65tripleblack

On an engine as old and non-stock as this, almost anything is possible. I've seen cases where a VERY SMALL leak in the combustion chamber at an exhaust valve due to someone having installed hardened seats will mimic a blown head gasket EXCEPT that it's VERY HARD to detect and doesn't always show up on a exhaust test of the coolant.

To the OP: As long as the mechanic didn't mess up your timing, then as stated, that is the only thing that he did that can affect low speed engine temp. Installing the puller fan will help you in the summertime but has no effect on your issue. IIWY, I'd lose the Torker intake manifold (single plane) and replace it with a dual plane like a stock one or an Edelbrock Performer. As you've learned, thermostat only governs minimum temp SO LONG AS THE HEAT REJECTION CAPACITY OF THE COOLING SYSTEM CAN MAINTAIN THAT TEMPERATURE. If you don't have a cracked or leaky head(s), then follow good advice and install a stock (stacked plate aluminum core) from DeWitts. They are expensive................call Tom DeWitt who is very helpful. He can sell you an alternative to the "showpiece" original Harrison reproduction which will do just as good a job, but at a more affordable price.

You have your work cut out for you.
Hang in there!
Joe

vetsvette2002

https://www.corvetteforum.com/forums...-jan-28-a.html
They are on sale too.

toddalin

Something to try that I haven't seen mentioned..., and YES I did this to my '64 and it helped when I had overheating problems.

Drill a small hole in the thermostat. I think mine is a bit smaller than in the video.

Nowhere Man

by that theory no SHP SB or any BB should have a over heating problem

65tripleblack

All water pumps have a bypass. Pumps used for SHP engines use an internal as well as an external bypass, pumps used for other engines have an internal bypass................that's the side where it mates to the block which has an extra hole.

Nowhere Man

so how does drilling a hole in the thermostat do anything

GTOguy

Drilling a small hole in the T-stat allows air to bleed through when you are filling the system, which allows easy filling without burping and making a mess. It's an easy way to top up your system in one shot, and eliminates air pockets.

Nowhere Man

I never had a problem or made a mess by filling the system while the engine is running

Surf454

Out of curiousity, Todd, what was your overheating issue? Was it puking coolant from the overflow hose like mine, or?

Also, did drilling the hole completely resolve that problem, or eventually did you need a new rad, or some other fix? Thanks.

Surf454

Appreciate your recommendation and encouragement, Joe!

I did a little research on your single plane vs. dual plane manifold and found that conventional wisdom (which it seems you are following) states single for racing and dual for the street. Also found this tidbit on superchevy.com:

As you can extrapolate from the above tests, it's easy to see that the manifolds perform pretty much as predicted by theory. A dual-plane simply makes more torque and power down low, but when the throttle is opened, the single-plane can eventually make comparable power (but it might take some work). Single-plane intakes can likely prove more powerful if the camshaft is revised to suit the intake.

I assume your suggestion to go dual plane was just the right thing to do for my driving application rather than a suggestion on a further fix for my coolant ejaculation problem.

MikeM

There is a bypass (around the thermostat in the right hand leg of the water pump. I'm like Nowhere. I don't see what drilling a hole in the thermostat does to improve filling, warm up, etc.

Duck916

It seems likely this is in the way the various hoses are hooked up in the vicinity of the expansion tank. Does the car not have a heater hooked up? That's how it looks to me.

One other thing I noticed which probably isn't causing this problem, but is associated with excessive heat at idle, is that the vacuum advance line is hooked up to the carb's ported vacuum source. It should be hooked up to the manifold vacuum source, which is the vacuum source on the driver's side front of the carb that's currently capped off (not the big one in the middle).

I'm not too far away from you (Santa Clarita), if you're still working on this, shoot me a PM and I might be able to drop by some time to help.

boxster99t

I flush my cooling system every 3-4 years, and that's how it's done. Very easy.

65tripleblack

That's the point. It doesn't do anything.

65tripleblack

Yes, it was. Nothing to do with your boil-over situation. It will make your driving experience more pleasurable further down the line.

The only way to check for gaps/cracks in the heads is a pressure test.

In the meantime, one way to check for how well your radiator is rejecting heat is to place your hand on the upper part of the radiator when the engine is HOT, and compare it to what you feel when you place it at the bottom when the engine is HOT. There should be a big difference top to bottom.

Surf454

Thank you, Duck, that's a swell offer, nice to meet somebody local that knows these cars! I will get the advance line hooked to the manifold vacuum source! Correct, heater core was leaking, and we live in such a warm place it wasn't worth investing to fix it. You driving a C2, too? (glad someone is!)

Duck916

Yes, I've got a '64 as well and it has an Edelbrock 1406 carb on it like yours. That's why I noticed the vacuum set up.

I'd be happy to help out some time. As others have said, these cars are pretty simple. Once you've spent some time with them, they are pretty reliable and easy to work on.

I'll double check the AIM set-up for a heater-delete car, as that's what you'll need.

toddalin

Typical boil over on shut down.

Between getting the radiator totally sealed around the shroud and putting the hole in the thermostat, I don't worry about boil over unless I sit in line and idle for over 1/2 hour (e.g., getting into a car show).

I do run a 160 degree Robertshaw thermostat, a 7-blade flex fan, and have a raised billet thermostat housing and the engine runs ~165 when moving.

If you've got the thermostat already, a hole is simple and you have nothing to loose by trying.

Surf454

Thanks, Todd. What's the function of the raised billet housing?

dunney

I'm going to guess getting it further away from the block to keep it cooler.

Sorry I'm late to the party on this one, but I tried to read all the posts and I think I can offer you some ill-informed advice.

I had a 66 some years ago, and as soon as I put an Edelbrock 750 on it, it started to overheat. I hate to say replace your carb (and possibly manifold), but the closer to original, the better the engine will run. I have another 66 now that's as close to original as possible, and it's been as cool as a cucumber for over 10 years.

If you haven't tried this already, have you flushed the coolant? I know it can be a little finicky sometimes if your 50/50 mixture sometimes ends up being 90/10 from constantly adding water and no coolant (or vice versa).

Did you try a different radiator? Maybe just buy one to try and save the receipt if you know what I mean.

Are you sure coolant is actually flowing? There was one savvy fella on here years ago (who probably shoulda been working at NASA), that installed a clear glass or PVC "pipe" in line between the radiator and the engine. He found that the coolant wasn't moving. I *think* the problem was a bad water pump. I had this happen to me as well. The radiator fan spins OK and everything looks fine, but the impeller inside the pump wasn't moving, so no flow.

My 2 cents are free. Good luck!