LQ4/L92 combo - Cam question

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Jul 1, 2010 | 05:23 PM

ramdaspadhye

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LQ4/L92 combo - Cam question

Opinions on a 227/239 .551/.551 on 108lsa for an LQ4/L92-headed carb setup?

Jul 2, 2010 | 09:12 AM

Jim85IROC

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From: Readsboro, VT

Seems like that cam would have a lot more overlap than most people consider "appropriate" with L92 heads, especially considering the LQ4's lower compression. I suspect that a whole lot less exhaust duration and a much wider LSA would be much better.

227/227 on a 112LSA, 227/230 on a 113LSA, etc.

Jul 2, 2010 | 02:24 PM

ramdaspadhye

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L92's perform better with a longer exhaust duration...

Jul 2, 2010 | 05:53 PM

toby

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that cam seems close. I would use lobes with more lift though.
A large split is not needed. Maybe 235/239 would be better. The 108lsa is
perfect for a carb setup just make sure it has about 4 degrees of advance
ground into it.

Jul 7, 2010 | 11:48 PM

ramdaspadhye

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I've done enough research to know these heads like at least 10 degrees of split...

Jul 8, 2010 | 09:41 AM

Patrick G

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From: Victoria, TX

Quote:

Originally Posted by ramdaspadhye

I've done enough research to know these heads like at least 10 degrees of split...

Don't be so easily convinced. The list of the fastest L92 racers (cars and trucks) is filled with cams that contain smaller splits (4-8 degrees). Remember, the L92 exhaust is slightly better than the LS2/LS6 exhaust port. So if a 239 lobe would have been too big with LS6 heads, then it's going to be too big for L92 heads.

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Jul 8, 2010 | 11:56 AM

Sales2@Texas-speed

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Agreed....it's not that the LS3/L92 exhaust port is bad, it's just not the super-hero that their intake port is. So you typically run similar exhaust specs to what you would have on the LS1's, but you don't need as much intake duration as they liked...and there-in is SOME split. We do not go crazy and throw 10º+ split at them like some do though and agree that 4-8º is plenty for most combos!

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