Frozen heat rizer?

johnfharding · February 17th, 2009, 07:13 PM

Upon disassembly of the remainder of the engine bay I found that the heat rizer was frozen mostly closed with a maximum of maybe a quarter inch open. I was thinking this would cause extreme back pressure or reroute the exhaust through the intake manifold and out the other side center exhaust port.

What is your take on this and would this cause a fair amount of performance loss as I would expect?

Thanks

Olds64 · February 18th, 2009, 05:44 AM

The 394 I had in my 64 98 had the same problem. I knocked out the valve and cut off the external bimetallic spring that activates the heat riser. This will definitely make your car run worse.

88 coupe · February 18th, 2009, 09:56 PM

Quote:

Originally Posted by johnfharding

........ would this cause a fair amount of performance loss as I would expect? ........

Yes, it would.

It is only used to help heat the carb/choke during warm up. In warmer climates, it has been common practice to wire them open, or to remove them completely.

Norm

johnfharding · February 18th, 2009, 11:02 PM

I will sure be interested to know what this thing will run like when I get done with it.

I would think with the issues I have found and the freshened up motor it should run a substantial amount better than before.

Bluevista · February 19th, 2009, 02:39 AM

The car should run a lot better. I had a wagon that happened to and the thing was a dog until it was diagnosed. Everybody wired those things open as mentioned or welded or brazed the shaft to keep it permanent. A manual choke was sometimes added because without the heat riser it wouldn't heat up the choke stove fast enough on some cars.

February 17th, 2009, 07:13 PM	#1 (permalink)
johnfharding Registered User Join Date: Sep 2008 Posts: 55	Frozen heat rizer? Upon disassembly of the remainder of the engine bay I found that the heat rizer was frozen mostly closed with a maximum of maybe a quarter inch open. I was thinking this would cause extreme back pressure or reroute the exhaust through the intake manifold and out the other side center exhaust port. What is your take on this and would this cause a fair amount of performance loss as I would expect? Thanks __________________ 1955 Olds and 2005 Corvette

February 18th, 2009, 05:44 AM	#2 (permalink)
Olds64 Landyacht Club President Join Date: Jul 2007 Location: Lawton, OK Posts: 4,286	The 394 I had in my 64 98 had the same problem. I knocked out the valve and cut off the external bimetallic spring that activates the heat riser. This will definitely make your car run worse. __________________ Ferris, my father loves this car more than life itself... Apparently, you don't understand! Ferris, he never drives it! He just rubs it with a diaper! Cameron Frye Ferris Bueller's Day Off 1986

February 18th, 2009, 11:02 PM	#4 (permalink)
johnfharding Registered User Join Date: Sep 2008 Posts: 55	hmm I will sure be interested to know what this thing will run like when I get done with it. I would think with the issues I have found and the freshened up motor it should run a substantial amount better than before. __________________ 1955 Olds and 2005 Corvette

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February 19th, 2009, 02:39 AM	#5 (permalink)
Bluevista Cruisin' the Vistas Join Date: Jul 2006 Location: Northeast Ohio Posts: 1,722	The car should run a lot better. I had a wagon that happened to and the thing was a dog until it was diagnosed. Everybody wired those things open as mentioned or welded or brazed the shaft to keep it permanent. A manual choke was sometimes added because without the heat riser it wouldn't heat up the choke stove fast enough on some cars.