Under hood heat

[Phil P.]

   Looking for ways to lower under hood temp. It would seem that eliminating the under hood blanket would help reduce under hood temp by allowing more room for air to circulate. Since I only drive in warm weather, I also plan on closing up the exhaust crossover in the intake manifold. What’s the best way?Currently after about an hour of driving on a hot day, heat build up is great enough to boil gas in the secondary float bowl that then percolates into the air horn. 

[sailingadventure]

While blocking off the exhaust crossover seem like a good solution, it will make your exhaust sound very harsh. I tried it on my car and changed it back because of the sound. I made a heat blanket when I restored my car. I used ironing board material with 1/8" foam sewn between. That material isn`t fireproof, but it will withstand a great deal of heat.

[EnduroDriver]

I wouldn't recommend removing the insulation, part of its job is reducing the impact of heat on the hood and paint. Fiberglass is a terrible choice for a hood for that reason but that's what we have to work with. 

The two things I'd recommend are switch to EFI, the idea being fuel the car more efficiently to simply generate less heat in the first place. And install an electric fan on the radiator. The factory fan is cute and simple but pretty much useless for moving air. Especially at low speed. Install something that can move air and carry that heat away. 

[Phil P.]

Thanks for your response , both of you. Your heat blanket is much more attractive than conventional ones. BTW I already use an electric fan. 

[Gunslinger]

Adding an air deflector under the front end is a big help...it directs air up into the radiator that would otherwise be wasted plus the deflector helps move air around the bottom of the engine bay and bottom of the vehicle where it otherwise cause turbulence and aerodynamic drag.

Of course while sitting still the deflector is of no help but at speed it drops the engine temps at least ten degrees in my experience.  Before Saturn was discontinued by GM they had a deflector that was a very easy install and worked and looked great.  Unfortunately I don't have the part number anymore.  It attached to the underside of the radiator saddle right where it would do the most good.  

[Dunkin]

How thick is your intake gasket to carburetor? 

[wildfelr]

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[Phil P.]

To Dunkin, gasket is standard 3 ply stapled together. Probably 3/16” or so. Can’t go any thicker as R2 bonnet is already touching the hood. 

[Geoff]

Aside from the notion to direct more air through the radiator (with which I agree), and aside from punching air evacuation holes/louvers in the car (hood and/or fenders), I would include adding Water Wetter to your cooling system.

https://www.redlineoil.com/waterwetter

[Ron Dame]

When my A II starts getting warm, I pop the hood, driving or not, an it allows enough extra air flow to cool it down a bit. It's not a pretty solution, but easy and quick when needed:

[silverstude]

When my A II starts getting warm, I pop the hood, driving.......   That's not a good idea

Edited Thursday at 02:09 PM by silverstude

[Footer]

Here’s an article in a recent Avanti Magazine. Mike

https://www.nostalgicmotorcars.net/uploads/1/2/4/8/124888690/nostalgic_cooloff_v2_aoai203__1_.pdf

[billsr2]

Ceramic coat the exhaust manifolds. They do the inside as well as the outside so it will make a huge diff. in heat as well as make them look great!

It will, however make the rest of the exhaust warmer so some exhaust wrap could be in order. You have learned that these cars are stupid hot?