spf water/oil temps?

anchor2 · #1 (**permalink**) 07-14-2008, 05:17 PM

I recently moved to the Palm Springs area of Calif from the SF Bay Area. Due to the heat down this way during the summer water/oil temps have become a concern. I have been hitting 110c on the water and 105c on the oil.

I wanted to know what is a safe heat for water and oil temp?

csx wnab · #2 (**permalink**) 07-14-2008, 05:30 PM

think about it. 100c=212f .i think 110-115 or120 would be as high as you'd want to go. i have found that oil is usually 10 or so higher depending on your pick-up point

RedBarchetta · #3 (**permalink**) 07-14-2008, 05:46 PM

110C = 230F. Anything north of 105C and I shut down. I was just out your way in Palm Desert on Saturday...105F (with some humidity, which is rare for the low desert). It was nasty...I was watching a Mickey Mantle League (high school) double header and was thinking to myself, "There is no freakin' way I could drive my Cobra out here mid-day." Drove the AC'd C5 instead and I think my water temps peaked at 212-214F.

You may have to research alternatives, such as a high volume water pump with matching "balanced" thermostat, or maybe just a thermostat change (lower opening point) will help to circulate the water faster? Worst case is you need to think of more capacity (i.e. larger radiator), but I'm not familiar with anyone that makes one for our cars.

Lots of Cobra owners here from the Phoenix area...perhaps they'll chime in with ideas.

-Dean #747

csx wnab · #4 (**permalink**) 07-14-2008, 05:50 PM

just solved an overheating issue on a 513" SPF. drove it on a 100 degree day and water temp never reached 85c. go ahead, ask me how!

anchor2 · #5 (**permalink**) 07-14-2008, 06:16 PM

thanks for the info....ok csx talk to me!

xlr8or · #6 (**permalink**) 07-14-2008, 06:28 PM

105 on the oil is fine...

Sounds like some shrouding, better fan, or different coolant mix is in order.

madmaxx · #7 (**permalink**) 07-14-2008, 07:23 PM

I live in Houston, temp is always 95 - 99F with 70% humidity. My fan kicks on automatically at 90C so the temp never goes above that, if I overide and turn the fan on with the switch I stay at 80C on the cooling and 85C on the oil. I have sat with the sun baking down in stop and go traffic for 45 minutes before and with the fan on cooling water stayed at 80C. Roush 427SR. Are you sure your fans are comming on? One thing I admire about the spf is the detail behind the scenes such as how the opening around the radiotor is completley sealed so as all the air must pass through the radiator ensuring cooling.

Badger · #8 (**permalink**) 07-14-2008, 07:31 PM

Superformance Cobras have really excellent radiators (heat exchangers) so excessive water temp is seldom a problem , even in high ambient conditions. The trick is keeping the oil temp high enough to give maximum efficiency but still controlled enough so that oil temps don't exceed 300F.The important thing to remember is keeping the oil above 212F so that any accumulated moisture is boiled off reducing the chance of acidity and water lurking in the engine oil. Superformance oil/water heat exchangers are sometimes too cool for the street and not capable enough to handle track work. A seperate oil cooler may be needed for track work. The best are thermo-controlled units so the oil temp isn't too cool on the street. Badger

Bill Wells · #9 (**permalink**) 07-14-2008, 07:39 PM

It is very rare for a SPF to overheat . Those fans should come on between 90-92 degrees C and oil temp at that time will many times all of a sudden be higher than water temps . Once water temps come down then the oil temp follows .

I would double check to make sure your fans are in fact operating correctly .

A problem that pops up now and then is when someone has mistakenly reversed the connections on the fans and one sucks air in but one is pushing air to the front . They should both be sucking air from the front of the car into the engine bay .

I have seen a rare fan failure as well when only one fan was operating .

Also make sure you have a proper 50/50 ratio of water to antifreeze . Too much antifreeze will increase the engine temps. Boiling temp with a 50/50 ratio should be about 235 degrees F .

Thermostat could be bad too. Or the thermal fan switch on the radiator.

Also , remember the accuracy of these gauges can leave a lot to be desired now and then too - however, so seldom does a SPF overheat that I would check for the surprises first . Bill

csx wnab · #10 (**permalink**) 07-14-2008, 08:35 PM

Quote:

Originally Posted by anchor2

thanks for the info....ok csx talk to me!

you have got to be sure to burp the cooling system. this gentleman brought his SPF to me for overheating. always boiling over. after draining coolant and only getting 1/2 gal. water. changed thermostat to mr gasket 180. ( if it sticks it sticks open). and as i filled back with water i burped it throughthe thermostat housing. took almost 4 gal. we had a heat spell on test day. drove cobra 18 miles one way for alignment. 100 degrees. thursday afternoon.appt. at 3pm. drove back to shop 18 miles. never got above 85c. burpping system is key

PANAVIA · #11 (**permalink**) 07-15-2008, 05:38 AM

Keeping it cool:

I usually drill a 1/8" hole in the thermostat itself to aid in air bleeding / burping during coolant fill. Some say to drill larger, but I like the idea of maintaining the integrity of the 'stat. (and using a 180 stat)

http://www.siliconvalleyoperations.com/thermohole.JPG

--also I usually put in one of those prestone 5/8" coolant tees in the top heater hose line about 12"-18" forward of the firewall to facilitate burping. (OK so it doesnt look 1965..NBD)

-it is also important to note that the SPF heater controls have a block off valve inline with the heater hoses as a part of the heater control unit under dash. this should be open during a coolant fill.

The other (simple) thing to check is making sure none of the coolant hoses themselves have any aggressive bends that are restricting coolant, and if the expansion tank is properly plumbed in.

--after that it gets into engine ignition timing and engine health discussions.
(restarted timing generates heat)

On the water pumps I saw a flow-kooler brand recently and basically they had welded in sheetmetal blades in between the normal impeller fins effectively doubling the number of blades. this may be cool at idle (haha) or 1500 PM, but I wonder when it would start to cavitate at high RPM as opposed to the stock pump, or an edel.

the other way to pinpoint this down would be to grab an IR thermometer and see if there are any hotspots (IE no coolant).

--Steve

Randy Moudry · #12 (**permalink**) 08-06-2008, 04:51 PM

I am not familiar with how "burp " the system. The expansion tank on my Cobra is higher than the radiator and the thermostat housing is also higher. Overheating here in Phoenix, Help!

Badger · #13 (**permalink**) 08-06-2008, 05:22 PM

Randy...air entrapped anywhere in the engine will lead to over heating. The ideal thing is to install small air-bleed petcocks at your top hose on the radiator (or any other high spot in the system) so you can modulate and control the amount of water and air moving through that hose. quick and dirty you can just raise nose of the car as far as possible so the top hose is the highest palace on the system. Then crack that hose loose (just enough so water and air will flow out) and run the engine. when you get bubbles of air you'll know you've made progress. Badger