Running Hot

[Curt & Linda Hoffman]

Odd thing- looking for ideas of what to explore.

I had an engine built- a 347 stroker. It had some issues causing it to be torn back down. But the good thing was it did not run hot. Seemed to stay below 200 degrees even when idling for a long time.

With the recent tear down to fix a problem I had them install a new Edelbrock intake and we installed a new distributor. Other than those and the replacement piston and rings to fix the issue, these were the only new parts I know of. Now the engine runs hot. I mean real hot. On the 78 degree day it was running up to 225 degrees on the streets with just a few lights. If I stayed on the highway I could keep it around 210 degrees. I got home and let it idle for a few minutes and quickly climbed to 250 when I shut it off. the fuel began to boil and the overflow tank spit out some. This is a real change from where it was before.

I was thinking of doing the following:
Make sure they have the correct thermostat in it- maybe they did something wierd this time around with the new intake
Make sure the fan is on correctly- it is a flex fan that worked fine before. Not even sure they could install incorrectly but will look tonight
Perhaps they installed the intake manifold gaskets incorrectly. I seem to recall from the two engines I build that you could put them on either upside down or wrong side and it might block some passaged. But my memory could be off here.

Since my time in the car is limited and I just did the temperature testing yesterday I haven’t expored anything yet. Thought I would throw this out in the meantime since I only had a few minutes tonight and didn’t think I would get out to the garage.

Curt Hoffman

[anonymous]

My first thought is to take it back to the engine builder and let him see what he can do.

My second thought is to talk to Jim Morrison. His Tiger (that is now Anthony’s) has a 347 in it. Maybe he can shed some light on the problem.

Fred B.

2

[Curt & Linda Hoffman]

I thought of taking it back, but I have had it back 4 times now and am beginning to think I can do it better myself. Plus, it was a 347 when it ran cool so am not sure the stroking is the issue so much as whatever happened with the last go around.

[v-mad]

Curt, the head gaskets can easily be reversed which blocks some cooling holes, but this usually only causes local overheating on one cylinder. A few things to try:

Could the thermostat be reversed in the housing?

Flex fan needs spacer to set correct position, so that may be missing?

I wonder if its an ignition or valve timing problem since the dizzy was changed?

New intake manifold may be sucking air causing weak mixture?

New piston is oversize or rings too tight?

[Eric and Bonnie and Bonnie Gibeaut]

Curt is the internal spring in place on the lower radiator hose? Is that hose collapsing when RPM’s increase? All the previous ideas are worth checking out especially the thermostat. I thought it didn’t get hot in Ohio??! Eric

[Curt & Linda Hoffman]

Hey, if I lived in SC I would have to have the car bronzed. No way could I drive it. I am waiting for snow again so the car feels good.

[Chuck & Wanda King]

Curt,

You’ll notice what Chris (V Mad) said, was the head gasket, not the intake. The head gasket can be easily reversed. The gasket should be marked FRONT, which should be placed to the front and up. This accounts for fore and aft as well as right and left. If it’s not, it can cause the kind of overheating you’re talking about. You’d like to think they’d have been sure to check this, but it happens. What Eric said about the spring in the lower hose can be a problem, but not so much at an idle, where you said the temperature really jumped up after a few minutes.
If new intake gaskets were placed with your new intake manifold, which I’m sure was the case, it’s possible that a blockage could be from a "punch out" at a water passage that didn’t release. I’d think this would be less likely and easier to spot than a reversed head gasket(s).
Obviously the only way to know whether it’s a reversed head gasket(s) is to pull the head(s), which is major. I hate to say it, but since the engine stayed so cool before this last teardown, this seems pretty likely. Best of luck, Let us know what you find to be the problem.

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