Topic: heat riser quest.
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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Hi all.
can anyone explain to me what the heat riser valve does on the passenger side exhaust manifold?
i'm currently running WITHOUT one and there was not one on my car when i purchased it. my new chambered exhaust fits up fine on that side without it.
does not having one affect performance in any way?
thanks.
jeff
can anyone explain to me what the heat riser valve does on the passenger side exhaust manifold?
i'm currently running WITHOUT one and there was not one on my car when i purchased it. my new chambered exhaust fits up fine on that side without it.
does not having one affect performance in any way?
thanks.
jeff
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
[QUOTE=Hmel '74] Hi all...can anyone explain to me what the heat riser valve does on the passenger side exhaust manifold?[/QUOTE]
They mostly just rattle a lot...
Actually, the purpose is to block exhaust flow out of that side, and re-route it up thru the intake manifold. This warms the intake air quicker, for faster warm up times, and reduces emissions.(so they say) The bi-metallic spring on the valve expands as it heats up, slowly opening the valve fully, for unrestricted exhaust flow...IF it's working properly.
But, they mostly just rattle a lot!
Not having one only effects warm up time...nothing else, as far as "performance".
They mostly just rattle a lot...
Actually, the purpose is to block exhaust flow out of that side, and re-route it up thru the intake manifold. This warms the intake air quicker, for faster warm up times, and reduces emissions.(so they say) The bi-metallic spring on the valve expands as it heats up, slowly opening the valve fully, for unrestricted exhaust flow...IF it's working properly.
But, they mostly just rattle a lot!
Not having one only effects warm up time...nothing else, as far as "performance".
Joel Adams
C3VR Lifetime Member #56 
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
thanks Joel! I liked your answer.
btw: for any new members who are on the fence about joining this site, I posted my question approximately 15 minutes ago and i got a response already - now that's service!!
HeyHmel, my 77 didn't have a heat riser connected when I bought it several years ago and its never been a problem.
gs77vet 2007-05-08 11:56:22
One of the great things that make this club nice is we do have many well informed members, agreed. Gene NICE RIDE
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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