What the max duration/lift for TF heads with stock hypers?
- Thread starter woodyy24
- Start date
ronburgundy
Member
It's called measuring piston to valve clearance. No two cars are the same. Take Daggar... I think he had TFTW heads and an E Cam on STOCK 86 pistons with no valve relieves. That just shouldn't work! But it did. You gotta check for yourself, then order a cam that will fit.
But.... If the 85 has the stock type, 4 relieves in the piston, the anything with 1.90-1.94 intake valves should fit up to no more then 230 degrees of duration. Stay under that number, and you should be ok. Max lift means nothing, seeing as max lift happens when the piston is all the way at the bottom of the cylinder.
Edit: Just noticed you said for TF heads... so I take they are TFTW heads... The same really goes for them, because of the twisted wedge design.
But.... If the 85 has the stock type, 4 relieves in the piston, the anything with 1.90-1.94 intake valves should fit up to no more then 230 degrees of duration. Stay under that number, and you should be ok. Max lift means nothing, seeing as max lift happens when the piston is all the way at the bottom of the cylinder.
Edit: Just noticed you said for TF heads... so I take they are TFTW heads... The same really goes for them, because of the twisted wedge design.
Yep...
Stock valve reliefs mean nothing for the TW heads. The valves don't line up with those reliefs anyway. Look at Trick Flows website. They have lift and duration guidlines listed in a PDF file someplace. If you think you're going to exceed their recommendations then you'll have to clay it up or replace your pistons with those with reliefs designed for the TW heads.
Stock valve reliefs mean nothing for the TW heads. The valves don't line up with those reliefs anyway. Look at Trick Flows website. They have lift and duration guidlines listed in a PDF file someplace. If you think you're going to exceed their recommendations then you'll have to clay it up or replace your pistons with those with reliefs designed for the TW heads.
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