Red hot headers ? Rich or lean ??
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Joined: May 2000
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From: Under my Car as usual :)
Red hot headers ? Rich or lean ??
I've seen so many threads about this lately, I figure I would post part of a article by none other than Smokey Yunick. Smokey is replying to a reader who has red hot headers on his circle track car.
"Red hot exhaust headers indicate a lot of heat an unburned fuel is being dumped out of the engine. It sounds liek your exhaust system is in the ball park. But check the back pressure at the highest RPM. A little bit bigger pipes won't hurt. Even well tuned engines will turn exhaust headers yellow hot. You've got 400-500 Cubic Feet per Minute at 1450 degrees F coming out of one 2.5" hole on each side. The exhaust temperature is usually determined by the efficiency of the combustion chamber including the piston shape. The ignition advance and air/fuel ratio will also influence the temperature. but the exhaust valve timing can really heat it up if you open the exhaust too quick and close it too late, you really dump heat out and lose horsepower. Most time when excessive header temperature is a problem, the camshaft is the cause.You might have a low battery or poor egine ground. If the ignition goes to hell you can be running into intermittent pre-ignition that can run cylinder temperatures an extra 300 degrees F really quick"
Hopefully this slings some light on the situation
-Shannon
"Red hot exhaust headers indicate a lot of heat an unburned fuel is being dumped out of the engine. It sounds liek your exhaust system is in the ball park. But check the back pressure at the highest RPM. A little bit bigger pipes won't hurt. Even well tuned engines will turn exhaust headers yellow hot. You've got 400-500 Cubic Feet per Minute at 1450 degrees F coming out of one 2.5" hole on each side. The exhaust temperature is usually determined by the efficiency of the combustion chamber including the piston shape. The ignition advance and air/fuel ratio will also influence the temperature. but the exhaust valve timing can really heat it up if you open the exhaust too quick and close it too late, you really dump heat out and lose horsepower. Most time when excessive header temperature is a problem, the camshaft is the cause.You might have a low battery or poor egine ground. If the ignition goes to hell you can be running into intermittent pre-ignition that can run cylinder temperatures an extra 300 degrees F really quick"
Hopefully this slings some light on the situation
-Shannon
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Joined: Oct 1999
Posts: 356
From: Oakland City, IN
Re: Red hot headers ? Rich or lean ??
Originally Posted by ChevyTuffD.A.
Well.........who is he??
Lets put it this way. Smokey Yunick
was (still is to some degree with everything we enjoy because of him) to the Chevrolet V8 what Einstein was to physics. His contribution was THAT great. Man, talk about thinking "outside the box"! Hell, he thought OUTSIDE THE CAR in Daytona one time! (the alternator with a propeller thing..). Do a google search and prepare to read for next year or so of your life..
Dave C.
Registered User
Joined: Jul 2003
Posts: 1,103
From: Hawaii
Re: Red hot headers ? Rich or lean ??
Lean!!!!!!!!!! Dog Nabbit!!!
No wait!! Clogged Cats!!!! Gawd Dang it!!!
No Wait!! Rich and burnt Valves!!!!! woulndt that have a popping sound??
Whatever man... I give up....
I am not gunna ask whose Smokey!! I just did =X
Marvin
No wait!! Clogged Cats!!!! Gawd Dang it!!!
No Wait!! Rich and burnt Valves!!!!! woulndt that have a popping sound??
Whatever man... I give up....
I am not gunna ask whose Smokey!!
I just did =XMarvin
Thread Starter
Registered User
Joined: May 2000
Posts: 1,327
From: Under my Car as usual :)
Re: Red hot headers ? Rich or lean ??
Yep, Smokey was a great innovator. His reverse rotation engines and wild setups were fabled. the story of his running a pushrod engine at Indy a few years is amazing. He is a great story teller to beat all
-Shannon
-Shannon
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