|
|
|
|
| Author |
|
|
Registered
Join Date: May 2006
Location: Durham, NH
Posts: 93
|
Oil pump issue?
Does the standard 964 pump have enough grunt on the scanvenge side to move enough volume to cool a 3.8?
Here's the details. The engine is a 1990 C2 3.6 upgraded to a 3.8 with the thin wall Perfect Bore jugs, JE 11.5:1 pistons and mild cams using the stock injection with a Cyntex chip. The problem I am running into is that it's running hot (250+) especially in 80 degree plus ambient temp. I'm running a B&B 24 X 5.5 X 2.5 front cooler with -16 AN lines but from some searching looks like I need a second cooler. Is anyone else using the Mocal t'stat? It appears that it could be restricting flow. Check the pic. Why would a company make such a thing? Although I have re-reouted the lines to allow larger wheels and tires looks like I will be plumbing the original t'stat back in there.  I have hood air ducting similar to the Elephant racing site (thanks for the detailed pics!) but this mod did not change the temp issue. I am still using the original 1973 oil tank .... I think those are all the bits, what have you guys found that works? Cheers |
||
09-20-2007, 05:39 PM
|
|
|
Registered
Join Date: May 2003
Posts: 3,346
|
The scavenge pump has to have enough capacity to keep the crankcase empty. Beyond that capacity will do no additional good. Did you cut an exit for the air from the cooler. I don't have an engine that big but I believe the guys in the GT classes have no problem with a single front cooler as long as the air can get through it.
-Andy
__________________
72 Carrera RS replica, Spec 911 racer |
||
|
09-20-2007, 08:50 PM
|
|
|
Registered
Join Date: May 2003
Posts: 3,346
|
Sorry I just finished reading your post about the air flow. Don't know what to suggest.
-Andy
__________________
72 Carrera RS replica, Spec 911 racer |
||
|
09-20-2007, 08:51 PM
|
|
|
Registered
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
|
Bob:
A 3.8 MUST have two coolers, period. If one wants HP & longeveity, strict control of oil temps is required and that means two coolers to maintain 180-195 deg temps. The Mocal thermostat is fine for the average wet sump oiling system but the factory Behr 911 ones are FAR better in terms of oil flow and protecting the cooler(s) from damage when cold. I would lose that Mocal unit in a NY minute. The '73 tank is small for these big (3.6 and 3.8 motors). We use a '74 or later tank with appropriate plumbing. Make sure your AFR's are OK since an 11.5:1 3.8 might be too lean for the software you have. Hope this helps a little.
__________________
Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
||
|
09-20-2007, 11:51 PM
|
|
