383 power upgrade help

RustyRatRod said
Regarding Trick Flow not recommending their heads for anything under 4.320 bore. The 383 bore is only .070" smaller. You're tellin me that .035" per side somehow keeps the Trick Flows from working on a 383? I'm callin horse crap. If the gurus wanna start talkin about valve shrouding and all that other crap to make themselves sound smart, I'm callin horse crap on them too.

How far can you open a 2.20" valve at a 15° angle before hitting the cylinder wall on a 4.25ish bore? It would be interesting to mock one up and find out.

I ran into the bore with the intake valve at a little over .800 lift with a 2.29" valve at 4.375" bore size. That was after heavily notching the bore on that block. I ended up going back to a 2.250" and am at the minimum radial clearance.

The other thing that you can run into is chamber footprint overlapping the bore.

A good example of this is the Indy 383 -13 heads vs. their 572 -13 heads. Each head is made to fit a minimum bore size with respect to chamber footprint, valve size, etc.

Aside from valve shrouding it is more of a packaging issue IMO.

Looking at many of the lower end heads, the valve unshroudong needs to start in the chamber. 511" in the GTS had that treatment along with some hooveling in the bowl.

That engine met my expectations on the dyno and so far is very promising during sanctioned and unsanctioned accelration contests between like minded enthusiasts. : D

A