roller more not change sweep. I also read that on BBC a lot of times it's the intake that's off but my intakes look good? Also why are my intake guides loose when the pattern looks good on them? Makes me wonder if I have more than one issue. I will attach pictures of the patterns on the valve tips shortly.
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10 to 4 comp.
Brodix Race Rite BB-2 Plus heads
Edelbrock RPM Air Gap
Quick Fuel 950 CFM Carb
Lunati Voodoo HR 231/239 @ .050, 600/600, 110 LSA
Johnson 2116 BBR lifters
Hooker Super Comp 2" primary headers
Tremec TKO 600 .82 overdrive