Hey, everybody! Anyone have any thoughts or opinions on this:
I have a 1967 289 with a few mods (.030 over, Performer intake, Holley 600cfm, .471 lift cam, Tri-Y headers). It also has a fairly new water pump, new five-core radiator and a new 160 degree t-stat. Typically the engine warms up pretty quickly and the needle on the stock water temp. gauge stays just below halfway, regardless of outside air temp or how long I drive. However, on warmer days (80 degrees or higher) if I get stuck in traffic, it starts to run hot. The needle has yet to get all the way into the "hot", but it gets close. And when I turn the engine off, it spits antifreeze from the overflow (but not while the car is running, only after I've turned it off...no catch can yet). It will also be slow to crank back up after one of these hot spells.
My question is this: Is this something I'm just going to have to learn to live with, due to the mods? Or is there something I can do about it? Invest in an electric fan set-up, maybe? I don't feel like there is anything mechanically wrong other than the fact that my cooling system can't quite keep up on hot days in traffic. Anybody have any advice? Thanks!

 

Alot of things can cause this. On my '68 I replaced every cooling part you can think of, and it still ran hot. Turned out to be the timing. The previous owner had installed the distributor without bringing the engine to top dead center. SO it never was in time, and as a result always ran very warm. I pulled the distributor, got the engine at #1 top dead center, re-installed the distributor correctly and the problem is no more. Hope this helps.

Dave

P.S. Beware of previous owners!

 

Ya, i had the same problem as well. I took my car to a radiator shop and had them flush it, turned out my radiator was 67% clogged. I've never had a problem since. I dont know if thats the case, but its worth a thought.

 

some people say 289s just run hot. my brothers has a 4 core radiator in it and runs hot under the same conditions. Before he got the 4core it was hell. Have you tried putting some coolant additive in: dont know what it is called water wetter? That should help you out a little.

 

Do you have the stock 4 blade fan? Cuz those are not very functional. A 6 blade flex fan will move alot of air.

 

does your car have a fan shroud on it? If not, get one as that will aid the fan in pulling the air thru the radiator.