you warp the valves because they are extremely hot inside the engine and when you have the open header you expose them to much cooler air and the transition from hot to cool over and over can warp the valve. My buddy ran open headers in his nova and after about a couple weeks several of them had to be replaced already.

Do it at your own risk man. I personally would highly reccomend against it

 

i have heard of the burnt valves also. I think i has to do with the exhaust backpressure being too hot and going back into the combustion chamber and burns the exhaust valve durring valve overlap at high rpm WOT

 

bro if you last a week with an open header I will give you $10

its not possible!

 

yea open header is nuts, i drove around the block once with it and about puked

 

Ugh! I hate the sound of 4 cylinders! Open is even worse!

I drove my Camaro around for a while with open long tubes until I finally got the exhaust done. Terribly loud, I even made a 2 hour freeway trip with it like that! Never again! Here's me doing a burnout with open headers http://67.19.106.107/92RSburnout.mpeg

 

that sounded right good lol. a 4 banger preaty much sounds like an alunimunm garbage can filled with rocks rolling down a hill on open header lol

 

I too have heard about the burning up the valves. But, wasnt sure it was true, anyways, it would only be a few days two at most till I get my exhaust welded on. I wouldnt go much over 2 maybe 3 rpms either. Open headers on IonNinja's Ion, yeah that was mad loud..


A week? Deal, wait whats the stipulations, you mean last a week without getting pulled over.. break something?

 

Thats it. Sorry I posted once in this thread and didn't look again.

 

go to my thread in this section about the pacesetter header review, i made a video just for you with open header before i had my exhaust put on. its 10x louder than the video makes it sound.

 

like everyone said. it will be loud. but it will throw a code for not having a cat. also if you don't use a downpipe with or without a cat. the heat from the exhaust will burn the coating on the firewall since the header is so short.

I ran mine like it and fucked the stuff all up.

 

^^ unless yo uhave a pacesetter like me, which then you pretty much have to run it without the exhaust on because you have to get it cut and welded, or you can cut it yourself and use the supplied clamp and clamp it together. but anyways, the end of the header is right where the heat shielding starts so it wont burn anything

 

getting pulled over...losing your hearing...etc

 

Valve warp is the easy fix (all head work is a ******* bitch and its not something you want to do).. i have also seen piston/head/block cracks from people running open headers.. that cold air can **** some **** up.