SideStep, I agree with MitchC that the Rev doul spring set-up is an excellent option also. They do not require machining on the heads, they drop right on.

But! I was never able to get a answer as to if they really give an extra margin of safety.

Some people said, well if one of the pair breaks, then you still have the other spring of the pair to hold the valve up and prevent the valve from falling into the piston.

Sounds good, but if that happens, how do you know the first spring has broken? What if it doesn't jam the valve open when it breaks? The good spring of the pair will work fine alone at low rpm, then the next time you hammer it, You will only have that one spring doing the work of two and presumedly it will break or cause valve float also.

Another failure mode is if one of the dual spring pairs breaks, it could jam the remaining spring in such a way as to make it not compress. Then you will break or bend a pushrod, with possible more collateral damage.

As you can see, a broken valve spring is a very bad thing! Right when I was picking my cam and heads and spring choices is last year when the 918's had the bad batch and many people lost engines.

That is why I went conservative with my smallish cam and stock 2002 Z06 springs, I felt it would be safe and last a long time.

One of the forum members had a dual spring break and his engine survived just fine, but it happened on a new cam first start up and the cause was the timing gear was one tooth off. So that was not a true test of dual springs being "safer", since it presumedly all happened at lower rpm.

 

Once again, thanks to all for the information and advice :thumbs:

:cheers:

 

Quote: "was just wondering if you have any dyno numbers or time slips on your Vette. I'm looking at doing just a cam and pulley and I'm interested in the same cam that you have. Can you hear that the Vette has a cam. Have you passed emissions? I'm like you and I want to be able to go 100K with little or no maintenance. Any info on your cam would be much appriciated."

RobsC5, I have no slips or dyno yet, not until spring. You can hear the cam a little bit, but most people would not notice. It is just more raggedy sounding and also shakes the car just a little tiny bit. if you let the car idle lower, there is a hint of lope.

Here in Connecticut, USA the emissions have been canceled for 2 to 4 years while they institute a new style testing system. So I do not know yet, but I have never even heard of that cam failing emissions anywhere, ever.

Basically, my car is like putting a cam, headers and pully on a 2002 Z06 engine, and cars with similar mods to mine are in the 375rwhp untuned, to 400rwhp tuned. Mine is not tuned at all yet, but it drives just as nice as before, no problems or quirks at all, my local Chevy dealer did all the intallation.

After 4000 rpms it pulls really hard, much, much more than stock.

 

CJS,

I just noticed in your signature that you had the ring-job done. I dropped mine off Monday for the same thing, suppose to pick it up Friday. Did you have any issues with it after the rings were replaced???

Thanks
:cheers:

 

:seeya Thanks for the quick answer CJS! :cheers:

 

I think most 114 LSA's are found in A4's and MN6's have a 112 LSA.

 

SideStep, I had the re-ring done at Bennett Chevy-Buick in New Milford Ct., thanks Eric(Service advisor, the best!) and Billy( Vette wrench supreme)!

When I got the car back I could not even tell they had done anything! They even washed and waxed the car for my pick-up enjoyment!

They did not even leave a scratch or mark inside or out!

The first thing I noticed is that the exhaust tips don't get black like before, they stay nice and clean now.

Not enough miles on it to to check actual oil comsuption though, but I am sure it will be fine now.

This dealer did not even sell me the car, even though I looked there and only live a mile away!

They only charged me $500 extra to put on all the mods in my sig at the same time as the re-ring!

So what was a very trumatic experience was really made great, thanks to these fine people.

 

I think you better plan on spring upgrades to get that much hp...