Oil pressure in right sweepers - Page 3 - Rennlist - Porsche Discussion Forums



Racing & Drivers Education Forum
Sponsored by:
Sponsored by:

Oil pressure in right sweepers

Reply
 
Thread Tools Search this Thread
Old 03-14-2017, 09:52 AM   #31
steved0x
Addict
Rennlist Member
 
Join Date: Oct 2013
Posts: 133
Default

The graph looks very good. What all did you do to your engine/oiling system to get these successful results? Is it a proprietary system?

Thank you,

Steve


Quote:
Originally Posted by CTS View Post
Well, you can see on the graph I just posted that the oil pressure changes only in response to changing rpm. If you look closely you can also see very small dips at 4900rpm. The Variocam solenoids steal a little oil pressure when they activate.

My previously posted graph shows the oil pressure going up and down wildly in response to G forces. This is what is happening inside most M96 or M97 engines when they are being driven hard.

It is not uncommon for the oil pressure to drop below 1 bar due to G forces. I accidentally and expensively proved to myself that the oil pump generates about .75 bar worth of air pressure even without any oil in the engine. So, if the pressure is below 1 bar there is essentially no oil being delivered to the bearings. The engine fails once it accumulates enough run time without oiled bearings.

These engines are remarkably tolerant of this situation. I cannot explain that.

Chris Cervelli
Cervelli Technical Service
steved0x is offline   Reply With Quote
Old 03-17-2017, 10:56 PM   #32
Bfan
User
 
Join Date: Jan 2011
Location: Near Reykjavik
Posts: 38
Default

I am curious to.
I am planing on plumbing two electric oil pumps to the heads. Pump the oil down into the deaerators in the sump. Kind of poor mans version of Porsches tandem scavenge pumps that run about $4000-$5000.
Ad this to a deep sump, improved horisontal baffles and an Accusump. Then monitor the result in similar way that you have been doing and see if I still get fluctuations....
Bfan is offline   Reply With Quote
Old 03-18-2017, 12:37 AM   #33
Schnell Gelb
Addict
Rennlist Member
 
Join Date: Apr 2014
Location: Los Angeles
Posts: 1,956
Default

This may help explain what tests were done later to proove the problem had been solved - but how?
Schnell Gelb is offline   Reply With Quote
Old 03-19-2017, 02:22 PM   #34
cbracerx
Addict
Rennlist Member
 
cbracerx's Avatar
 
Join Date: Nov 2005
Location: New Hope, PA
Posts: 1,140
Default

Chris did you add another scavenge pump and pickup? I had the TTP pump on my 987.1S along with accusump, X51 baffle and 996 Defoamers. It has held together for quite a while now (on the third owner). Expensive setup but cheaper than new engine.
cbracerx is offline   Reply With Quote
Old 04-03-2017, 08:48 PM   #35
cbracerx
Addict
Rennlist Member
 
cbracerx's Avatar
 
Join Date: Nov 2005
Location: New Hope, PA
Posts: 1,140
Default

Quote:
Originally Posted by cbracerx View Post
Chris did you add another scavenge pump and pickup? I had the TTP pump on my 987.1S along with accusump, X51 baffle and 996 Defoamers. It has held together for quite a while now (on the third owner). Expensive setup but cheaper than new engine.
So I recently heard that the third owner killed the engine "with slicks" but I don't know the exact failure mode. Still very interested in learning what Chris came up with!

EDIT: Looks like Chris has a solution: https://rennlist.com/forums/racing-a...mp-system.html

Last edited by cbracerx; 04-03-2017 at 08:57 PM. Reason: Added link
cbracerx is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Can someone explain how the Scavenger Pumps are set up? Hella-Buggin' 997 Forum 20 03-24-2017 02:03 PM
Oil Pressure Question Blue Chip 996 Forum 40 10-12-2016 11:19 PM
944 v. Miata (long) BeerBurner 924/931/944/951/968 Forum 44 06-29-2016 04:45 PM
Suspected Lifter Noise After Auto-x Run Devil Boy 997 Forum 11 11-23-2015 04:24 PM
928 Track data during high G turns (pics of gauges mid qualifying) mark kibort 928 Forum 44 11-07-2015 01:04 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -3. The time now is 04:30 AM.


Copyright © 1998 - 2017 Rennlist.com
 
  • Ask a Question
    Get answers from community experts
What's your question?
Send