C-2 Cooling Problem (HOT Item)

[Fred M.]

I realize this is an age old issue but one that I must bring up, again. My 64' Conv 327/300 still runs hot (210-250) even though the engine is stock to include the cooling system. I know the radiator has good flow, water pump and fan clutch is working OK, and my hoses aren't stopped up or collapsing. Even checked the diameter of the water pump pulley (7 1/2"), everything checks out. Has anyone every tried removing the fan and clutch and installing an electric fan? If so, what was the outcome? I've heard through various sources that a "Be Cool" radiator is the way to go. So again, anyone ever tried changing to a Be Cool radiator, and if so, how much cooler did your car run? Really don't want to change my car's original components but seriously considering some kind of a change.

Thanks in advance

[Patrick H.]

1964 Cooling Problem (HOT Item)

Fred,

Two thoughts,

1) What type of radiator do you have, and how old? "Good flow" doesn't mean much to me in a 30 year old radiator. Also, if you have a copper replacement, all bets are off.

2) Have you EVER replaced your coolant temp sensor, especially recently or around the time this all started? Anything other than the one installed originally are notoriously inaccurate.

I'd use an IR temp gun to verify your temps, and see if they match your gauge.

Patrick

[Donald L.]

Re: C-2 Cooling Problem (HOT Item)

Fred-Many threads have been about this subject but assuming the specs. on your car are right( timing, radiator flow, air flow through radiator ect) one must
ascertain that you are actually running hot.An accurate way would be to substute a mech. gauge.If there is a difference its probaly the sender.You will
need one with about 700 ohms impedence for good accuracy.(measure tip to ground at room temp.)Thinking about it you should measure your present sender first
and see whether it falls into an acceptale tolerance.Been there,done it.

Donald 31176

[Tom Merkel]

Re: 1964 Cooling Problem (HOT Item)

Fred - Pay attention to Patrick's question about 'copper core rads'. I learned some valuable lessons recently by thinking a CU core rad will properly cool a SB '67. It won't, and I'll let others tell you why. You'll need to go the AL route, and I assume that's what was stock in '64. It was in '67.

I couldn't get my SB to run @ 180 degs., and with this board's advice, I learned that my CU replacement rad was not providing sufficient BTU exchange, i.,e. didn't cool it down.

So, my first-hand experience says match the rad with stock, and (most likely) you'll need an AL one. Take a look at DeWitt's web site.

Good luck.

Tom

[Jack H.]

Add on

What Pat and others say about VERIFYING the accuracy of the dash guage is VITAL before you do ANYTHING in the way of troubleshooting!!!!!!!! This is a system issue and it 'takes two to tango' before you begin changing this/that. The 'system' consists of three components (1) temp sender, (2) gauge, and (3) the 'nest' -- wiring + characteristics of alternator/regulator. If any one (or more) of these items are out of spec, you can expect 'false' readings in the cockpit.

Absent a 'solid' secondary temperature measuring reference instrument (IR thermometer, mechanical thermometer), you can take the 'roadside' approach. If the coolant temp is REALLY reaching 250F, then I'd expect you to be reporting geysers of coolant and steam errupting from your rad cap/overflow system and you're NOT. This makes me suspicious of the cockpit/nest....

The human body is +90% water and you have self-protection instincts. You can use them to get a ballpark (roadside test) on what's really happening. With the engine hot and idling, lift the hood and being careful not to get fingers into the fan, grab the upper rad hose.

If you can grit your teeth and hold it for ANY appreciable time (even a second), I assure you the coolant temp is 195F or less REGARDLESS of what the dash gauge reads! If it's above this, your human instincts will NOT let you touch/hold and your reflex action will cause you to release IMMEDIATELY.

Once you know the 'truth' about the system coolant temp, you can begin to intelligently debug and, perhaps, avoid spending the GNP on replacement parts that weren't needed in the first place.... Let us know what you find, even simple things like 'grit' in the rubber gasket of the rad cap, a loose hose clamp here/there, can generate similar symptoms -- the 'hot Vette syndrome'....

[Eric H.]

Re: C-2 Cooling Problem (HOT Item)

Recently when the intake manifold was off on my midyear, I dangled the temperature sensor, while still hooked to the wiring harness, in pot of water while it was boiling. This way I could see what my temperature gauge was indicating with the sending unit at 212 degrees. I had two sending units to try out. One read 10-15 degrees high and the other was real close. There was about a 10 degree difference in the two 180 degree thermostats that I threw in while the water was heating up. Now, I know exactly what the gauge is indicating.

