[I8ACMRO]

Originally Posted by y2k02 installed hight 1.57 coil bind .952 That leaves .618 lift before bind your cams .571 lift Leaves .047 clearance I don't know why they rate them for .550 lift.

Probably for extra safety I guess lol.

[hardhitter]

Originally Posted by I8ACMRO What is your power output? Ported heads are NOT going to hurt your engine.

I'm at around 450rwhp right now so with cams and heads I think something would break.

Originally Posted by y2k02 installed hight 1.57 coil bind .952 That leaves .618 lift before bind your cams .571 lift Leaves .047 clearance I don't know why they rate them for .550 lift.

So the ones I have are okay?

[I8ACMRO]

Originally Posted by hardhitter I'm at around 450rwhp right now so with cams and heads I think something would break.

You're on stock internals at that level? I wouldn't even do cams then until a built bottom end.

[hardhitter]

Originally Posted by I8ACMRO You're on stock internals at that level? I wouldn't even do cams then until a built bottom end.

I'm going to lower the boost some to compensate.. that was at 14psi.

[y2k02]

Originally Posted by I8ACMRO What is your power output? Ported heads are NOT going to hurt your engine.

He has no need for ported heads with stock rods & pistons. Guys have made 600rwhp with stock unported heads. If he had ported heads it would just take less boost to make same power to which he is limited to around 430rw.

[hardhitter]

Originally Posted by y2k02 installed hight 1.57 coil bind .952 That leaves .618 lift before bind your cams .571 lift Leaves .047 clearance I don't know why they rate them for .550 lift.

Use this simple formula to calculate the maximum valve lift for a specific spring:

Installed Height - Coil Bind - .060” = Maximum Recommended Valve Lift

This formula is a general guideline for calculating maximum valve lift with a safety margin of .060”. Other factors such as rpm will also affect valve spring selection, however this is a good formula to use in most performance applications.


Jim at CMS said that these springs were okay to use with N/a vt stage 2 cams with 560"/.575" lift

Do you think I'll still be okay with a lower safety margin?

[limited]

I personally don't like to exceed manufactures guidelines, they are there for a reason and not a number pulled out of a hat. .060 safety margin has some r&d behind it.
In the end it is your call.

If your concerned, just run some offset retainers, they will give you another .060 and you won't lose to much seat pressure because I believe the beehives have a heathy one anyway

[RyanGT]

Maybe, maybe not. Question is do you want to risk doing this twice And having to buy new springs and not be able to sell or return your current ones that are still in box.

[limited]

If these cams are new, return them for 2.5's..problem solved

[limited]

Originally Posted by I8ACMRO I wouldn't say "No VT's have PTV issues" Cuz aa buddy of mine had PTV issues w/ his VT cams...

If the motor was stock,it wasn't because of the cams

[Scott2001GT]

Originally Posted by hardhitter I'm going to lower the boost some to compensate.. that was at 14psi.

Yeah 14psi is crazy! Rather make 450rwhp with 10psi with the head work and cams!(roush guess on psi) But rather have the same power but with less psi.

Originally Posted by limited If these cams are new, return them for 2.5's..problem solved

Or the CMS stage3 blower cams! haha

[ajm]

Originally Posted by hardhitter I was looking at that set but it says machine work is required for stock heads.

You can buy the springs themseleves w/o locks,retainers,etc from patriot. I think they run about 150 or so for the whole set.

[y2k02]

The comp high load springs have a max lift of .650 leaving only .020 till coil bind.
The nextek springs max lift of .580 only leaves .020 till coil bind also.

I just called comp themselves and they said your springs will be fine with the .047 clearance.


If you are really worried. You could buy just 8 high load springs for the exhaust side here.
http://www.compperformancegroupstore...Category_Code=