Frankie the Fink

I'm in the heat of Orlando with a 270HP solid lifter original '61 and, after adding a vacuum advance, removing the fan clutch and adding a spacer/better fan, (kept same radiator) and padding all the holes around the crummy fitting original fan shroud I run 160 deg to 180 deg with an occasional excursion up to 190 when stuck in traffic in 98+ deg weather. Car cools right down once moving. Before these changes the temp gauge would creep up to like 220 and I wasn't happy with that at all.

I DID have to block off the heat risers and fabricate some carb spacers to stop the fuel percolation issues on today's crapola gas.

Fawndeuce

I don't know if I totally agree with you on this. I have the bone stock 327/300 in my '62 with the original rad. It was running at 195ish at all times, city or highway regardless of outside temp. When I replaced the coolant, I saw that the PO had installed a 195 t-stat, so I replaced it with a 180. The car now runs at about 180ish, city or highway regardless of outside temp etc...



Paul

BarryK

that would be correct. when there was a 195º t-stat in there the MINIMUM operating temp would be 195º since that's the point that the t-stat will start to open to allow coolant to flow.
By changing out to a 180º t-stat your new minimum operating temp is 180º.
If your cooling system is in good condition and has the capacity to to cool efficiently enough you can pretty much keep the operating temp at or close to the t-stat temp which in your case seems to be.

On the other hand, if the cooling system was lacking, lets say a low BTU level radiator that can't cool well enough, airflow problems, or whatever, just because you changed out to a lower t-stat temp doesn't mean the actual operating temp will go down.
If your motor and the condition of the cooling system dictates that your motor wants to run at 210º for example it wouldn't matter if you had in a 160º, 180º, 195º or whatever t-stat.
The t-stat will only control the MINIMUM operating temp, not how high the actual operating temp may go up to

stratplus

I think I was wrong in telling you about my 180 degree reading. Because my tstat housing is chrome it may have given me a lower IR reading than it should have. After a long ride, I checked the intake manifold just after the housing in a couple of different places real close to the housing and it read 193, 192, 191.
So, based on this I will say that my new average is 192 and not 180.

SupremeDeluxe

Today is the first really hot day in Chicago this season, and my "new" 66 L-79 seemed to be hovering between 210 and 220 in traffic. Based on my experience with a prior L-79 and the big block 71 I had, this seemed a little high for my preference. While mostly correct, my car does have a copper/brass radiator which I intend to replace in due time. For grins, I looked in the owner's manual, and it states "During normal operation, gauge will indicate around the 210 mark. Hard driving, heavy traffic with stop and go, or prolonged idling in hot weather will produce a reading around the 230 mark."

Coves4me

One item that is sometimes overlooked is the type of gasoline we put in our cars. The carburetors of the 60's were calibrated with a stronger blend of gas that had a higher octane and other ingredients without worry of emission regulations. In most large metropolitan areas, such as D/FW, we are now forced to run "reformulated gasoline" that is "oxygenated" with oxygen molecules. As such, the gasoline runs leaner in the combustion chamber because the fuel contains oxygen designed to make it burn more efficiently. I know of no chart or article that can crossover metering jets in 60's carbs to what would be needed to run oxygenated fuel in the same carb today. However, through trial and error, I have found that a 5% to 10% increase in main metering jet size improves my engines performance, makes them cooler running and they seem to run smoother with less likelihood for hard starting and percolation. Unfortunately, gas mileage suffers with the increased jet sizes, but my engines do run cooler.
This advice is worth what it cost ya!! Good luck.

split1963

you and me both brother, in LA traffic I get all stressed out, I have installed a Dewitts big block rad with 17" brushless fan and new aluminum water pump, controlling timing with my Sniper EFI CD box and locked out distributer, 180 tstat, I am at 183-185 cruising with an EFI digital display and 190 in traffic. from what I am reading this post is 200 is ok, from my diesel truck forum they say outside temp plus 100 degrees is normal. the other way to look at this is freeway speeds getting hot not enough radiator, idle and getting hot not enough fan. Tstat is as they all say just controls how fast it warms up.

Bluestripe67

split1963, this is a 15 yr old post. Dennis

split1963

this has been tested with my EFI Sniper set up and is absolutely correct, simply enriching fuel will keep it cooler so will adding timing at idle so all those guys that remove the vacuum canister is ok for drag racing not idling at a stop light

split1963

LOL, the entire forum is nothing but I am overheating help!!! I finally got my temps under control, prob number one talked about topic

ChrisBlair

Old thread but I guess it goes to show that this is needed info. I don't read old threads top to bottom but when an overheat thread comes up, I like to mention 1) that the over-pressure in your cooling system means your boil over temp is around 247*F with a 15psi system, and 2) idiot lights became standard because concerned people "read into" their gauges too much and saw possible issues when there were usually none. Manufacturers addressed the problem but only alerting the driver when an issue was present.

If I have a car running 200* as the norm, it might make me look into what's going on but I wouldn't actually worry.