Skip to main content

My '74L has always run pretty hot -- as I guess is the case with all Panteras -- but lately seems to be running even hotter. I live in Texas, so the problem has even become greater as the summer has approached. It has the twin fan conversion and, of course, the "Hibachi" cut-outs in the hood. I drove it last week (outside temperature was around 95) and, when I got in some slow and go traffic, the temperature increased from around 190 to the red zone around 220. Obviously, it may be that the gauge is not accurate, but it seems more likely that something else has changed that it is making the engine run too hot. Should I think about replacing the radiator, or are there some other things I should try before taking that step? If I want to consider a different radiator, can someone recommend some good ones that will solve my temperature problem?
Original Post

Replies sorted oldest to newest

There are so many opportunities for a stone-stock Pantera to overheat. Our cars are seemingly always marginal in regards to radiators, so if you're still running the original 32-tr-old unit, that may be some or most of your problem. I suggest you replace the stock rad with one of the more modern units available. Additionally, I've never gotten more than a year out of any thermostat since we bought the car. A thermostat that doesn't open fully will restrict water flow. The hookup between surge tank and the overflow tank is usually bad, which doesn't allow hreat-displaced water to be sucked back into the engine on cool-down. This means that the cooling system is perpetually low on water which will cause warm/hot running. Finally, if you don't run a top cover (between hood hinge and radiator top), you'll lose enough air coming in from the grille to make it run hot.
I was just thinking of radiator issues today too. In my stock Pantera, I previousely had a Hall Phoenix (the huge radiator), and the Mariha pusher fans and one sucker fan. With this in the car, it never ran above 190. However, it got a leak, and rather than fix it, I traded it for a new one at Hall, which was smaller (they no longer had the huge Phoenix radiator). They indicated that the new one was better. However, now I am sad I traded it because it isn't apparently as good in cooling (my opinion), beacuse I reach 220 or so on occasion, even with all the same fan set up. Never overheating, but hotter. Not to knock the product, but I wish I had kept the Phoenix radiator. If someone is offering one of the Phoenix radiators you may want to condider that (I saw one on ebay before).

In my Group 4 I have an aluminum radiator with two sucker fans, and this radiator is perfect, never running past 190, even with big horsepower and at a standstill. It says Ron Davis Racing on it, and even has what I believe to be his phone # on it (602) 269-9194. Probably the same as other Pantera vendors, but you may want to ask about this as an option if you are looking at radiators.

But as Jack says, overheating could be caused by many problems, not just radiator.
Jack and DOES 200, thanks for your responses. I do have a top cover, so need to look at some of the other things you've mentioned. I friend of mine recommended Griffin aluminum radiators, but some of the sites I've found that list Griffins don't include an offering for Pantera. I've e-mailed a couple of them, so hopefully they'll respond -- either with some info relative to availability of a unit for the Pantera, or with some alternatives.
Im running the lay down brass radiator/with two spal sucker fans from pantera performance in colorado.I love it!The car runs at whatever temp thermostat i put in it(ive run 160/180/195degree to see whatthe motor likes).Im also using a regular 302/351w thermostat with the bypas plugged.If you are using the same thermostat(different than the 351c thermostat) with out the plug or special waterpump your car will run hotter.this happens alot were the guy at the parts store doesnt know that a cleveland is different.good luck
The current 'hot' radiator is the aluminum Fluidyne made specifically for the Pantera. It weighs 17 lbs dry (compare THAT to your 60-lb brass Phoenix!) and can work either laid forward or standing up. A Flexilite shrouded dual fan assembly fits perfectly on the back side. 600-horse big-block Panteras use this combination and do not overheat. All the current Pantera parts vendors sell this combination, including your Host of this website. Be aware there are some pitfalls in trying to piece this combination together from non-Pantera sources, though.
Will sucker fans fit behind a vertical radiator? Should I use pusher and sucker fans? I have a 100 Amp alternator and am not concerned about electrical draw even at idle in a traffic jam.

Is there an easy way to ask all the vendors to send me catalogs, or just phone them all up and ask?

I truly appreciate the education received from this Bullitan Board. Thank you all.
I just had the same problem, and was thinking about replacing the radiator. However, before spending the $$, you probably should verify that your problem really is the radiator.

I'd see if you can borrow one of those IR heat guns that measure temperature and see what is happening. If you see that the radiator temperature is only 120 degrees on the intake, for example, then replacing the radiator will have no effect - you have a blockage before the coolant gets there. For example, your thermostat.

In my case, I was all set to buy a new radiator when I discovered that despite an overheating engine, the radiator was sort of cool. Turns out that debris (seals, gaskets, rubber parts) had come loose and was blocking coolant flow to the radiator.

Before spending money to replace a part, I'd want to be sure that I was replacing the defective part. Put another way, addressing the cause, and not just the symptom!

------------------
Charlie McCall
1985 DeTomaso Pantera GT5-S #9375
"Raising Pantera Awareness across Europe"
http://briefcase.yahoo.com/gt5s_1985
I had that same problem with mine. I took it to my parents radiator shop and found out that the radiator was plugged with silicone. Mine had the triple pass tanks. I took them out and replaced them. The problem still exisited. It ended up that the prior owner had put the wrong thermostat in it. After arguing with the parts man I got the correct one with the bypass cutoff. I have had no problem since then. Of course I havent driven it this summer beings the army has me in Iraq.
Mr Norman, shrouded sucker fans will fit on a vertical radiator if you choose, but dealing with the hose clamps and shroud mounts is brutal to knuckles. The only reason we lay the radiator forward is for convenience in installing such things.Of course, the removal of the pusher fans and their mounting sheet metal, and the severe shortening of the top cover do remove some weight.If you use a full shroud on the back, you'l likely NOT need a pusher fan in front. On my car and a few more, we're running two sucker fans with the AC condenser up in front of the radiator, and still don't need a 3rd fan.
Thank you for the explanation of theory on the lay down radiator modification, Mr. DeRyke. I've always thought it was for air flow maximization under the vehicle's chassis. I was contemplating this, but as my Pantera has new pusher fans, and has never gone over 120 even when my heart was beating close to 200, I'll wait to lay down the radiator until it is time to install new sucker fans with a shroud.

If I may ask your opinion on another topic, I hope you'll indulge me. I posted a 100 Amp NAPA alternator installation procedure, but new to this Bulliten Board, I posted it in the 'Announcements' section a week or so ago. The concern I have is it is VERY CLOSE to the engine block in the back, being about 1" thicker than the original alternator, also it is 6" diameter, and VERY CLOSE TO THE FRONT ENGINE ACCESS PANEL, and I put the smaller fan from the smaller alternator on for clearance purposes, so my concern is, in your opinion, is there any risk of overheating of this alternator, due to restricted airflow through it?

I love it, it powers everything with real authority at low RPM (which raises a question, are they safe at hi RPM, I don't know if this alternator was originally from a Semi Truck, RV, or what.) My car starts in under 1 second flat, even if it hasn't been driven in a week or two. But safety is always important.

Thank you for the dedication you have to answering everybody's technical questions. I will try to help with information when I can, and I think I can manage to get my 'New Topic Posts' under the right section from now on, with the exception of tonight's previous Post on Windshield Wiper Motor Overhaul. Sorry, I was surfing various Posts and wanted to contribute something helpful since it was raining this evening.

Respectfully,

Ron Norman
Post
×
×
×
×
Link copied to your clipboard.
×