[evilsn95]

what the highest lift cam i can put in 351w before valve to piston touch. i have tri state heads with .600" springs. motor has e303 cam when purchased but i dont care for it, this is just a weekend car.

[69fastback]

There is no way to answer that. There are a billion factors. The ONLY way to know, is to put the cam in and check it. And FWIW, how long the valve stays open is more crucial than how far it opens when it comes to P to V clearance.

And I would never use springs that come on a head with an aftermarket cam, just because the head manufacturer says they're good to XXX amount of lift. Always check with the cam manufacturer. Proper valve springs are crucial to your engine.

[evilsn95]

Originally Posted by 69fastback There is no way to answer that. There are a billion factors. The ONLY way to know, is to put the cam in and check it. And FWIW, how long the valve stays open is more crucial than how far it opens when it comes to P to V clearance. And I would never use springs that come on a head with an aftermarket cam, just because the head manufacturer says they're good to XXX amount of lift. Always check with the cam manufacturer. Proper valve springs are crucial to your engine.

the spring are comp cam 950-16 was told there good for .600".. the cam im looking at has .576" just didnt want valve and piston touch. guess ill have to do the clay in the piston trick really wasnt try to take the heads off.

[Bubba95SN]

Peace of mind is worth the time and money. Incredibly expensive should the piston kiss the valves.

[evilsn95]

Originally Posted by Bubba95SN Peace of mind is worth the time and money. Incredibly expensive should the piston kiss the valves.

so very true, pulling the head

[Cobraman1024]

Originally Posted by evilsn95 the spring are comp cam 950-16 was told there good for .600".. the cam im looking at has .576" just didnt want valve and piston touch. guess ill have to do the clay in the piston trick really wasnt try to take the heads off.

You also may not know how long those springs have been on the heads; i.e. how "used" they are. I'm surprised you weren't offered a spring set or at least recommended a spring set for the cam you're looking at for your engine.

[evilsn95]

Originally Posted by Cobraman1024 You also may not know how long those springs have been on the heads; i.e. how "used" they are. I'm surprised you weren't offered a spring set or at least recommended a spring set for the cam you're looking at for your engine.

the motor was put together 4 month ago. i've had it for 2 weeks want to change a few things. heads are 4 month old. if i get the comp cam kit the spring are 987-16. ill have to look the spec up on mine or call comp cam. i'm just wanting to know if i was the get this cam or even the cam kit would it fit without my valves hitting. or what the highest lift to be safe for the 351w it a 95 roller motor..

[fogged306]

Originally Posted by evilsn95 the motor was put together 4 month ago. i've had it for 2 weeks want to change a few things. heads are 4 month old. if i get the comp cam kit the spring are 987-16. ill have to look the spec up on mine or call comp cam. i'm just wanting to know if i was the get this cam or even the cam kit would it fit without my valves hitting. or what the highest lift to be safe for the 351w it a 95 roller motor..

Like fastback said, it's not lift you need to be concerned with as much as it is duration. Think about where the piston is at peak valve lift. At BDC. How long the valve hangs there is going to be much more important when that piston starts coming back up to TDC.

worst case, you have to notch the pistons. It's actually easier than a lot of people think it is.

And fuck all that good to .xxx lift stuff for springs. You want the right installed height, and to know what the pressure the cam calls for at the seat and open, and you want to get optimal coil bind distances for more stability at higher RPMs, generally between .100 and .060 away from bind.

[evilsn95]

Originally Posted by fogged306 Like fastback said, it's not lift you need to be concerned with as much as it is duration. Think about where the piston is at peak valve lift. At BDC. How long the valve hangs there is going to be much more important when that piston starts coming back up to TDC. worst case, you have to notch the pistons. It's actually easier than a lot of people think it is. And fuck all that good to .xxx lift stuff for springs. You want the right installed height, and to know what the pressure the cam calls for at the seat and open, and you want to get optimal coil bind distances for more stability at higher RPMs, generally between .100 and .060 away from bind.

i got the cam kit to be on the safe side. i know how easy it is to flycut i built a 4.6 with 278 cams before this had to flycut the pistons. my first build with a 351 just trying to learn alittle about the motor. the duration is 294 and @ .050 it 242.. thanks for the info everyone