94-95 with gt40 heads valve clearance

[Devbot]

Can anyone help. I have a 95 gt with gt40 heads. Heads have been done right by a well known local machinist who's a ford guy. Ferrea valves, comp springs, I have a tfs1 on the way. The math I've done has shown to have a .540 lift with 1.7 crane rockers (that's what I bought the engine with). Is that lift acceptable with stock pistons? I'm willing to put the clay on the piston and do the test, but if someone already has the answer I'd rather avoid doing it. Also, will stock pushrods work?

 

[revhead347]

.540 sounds really high on a stock piston. It varies so much with deck height, cam duration, etc that it is unlikely you will get a for sure answer anywhere on the internet. You can always back down to a 1.60" rocker which is what the cam was designed to run with anyway. Just for reference, playdoh is 50 cents/can at Walmart and works perfect for checking clearances.

Kurt

 

[7991LXnSHO]

Agreed, Play Dough or modeling clay and a test assembly is a whole lot cheaper sand less aggravating than even one bent valve.
I know my new engine for a resto mod of my first car was test fit at least twice.

 

[rockyracoon]

I have that cam with aluminum heads and am running 1.6 roller rockers. When I ran clay with 4 degrees of advance the valves cut the clay within a whisker of the stock pistons .

 

[revhead347]

I have that cam with aluminum heads and am running 1.6 roller rockers. When I ran clay with 4 degrees of advance the valves cut the clay within a whisker of the stock pistons .

Well there you go. Fly cut the pistons. A whisker is not enough margin by far.

Kurt

 

[rockyracoon]

My comment being said. There is ample room with the cam dropped in straight up but I would be wary even then with 1.7 rockers. Probably best to clay your setup as well.