Running Really Hot on the Track, I don't necessarily mean fast |
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Running Really Hot on the Track, I don't necessarily mean fast |
ww914 |
May 10 2014, 03:51 PM
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#1
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914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
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 |
May 28 2014, 10:17 PM
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#2
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Member Group: Members Posts: 295 Joined: 10-November 13 From: Hayward CA Member No.: 16,628 Region Association: None |
Have you tried 180 air 160 mains or possible 190 airs 155 mains. Interested in the WOT numbers Also what venturis? 32mm i assume
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ww914 |
May 29 2014, 08:43 AM
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#3
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914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
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 |
Jul 9 2014, 09:05 AM
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#4
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914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
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......... |
ww914 |
Jul 9 2014, 09:25 AM
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#5
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914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
Here's another shot:
Here is the engine compartment inlet: Well that's the picture story, but here are the numbers. Before I did any of this, I made sure my A/F mixture was correct. After playing with main jets, I ended up with this: 12.0 at WOT 160 mains, 180 a/c jets and timing at 30 degs My #3 CHT was 397 degrees and my oil temp was 250 degrees with hard driving. This when I removed the engine to install the cooler bypass My CHT on #3 went down to 350 degrees, but my oil temp was still 240 - 250 degrees I then added the manifold to the front of the cooler Oil temp down to about 240 and CHT #3 was 348 I then added the other hose from the engine compartment with the dual inlet shroud and a pair of Spal 5" fans. At 70 - 80 on the freeway I stay at or below 220 degrees HAPPY WITH THIS!!! CHT #3 were still a little high at 360-375 but not bad for running in 4th gear at 80 mph. Foley's is not a big fan of oil cooler fans, but with these fans, it definitely brought my oil temps to an acceptable level. I am convinced that in order to take this car on the track for more than two laps, I would have to move the oil cooler to the front. Any other suggestions are welcomed, but right now for normal freeway driving and auto cross, I am good. I may play with the jetting a little more, but right now I think I will let all of this settle in. |
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