Thread: Safe max rev on SRXXVE cams

I bought the Crowers dual valve springs & titanium retainers for my VE motor. I am sure Greg V has them, or Crower's website. you can even buy the Crower set on eBay as well.

The only way to tell which springs you have is by Removing the valve springs and measuring the seat and open pressures. There are springs that are about 145lbs open and ones that are 160 lbs open.

Classic, If you dyno your car with stock sr20ve cams and if it peaks at 6800rpm and flat lines to about 7,500 solid, then you have the 160lb open springs, if you peak at 6,800rpm and it starts to roll off after 7,000rpm then you have the 145 lb springs and the power rolling off is valve float.

I have an sr16VE head, so I am not sure which springs I have in there now. But I can tell you the ramp angles on the VET cams is way more aggressive than the standard VE cams. I run to 7500rpm now with peak rpm hitting about 8100 peak when bouncing the rev limit. I just want a margin of safety there so I can rev up to about 9K.

I have seen some evidence of valve springs causing some damage on other engines by literally pulling the valve through the seat. I don't think that is an issue here with the SR20 engines. I don't think that the springs have enough pressure to do that, but I want to keep it stock for now. I may still do springs, but I would like to see how far the stock stuff can take me. I like to keep things simple. Changing springs on a VE is gravy though, I just wanna avoid it if possible.

I would love to run SR16ve cams ....but I worried that they would contact the pistons as I dont have reliefs in the pistons in the motor .....So I will be running the SR20ve ones intill I take the head back off for work ....then I am going through with the 90mm bore , I at 87mm right now so I figure with springs and most likely retainers I set the rev limit at 8k that be safe from what I am gathering ....

All sr16ve springs are the softer ones other than the very first year built. The VET cams are not as aggressive as you think. They have a lower lift profile and are more comparable to stock DE cams. The VET cams are more "stable" than sr20ve cams though. If you want a 9000rpm ceiling for safety then you will have to run sr16ve cams.

It doesn't feel like it rolls off until my tachometer reads about 7700-7800 so it seems i have the stiffer springs.

??? Lower lift profile? 11mm intake and 11.3 exhaust. Nearly same lift as the sr16 @ 11mm on both.

Except I only have a 248* duration, instead of 280*.

Sorry, Typo on my part, I meant SLOWER profile. The part of the cam lobe that they dont show you is the opening and closing ramps. The VET cams still crack the valves slower on and off the seat than the std sr20ve cams. The duration listed is at a spec lift point which is not anywhere comparable apples to apples to "normal" cam specs.

Oh I got ya. I will stick with the 20ve cams if I get valve springs, or the sr16 cams if I stay without.

Personally, I think the VET cams are great for smaller turbo motors, like GT2871 or DPT setups. but for larger turbo's the sr20ve/16ve cams are going to make more power.