i have a few friends that have told me that if i run a complete straight pipe exaust i will burn out my valves, anyone have another opinoin on this?

 

They're wrong. If cold air enters the valves they will burn. But with headers or straight pipe it won't happen. How do you think people at the track run open headers. You'll be fine.

 

Where did you hear that? I know that if you run lean you can burn a valve, but never heard that if cold air hits a valve that it'll burn a valve.

Not saying that's wrong, but it makes about as much sense as saying that you'll burn your hand if you run it under cold water.

AJ

 

I've heard it from my brother and other members on this board. That's one reason you don't start an engine without manifolds or headers. The air will enter and burn them.

 

But if you run it under cold water long enough it will start to "burn" right.

 

It doesn't "burn" the valves. Basically what happens is once the motor is turned off the air hits the valves, they cool too quickly and warp. It does happen, but i don't think It's happened to anyone i know. I think this could "possibly" be a problem in cold climates such as mine during the winter if your running open headers. I really don't think running it once or twice or to the exhaust shop is going to do any major damage. If it makes you that paranoid, after you shut the car down, stuff a rag or 2 in the outlet of your manifold/header.

Just think of it as welding steel, if you dunk it in a bucket of water to cool it faster you end up tempering the steel, which in turn would actually make the weld more brittle. So one jump in if I'm wrong here.

 

Correct cold air hitting anything really hot (those things are freakin HOT!!!) Will warp / damage them. Heating a piece of diamond plate to 3000* then hitting it with a shower of water then throwing it on concrete will yield a smashed piece of diamond plate - A metal you normally cant even BEND unless its Red HOT. Valves will WARP and die when exposed to cold air right after being run and hot. The idea about shoving a rag into the header is a good one, i think ill try that. Beware cold climates... its never safe to run open headers there, not on our cars which have the "shorties" - the long style header is alot safer...