View Single Post
Old 11-16-2013, 07:16 PM
davidmij davidmij is offline
Join Date: Jan 17 2011
Posts: 660
davidmij is on a distinguished road
Default New motor running hot

Hey Gents, I finally fired up my new motor (1967 390). The builder said to start it and run it at 2000 RPM for 20 minutes. I got to about 10 minutes and it reached 230 degree and was very hot, so, I shut it down.
My father-in law said the fan clutch was shot and that it wasn't spinning no where near fast enough. Is that enough to make it get so hot so fast?

Also, I think understand the coolant flow in the engine, however what does the short nozzle between the intake manifold and the pump do?

One more, what is the purpose of running the engine so high for 20 minutes? I thought it was so the hydraulic lifters and rest of the engine get good oil flow. I was told once that if you don't do that you can ruin your cam.

I let it cool down for an hour, drained the water, then added a gallon of anti freeze and ran it again. This time it got up to 220 degrees in 5 minutes so I shut it down again. I wanted to get some anti freeze in the block. It's supposed to get in the low 30's tonight and I didn't want to risk a freeze.

thx, Dave J
Reply With Quote