intake manifold heat crossover...
Thread Starter
Instructor
Joined: Aug 2001
Posts: 120
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From: westmoreland n.h.
intake manifold heat crossover...
does anyone know what the heat cross over is for , and do i need it. can i block it off. i'm replacing the intake with an edelbrock performer rpm. :chevy
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: intake manifold heat crossover... (dash8)
Combined with the heat riser valve on the passenger's side exhaust manifold fitting....which closed when cold forcing the hot gasses up and over under the intake manifold, making the manifold and carb warm up quickly....good for cold weather, pain in the butt for SW and Florida....
the valves can stick partly shut or even totally shut, overheating the intake...and frying things....
IN general, you can use an electric choke for starting purposes and heated pull off, and save the manifold stress from heating...
so the answer is YES you can block it off....
but, if the heads and the manifold both have passages, forget about using gaskets to block it off, they will burn our in a hurry....
so thing to do is....fill the manifold heat rise passage with plaster of paris, let it cure, then install....messy job, but takes care of the problem permanently.....not worth doing on a stock manifold though, expecially one with EGR passages....
GENE
the valves can stick partly shut or even totally shut, overheating the intake...and frying things....
IN general, you can use an electric choke for starting purposes and heated pull off, and save the manifold stress from heating...
so the answer is YES you can block it off....
but, if the heads and the manifold both have passages, forget about using gaskets to block it off, they will burn our in a hurry....
so thing to do is....fill the manifold heat rise passage with plaster of paris, let it cure, then install....messy job, but takes care of the problem permanently.....not worth doing on a stock manifold though, expecially one with EGR passages....
GENE
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Joined: Jun 1999
Posts: 7,117
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From: Dove Mountain Arizona
Re: intake manifold heat crossover... (dash8)
You do not need it, as a matter of fact most aftermarket alum intakes are already blocked off in this area. The passage is/was used to heat up the area around the carb for better atomization of fuel when the engine is cold.
Thread Starter
Instructor
Joined: Aug 2001
Posts: 120
Likes: 0
From: westmoreland n.h.
Re: intake manifold heat crossover... (dash8)
thanks gentlemen, that helps alot. since i only run it in warm weather, i think i'll block off the crossover. thanks again........ :flag