Do not do this when gasoline is present, and do not catch your car on fire!!!!

BTW, I went to the Dewitts reproduction radiator from a copper radiator about two years ago. The aluminum radiator functions very well in Houston summer conditions. Unfortunately, I do not do too well in those same conditions.

Ric

[Fred M.]

Re: '64 Cooling Problem (HOT Item) (Thanks to all)

All good advice. Definitely will verify the reading on my gauge before doing anything this else. BTW, my radiator is an original Harrison, dated 63K, not a copper unit. Didn't mention it but my thermostat is 160 degree that has been verified to be fully open at 175 and my coolant ratio is 1:1 so it can go over 212 degrees without boiling over. Thanks again to all.

[John H.]

Re: '64 Cooling Problem (HOT Item) (Thanks to all)

Fred -

In spite of what the radiator shops tell you, "Flow Tests" mean absolutely nothing in diagnosing the effectiveness of a radiator, except to indicate that it isn't clogged - what matters is its ability to reject heat through its plates/tubes to the air passing through it. If your radiator is indeed the original, you are close to a world record for aluminum radiator longevity, and it has probably lost 30%-50% of its heat transfer capability due to internal scale and corrosion becoming insulation on the interior plate surfaces, and there's no "reviving" an old aluminum radiator. Assuming your temperature verification (an I.R. gun "shot" of the thermostat housing works best) and correlation with your gauge reading is correct, it's radiator time, and there's only ONE choice for effectiveness and peace of mind - the DeWitts Harrison repro.

[Patrick H.]

Re: '64 Cooling Problem (HOT Item) (Thanks to all)

Agree. This is part of what I was trying to get at. I'd seriously consider removing your radiator and putting it on the wall as a car trophy like some of the items John has on his garage wall. After 40 years, it's time for a new one.

Patrick

[Duke W.]

Re: '64 Cooling Problem (HOT Item) (Thanks to all)

Good advice from all. Sounds like you have checked everything except the coolant temp sensor/gage accuracy. If it checks out, buy a new DeWitts. Also, reinstall a 180 degree thermostat.

As an original owner of a SWC I can assure you that they did not overheat when new, and the cooling system is very well designed. The key is the radiator. As John said, you're at a near record for an aluminum radiator, and a new DeWittes should last another 38 years. Resist the urge to save a hundred bucks with a copper replacement. They don't have the cooling capacity of the orignal design Harrison that DeWitts now produced.

Duke

[john pickens]

Re: '64 Cooling Problem (HOT Item) (Thanks to all)

An additional question-I have seen several threads recommending a 180 degree
thermostat for C2 both small and large block. Others prefer 160. Is the main issue lack of complete ignition of the mixture at 160? My 327/350 seems to run well with a 160 thermostat and gauge never elevates past 180-185 even with extended highway driving. Of course I haven't checked for plug fouling.Any other objective evidence to look for that would suggest a 160 is not acceptable?

[John H.]

Re: '64 Cooling Problem (HOT Item) (Thanks to all)

John -

In cooler weather when the cooling system has the excess capacity to bring the engine down to 160 with a 160 thermostat (which sets the MINIMUM operating temperature and has no effect whatsoever on normal operating temperature), that doesn't allow the oil to get hot enough to boil off condensates and blow-by contaminants, which allows acidic sludge to form faster in the sump. 160 thermostats were intended to be used with the old, old alcohol-based cheapo aftermarket anti-freezes that were sold in the 50's and early 60's as a low-cost alternative to conventional ethylene glycol-based anti-freezes. Your engine was designed to use a 180 thermostat, which will keep it operating at a temperature adequate to boil off contaminants in the oil. The only thing that determines operating temperature is the radiator's capacity to reject heat and the airflow through it; if an engine is truly "running hot" or "overheating", substituting a lower-rated thermostat will have no effect whatsoever on that problem.

[Duke W.]

Re: '64 Cooling Problem (HOT Item) (Thanks to all)

Agree with John. OEMs switched to 180 thermostats with the introduction of ethylene glycol antifreeze and this is the type you should use.

Also, GM over the years has always stated that the higher the jacket temperature, the lower the piston-ring-cylinder wall friction, which shows up as more power at the brake.

Duke