[Rhansen]

On hot days my underhood temp. gets high enough to cause my secondaries to boil over. I put a heat diffuser under the carb, and switched to water wetter in the cooling sytem. Coolant temps never get over 210. I finally got fed up and cut about 14 holes in a junk hood with an 1 5/8" hole saw. That helped more than anything. I'm thinking my headers are radiating too much heat into the engine compartment. Any one had this problem or have any ideas?

 

[RANDY406]

I think your going to have to bite the bullet and get a cowl hood.A temporary fix is to put a spacer (around 1/2" and use longer bolts)between the hood and hinge on the 2 back bolts.This will hold the back of the hood up and let some heat out.

 

[RedSpeck_09]

better fans might help

 

[Rhansen]

Using two 14" elec. fans - one pusher and one puller. Also using BeCool alum. radiator and a Flow Kooler impeller disk in the water pump and removed the guts from a thermostat to make a restrictor.

 

[mcgruff1]

Ever thought of pulling your inner fenders? If your low enough you probably cant even notice them gone...

 

[ghight]

This is a very small thing, but try it. It free. Remove the rubber strip in the back that seals off the hood. It will lower the under hood temps a little. Good chance it won't lower it enough, but you never know.

I'm kind of diggin' the holes in the old hood idea! Don't see that much! :dunno:

 

[jameskirk1]

You may want to double check your base timing and idle mixture...Might want to try some header wrap or blankets...just another .02

 

[Rhansen]

I set the idle with a vac. gauge. Timing is 12* initial and 36* total with no vacuum advance (every time I hook up the vac. advance the motor fights itself at part throttle, prolly need a can with less advance). Thought about the inner fender thing but won't that throw a bunch of dirt etc. into the engine bay? Also was told to stay away from header wraps - rusts quicker and voids warranty.

 

[jameskirk1]

Hey bro, I just thought up with THE EASIEST FIX!!!!

Just floor it more often!!!...Use up that fuel in the secondary side and replace it with some that's fresh and cool from the tank...That must be why mine has never boiled over...LOL!!!

Would the headers rust under the wrap even if they were painted first? I painted mine with ultra high temp paint and have ran them for over a year...No flakes/rust or anything...yet...

 

[Rhansen]

Dunno about the paint thing, just got a lot of neg. feedback about header wrap from my stepdad (who raced more vehicles than I will prob. ever own) and a few people at the track. What about a Phenolic carb spacer?

 

[ghight]

Wrapping headers can cause the metal to form small cracks and become brittle over time. It's still not that bad though because headers usually don't last long to begin with. 10 years is considered a long time for any kind of header except the ceramic coated ones.

I'd just fab up a piece of metal to shroud the headers with kind of like heat shield or use some of the heat insulation tape on the carb bowls. Might look goofey but it beats the alternatives. Nothing is going to look good anyway.

 

[RANDY406]

Header wrap will kill the tubes.Aphenolic spacer won't help becuase, your not getting the heat from the intake,it's radiating from every thing else.

If you take out the fenderwells you will sling crap all over your engine compartment.You could try to cut them up from the frame some to allow more air.Mine were cut for the hooker headers and still kept everything clean.

If it isn't gone already remove the weather stripping at the rear of the hood like ghight said and space the rear up.These mods are free and easy.

Do you have a drop base aircleaner on it?They are notorious for trapping heat around the carb.

Just thought of something else,my firewall is notched right above the distributor and next to the wiper motor.This makes a clear path into the cowl area.Might be just enough to get rid of some heat.

 

[Rhansen]

no drop base air cleaner, notched firewall, or weatherstrip. Will try spacer on hinge. Was wondering how phenolic spacer compares to heat diffuser. May take combination of things to fix problem.

 

[RANDY406]

If I remember correctly from previous posts you have a dual plane intake.If you do get the spacer I think you want it to be the 4 hole type,and keep your shield closest to the carb.
I had the same problem years ago when backwoods racing .It would only happen after I ran it then shut it down (heat soak).I can't remember how much the raised hood helped.But I know if I didn't have the Moroso dropped air cleaner on I never had a problem.

 

[yellow brick]

the engine bay "pressurizes", just look at any spots where you can aid air flow, air goin in the engine must come out (or at least most of it, you could trim the inner fender well back a inch or two, that would help alot

 

[Tek]

I'd got with ceramic header paint for the cheapest way and if you have more money, heat wrap. If your engine runs at a good temp, but just have a lot of heat, exhaust is the main culprit. exhaust is the hottest thing under their. some header wrap would definetly help.

 

[John Hammer]

ceramic coated headers=heat reduction under the hood.

they are worth every penny.

-hammer

 

[SmBlokS10]

You are wasting your time with most of these replies. Mine boiled over doing the same exact thing. Switched to a Phenolic 1" spacer under the carb. Still boiled over. Adjusted the floats to an exact science, and it helped some, but each time I parked the vehicle, I noticed a fuel smell. I would lift my air cleaner and the secondaries would be leaking and steaming from the carb.

If you are running a 195 degree thermostat, you'll notice that your secondaries boil over after you are parked with the engine off. Thats because the engine is still heating up, but your fans aren't cooling the engine anymore. Mine would begin to boil around 210 degrees. You might be able to try wiring in your fans to run to full power instead of switched with a variable thermostat on the fans to shut off at 185. ???????

Other than that, I am running an Engine driven fan, and the best I could do was switch to a 180 deg. thermostat.

Problem solved. Mine doesn't boil over anymore. When parked, it never gets above 195.

 

[Rhansen]

I was using an engine driven fan but I removed it so I could access the front of the motor easier (I did a couple of cam swaps) - the rad. pulls out now with three bolts, two elec. connections, and two hose clamps. The elec. fans are wired direct to the battery with a toggle switch for each one. The thermostat was just a shell - I removed the guts after trying a 185 and a 160. I could try the engine driven fan again - but as a last resort. I've got a couple of things to try first, not to mention waiting for hot enough weather to even have a problem.

 

[jameskirk1]

You are wasting your time with most of these replies.

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