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Anyone use a 0 overlap cam on purpose?

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Old 09-30-2011, 11:52 AM
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Default Anyone use a 0 overlap cam on purpose?

I would really like to know if anyone has used something along the lines of a 236/236 - 118 cam. This should still be big, have no overlap, smell better, etc, right? Probably would need some low compression pistons since PTV would be an issue....Would it make a good FI cam for a 408?
Old 09-30-2011, 01:14 PM
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Originally Posted by Higgs Boson
I would really like to know if anyone has used something along the lines of a 236/236 - 118 cam. This should still be big, have no overlap, smell better, etc, right? Probably would need some low compression pistons since PTV would be an issue....Would it make a good FI cam for a 408?
from what i understand the less the overlap the less lope
Old 09-30-2011, 01:57 PM
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Originally Posted by 3rdCoastPowerSports
from what i understand the less the overlap the less lope
well yeah, but also less top end power but I am mainly wondering about cylinder pressures even with low compression and how much less top end with that sort of duration.

right now my cam is 236/244 on a 114 and has 12 degrees of overlap. i want to know if going to zero degrees is going to make a difference in the smell, the idle quality, the power curve effects, ptv clearance with that lsa, etc.
Old 09-30-2011, 04:23 PM
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It would idle/smell better and you'd actually have more PTV because of the wider lsa. It's going to peak higher in the powerband, but have a very wide curve. It wouldn't necessarily be better for boost because of no exhaust bias though and it wouldn't need lower compression as cylinder pressure would go down with the later IVC point.
Old 09-30-2011, 08:15 PM
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The cam I just bought for my LS3-headed 402 has no overlap. LS3 heads don't respond well to cams with a lot of overlap, so it's really not uncommon to see little or no overlap on LS3-headed cars. Most mild cams don't have any overlap either.
Old 09-30-2011, 11:54 PM
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Originally Posted by SNLPerformance
It would idle/smell better and you'd actually have more PTV because of the wider lsa. It's going to peak higher in the powerband, but have a very wide curve. It wouldn't necessarily be better for boost because of no exhaust bias though and it wouldn't need lower compression as cylinder pressure would go down with the later IVC point.
What if boost was from a supercharger and not a turbo? Exhaust bias wouldn't matter?
Old 10-03-2011, 01:19 PM
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I was actually assuming it was a supercharger. It would probably work well with a turbo depending on it's efficiency. Really need to know more about the complete set-up to say, I think it'd be interesting to use your current cam and then pull it out to see the gains.
Old 10-04-2011, 06:46 PM
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Originally Posted by SNLPerformance
It would idle/smell better and you'd actually have more PTV because of the wider lsa. It's going to peak higher in the powerband, but have a very wide curve. It wouldn't necessarily be better for boost because of no exhaust bias though and it wouldn't need lower compression as cylinder pressure would go down with the later IVC point.
Really? a peak hp higher in the band and lower cylinder pressures?

I'm thinking this would be a very good EFI cam, but I would be very worried about detonation with no overlap. But hey...that's just what I'm thinking. I need to think more about SNL's statement. But with no overlap, all the charge is staying in the cylinder.



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