The Stovebolt Site Forums The Shop Area Engine Shop getting the engine compartment cooler question

I have a 400 sbc in a 50 1/2 ton engine compartment. And as a lot of folks know the sbc engine takes up a lot of space in the compartment. I noticed that after running the truck for a while that it gets pretty hot in the compartment. I was wondering if anyone has noticed the same thing and what kind of solutions you might have to help cool the engine compartment a little other then putting a air scoop on the hood. Living here in the south it gets pretty hot in the summer. I was debating on maybe putting some holes in the inner fender wall to help disapate some of the heat. But I don't really now if this would help any or not. Any suggestions on getting rid of some of the heat in the engine compartment would be great.

I know you don't want to hear this, but in the first place your tubing headers(how did I know?)are the greatest source of unnecessary heat.OK thats said.
Increase the airflow through with larger airmover.
Cool the necessary heat contributors with a cooler running engine (thermostat).
Move the A/C condenser so it doesn't contribute.
Airflow through the engine compartment should be in at the front and out downward over the engine/exhaust system.
Wrap or coat heat emitters with insulation(unless they are the cooling system)
I understand your hesitancy to make some compromises because they don't look "cool" but be challenged to work with these as you can until you're satisfied.
Remember there is no reason the 400 can't be made to run just as cool under the hood as the original 6 pack doing the same work.
It takes x horsepower and fuel to move it down the road at a given speed/load regardless of the engine.In fact the more efficient modern engine SHOULD reject LESS heat to the exterior.
Ok time to hear from others.

Thank you for the reply and the good advice. But I'am not running tubing headers just plain old ram horn exhaust manifolds. But those ram horn manifolds do put out a lot of heat. And the advice you gave to wrap the exhaust pipes is a good option to help on the heat. And changing the thermostat would help to. I didn't install any A/C just a power steering pump. as far as the engine compartment looking cool. That really doesn't matter to me. I tried to keep the truck looking as original as paossible on the outside. And i would have went with a 6 cylinder engine but the truck came with the 400 and th350 already in it so i went with that. But like you said, the exhaust manifolds are the biggest source of heat. If I could find a way to cool the ram horn manifolds that would help a bunch

Working a stock truck with 6 cyl on a hot day I've often stopped and opened the hood or at least cracked it while going for lunch or whatever. Let that hot air out the top instead of baking in there.
Driving down the road (hood closed...) with air moving the under hood heat didn't seem to be a problem but thats stock.

Grigg

Mount a couple of 12 volt marine bilge ventilating blowers ahead of the manifolds, and let the air they provide blow across the manifold/exhaust pipe area. It will help if the intake air to the blowers comes from beside the radiator where it's several degrees cooler than the air behind the core support. Angle the blower outlets so the air is blown at a downward angle as it passes the manifolds.
Jerry

Can gain a little cooling by blocking the heat passage in the intake manifold.
Gaskets to block it once were available but we just cut and inserted a steel shim between the gasket and head.My usual source was antifreeze can bottoms but just try to find one of those today.I think a piece cut from a section of vent or heat ducting would be about right.Never need manifold heat in Tennessee or 'Bama but be aware the dual exhaust will now sound "different"at low speeds, somewhat louder,the pulsation sound will be more evident--like you can distinguish pulsations one side from the other.
The first one of these we did we worked halfa day to prove to the owner it wasn't missing--the sound change had him fooled and us too.
Factory fuel injection had no need for manifold heat right up to the last SBC so the sound difference can be related to any of those with duals.
Hotrod Lincoln will remember the old flathead Ford trick they referred to as pitting pennies in the manifold.Actually in the gasket I think to block the heat.

Jerry, That was one of the solutions I was thinking about. but I never would have thought about using a bilge fan, thanks.

Bob, there is a Offenhauser 360 intake on the engine, were would the heat passage be on it?

The heat passages are located in the center of the intake manifold/head flange and let exhaust from 1 exhaust port on each head communicate with a cavity under the plenum and pass on to the other head/manifold depending on pressure differential.
The heat passage in the intake manifold center flange will be a raised area,center of the plenum with a manifold bolt on each side of it.
With single exhaust, when the manifold heat valve at 1 exhaust manifold outlet is closed, gases from that bank must pass through the intake manifold to get to the other bank exhaust manifold--unless the pressure can overcome the heat valve spring and open the valve.All this heats the intake manifold/mixture.Not a performance enhancing thing unless you are warming the engine in cold weather for street action.

thanks for the info, I don't race the trcuk just cruise around town in it and pick up some feed and haul hay in the bed.so if the solution takes away some of the performance that would be okay. I have just been a little concerned about the heat in the ehngine compartment. This is the first truck I restored that had a V8 in it. And the engine looks pretty tight in the compartment. So I was wondering what some of the other folks did to help the heat issue. Maybe I'm making to big of a deal about the heat and that is just normal when a V8 has been put into one of these trucks.

yes, you're too concerned about it, there's folks in much hotter places than you who have hotter engines in small spaces, if the paint starts peeling off the hood, then worry the only temp you need worry about is the one on your gauge

Bill

I doubt that your underhood temp comes close to that seen on many of the current automibiles.These modern Honda and Toyota and 454 powered motor homes of a few years ago have me shaking my head.
Rubber things underhood of the modern stuff has a hard life.
I really think you have a good working package there.
That 400 will give some grunt down low but may be a little thirsty.An AIR COOLED transmission cooler is a necessity for lower cooling system loads and better transmission life and make sure the ignition timing is not retarded as that can increase operating temperatures of the exhaust.

I re did the timing and opened up the inner fender wall some and that helped a great deal. Thanks for all the replies and advice. Hopefully the thread will help someone else out to.

Engine compartments do heat up when you turn the engine off but it's be nice to know just how hot it is going down the road. It got me to thinking it'd be a good idea to put a thermometer under the hood that you can monitor going down the road. I think you'd be surprised.
When I wired in my electric fan I also installed a switch that I could operate manually. When I pull the panel into the shop and get out I can feel the heat radiate through the grille. Sooo, when I pull in and cut the engine off I flip the fan switch on and let it blow for a minute or two before totally shutting it off. I know we can't always do this but I do it when I can.

....still interested just how much the temp is going down the road. MMMmmmm

Well, I wrapped the exhaust pipe where it comes down from the exhaust manifold and stopped where the pipes leave the compartment. And I made a few vent holes in the inner fenders. After I re did the timing. This helped out a bunch on the heat issue. I'm trying to figure out what to do about the ram horn exhaust manifolds.