Valve Seat Pressure

[Jeff Rand]

My friend is running a 274 cubic inch stage 2 with a solid roller cam about 230 duration and 590" lift. The setup is Innovative 74 turbo, Mease intake, M&A heads, turbo 400 trans. (with trans brake) shifting at 6500 rpm's,and Ford 9" with 3.90 gears. He is using conical springs with a seat pressure of 150 lbs. The car is not running up to its potential (10.30 @ 134 mph at about 26# of boost) and he is now taking a look at the valve springs. The advice that he is getting is that he would need a least 200 lbs. of seat pressure on a solid roller the keep the springs closed at the higher rpm's. Anyone have experience with type of setup?
Thanks,
Jeff

 

[TurboDave]

My friend is running a 274 cubic inch stage 2 with a solid roller cam about 230 duration and 590" lift. The setup is Innovative 74 turbo, Mease intake, M&A heads, turbo 400 trans. (with trans brake) shifting at 6500 rpm's,and Ford 9" with 3.90 gears. He is using conical springs with a seat pressure of 150 lbs. The car is not running up to its potential (10.30 @ 134 mph at about 26# of boost) and he is now taking a look at the valve springs. The advice that he is getting is that he would need a least 200 lbs. of seat pressure on a solid roller the keep the springs closed at the higher rpm's. Anyone have experience with type of setup?
Thanks,
Jeff

I'm certainly no expert, but common sense tells me that 150# springs on that setup are significantly low. That motor should be able to twist some pretty healthy rpm, and as such probably should be running at least 200# on the seat.

 

[Jeff Rand]

Dave that is the advice that my friend got from both Kenny and Comp cams.
Regards,
Jeff

 

[750H.P.V6]

Jeff,

I was running a very similar cam profile in my Stage II motor and I was using a spring with 200lbs seat pressure and approx 500lbs open.

Neal

Dave that is the advice that my friend got from both Kenny and Comp cams.
Regards,
Jeff

 

[Otto J]

I was running conical with my hydraulic roller at 180 at seat.Im sure you need more than 150 on a solid