1980Guy

Marc,

I have been fighting a hot engine in mine for a while. My fan shroud was shot when I did my motor replacement so I didn't reinstall it. Consequently I am running warm, although it is encouraging to see here that the water neck temp should be higher than the head temp. My heads don't have a sender provision so I had to mount my sender in the thermostat housing. I am running a 180* thermostat and I generally run about 185-210 most of the time. Idling in traffic gets scary at times so I am going to try to install an auxiliary fan. I have another thread on here asking for some help getting the wiring diagram down, so if you are interested I can link you over there and I will post pics when everything is finally hooked up. I am going to try to use a 12" pusher initially just to give it a bit more help. Something to consider.

marc9889

Update / recap - I've made great progress on getting the temps down in my LS-5 / 454 car. Even with the factory radiator (not aluminum), I'm rarely seeing 210 degrees anymore, even around town. This is what the improvement can be attributed to:

- Make sure you aren't losing any coolant. (I had pin holes in the radiator and expansion tank.)
- Drill two .250" holes in the skirt of your 180 degree thermostat.
- Run 93 octane fuel (in any engine with higher than a 9:1 compression ratio)
- Run 80/20 distilled water to antifreeze ratio and add a full bottle of Water Wetter
- Run vacuum advance from manifold, not from carburetor (this made a really, really big difference in the operating temperature). While you are at it, replace all the caps on your carb vacuum ports with new ones. (Costs less than $5)
- Set ignition timing to 36 degrees at 3000 rpm. I got my best results by setting the time to 36@3000, then making several very minor adjustments until the car to run smoothly.
- Make sure your lower (vacuum side) radiator hose has a coil in it so that it doesn't collapse under pressure.

*not running a high volume water pump
*not running a high flow thermostat

Schaggy

I have had a lot of cooling problems with my '72 small-block and everything described here has been part of the fix (aluminum rad, timing, vacuum, chin spoiler, electric fans, high-flow water pump, water wetter). The only thing that I changed that was not mentioned here (and may be helpful to you) was the lower rad hose. I put in the one with the spring to make sure it doesn't flatten out and reduce coolant flow.

You can find an example of the BB version here:

http://www.ecklerscorvette.com/corve...1969-1974.html

Good luck!

Mike Ward

I'd say that these two adjustments were responsible for 99.9% of the cooler running at idle. The rest, especially higher octane gas, did little or nothing.

marc9889

The higher octane fuel allowed me to set the ignition timing so that the engine ran cooler without detonation.

Mike Ward

Did you actually experience detonation? Your '72 should run just fine on regular.

marc9889

Absolutely. I experimented with 87 Octane, 89 Octane, and 93 Octane, and the result was exponentially better as the octane went up.