Oil & Water Temps

On most Panteras, the water and oil temps (once you get calibrated gauges, which will not likely be stock) will depend on what speed you're driving. For instance, on my street Pantera in 5th gear, the oil & water temps are within 5 degrees up to about 125mph, then the water temp stays at around 200 while the oil temp starts its climb. At 145mph, the water is still at 200 but oil is around 245. Faster = more of the same, so if you envision this as a steady diet, you need an oil cooler, and I suggest a water-to-oil heat exchanger. Air-to-oil coolers are a complete waste of time unless you are able to chop a large hole somewhere, with a well-designed NACA duct; the Pantera body is sufficiently slick, and the boundary layer is thick enough, that one cannot duct enough air to a rear-mounted cooler to do much good. A water-to-oil cooler will also require a better than stock radiator and a few other mods.

I don't have an Oil Temp Gauge, I have an Oil Pressure Gauge only. My Water Temp is 195 to 210. Goes to 220 when I'm really hot- rodding around. My thermostat is a 190. This data is from May and June 2003. At 80 mph to 90 mph steady freeway driving across the California border around Needles, CA at the turn off for Lake Havasu City, AZ, where it was really hot mid-May, like 100 degrees outside, my Pantera was running 195 to 200 Water Temp.

My cat's been out-of-service in July when the ambient temp has been over 100 degrees. It was in the low to mid 90's outside last month, out here. So, I don't have info for city driving (traffic) when outside temps are over 100.

Jack,
At what Oil Temp is it becoming a risk of blowing an engine? Is it alright to go to, say, 260 degrees for a few minutes with a stock 351-C with 43,000 miles? I don't wanna be buying a motor next month, but there's this stretch of deserted road....

Also, on that note, can a guy just really push the cat up to those speeds and then back down for a really short duration of time without causing too much temperature increase in the tires. My tires say Temperature B and some numbers followed by -AV. Also said Traction A and Max Load 462 Kg (1019 Lbs.) @ 35 psi. Don't wanna be answering questions from St. Peter soon....

A Corvette Guy was explaining that his tires could withstand certain speeds (125 mph? 140 mph? I forget) for up to three (3) minutes.

Not that I'd ever do anything like that, Go that fast and all....

My temps are similar to those seen by Jack, but at slightly lower speeds, since the 345/35/15 tires are a lot smaller in diameter. Where I live in Europe, speed enforcement is pretty minimal so I drive by oil temperature more than speed limit. If I want to cruise at more than 120mph or so, my oil temp starts to climb to 280... Backing down to 120 lowers the oil temp to perhaps 230.

This phenomenon is more rpm related than speed related - I'm sure Jack and I are seeing the same thing at the same rpm, but our speed is different due to tire size.

It takes perhaps 10 minutes of extreme high speed cruising for the oil temp to climb into the "red" zone, so 2-3 minutes ought to be ok, temp wise.

As far as tires go, my understanding is that to be rated a certain speed, they must be able to withstand continuous running at that speed. They can withstand short bursts at higher speeds, but not continuous running.

I don't think there is a definition for "short burst", it depends on how quickly the heat builds up. But your burst may turn into a burst of another kind that can have rather permanent consequences... You'll probably be fine, but how lucky are you feeling?

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Charlie McCall
1985 DeTomaso Pantera GT5-S #9375
"Raising Pantera Awareness across Europe"
http://briefcase.yahoo.com/gt5s_1985

OK- this is strictly a guess, but based on Antenucci's car at recent SS events, he has been able to make the engine survive 275 degrees oil temp for a few minutes, using full-synthetic 30-wt (I think) oil and watching his oil temp gauge like a hawk! In fact, befor Dennis got his Fluidyne water-to-oil heat exchanger, he actually drove based on the oil temp gauge- up to 275, then back off a few hundred rpm until the oil temp dropped, then pushed it again (all above 165mph for long periods). Problem is, oil temp senders are invariably in the bottom of the pan, so the oil in your crank bearings is very likely 100 degrees hotter! You are really pushing the limits here IMHO to do this more than a few seconds, as 30-wt that hot is as thin as WD-40! The big Fluidyne heat exchanger reportedly dropped his oil temp 15 or so degrees under the same conditions, which is OK for synthetic oil. I think I'd check all my rod & main bearings for copper color after one of these sessions, and replace them if I saw even a trace of copper.

I am curious about oil temps, I bought the white faced gauge kit from Hall and it included an oil temp gauge and sender. I asked Gary where the sender was mounted and his response was to remove the little allen plug above the fuel pump and mount it there in the block. I have seen other aftermarket kits where the sender mounts in the middle of the the oil pan drain plug. I am wondering if there is a differnce in temperature readings depending on where the sender is mounted? I have noticed oil temps near 275 at highway cruising speeds when the water temp is a steady 190 - 200. Any ideas on this?
thanks
Gary #06984

Something is extremly wrong! As I said, oil temps should be within a few degres of the water temp, and should track water temps at light loads. When the engine starts working hard (as, above 125 mph), oil temps go us while water temps stay about the same. Do you have a good, baffled 10-qt oil pan? Most that I've seen do in fact have a temp gauge boss. In any case, I would suggest moving the sender from the block to the lower part of the pan.That spot you're using is directly in the outlet of the oil pump, and while it may be a perfectly adequate place, no one else uses it so we have no point of reference to your readings.