How hot is HOT?

Questions

When do the high temp excursions occur? i.e. during warm up, stop & go driving, after a long high speed (freeway/turnpike) drive?

When does the temp gage needle bounce from 160 to 230?

Which radiator is installed in the car? i.e. Hall Phoenix, Fluidyne, Ron Davis, oem, etc

Which thermostat is installed in the motor?

When is the last time you manually vented the radiator?

-G

I set up a dual temp gauge system because I too did not trust the factory gauge. The factory gauge sending unit is in the engine block and the backup gauge is in the pressure tank. Once every thing gets up to temp they read about the same now that I removed the resistors (2) from the stock gauge.

quote:

Originally posted by nemophoto:
I have a 1972 early "L" with about 60,000 miles. I bought it about five years ago and it sat in various mechanics garages until I found a good restoration guy to do just basic mechanical work, rather than a restoration. (If you live in Central PA, I highly recommend Kelby Steele at Steele Motors in Enola, PA.) Anyway, I finally got the car back on the road in late March and drive it a few times a week. I have to admit, the temp gauge often scares the crap out of me, especially on warm days. The cooling system has had mods: stainless steel tanks and pipes, high output pusher fans (I think I got them a while back from Hall). Still, the norm seems to be the mark before you hit 230. Is this the norm, or should it be running much cooler? At it's worst it creeps awfully close to 230. I also wonder if it's actually the gauge (and that all is fine) since I've sometimes seen the gauge erratically bounce between the "norm" and 160. I've also thought of using Red Line's Water Wetter. Anyone used that with any success. Thanks for the input.

Nemo

Don't trust the factory temperature gauge. The sender is not matched to the gauge on these cars for starters. Ford had a technical service bulletin that actually had the mechanics at the dealerships install a resister in the wire going to the gauge to reduce temperatures. I played around with some resisters and actually had my factory gauge quite close, but I never completely trusted it.

If your gauge is jumping around, you most likely have a bad ground or a loose connection somewhere. You should look at the gound to start with. Get a temperature gun and shoot the water outlet line from the engine and compare the temperature reading between it and the gauge. There is a shop in New Mexico that can take the Veglia oil pressure and water temperature gauges and install VDO? internals with a matching sending unit. The gauges will look factory, but at least the sending units will be matched. That will give you a good idea of how hot this engine is actually running during all types of driving conditions.

I tried Water Wetter years ago and didn't see much of a change in operating temperatures. It can't hurt to use it, but I wouldn't expect any miracles.

There are also the other items that others here are suggesting, such as making sure there is no air in the system. These are all very good suggestions being made by some very knowledgeable members.

1. Where is your temp sender mounted - it should be mounted in the block right above the water pump.
2. Get an Infrared Temp Gun and check actual engine temperature - I found my temp gauge was spot on, within 1-2 degrees as best as I could "eyeball" the gauge.
3. Run a 2nd mechanical temp gauge for peace of mind - stick it under the seat or someplace you can grab it if you need to check the veracity of the reading on your Veglia gauge. I did this with my 66 Mustang.

The ideal Temp Gauge would be the type with the Capillary tube ... basically a mechanical gauge more or less ... same with the oil pressure gauge if your really concerned about accurate readings.

Ron

Nemo, For me, the mark before 230 is my ideal spot. My IR thermometer shows between 192-195 at the radiator inlet. It is about the same out of the engine. I installed a new radiator a couple of months ago. Last weekend I drove for 40 minutes through neighborhoods, never getting out of second gear & usually less than 30 mph. Outside temp was 93 degrees, high humidity. I was trying to see if I could get it to overheat. My gauge never budged from the mark. The IR thermometer confirmed the temps. Returned home & idled for a good 20 minutes. Gauge actually dropped & fell below the mark.

Thanks for all the great questions and input.

