Running Really Hot on the Track, I don't necessarily mean fast Options

[ww914]

Yesterday at Buttonwillow for our DE, the temperature was not all that hot, but I could only get in 2 laps at race speed before my CHT gauge started hollering at me. Here are the maximum values from yesterday:
Cyl #1 384 degrees
Cyl #2 357 degrees
Cyl #3 433 degrees
Cyl #4 402 degrees

I have the alarm set at 400 degrees, so each time it reached that temp, I backed off and let it cool down and finished each session with just a Sunday drive. Here's what I have:
My engine is a 2270 built by Original Customs
2 40 DLRAs:
150 main jets
180 air correction jets
34 venturis
9164.2 emulsion tubes
75 idle jets
50 pump jets

Both carbs are accurately sync'd and the a/f gauge shows between 13 - 14 all through the progression to WOT
The timing is set to about 30 degrees

I am running a stock cooling system with the thermostat and flaps working properly. I pulled engine tin to look for obstructions. None.

I am running a Sebtrab 8 x 10 oil cooler but my temps are over 220 when pushing it hard. No fans.

I am not sure where to go from here: alternate cooling, larger oil cooler, fans? Any suggestions would be appreciated.

[PotterPorsche]

Have you tried 180 air 160 mains or possible 190 airs 155 mains. Interested in the WOT numbers Also what venturis? 32mm i assume

[ww914]

Have you tried 180 air 160 mains or possible 190 airs 155 mains. Interested in the WOT numbers Also what venturis? 32mm i assume

I am running 160 mains with 180 A/C which got my WOT at redline a/f readings to around 12.0, through 34 venturis, but the cyl temps were still too high, especially #3. The oil temps were also running too high 230 to 250.

I am almost ready to re-install the engine with the few things I found wrong and with Tangerine Racing remote oil cooler kit. We'll see what happens.

[ww914]

Have you tried 180 air 160 mains or possible 190 airs 155 mains. Interested in the WOT numbers Also what venturis? 32mm i assume

I am running 160 mains with 180 A/C which got my WOT at redline a/f readings to around 12.0, through 34 venturis, but the cyl temps were still too high, especially #3. The oil temps were also running too high 230 to 250.

I am almost ready to re-install the engine with the few things I found wrong and with Tangerine Racing remote oil cooler kit. We'll see what happens.

OK, after re-installing the engine with some modifications that I will show you, I believe I have done everything I can do to lower my cyl head temps and oil temps. I think JP Stein may be right about these engines, one can only do so much. Oh, I am sure there is more I could do, but I am not sure I would be getting the bang for the buck. I have already spent a small fortune. Am I where I want to be? Maybe not, but I am definitely feeling better about my temperatures. Here is what I did:

When I removed the engine, I found a few minor things wrong that I corrected. I found my missing alternator cover inside the impeller. I also found that I had two blades missing. Corrected both of the problems.

I also installed the Tangerine Racing remote oil cooler kit, which eliminates the stock oil cooler and re-routes that air to #3 & 4 cylinders. You can see the plate installed where the air used to go down to the stock oil cooler.



I have positioned the oil cooler in several different spots in the rear passenger side of the car. None seemed to work better than others. Here is one of those positions:



I then added 3" hose and a NACA duct:





It was about this time, I installed Chris Foley's pressure relief valve. Didn't see a big difference, but Chris assures me that oil was now for sure going to the cooler and that is a good thing. I think all these little things add up to more improvement.

Next, I made an single inlet shroud to pick up most of the cooler air from the NACA duct. That helped, but I was still not satisfied, so I made a dual inlet shroud and picked up more air from the engine compartment, close to the new GT lid I bought. Here's the shroud on the workbench.



Here it is installed.



You can see the inline oil thermstat in the above left

To be continued.........