Running Really Hot on the Track, I don't necessarily mean fast |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Running Really Hot on the Track, I don't necessarily mean fast |
ww914 |
May 10 2014, 03:51 PM
Post
#41
|
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. |
Randal |
May 10 2014, 06:34 PM
Post
#42
|
Advanced Member Group: Members Posts: 4,446 Joined: 29-May 03 From: Los Altos, CA Member No.: 750 |
Where is your external oil cooler? And how is the air currently extracted? |
ww914 |
May 10 2014, 07:18 PM
Post
#43
|
914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
|
Randal |
May 11 2014, 09:51 PM
Post
#44
|
Advanced Member Group: Members Posts: 4,446 Joined: 29-May 03 From: Los Altos, CA Member No.: 750 |
Where is your external oil cooler? And how is the air currently extracted? It is on the passenger side rear, as low as a dare to go. There is quite a bit of space behind it. I can't tell if the cooler is just hanging there or do you have a front shroud to direct funnel the air through the cooler? Plenty of space in back, but without capturing the air and forcing it through the cooler you are likely losing a bunch of cfm's that would help to cool the oil. Can you run a (big) tube from the front of the car to to the engine firewall in front of the fan? All the old guys used to do that and it works. I think Foley's car has one of those tubes. He could tell you how much it helped. |
ww914 |
May 12 2014, 08:46 AM
Post
#45
|
914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
QUOTE I can't tell if the cooler is just hanging there or do you have a front shroud to direct funnel the air through the cooler? Plenty of space in back, but without capturing the air and forcing it through the cooler you are likely losing a bunch of cfm's that would help to cool the oil. Can you run a (big) tube from the front of the car to to the engine firewall in front of the fan? All the old guys used to do that and it works. I think Foley's car has one of those tubes. He could tell you how much it helped. I did some further checking of a/f and cyl temps yesterday. With the original setup I ran the car pretty hard on a remote stretch of road to try to simulate the track. The first run showed this: 13.5 at redline #1 336 #2 291 #3 368 #4 339 This was with 150 mains and 180 a/c jets After changing the 180s to 170s, I got a better a/f reading, but temps were higher. Maybe because everything was just hotter by then. Second run showed: 12.6 at redline #1 343 #2 311 #3 384 #4 357 At cruise on the way home, after resetting the CHT, I got the following max CHT readings at 60 mph in 4th gear: #1 332 #2 300 #3 381 #4 341 Today, I am going to move my oil catch can and move my oil cooler down a couple of inches and rework the air scoop. My oil temps were running just a bit over 220 and my oil pressure was good. Tomorrow I will pick up some larger jets to play with and see what happens. As I think about other fixes, I have come up with these ideas: Installing Foley's remote oil cooler set up that eliminates the stock cooler and adds a deflector to get more air to 3 & 4. Adding a GT all screen deck lid. Installing a FAT fan setup with a 911 blower. Installing NACA air ducts on the side of the car to get more air to the blower. Comments welcomed. |
Lo-Fi Version | Time is now: 11th June 2024 - 07:13 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |