Planning for 408 - Possible Solid Flat Tappet cams

cawcislo said

Got a reply from jones cams. Hers what they recommended. 244/252 duration at 0.50, .547/.546 lift 110 Lsa which looks to be one or 1.5 steps upfrom the cams I listed in post #1. I’m sure their lobe profiles may be different than the off the shelf cams I could get. Thoughts?

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I can't think of a single reason to split the duration like that, and then end up at a 110 LSA.

They (cam grinders) do that so they can get the RPM the customer wants, but not get the power. That cam will give up mid range power like mad for some small gains at peak power (maybe) and some gains after peak (probably) while giving up power in the middle.

There is an exellent tech article in the March 2020 Hot Rod where Billy Godbold (Comp cams) explains this much more clearly that I can, and also covers "centering" the overlap triangle.

So with the above grind, the grinder either added exhaust duration (most likely) or reduced intake duration (or some of both) to try and get a smooth idle, and maybe pick up some vacuum at idle.

If that's what you want, then that's a good grind. If you don't want to give up a bunch of mid range power, and don't care if over rev power is down, then I'd ask for something else.