Quote:
Originally Posted by tom s
Comp told me you give up 8 degrees of duration and what ever lift you use.6 thou will loose 9 with 1.5s.Solid roller cams have the numbers built in with the lash they suggest.That was with the OF cams.Thats why they call it a crutch I guess.Mike Jones says the same thing.Tom
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That is if they are lashed loose. Add up .006” cold lash then the expansion on top of that with and aluminum head your ending up at about .012” lash.
Mike is a sharp guy, he might very well have something better.
I have one engine with E heads and Howard’s .4” lobe lift profile with slightly used (dyno time) comp solid lifters with pin oiling I picked up for $250.
The other is a iron head engine with .3823” lobe lift and $430 Doug Herbert pin oiler mechanical lifters from Butler.
https://butlerperformance.com/b-9994...rt-racing.html
If I don’t like it or something comes down the road that looks better, and can always swap over the HR lifters. So far, not reason too.
I think a XFI is actually a bit too aggressive to run as a hybrid with aluminum heads. The Howard’s I have is close to as aggressive though. The bigger rocker arm ratio actually helps on a hybrid if the cam is aggressive like an XFI.