The temps will often hover at (indicated) about 160 for a while. Generally with constant highway driving (i.e. - tach over 2000), the temps start to climb and stay there. This evening was cool and rainy (I was driving the car back from the shop where they were trying to sort out a stuck window and very dim/off instrument lights), and the car ran cooly for most of the 40 minute drive (lower speeds, secondary roads, not much traffic). I've never really hit 230 on the gauge but it's hovered very close at times. The bouncing is often momentary (downward), then settles back up.

The mechanic/restorer who worked on the car had noticed the high temps after running a while and used an IR gun on the engine and found it seemed to be "normal". It sounds as though the mistrust of the original gauge is pretty common. I even saw (maybe on Hall or PIM, saw replacement gauges and sending units for all the instruments. I was tempted to order the bunch, but part of me wants to keep as much of the original stock stuff that I can. The radiator is the stock unit. I'm trying to remember, but I believe it was flushed this winter as part of the work I had done. I really thought the 10-blad/high CFM fans would be the solution, but it sounds as though I may want to replace it at some point with a Fluidyne or some other. My wife is not hot on me owning the car (as with most women, a car is for transport from A to B, so I have to be judicious with how much and what I spend. Fortunately, it all comes from another account!

Do you guys think its' worth replacing the gauges and sending units? The guy who's been working on the car tries to save me money -- i.e. - not spend it if I don't have to. His feeling is, if the car isn't blowing steam or leaking after a drive, I'm probably OK. It seems so weird that this is such a consistent, notorious issue.

Bottom line is, if it isn't overheating you are ok. Sometimes having gauges just causes us to worry. If there are no leaks and it never boils over then drive it and enjoy it...

A gage that goes to zero indicates the measuring circuit is going "open" ... i.e. loosing contact somewhere.

A gage that pegs out erroneously indicates a short circuit or grounding issue.

An erroneous high reading indicates too little resistance ... no explanation

The first place to check is where the resistors are installed in the circuit.

The oem gage will be fine, if not perfectly accurate, once your electrical gremlin is resolved.

Befor you go crazy modifying the system or spending money on parts, make sure your Pantera has the correct thermostat & all the air is bled from the radiator.

They say "pusher fans" are less efficient at moving air than "puller fans". The Hall Pantera "Phoenix" radiator has the most "open" core of any of the radiators available for the Pantera; in other words, it is the least restrictive to air flow. This makes the Phoenix radiator the best choice for use with oem style "pusher fans". I am sure that is why Gary Hall selected that radiator in the first place.

The Fluidyne & Ron Davis radiators are better used with "puller fans" mounted behind the radiator. Aluminum radiators are light weight, but they are much more finicky about the properties of the anti-freeze, water and additives, they are more easily damaged by poor coolant chemistry.

The oem radiator is 40 years old, the reason it has survived 40 years is because its made of copper rather than aluminum. Copper radiators are far more resistant to poor coolant chemistry. Copper radiators are also repairable, no such luck with aluminum radiators.

-G

I put in the VDO gauges and stored away the Veglias. I haven't seen these kind of issues with them. The Veglias lie a lot and the sender is a Ford sender and the calibration to the Veglia is off a little.

Symptoms you are describing are associated with a bad thermostat, or a thermostat on it's way out. It is the fuseable link to the system, i.e., cheap. Some only last a couple of years. I'd change it first before I did anything else and see if it fixes the issue.

I'd recommend running a 180 thermostat. It's a compromise between 160 and 192.

If you check the thermostat, verify that you have the unique Cleveland style in. There are still mechanics who don't know the difference and will swear to you they put the right one in there.

Also, if the water pump was changed, there are some like the Wieand which do not have the bypass hole in them by design. You do not want that in the Pantera.

You want the bypass. Do not mess around with modifying the original design system. It is strange but does work the way it was designed.

Capacity of the original radiator is fine. It can be improved by making it a true crossflow but that isn't imperative. It will work as originally designed and built.

There was a design change on the goose neck in the system from the early cars. The early design was causing some issues like this.

