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Old 07-15-2016, 02:12 PM
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moore_rb moore_rb is offline
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Cobra Make, Engine: All original, with Chevy engine since 1964
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Quote:
Originally Posted by FUNFER2 View Post
"A wide lsa is required to limit reversion"
How much lobe seperation, was my question.
there is no magic LSA number to make things all warm and fuzzy...

valve overlap is the real factor, and overlap is a function of LSA and duration taken together.

but like I posted earlier, 112 degrees LSA, or smaller, is typically where most aggressive street/strip cams begin messing with your MAP and your manifold vacuum

114 could be considered a safer, but again- it also depends on how much duration at .050 you are running- a super long duration cam (240+ at .050) is probably still going to introduce overlap instability, regardless of how wide the LSA is...

But when it comes to the question of how well your cam might (or might not) co-exist with EFI, just let your eyes and ears be your guide-

If your cam makes your idle sound like a Harley Davidson, and if your engine shakes the whole car while it's idling, then it's a fair bet that tuning a speed density EFI system to work smoothly with that cam is going to take time, effort, and money.

It will be a little easier if you have a MAFS , but again- no current 8-stack system uses MAF
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Last edited by moore_rb; 07-15-2016 at 06:02 PM.. Reason: added info about MAF being easier to tune for idle
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