Topic: Operating Temperature


daoust    -- 08-20-2012 @ 6:46 AM
  I have a '47 Ford convertible. Original flathead V8. I drove it about 75 miles each way from NH to Boston yesterday. I have after-market dual temp gauges installed. I had Skip Haney recondition the water pumps this spring. I'm running a 50/50 coolant mix.

On the way down (leaving at 8:00 AM) she ran in the 190-210 degree range. The right side always seems run about 5 degrees hotter than the left. On the way back (at about 2:00 PM) she ran hotter; slowing climbing to almost 230 degrees by the time I got home. The ambient outdoor temp never got out of the 70s. When I got home, I let her cool and she took about a gallon of water to refill the system.

I had some over-heating issues last year. I had the radiator "rodded" and that seemed to help. I have a series of questions:

What should be the correct operating temp?

I'm thinking about have the radiator "re-cored." Will that help?

Is there anything else I can do to get her to run a bit cooler? I'd like to drive it without constantly worrying about overheating.

Any suggestions greatly appreciated.

David Daoust


doning    -- 08-20-2012 @ 9:11 AM
  On my '37, I'm running 160 deg. stats with a rodded out radiator and ( knock-on-wood ) my temp gauge stays right at 165. Doesn't manner if it's 65 or 95 deg's. outside. When I'm stopped at a light it'll start moving up but cools right down when I start driving again. Your block good and clean inside?


daoust    -- 08-20-2012 @ 9:29 AM
  Yes, we had the heads off this spring and it looked good.

David Daoust


Dale Fairfax    -- 08-20-2012 @ 9:36 AM
  There are several things at play here: Is your ignition timing where it should be? Too far retarded will make it run hot. Are you running a pressure cap? One that doesn't seat or of too low a capacity will cause you to lose coolant. It sounds like on your outbound leg the 190+ temp might have pushed coolant out to the point where you were low. On the return leg the lower coolant level would have contributed to even higher temperatures. Has your engine ever been apart? If it's original to the car and has never been rebuilt, chances are the water jacket is full of corrosion and foundry sand. Some folks have had success with a vinegar flush (in the car with lower hoses off and uppers disconnected from radiator).


supereal    -- 08-20-2012 @ 12:19 PM
  I, too, have a '47 convertible. When I bought it, the seller claimed that "the radiator had been rebuilt". However, you couldn't drive around the block before the gauge went almost all the way to the hot side.I did all the usual checks for head gaskets, block cracks, etc, and found that the radiator was the problem. I installed a new one and, even with the old style pumps, I can run in traffic on 100 degree days, and the gauge never goes far above the middle. On the hiway, it stays in the center. I use 160 degree thermostats, as well. A partially plugged radiator not only fails to cool properly, but the restricted flow will cause the top tank to overfill, hastening the loss of coolant, even with a good 4# cap. I've chased overheating for half a century in old cars, and found such problems as dragging brakes due to a bad master cylinder, the wrong belt that slips in the pulleys, etc. The "bottom line" is that a coat of lime in the radiator or block no thicker than a coat of paint can reduce efficiency by 20-40%. All the boiling and rodding of the core will not remove it all. When you add in the lesser efficiency of antifreeze, the result is more problems. Try running just water with some anti rust. Many advise "water wetter", but I've never seen much, if any, change.


daoust    -- 08-20-2012 @ 12:53 PM
  Thanks Supereal. I dont think the engine in mine is the problem either. I think I might be investing in a brand new radiator. I'm tired of driving around glancing at the temp gauge every few seconds.

David Daoust


Stroker    -- 08-20-2012 @ 1:39 PM
  In addition to the excellent advice already given, I'd use only distilled water as a basis for
your coolant of choice. It doesn't take much lime in "ditch water" to quickly affect the heat transfer ability of your radiator or block. I have used distilled water since the late 50's, and can vouch for the difference it makes in lime build up, as well as greatly reduced electrolysis on aluminum head/iron block combinations. It's not that expensive, and in my humble opinion it is well worth the trouble.


42guy    -- 08-20-2012 @ 4:29 PM
  I use 160 stats with 50/50 dist. water and Sierra(sp) anti freeze. Normal running temp with after market guages is 165. Going up a long hill which we have plenty of in the n Northeast, it may go to 180 and drops back to 165 when she levels out on the flats. I am using Speedway pumps for several years only because I didn't have 2 good cores to send to Skip.


daoust    -- 09-01-2012 @ 9:30 AM
  Had the radiator re-cored . Re-installed it today. Running 50/50 mix. Took her for a good run after installing and temp never got over 160.

Hopefully problem solved.

David Daoust


mdurhan    -- 09-03-2012 @ 11:45 AM
  Now, THIS is a valuable and beneficial thread on the EFV8 forum. Very, very helpful. "Much-o Grassy-Us". Mike

"Son, if you want to live to be as old as me.... then don't fool around with electricty nor married women." - Ol' Man Clayton Boggess, Arcadia, Florida


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