Roger60

67 Cutlass 330 hi comp a/c 4 core rad (recored at some point) std fan and clutch. No trans cooler. Heats up (210+) at stop light and when run with a/c on. Need tips on how to cool in 95 deg Florida summer heat. Thanks.

70sgeek

I'm here in Tampa, with a '72 cutlass 350 running a 2-core aluminum rad with 1" tubes, along with stock fan shroud, 5 blade Hayden metal fan (not a flex fan) with thermal clutch. Also running a Milodon hi vol water pump with 180 t-stat.

Runs 180 at idle and about 190 at idle with a/c on. At speed typically stays under 190


So at least consider upgrading to a good aluminum rad - there are companies making direct drop-in units that look factory and if painted in black radiator paint, just about pass for factory as well. Make sure your hoses are good and that your bottom hose has a coil in it to keep it from collapsing.


you might also want to try adding a wetting agent to your coolant, there are several that reportedly help drop your operating temps - I think Redline makes one that is fairly well regarded

Fun71

Does you car have a fan shroud? If not, install one.

Roger60

A guy at a car show told me about an aftermarket non-clutch fan that he uses with good results, but I never found out anything more. My thoughts were to go with a 4 core aluminum radiator. I've seen them with dual electric cooling fans. Would that be an improvement over the clutch fan? I don't have the room for an auxiliary fan. Set-up now is purely stock, but I'm not concerned with total originality. And yes, I have a fan shroud.

oldcutlass

While 210* is not terribly hot with extended idling if that's as high as it goes, please answer all of the following questions. We'll start with Kens, does the car have a shroud? What temperature is your thermostat? What temperature does the car run at cruise speed? What is your timing and what distributor (points, hei, etc) are you running? Where is your vacuum advance connected, ported or manifold?

Olds64

Eric and Ken's questions are all legitamate.

To answer your question about an aluminum readiator all you have to do is a quick search to find mixed reviews on aftermarket radiators. IMHO, staying with a stock setup is your best bet.

olds 307 and 403

A fan shroud is good idea, it will no doubt help. The fan is probably the 4 blade that came standard on a non A/C car, my 70S has one, it works quite well. I know a guy with a 403 in G body ran much cooler with the 4 blade fixed vs his stock 5 blade clutch fan. A 2 core aluminum with 1" or bigger tubes will cool just as well as the 4 core and let more air through.

joe_padavano

When these cars were new, they had a three row copper radiator, clutch fan, shroud, and didn't overheat in Florida or even at the GM proving grounds in Arizona. Heroics like aftermarket radiators, electric fans, etc, etc, were not needed. Figure out why your car runs hot. Have you verified that the vacuum advance is working properly? Have you adjusted for the lean burning effect of today's ethanol-laced fuel? Have you verified that the cooling jacket is clear of rust and sediment?

Roger60

To answer your questions: Yes I do have a stock fan shroud. A 5 or 6 blade ( I forget) stock cooling fan with stock clutch. When I bought the car, the radiator was clean and looked to just have been painted and it came from someone who would not have done that for show. I have accel pointless ignition, timing is set to specs, don't recall the exact advance, and the vacuum advance works fine. Without the air on, I'm running 190 (have a 190 thermostat and watch the gauge to see it open). Stop for a light and it goes to 195-205 then back down again when moving. Yesterday (90-93 degrees) with the air on, I was up to 210-220 when moving after about 5-7 miles. Almost home at that point. I use premium gas. 50/50 coolant. I've installed an overflow bottle, but it never overflows. I agree, it worked back in 67 in hot conditions, why not now. But then tech has advanced, so.....

joe_padavano

What does "tech" have to do with it? Again, what's changed from 1967 is that unless you go out of your way to run ethanol-free gasoline, your carb is running lean, which leads to overheating. Also, with a 16 psi cooling system, water boils at about 250 F. A short-term peak of 210 is normal, so long as the temp stabilizes there and doesn't keep climbing.

joe_padavano

All this tells me is that INITIAL timing is set to spec (which may or may not be the right number for today's gasoline). How do the mechanical and vacuum advance curves compare to OEM for your engine?

joe_padavano

By the way, here's an interesting article. Stoichiometric for gasoline is 14.7. E10 is 14.08. E15 is 13.79.

oldcutlass

For starters you don't need a 190* thermostat in Florida. Spin your fan with the engine off with your hand it should shoud move about 1/2-1 blade. When running it should draw a lot of air through the radiator. With that said, a thermostat begins to open at the temp setting so the 195-205 is normal. With the additional load of the a/c your temps also going to 210/220 is somewhat normal also. What I would try is hook your vacuum advance to manifold vacuum then lower your idle rpm back down. Make sure your carb is not on the lean side at idle, adjust to highest vacuum or rpm. Make sure your timing is correct, plugs and wires are good.

