Is this cam too big for my little 5.3?
10-20-2006, 06:01 PM
#12
Yeah, I never really got in to cams to much. I was thinking of going with a roller cam, is that recomended? If so, what parts would I need to support it? I dont think my 918's little 130lbs seat preasure is good enough for higher rpm and 20psi+ (at 6400rpm). I was reading somewhere that I should shoot for 180lbs seat preasure for high boost. That might be alittle much for my power level but they where talking about the same amount of boost I have run 20-25psi. I plan on runing 20psi, but would like a valve spring that can hang with my next motor, inwhitch may go higher than 20psi.
10-21-2006, 12:40 AM
#14
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parish has a thread going on over on tech about valve springs, right now with his turbo 408 i think, he is experiencing valve float around 6000rpm at about 20psi with comp 921 but he only had 118lb seat pressure and he's going with some dual springs with 140lb, he also heard that 180 was recommended for that high boost but that kind of pressure can play devil on stock lifters. when you say roller cam i assume you are meaning solid lifter, i dont know that much about that side of cams and all but i know it doesnt exactly lend it self to valvetrain longevity. theres alot of violent events going on and no hydraulics to dampen to force.
BTW, that cam you listed on the first post, it has a positive overlap so you would ba sacrificing some of your turbo efficiency
BTW, that cam you listed on the first post, it has a positive overlap so you would ba sacrificing some of your turbo efficiency
10-21-2006, 12:18 PM
#15
Good info, thanks. I think I did read 180 seat preasure somewhere on ls1 tech and parish was in it. I think the 921 spring is supost to have 135lbs, but now only have 118 because of wear, right. The 918 is suppost to have 130lbs seat preasure. Is the spring he's going with, the patriot gold springs? I was thinkin of useing that spring.
10-23-2006, 11:31 AM
#18
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how are you getting that thing out of the hole? First, i would concentrate on gettting the most i could out of the first 330' of track. With your setup in a 4500# truck, you oughta be in the mid to lower 11s (dunno your time)
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