How much valve lift from a X/J head

[Cudafever]

As I port my heads and the the flow is starting to show up, in the .550-.600 range. I'm beginning to wonder how much lift i can put in this head, and still us the factory or posi lock type seals.

 

[moper]

Factory type seals are too wide for the dual springs modern cams need. The seal wont fit in the spring. So you have to cut the guide smaller in diameter. The stock retainer will hit somewhere around .520 or so depending on the engine so at the same time you make the guide shorter. Also, the spring won't fit in the spring seat on the head. You have to cut the spring seats for the inner spring too.

 

[godfatherofchry]

if the valve Gide is good Y use the seal i don't.

 

[Cudafever]

if the valve Gide is good Y use the seal i don't.

For a race only i guess i could do that. Yes the guides are brass/Bronze? less then 5000 miles on them.

I wasn't planing on taking these head to the machine shop.........so i guess that could be an option.

I know that crushing the stock valve seal, i can barely test flow at .600" of lift :happy7: