reducing under-hood temps

[69redrunner]

I'd like to reduce the ambient temperature under the hood. I'm wondering if switching from a copper/brass radiator to an aluminum radiator will have any effect.

Not running headers. Don't currently have a fan shroud.

 

[beezee]

I have EFI and the air temps can reach 120-130 degrees entering the throttle body while the engine temps at 170-180. Thinking of a 6 pack hood or Spectre ducted air cleaner to lower air intake temps to ambient.

 

[Hemi 354]

Past experience on my 68 GTX. In 1970, I had a air scoop fabricated at the welding shop--all aluminum--that fit UNDER the front bumper and directed air up into the engine compartment. WHOOSH !!! What a breath of fresh air. The air scoop only had about a 1 1/2" opening, but ran all the way across (and under) my front bumper and forced air upward. Not seen anything like this since. I'll post pics if I can dig one up. It cut my ambient air temp down tremendously.

 

[lewtot184]

cast iron exhaust manifolds will run over 700f. the factory 22" radiator is only a 2 row. air-grabber/ramcharger fresh air stuff actually impedes air flow under the hood. a lot of stuff to look at.

 

[69redrunner]

I do have an air grabber, so combustion air is cooler.
Just looking for options to help reduce fuel vaporization issue.
I've wrapped the fuel lines, blocked the crossover, have a phenolic spacer.

 

[67 coronet]

I do have an air grabber, so combustion air is cooler.
Just looking for options to help reduce fuel vaporization issue.
I've wrapped the fuel lines, blocked the crossover, have a phenolic spacer.

is your fuel vaporizing under the hood for sure?common to happen further down the line.fuel line nearest point to exhaust pipe.pipe wrap will solve that normally.aluminum rad will not reduce underhood temp.same heat still going to same area.

 

[69redrunner]

I've put insulating tube shield on all fuel lines and hoses under the hood. I do plan on doing the same where the lines run along the frame, and using two types of material near the manifold and pipe.

 

[hammond472]

Copper conducts heat better than aluminum but aluminum conditions better than brass. It has something to do with the metals free flowing electrons. I double an aluminum radiator will lower your under hood temp but a fan shroud will lower your engines block temp. Also wrapping your exhaust will help. Are you running a thermal isolating spacer between the carb and the intake? They help a lot for carb heat soak issues. I have also had good results experimenting with different temp thermostats especially with modified cooling systems.

 

[lewtot184]

I do have an air grabber, so combustion air is cooler.
Just looking for options to help reduce fuel vaporization issue.
I've wrapped the fuel lines, blocked the crossover, have a phenolic spacer.

i have the same condition with my 69 r/t and haven't found a solution. i don't have vapor lock problems and do use a vapor seperator with return line. i think when all that iron takes a heat set your toast.

 

[Brandy]

I really like that idea about the scoop under the front end. I would have to find a way to hide it though. I wonder how fast you can go before the hood starts bulging up?

 

[1967coronet]

is the heads & {aluminum ?} intake heat cross over for the choke well blocked off or open ?

 

[69redrunner]

Iron 906 heads, eddy aluminum intake, felpro valley pan with crossover blocked.

 

[Hemi 354]

In reply to when the hood starts to bulge up,...that never was problem. I received air ok, but NOT that much air. Additionally, I had pins in the hood.

 

[747mopar]

Iron 906 heads, eddy aluminum intake, felpro valley pan with crossover blocked.

Sounds like what I have, I had issues but putting a Mr Gasket heat dissipater and the insulated tube on the fuel line by the headers cleared it up.

 

[HT413]

These cars ran fine with out that air dam sucking air into the engine bay. I would look at fuel line routing - if the fuel is boiled down low near the exhaust as said above, the vapor will rise up to the highest point in the system.

Besides, that air dam would turn the engine bay into a parachute, I'd imagine if it cooled the engine bay noticeably, the parachute effect would also be noticeable.

 

[Hemi 354]

Parachute? No-way. I was only on the street --not dragging the car. Like I said, the opening was only about 1 1/2 inch--but about 3 feet wide. I know that on my Stewart Warner Gauges, my temp ran much cooler. Actually, I'm thinking about doing that to my 66 Belvedere. While being a MOPAR person for over 50 years, I've tried about every trick in the book, and added a few chapters of my own. I got the idea when working at the Cotton Owens garage in South Carolina during the early 60's.

 

[Dennis H]

As already said - leave radiator alone. Coated Ceramic headers reduced under hood temps by 100 degrees for me. Shroud is a must. Also wrapped and moved fuel lines back and carb spacer 1/2 inch. Ethynol can still be a pia.

 

[red 69 runner]

i had the same problem,ditched the Eddy carb and spacer,put on a Holley with no spacer and problem solved.

 

[383man]

What I had found that would happen on my 63 sometimes is the cheap pump gas will start to boil in the carb bowls and flood the eng. Never had this problem up until a few years ago when they added more ethanal to the pump gas. The ethanal lets the gas boil at a lower temp and it will do it even with the car running at 185 to 190. I added the phenolic spacer and a heat shield under my carb and then ran the fuel line up in the pass wheelwell and come in a hole in the fenderwell near the carb. It helped as it did not do it at all last summer. But when I drove my 63 in November on a 62 degree day it started to do it after a hot soak as I forgot they had changed the gas to winter blend already and I could tell as it adds even more ethanal. You dont have this problem on modern cars as they have the fuel under higher press with fuel injection and that raises the fuels boiling point. All you can do is the basics like the carb spacer (wood works great also) and insulate the fuel lines and keep it away from heat as much as you can. Now if you get vapor lock (lack of fuel) thats another type of problem but the fuel with this ethanal is boiling in the carb some and the eng loads up from rich as thats what I am seeing. Also adding some race gas or octane booster will help also. You can see the phenonlic spacer and heat shield I run. Ron

 

[SlinktRR]

I'd like to reduce the ambient temperature under the hood. I'm wondering if switching from a copper/brass radiator to an aluminum radiator will have any effect.

Not running headers. Don't currently have a fan shroud.

Keep the radiator you have, add a fan shroud, that should be enough.