Heat Riser Question
Thread Starter
Instructor
Joined: Jun 2010
Posts: 129
Likes: 11
From: Treasure Coast Florida
Heat Riser Question
It has been a long time since I had to worry about a Chevy Heat Riser. My friend just purchased a 65 Stingray with factory side pipes. I have only looked at the car so far when it has been stone cold and I notice that the weight for the heat riser is pointing away from the engine as I remember. My memory of Chevy heat risers is that the weight dropped down as the car got hot. When I looked at his car it did not appear as if the weight would clear the frame when it dropped. I reached down and moved the value and it seems to open as the weight moved upward. Is this normal for a 65? Did not seem logical that the bimetal spring would have to lift the weight as it opened the value.
Thank You
Thank You
Le Mans Master
Joined: Dec 2007
Posts: 8,000
Likes: 659
From: Puget Sound
Whether or not it has side exhaust makes no difference. Small block cars had the weight to the rear and pointing outward toward the frame. Big block cars had the weight in the front and pointing toward the starter. When cold, the weight should be in the "up" position and drop down when it gets warm.
Thread Starter
Instructor
Joined: Jun 2010
Posts: 129
Likes: 11
From: Treasure Coast Florida
So, my memory is correct that the weight drops as the car gets hot. I will have to look at the car again but the weight can only be lifted and it will not drop. What the heck did someone install in the car??
Team Owner
Joined: Mar 2003
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From: Greenville, Indiana
Last edited by MikeM; Dec 8, 2017 at 02:54 PM.
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Safety Car
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Most useless invention ever. I never use one because they always lock up and are nothing but trouble. I was never sure if the purpose was for the choke to heat up faster or engine. Either way not needed, except to rust out your pass exhaust faster.
Race Director
Joined: Apr 2005
Posts: 11,264
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From: Bowling Green, Kentucky
While I agree that they are not needed for our recreational cars and southern climate cars, they served a purpose for winter driving up north for our daily drivers back in the day.
The main issue with early corrosion on the passenger side exhaust was due to the EDC/EDB corrosive lead scavengers used in leaded fuel. They produced HCL (hydrochloric) and HBR (hydrobromic) acids when burned and combined with water vapor from the combustion process...........and are much more corrosive than CO2 produced acid. Eliminating lead in gasoline was the major step for eliminating early exhaust/tail pipe corrosion.
FWIW.
Larry
Race Director
Joined: Jun 2006
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From: Inverness FL
St. Jude Donor '07
Moxie:
While I agree that they are not needed for our recreational cars and southern climate cars, they served a purpose for winter driving up north for our daily drivers back in the day.
The main issue with early corrosion on the passenger side exhaust was due to the EDC/EDB corrosive lead scavengers used in leaded fuel. They produced HCL (hydrochloric) and HBR (hydrobromic) acids when burned and combined with water vapor from the combustion process...........and are much more corrosive than CO2 produced acid. Eliminating lead in gasoline was the major step for eliminating early exhaust/tail pipe corrosion.
FWIW.
Larry
While I agree that they are not needed for our recreational cars and southern climate cars, they served a purpose for winter driving up north for our daily drivers back in the day.
The main issue with early corrosion on the passenger side exhaust was due to the EDC/EDB corrosive lead scavengers used in leaded fuel. They produced HCL (hydrochloric) and HBR (hydrobromic) acids when burned and combined with water vapor from the combustion process...........and are much more corrosive than CO2 produced acid. Eliminating lead in gasoline was the major step for eliminating early exhaust/tail pipe corrosion.
FWIW.
Larry
Bill
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Duke
Last edited by SWCDuke; Dec 9, 2017 at 09:41 AM.
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Le Mans Master
Joined: Jan 2002
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I live in SD, and with the heat passage blocked off, and the spacer installed in place of the riser valve, the car starts just fine.
I don’t drive in the winter, but do start the car often year round. In the winter my garage can get in the high 30’s. Two pumps of the pedal and it fires right up.
I did leave it out in the driveway one January day for about 12 hours at single digit temps. The kind of cold where you sit in the seat, and the seat is rock hard. Two pumps of the pedal, and it fired right off and idled on the choke.
I don’t drive in the winter, but do start the car often year round. In the winter my garage can get in the high 30’s. Two pumps of the pedal and it fires right up.
I did leave it out in the driveway one January day for about 12 hours at single digit temps. The kind of cold where you sit in the seat, and the seat is rock hard. Two pumps of the pedal, and it fired right off and idled on the choke.