Fun71

And my 47 year old car doesn't overheat in 110º+ Arizona summers with a four core copper/brass radiator, factory clutch fan, and factory shroud.

Since your engine heats up when stopped but cools down once you get moving, I agree with oldcutlass that you should check your fan clutch. The symptoms indicate not enough air flow with the vehicle stopped, but sufficient air flow after it starts moving.

olds 307 and 403

A 160 or 180 thermostat as mentioned, buy a severe duty clutch fan to start, they do wear out. The Accel small cap electronic is the same distributor as my Mallory Breakerless, at least it used to be. The curve as they come should be close but more aggressive compared to the stock points curve, it shows 20 mechanical, all in by 2100 rpm

oldcutlass

I was under the impression he was running this:
https://www.summitracing.com/parts/a...0acc/overview/

olds 307 and 403

I assumed this one
https://www.jegs.com/i/Accel/110/52103/10002/-1

joe_padavano

If the car is running at 210 (which is NOT a problem), how does changing the t-stat change that?

oldcutlass

If he's using that one, then like you said the stock timing settings are N/A. Now we wait...

olds 307 and 403

It really doesn't make a huge difference but why have a Thermostat that opens at 195 in Florida? He says 210-220, which is a bit too warm for my liking. I say the severe duty clutch will make a big difference since he has a shroud and if it is the 6 blade fan.

Roger60

All good advice, thanks. Will check my clutch as I think it may be old or even the original. I have the 2010ACC breakerless point kit. I will move the vac line as well and see if there is a difference. 160-180 thermostat? I'll look into that too.

olds 307 and 403

A point eliminator, got it, a stock curve then. Start with the extreme duty clutch.

Roger60

Thanks. Have had no luck locating a severe duty clutch. Standard is the best I can find, at least online for a 67 330. What if any interchange is available? Thermal or non thermal? Tried Summit and Jegs, all the locals and even ebay.

AZ520

Desert Rat here, I have 110 degrees to deal with with, I run 160 high flow t-stat, high flow h20 pump, 4 core aluminum rad, electric ebay fan, hood spacers to vent heat from engine comp. In traffic in will rise to around 200, cruising interstate in the inferno at 2500 rpm runs 180. These old *** engines need all the help you can throw at them, especially if they are bored over, old rusty blocks and heads, higher comp. etc, etc.

olds 307 and 403

Go to Hayden's site. Joe will know if they changed the fan clutch, bolt pattern etc. I know it is available for later cars. You are right, only standard duty replacement, even for the 442 and 400 engine option for 67.
http://www.haydenauto.com/Online%20C...g/Content.aspx

76olds

I would choose the standard thermal clutch fan, 210-220 with a 195 T-stat isn't terribly high on a hot Florida day in the city.
As others mentioned a 160 or 180 would be optimum, my choice would be the 180 with the 4 row copper rad.

Eric

olds 307 and 403

Get a Robert Shaw 180 thermostat, a fan clutch for a 1970 Vista Cruiser with a 455 and either the Champion 2 core with 1" tubes or this one, assuming a 67 has the wider rad
http://www.autocityclassic.com/cheve...tor-sl-282-at/

oldcutlass

I would not jump in there with a new radiator yet. Connect your vacuum advance to manifold vacuum and adjust your carb accordingly. The Stant Superstat is also a good choice for a thermostat.

76olds

I agree with Oldcutlass on the rad.
If the fins are good, not loose or dry rotted, also not too much buildup around the tubes in the rad, ( Good flow ) I would keep the 4 row copper core as long as you can.
Continue to re-core it over the years if you can find a rad shop that will do it.

Eric

Roger60

Found that a clutch for a 69 350 fits, FYI. And a 180* Robertshaw. Eric, I respect your knowledge as always, and plan to move the vacuum to manifold as you suggested, and reset the idle. But I'm curious, how does that affect engine cooling?

oldcutlass

At idle and low load high vacuum engine states, the fuel charge is relatively lean and burns slower. You need the extra advance to complete the burn and maximize efficiency. A perk to manifold vacuum is a cooler running engine.

Roger60

Makes sense, thanks.