vetteguy75

Spent most of the afternoon installing the Holley Carb heat shield. As usual, nothing fits a C3 Corvette "out of the box". I had to trim here & trim there to make it fit correctly. Thank God for Dremel tools. Also found out, if you put the aluminum shield to a polishing wheel, it polishes up quite nicely.

Anyway, my question is: do they really work? keeping the heat away from the carb?


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Roco71

I am not sure if they work or not but nice work on the shield and nice job on the post!

69Vett

a heat sheild will drop your carb. temperature by about 100 degrees.
it is a very good thing.

scottyp99

Does anybody know if polishing the aluminum makes it reflect heat any better?


Scott

vetteguy75

Good Question.....

vetteguy75

cv67

Not sure about the 100 deg thing but sure it makes a noticeable difference.

JohnnyLT1Runner

How much of a difference? I could really use one of these.

birdsmith

Simply put the heat 'shield' acts like fins on a motorcycle engine case or the heat sink in numerous electronic components. It absorbs engine heat from the engine that would otherwise be absorbed by the denser zinc in the carburetor and allows it to be dissipated. If anything, polishing it would have a negative effect on heat dissipation since the smoother surface would have less overall area with which to dissipate said heat, but the difference would be negligible.

69Vett

polishing would make almost no measureable differance,
I am assuming, along with the sheild you isolated your carb,
with a thicker composite gasket, just the isloation with a gasket,
will drop the carb almost 100 degrees I measured it.
with a running warmed up engine, you cannot hold your hand on a carb.
more than a few seconds, Isolate the same carb
it will actually get very cold, amazing differance.

toddalin

Does it?

Or does is serve as a reflector, reflecting the heat from the heat riser and manifolds back away from the carb? In that case, polishing would have a positive, though negligible impact.

I don't know know..., could go either way?

WTFizzit

I don't really see it working that way. Presumably the carb should be considerably cooler (than the rest of the engine) due to the constant flow of (hopefully) cooler fuel and intake air moving through it. It will be picking up heat from physical contact with the engine and radiant engine heat, plus convective contact with hot underhood air. Insulating the carb from direct conducted engine heat makes a big difference (the base insulator), and the heat shield should block some of the radiant engine heat. However, if the shield is in direct contact with the carb (especially one made of aluminum, which has VERY high thermal conductivity), the shield might be "sinking" radiant and maybe convective heat toward the carb. There is no such thing as cold-----"cold" is just a relative lack of heat, and heat tends to move from areas of higher heat to areas of lower heat, trying to reach equalibrium. Its been a long time since physics class and I feel like I'm maybe sticking my neck out with my analysis, but, hey, that's what these forums are all about, right? Healthy debate and thorough humiliation!

MotorHead

First thing I took off when I bought mine 10 years ago. Buncha fluff, can you tell me what the heat shield will do for you ? But at least you have the skills and realize you have to modify aftermarket parts almost all the time opposed to those that think everything should just bolt right up, and start blaming a vendor. You could actually have done that, name the vendor and say the part didn't fit and have a hissy fit.

Paul L

There is one for the Q-Jet as well.

Tim H

A wood or plastic one might help but a metal one at best stops some heat from rising around the carb base but thats it.

vetteguy75

The I way installed mine, was(in order from the intake manifold to the carb)



1) card board gasket (top left in picture) 2) Aluminum Heat Shield 3) 1/4" thick composite gasket (bottom left) and 4) the carb itself