Cooling a 460/Head Gaskets

[Dominik]

good morning,

as basic as it sounds: it's about airflow, if the mechanicals are okay.
your fans should nor come on at all when you travel at speeds over 30mph.

if they come on, you have to shroud your radiator more. Now yours is fully covered, which is not needed unless you are racing. I feel that underhood temperatures are much lower leaving the upper part of the radiator unshrouded.

that also results in colder feet. Also don't forget, the engine itself radiates a lot of heat, so you need some air flow.

to test your fan's capacity, heat the car up (disconenct the fans) to 210F, park the front of the car near a wall or restrict airflow with cardboard and now let the fans do the work.

that test will cover your stop and go traffic. Temperatur should drop.
Calibrate your water temp instrument!!!

with the radiator nicely shrouded you should be able to travel at 55mph to the next meeting without problems.
if the fans come on (you see that watching the Voltmeter flick for a moment and show a slightly lower reading), you probably have air trapped in the system or a mechanical problem.

keep an eye on your radiator cap, make sure it's not too weak and lets coolant out!

Track racing is a totally different story...
Drag racing: travel back to the pits going moderately fast to improve airflow through the radiator.
Chassis Dyno: you need a very strong fan to simulate airflow at 130 mph +, if you measure in 4th gear at max RPM.

also: make sure your ignition is not too retarded at low engine speeds.
an indicator for this are red hot headers at idle or slow vehicle speed, or melted hoses!

got the idea? :-)

dominik

[ByronRACE]

My engine may be a little weird, but it's still basically a 385 series (460) foundation and it's in a West Coast. I disliked the way west coast did the coolant system. The expansion tank was unnecessary and large, the fill point was relatively low, there was no provision for removing trapped air from the back of the heads, etc. It looked prone to air lock and all the additional plumbing they added everywhere showed they were battling this problem.

I did things differently in my build. I put two fittings in the back of my intake manifold at the water passages to bleed a small amount of coolant forward bypassing the thermostat. I tied these lines into the thermostat housing. The thermostat housing is also the fill point and is the highest point in the engine compartment. Everything from the housing is down hill. I have a burp tank in the front right corner on the end of a 1/4" hose and it's set up to draw the fluid back into the thermostat housing if/when needed. The radiator is West Coast's "10 core" unit that I'm honestly not that thrilled with. It's brass, heavy as hell, and the fin density is poor. I would have done much better with my dollar to have an aluminum one fabricated locally. My water pump is a Meziere WP337 remote mounted low on the passengers side between the steering rack and the radiator. For fans, I have two 13" spal pushers on the front of the radiator with no shroud, and that's it. 1710CFM each.

Idles forever at 180deg F at 900rpm idle. Holds 185-190 at 2500rpm sustained stationary high-idle. Actual use, temp is 180-190. This engine is supercharged as well, so will generate more heat than normal. 2 fans come on if I'm at idle for a long time, otherwise just one. I have a fan controller built into my dash instrumentation.

When I fired this thing up the first time, I just fired it and let it come up to temp, then shut it off and let it cool completely. Then I opened the stop cock on the overflow and drained about 2cups of coolant, popped the cap and added about another 4 cups. That's it...level has remained the same and I've never seen anything out of the overflow since.

Anyway, just thought another combo might be interesting to note.