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Old 04-22-2009, 09:29 AM   #7 (permalink)
Daox
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Quote:
Originally Posted by Big Dave View Post
That's what Ford and Toyota did.

Grind the intake valve to stay open into the compression stroke. Viola! The power stroke is longer than the compression stroke and you have achieved Atkinson.
Not nearly being a cam expert, I really have no idea where I'd start. Would a normal cam regrind shop be able to do this? I'm thinking it would be well out of their scope. Performance shops usually know squat about efficiency enhancements.

Also, your method would require welding on additional material I assume. I've heard some bad things about running welded regrinds, but I'm sure they can't be that bad. On the other hand, my idea only includes grinding. Yours obviously would provide larger FE gains, mine would be cheaper although I don't have any idea how much cheaper.


Thanks for the info on the magazine articles Christ. I assume I can get those online somehow? I checked Hot Rod's website, but I couldn't find where I could get old articles.
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