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running open header will burn your exhaust valves
theres no time refference to refer to
the longer you go the worse your valves get period
I've heard this before but you have to ask yourself, logically, does this make sense? Having an open header will put the cooler outside air closer to your exhaust valves, so when have you heard of cool air "burning" a valve?? I see a lot of drag cars running what pretty much amounts to an open header and they're valves are fine. Unless you can point to some hard data showing that exhaust valves will be burned I pretty much think it's a myth.
Of course the car will be LOUD as hell and you'll throw codes from your downstream O2 sensor but I don't see how it'll hurt anything.

P.S.
Just to let ya' know that I'm not talking trash, here's a couple links.
Will it hurt the car any if you have open headers? - Yahoo! Answers
Engine & fuel engineering - Open Header = Burnt Exhaust Valves? Myth?
 
^You have to remember this fact. Drag cars with "open headers" which is basically what they are yes, anyways they are only running that quarter/eighth of a mile then cutting the car off, then the motor gets rebuilt. So its not the same thing as driving a car daily. But like i was saying its just a thought.
 
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^You have to remember this fact. Drag cars with "open headers" which is basically what they are yes, anyways they are only running that quarter/eighth of a mile then cutting the car off, then the motor gets rebuilt. So its not the same thing as driving a car daily. But like i was saying its just a thought.
thats exactly right. the valves on the street cars need a certain amount of backpressure to work right. when u have open headers u kill that back pressure
 
more specifically the track cars generally run in that higher rpm range too where the open header concept will help, but our cars run in a relatively low rpm range which makes the opposite effect of hurting torque.
 
Discussion starter · #8 ·
Alright, only reason I asked is because I took my exhaust off tonight...well, the catback, so right now I'm just running with the o/r x.
 
Alright, only reason I asked is because I took my exhaust off tonight...well, the catback, so right now I'm just running with the o/r x.
you should be fine with a mid pipe on, as long as you are getting the scavenging and everything.
 
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Actually it is velocity you want, not back pressure. The reason valves get burnt is because the engine runs leaner with open exhaust or a straight through exhaust, because there is no back pressure to to build up and have the engine working against, therefore more air is drawn in and your air fuel mixture becomes lean, if richened up properly it will achieve close to optimal 14.7 A/F ratio again and no burned valves. Back pressure being needed for torque is a myth. Ideally velocity will help the engine make power but back pressure will hurt power.
 
Really old thread man. I think the discussion is over. lol
 
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new ppl need to L2 dates, and not just go back 50 pages and start posting lol
 
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