[Vettezuki]

From what I can imagine and know about physics, I'm gonna have to agree with Guy. A Centri or Turbo is blowing compressed air into the intake, on a roots, you have a very large spinning mass as part of the intake, it must be torqing into and away from the heads all the time; a kind of ratcheting effect . . . 10s of thousands of times. Mechanically, it seems like a much more violent environment/system.

[Shaolin Crane]

Originally Posted by Vettezuki

From what I can imagine and know about physics, I'm gonna have to agree with Guy. A Centri or Turbo is blowing compressed air into the intake, on a roots, you have a very large spinning mass as part of the intake, it must be torqing into and away from the heads all the time; a kind of ratcheting effect . . . 10s of thousands of times. Mechanically, it seems like a much more violent environment/system.

That's exactly what happens. Ed Curtis has confirmed this and there is a reason why the NHRA requires blower straps for roots applications.

[enkeivette]

I wasnt thinking physically more stressful, but ya, I could def see that.

Actually Ive seen a roots blower pop off of a motor before, but it popped off at the base plate/ blower intake manifold, not at the heads.

[fiveohwblow]

Originally Posted by Shaolin Crane

If only it was as simple as that, the way the roots puts stress on the heads is completely different then a centri since its constantly stressing them, the KB fox guys have an issue with it, they have even higher inlet temps at lower boost and the threads are a plenty. Like I said, Rons car is a freak. Dan Pina the drift patrol driver has an identical setup to Ron and I and he has always been plagued with head gasket issues. He even has the big daddy boss r block with 1/2" deck hardware and he is still plagued with them.

The SBF sucks monkey dick for boost, n/a they're great, but any power adder has great potential for problems

Wut?? SBF sucks for boost? That's new to me...

[Shaolin Crane]

Originally Posted by fiveohwblow

Wut?? SBF sucks for boost? That's new to me...

Tis true. Talk to me when you run your car as hard as Ron and I do. His car is a freak, venture over to corner carvers and yellow bullet and you'll see how many sbf dudes are having head gaskets issues.

[Vettezuki]

Did factory boosted SBFs (e.g., Cobra) have similar common problems? Maybe it's a common problem of people trying to reach for power on the cheap. I don't think Joe, who has run boosted motors hard has had any kind of unusual HG problems.

[Shaolin Crane]

Completely different engine OHV vs OHC. The 4.6 in the cobra is good for about 800rwhp on stock internals. Modular motors were meant for boost. Sbf not so much. I definitely think it makes a HUGE difference if you plan out the hardware you're using and use an appropriate cam. I know the boosted road course guys are plagued with problems. There are plenty of dudes (like Justin) who make great power and rarely race and they'll last. Problem is the entire sbf is fighting itself when making power 450+ is where you start rolling the dice every time you race your can cause the block likes to spilt itself in half.

[Vettezuki]

I forget what they're called, but doesn't just a little reinforcement across the pan and valley up that a couple hundred HP?

[Shaolin Crane]

For a sbf? No, girdles just keep all your shit from flying all over the place when it breaks. Maybe 75hp if you have a valley girdle and main girdle, maybe...

[enkeivette]

Originally Posted by Shaolin Crane

Tis true. Talk to me when you run your car as hard as Ron and I do. His car is a freak, venture over to corner carvers and yellow bullet and you'll see how many sbf dudes are having head gaskets issues.

Is one of your foxes actually blown and running? Whats your setup? I thought you were just putting stuff together.

And Ive heard girdles are for strength too. Seems like this week you just cant type anything that I dont disagree with. (And yes that was a proper double negative. Suck that high school language arts teachers.)