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My buddy has a very nice body off restored 62 with the 340 HP engine. He dident do the resto so he really doesent know to what the engine might have been bored out too etc. He put in a new "Be Cool aluminum radiator and its still running about 205-210 degrees. New clutch fan, checked that out. Replaced the coolent with the Dexcool, new thermostat. I can only think of a high flow water pump?? Are the cylinder walls to thin now?? Its been cool here in Massachusetts now of course, Im afraid it will boil over next summer. Any suggestions?? Thanks......Ray
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Re: 62' 340 HP running to hot
First thing is "is it really running hot" (what is--is) If the temp sender has been replaced, there is about a 90% chance that the gauge is simply reading incorrectly. check the resistance on the temp sender with the engine cold. it hould be about 750 ohms. Most replacements are less and the error is continued up the temp scale (or down the resistance scale...) you get the picture. Start there and see where it really is temp wise. -
New Coolant
Yes, what Bill said is dead on. First find out what the water temp really is. You might temporarily install a Stewart Warner mechanical temp gauge. If you've really got a problem get back to us.
1962 was a very problematic year for C1 temperature control with the solid lifter cars. The added displacement of 327 cu.in. required more cooling and at wide open throttle under certain temperature-humidity conditions the 916 radiator just wouldn't cool the engine. Duntov was dispatched to the Arizona proving grounds to solve the problem and came up with radiator side seals held in with Robbins clips. This improved the situation but didn't solve the problem. I have copies of his letters to GM Engineering requesting part numbers and paperwork to make the side seal part of production.
While at the unveiling of the Cunningham #3 car in New York last weekend I talked with a gentleman getting ready to market an new coolant. The product is a propylene glycol that boils at 325 degrees and freezes at 25 below. Tests show compatibility with aluminum radiators. He told me that tests were made with several chronic overheaters and the new coolant kept them cool under all operating conditions. He said that when passing a hot spot in the engine the coolant didn't convert to steam and was able to carry away the extra heat with no problems. This gentleman manufactures replica Cunningham C4R cars and says that the coolant is the ONLY way he can keep his engines cool.
I suspect that us C1 folks will want to experiment with this new product.
Dale.Comment
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Re: New Coolant
Ray, another vote to check the temp sensor. I have a 63 340hp and after indicating normal for months all of a sudden I started getting higher temps. Replaced it with a PEP boys and it showed 210+, did the old meat thermometer trick in the overflow tank and she was showing 170! The final solution was buying an old ,but working temp sensor from Chicago Corvette for about 35 bucks. It now reads about 170 , close counts as far I'm concerned , once in while we get lucky.Comment
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Re: 62' 340 HP running to hot
Ray - Ditto on all the responses above. There are also several great articles on the temp sender culprit in Restorer issues; Spring 78, Fall 89, and Spring 90. My 62 340 also showed hot, but never "felt" or sounded hot, performance-wise. For the July road trip to National, I put in a temporary Stewart Warner mechanical gauge/probe. Ran 170-190 all the way, except for 220-240 at construction gridlock on I-40 in Knoxville and never a sign of boil over. I got a good inexpensive base line to eliminate other contributors. Finding a reliable temp sender will be the challenge. Good luck......DickComment
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My 'hot' '62 solution....
I had all of the 'overheating' troubles with my '62/340 too, until Joe Calcagno told me to stick a meat thermometer in the o/f tank, run it 15 minues at fast idle and see what it REALLY is running at. PROBLEM SOLVED !! Then, I went to Radio Shack and bought a group of varying ( 10-8-5-3-1 ohm ) resistors. Put them in series in the circuit until the guage reads right. I soldered up right combination, shrink wrapped them, and made electrical fittings to fit the sender top and the wire plug. Take it out for Judging, put it in for driving. Easy.Comment
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Yes but
You get an accurate temp reading at that idle temp only! The resistor skews the rest of the range and the readings at other temperatures are WAY off. Extremely nonlinear!
Dale.Comment
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Re: Yes but
Try a temp sender from AutoZone. $5.99. Tell them you want one for a 19XX Vette. I've bought a couple and they read within 5 deg of what an infrared thermometer says the temp is.Comment
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Minus 5
for non GM aftermarket replacement!Comment
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Re: Minus 5
Rev, when you got done grading my car, I'd probably have a negative. At least I'd know how hot it was running. I have a Delco unit now that seems to read right, but the Autozone units look just like the Delcos and are priced right, and will do someone until they can find an accurate Delco unit.Comment
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Re: 62' 340 HP running to hot
Is the manifold heat riser moving freely? Made mine run hot.Comment
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