Degreeing cam issue

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supertruck

supertruck

Unretired Old Fart stock car racer
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Installing a Comp solid cam in my 340 build, the Xtreme Energy XS268. I've degreed a few cams in the past but not seen this problem. Cam card for valve timing at 0.015 tappet lift specifies intake open at 28, exhaust open at 71. Adding an offset crank key got the intake spot on at 28 degrees, but the exhaust is at 62, 9 degrees off. I've had to split the difference on other cams, but never had one where the intake was spot on but the exhaust was so far off. Any suggestions? BTW, we calculated the lobe separation at 111, not the 110 advertised. Think a call to Comp tech line is in order?
 
Was trying to look this cam up but there are errors on the web site. Unless its a custom grind, most cams can be installed straight up without any issues?
 
supertruck said:
Installing a Comp solid cam in my 340 build, the Xtreme Energy XS268. I've degreed a few cams in the past but not seen this problem. Cam card for valve timing at 0.015 tappet lift specifies intake open at 28, exhaust open at 71. Adding an offset crank key got the intake spot on at 28 degrees, but the exhaust is at 62, 9 degrees off. I've had to split the difference on other cams, but never had one where the intake was spot on but the exhaust was so far off. Any suggestions? BTW, we calculated the lobe separation at 111, not the 110 advertised. Think a call to Comp tech line is in order?
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If it's a Comp ground on a 110 their defacto install is 4* advanced. That would be 106.

.015 lifter rise is not a good way to degree the cam. Way too close to the ramps. Either time it to the .050 lifter rise or better yet, install it at 106 and run it.
 
Thanks guys. Comp tech gave me the .050 numbers so I'll try that. Or follow Yellow Rose. A very knowledgeable guy
 
the DC and MP books recommend the centerline method for degreeing the cam. That's what I would recommend also. You can check cam events at 0.050" afterwards.
 
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