Inexplicably some Panteras have more problems then others in bleeding the air out of the system at the radiaor. I wouldn't be shocked if your car was one of them. Sometimes the only thing you can do is stand the car on its nose to bleed the system or install a bleeder near the radiator. Wait till you hear the air hissing out. You'll be shocked.

If you are running the original steel under car radiator "pipes" it isn't impossible for them to have internal corrosion and be flaking off rust that is working like a flapper valve in the radiator. It's not a bad idea to change them out to the stainless.

Got my cars 40 years. Married 26. Your call on the lady or the tiger? By now, she should be wise enough to leave you and the Pantera alone? The cars look as good as they did 40 years ago and can be restored. She doesn't, and can't. Food for thought?

The 'normal' water temp for a nearly stock 351-C in a Pantera at cruise speeds is 200-210F; changing to a lower rated thermostat will do nothing, in my experience. The '71-'72 gauge is 0-230F while a '73-up gauge is 0-260F and is a 'stock-upgrade' that often reads closer to true temps. Most of the problem lies with the sender; the oil pressure sender is similarly 'off' so your pressure will often show far lower than is true. A poor ground on the gauge(s) or a particularly inaccurate sender(s) will give the above problems, as will a worn-out thermostat. As Kenn said, I'm one of those who gets about 1 yr out of any given thermostat.

Another cause of climbing water temps is a mis-timed ignition. If your mechanic wasn't specifically looking, the 40-yr-old harmonic balancer on the crank may have slipped it's position so the timing mark shifted. If he then adjusted it to the mark, the engine can be as much as 10 degrees retarded, where it will run hot.
Much the same thing happens with over-aged timing chains- the chain wears due to the easy high rpms possible with a 351-C along with the very heavy valves. The result is an engine that has it's whole valve train retarded (relative to the crankshaft) on acceleration, and advanced during deceleration- exactly opposite of what you want. This also induces engine heating. An average 351-C gets roughly 20,000 miles out of even a heavy-duty timing chain, and less from a stock chain.

If you do everything suggested above and the car still overheats (and by that I mean it spits coolant out the overflow, since your gauge is not trustworthy), the ONLY fix is a new, bigger radiator along with much larger sucker fans mounted in a shroud, replacing the stock toy pusher fans. I have tried absolutely all possible upgrades to control water temps in our '72 L, and replacing the rad' plus fans were the only ones that actually lowered cruise water temperatures. There are good reasons why most Panteras are not stock....

Correct thermostat.

quote:

Originally posted by Marlin Jack:
...Not One Word Mentioned about the 'Restrictor Plate'?

We all left that for you. We knew you were watching.

Hello

I have screwed-tops on my 2 water tanks on the car (they are labelled from BMW) ?
Did you ever see that ?
regards
Philippe

I have seen this debated before. But, What about hood vents?

quote:

Originally posted by captaintobeys:
I have seen this debated before. But, What about hood vents?

I saw about a two to five degree temperature drop at idle after installing hood vents. At the time I was using VDO gauges in the car, so the temperature readings were accurate.

When my car had the stock radiator and fans in it, I removed the grills in the hood cut outs and put two odd looking deflectors in front of the cut outs. I saw this done on a Sebring car so I decided to try it, it only took a few minutes. It lowered my at speed temps about five degrees which I really needed. It creates a vacume and pulls the hot air through. Now, my car is fully moded and runs very good and very cool. I have full cooling mods and ice cold A/C, I couldn't be happier with it. Custom radiator from McCullach (sp), Only one single sucker fan 16" spal, cooling tubes, I did the cooling tank mods, flowcooler pump w/anti cavitation plate, I retained the vortex generator on the hood and I never, never see more than about 185 degrees, even when it's 95 outside.....

I am in SW Florida. Could you post or send me a picture?

I admit, it's kinda' ugly....

But, at the time I really needed the temp drop it provided.... This was a quick job just to test it's performance. It worked so I just left it. I don't even need it anymore but it helped my stock system cope...