1966 427 425HP overheating

[Duke W.]

Re: 1966 427 425HP overheating

Well, just pulled the radiator. It is most defiantly original to the car and has been painted a few times. Also the core vents have seen their days. Many are bent in. I think here lies the problem. The car recently was timed and tuned when a complete ignition system was installed. K66, coil, distributer, alternator and voltage regulator. The fan clutch works fine. If need be, I will check the ignition wires. Thank all of you for your input.

Use a small LED flashlight to look down the fill port. Do you see deposit buildup at the tube ends? If so the tubes are probably internally clogged, too. You can have it evaluated at an old fashioned radiator shop if you can find one. They can pressure test, remove the side tanks and "rod out" the tubes to remove the deposits. Also check the tube end plates for seepage, and if necessary the end plate can be removed and resoldered to the core.

If you need a new core, Tom DeWitt is probably the first guy to talk to if you want OE tube and fin count, which should be in the AMA specs. Also, does is have the original clip on metal tag that has the radiator code and part number? If it's still there remove it for safekeeping and reinstall it when the radiator work is complete.

Duke

[Duke W.]

Re: 1966 427 425HP overheating

You can buy a core fin "comb" to straighten them out. Yes, you may need to re-core the radiator but I would explain to the radiator shop that you would rather flush and repair the original core at all cost in order to maintain originality if possible.

I'd like to know more about this "tube comb". I've always used cocktail toothpicks, which work pretty well and don't damage the fins, but it takes a bit of time to do a whole core.

Duke

[Duke W.]

Re: 1966 427 425HP overheating

Just a thought, try https://www.evanscoolant.com/product...mance-coolant/

My buddy has it in his 65 396. He can sit and let it idle in the middle of the summer and nothing happens. You need a complete flush/clean-out of the old fluid. The boiling point is 375+.

The coolant may not boil, but once the vapor pressure reaches 15 psi the pressure cap will release and expel coolant, and once the coolant temp gets over about 250F the engine could detonate itself to death.

Back in the 1930s when Sam Heron was head of the Wright-Pat Aeronautical Systems Division overseeing the "hyper" engine projects (a number of experimental "high performance" aircraft engines) one of the philosophies to achieve higher thermal efficiency was running straight ethylene glycol at 300 degrees F, but detonation proved to be the undoing of that theory. Most of these engines were fairly small - about 1500 CID - a bit less than the production Allison V-1710, but the old adage: " there's no substitute for cubic inches" was proved by the likes of the Pratt and Whitney R-2800 that went into production a few months before Pearl Harbor.

Toward the end of WW II all these projects were cancelled when it became clear that turbines were the future of aircraft propulsion. Chrysler designed a liquid cooled V-16 with a center power take of to mitigate torsional vibration issues and actually paid out of there own pocket to do an experimental installation in a P-47, but it didn't perform any better than with the proven R-2800. I don't recall the name of the chief engineer on that project, but he went on to design the original Chrysler Hemi.

One of the most interesting of these engine projects was the R-7750, a 36-cylinder liquid cooled radial that was basically four SOHC 2-valve inline fours on a common crankshaft. Design take-off power was 5000. Two examples were built and tested, and I think one survived and is owned by the Smithsonian Air and Space Museum. The engine was originally designed to power the B-36, but the 3000 HP R-4360 was substituted that proved to be grossly underpowered, which is why the four J-47 jet engines (modified to burn avgas) were added.

Duke

[Joe T.]

Re: 1966 427 425HP overheating

Took it to a radiator shop. The core had a lot of deposits on the ends along with many bent core fins. The tanks had been repaired twice. Cost to repair and re-core was close to purchasing a new BC66M which is identical to my original from DeWitt. I have a new one in the mail.

[Bob W.]

Re: 1966 427 425HP overheating

Joe I think that you made the smart choice. Tom DeWitt makes a great product.

Bob

[Duke W.]

Re: 1966 427 425HP overheating

Agree. Getting over fifty years out of an OE radiator even after a couple of repairs is a pretty good record. Use a 50-50 mix of Zerex G-05 and distilled water, change it at least every five years and that new DeWitts radiator will likely outlive most of us.

Duke

[Joe T.]

Re: 1966 427 425HP overheating

A big thanks to all of you for your recommendations and help.

[Darryl D.]

Re: 1966 427 425HP overheating

I'd like to know more about this "tube comb". I've always used cocktail toothpicks, which work pretty well and don't damage the fins, but it takes a bit of time to do a whole core.

Duke

Here you go Duke.

http://www.ebay.com/itm/like/292306807507

[Duke W.]

Re: 1966 427 425HP overheating

Thanks, Darryl.

Duke