Safe Engine Temperature while road racing

[coolcobra]

I got back from road racing my SVT cobra at the Streets of Willow event this past weekend. I had installed a temperature gauge with the sending unit located at the tapped whole on the lower driver side of the block. In normal driving the temperatue reads between 190 and 200F, with the Ford temperatue gauge in the middle.

While chasing two Shelby Cobras around the track for 15 minutes at 75 F outside temperature, and eventually passing them, my temperature moved up to 237F, while the Ford gauge was still in the middle. The question I have is, what is the maximum safe temperature while road racing? I have 480hp to the rear wheels, ported blower, 8lb lower pulley, and after market intercooler heat exchanger, and running Mobil 1 synthetic. I told my self that 250F was the max.

I am planning to join the Orange County Shelby Cobra club for the large track event at Willow Springs next month, with top speeds approaching 150mph, and what temperature should I stop running?

 

[Shadowgray03]

I got back from road racing my SVT cobra at the Streets of Willow event this past weekend. I had installed a temperature gauge with the sending unit located at the tapped whole on the lower driver side of the block. In normal driving the temperatue reads between 190 and 200F, with the Ford temperatue gauge in the middle.

While chasing two Shelby Cobras around the track for 15 minutes at 75 F outside temperature, and eventually passing them, my temperature moved up to 237F, while the Ford gauge was still in the middle. The question I have is, what is the maximum safe temperature while road racing? I have 480hp to the rear wheels, ported blower, 8lb lower pulley, and after market intercooler heat exchanger, and running Mobil 1 synthetic. I told my self that 250F was the max.

I am planning to join the Orange County Shelby Cobra club for the large track event at Willow Springs next month, with top speeds approaching 150mph, and what temperature should I stop running?

Well, at 500ft elevation and at a barometric pressure of 29.921hg water will boil at approx 211deg F, I sure as heck wouldnt like to see temps hitting 237F. Granted under pressure in a sealed system the boiling point will rise but you also have to remember that the temp sensor is not at the hot spot so there will be some cooling of the coolant before it gets to the sensor. In my opinion you should at least be running a larger radiator and higher volume water pump. The majority of failures these cars experience are heat related.

 

[ModsAway]

Well, at 500ft elevation and at a barometric pressure of 29.921hg water will boil at approx 211deg F, I sure as heck wouldnt like to see temps hitting 237F. Granted under pressure in a sealed system the boiling point will rise but you also have to remember that the temp sensor is not at the hot spot so there will be some cooling of the coolant before it gets to the sensor. In my opinion you should at least be running a larger radiator and higher volume water pump. The majority of failures these cars experience are heat related.

Actually his gauge sender IS in the hot spot of the engine as he stated the lower driver side tapped plug (between 7&8 cylinders). I have seen mentioned here that this "hot" spot runs approximately 20 degrees warmer than the stock temp gauge location.

And.... thats about all I can contribute as I to have been logging my temperatures as of late (digital diagnostics, autometer gauge in the mail).

I have seen upwards of 212 degrees in stop and go traffic (thanks to Fords fan settings) but usually run somewhere between 180-190 while at "moderate" or highway speeds.

Looking forward to hearing more comments on peoples running temperatures.

 

[Cheyne]

At the Runoffs last year I keeped putting the computer in to limp mode after 7ish laps at Mid-Ohio which was around 249F. We installed a Steeda/C&R radiator and drilled a 1/8" hole in the thermostat to get the car down to 230F which I considered okay. The air temp was around 80F. We were using water with water wetter. My shift point was 7200rpm and then engine rarely went below 6000rpm during the race, about 40 minutes. I had cooling problems all season once we got out of the cooler Spring air temps.

Cheyne

 

[Shadowgray03]

Actually his gauge sender IS in the hot spot of the engine as he stated the lower driver side tapped plug (between 7&8 cylinders). I have seen mentioned here that this "hot" spot runs approximately 20 degrees warmer than the stock temp gauge location.

And.... thats about all I can contribute as I to have been logging my temperatures as of late (digital diagnostics, autometer gauge in the mail).

I have seen upwards of 212 degrees in stop and go traffic (thanks to Fords fan settings) but usually run somewhere between 180-190 while at "moderate" or highway speeds.

Looking forward to hearing more comments on peoples running temperatures.

So is the sender in the block or the head? SOunds like the block to me which I still would not consider the hotest spot, albeit much more accurate than the stock location. The plugs are drawing heat out of combustion chamber into the head and the reported poor flow characteristics of the rear of the head would lead me to beleive the coolant temps in the head would be hotter yet than what is reported by the sender in the block.

As for temps in stop and go traffic I think some of the blame for high temps isnt just the stock fan setting but due to lower engine RPM and in turn less coolant flow due to slower water pump RPM.

 

[ModsAway]

Two good points Shadowgray03, I meant the "hot" spot that you can plug into. I wouldn't doubt some of the guys here can get a temp sender into the head somehow but I know I wouldn't try it. I will stick to the already tapped hole in the block.

Anyone else have specific numbers on what temps they are seeing while racing? Or on the street for that matter.

 

[V8Mustang]

subscribing

 

[HISSMAN]

I just did five 125MPH runs in a 6 miles stretch coupled with some stop and go at the end of the run, and temps did not get above 198 degrees, and theyaveraged 191 degrees with a low temp of 182 degrees. I have a Gords heat exchanger running 75% water, 10% Water wetter, and 15% Yellow prestone coolant in both the intercooler and radiator. I also have the LDC Chicago cooling mod.

Elevation 581ft, Temperature was 78 degrees.

 

[ModsAway]

Digital diagnostics or temp gauge HISSMAN? Where is the sender?

 

[HISSMAN]

digital.

 

[coolcobra]

Temperature during road racing

What was the time frame for your 5 runs? It takes about 7 to 10 minutes for the engine temperature to rise during the road race event to the 235F range. I do have a bigger heat exchanger for the innercooler, running about 50-50 water.

Also myblower is ported and should have less heat dissipation than stock, which should lower the heat load.

I am considering installing a Fluidyne larger radiator. Also, been reading up on the Evans cooling products. Anyone have an opinion on these two cooling mods?

 

[HISSMAN]

My engine was a full running temps when I started, and the time frame was about 5-10 minutes. I am not sure exactly. But as soon as I would let off and slow to 70 mph the temps was start to fall very quickly.

 

[ModsAway]

The cooling system for road use is actually quite good, high winds without massive load on the highway quickly equalizes the temperature. The trouble or difference with road/track racing is we never give the car an opportunity to cool down it is simply constant wide open throttle (including out of low speed turns) with no cool down time.

I found I would lift off early in the straights simply for that added cool down time...Not to mention it was easier on my brakes as well.