05-15-2019, 06:34 AM
|
#1
|
Artist, 986S tinkerer
Join Date: Aug 2013
Location: Montreal, Canada
Posts: 1,821
|
My conclusion: tell me if I知 wrong
Just finishe the post mortem on my 3.2 engine that blew all to hell at the track. It seems pretty clear what happened and I think I know why. New video:
https://youtu.be/IrJl2uHrzaY
__________________
James now has: 2008 987S 6 speed
Crashed: 2010 987.2 pdk in speed yellow!
Sold to a cool racer chick: 2004 986 S
YouTube channel: the PORSCHE as seen by NewArt
www.youtube.com/channel/UCohdrH2xHTklM1thxk0KKOQ?
|
|
|
05-15-2019, 07:25 AM
|
#2
|
Registered User
Join Date: Dec 2015
Location: Denver
Posts: 866
|
Quote:
Originally Posted by NewArt
Just finishe the post mortem on my 3.2 engine that blew all to hell at the track. It seems pretty clear what happened and I think I know why. New video:
https://youtu.be/IrJl2uHrzaY
|
That's a very interesting analysis and breakdown of various layers of the engine. So, it sounds like the core problem was caused by lack of oil lubrication.
__________________
5280 Cruising @High Altitude
Seal Gray & K&N Filter
|
|
|
05-15-2019, 08:11 AM
|
#3
|
Track rat
Join Date: Nov 2006
Location: Southern ID
Posts: 3,701
|
Yep, oil starvation is the most common reason for an m96 track driven motor to scatter parts. High G left sweeper followed by a deep braking zone, and/or downshift over-rev cavitating the oil pickup.. Bye bye!
__________________
2009 Cayman 2.9L PDK (with a few tweaks)
PCA-GPX Chief Driving Instructor-Ret.
|
|
|
05-15-2019, 10:07 AM
|
#4
|
Registered User
Join Date: Dec 2009
Location: Orange County, CA
Posts: 1,848
|
Quote:
Originally Posted by Topless
Yep, oil starvation is the most common reason for an m96 track driven motor to scatter parts. High G left sweeper followed by a deep braking zone, and/or downshift over-rev cavitating the oil pickup.. Bye bye!
|
Also, another related failure could be caused when the con rod bolts stretch, which leads to a spinning bearing, loss of oil pressure...
It is assumed that the connecting rod bolts stretch by continuous high rpm's (metal fatigue perhaps..?)
|
|
|
05-15-2019, 10:47 AM
|
#5
|
Registered User
Join Date: Jan 2014
Location: New Jersey
Posts: 1,631
|
Interesting that your Mantis Sport deep sump kit 2 wasn't enough to prevent starvation, maybe it was rod bolt stretch?
__________________
Current: 2022 718 Cayman GT4, PDK bone stock (the dark side).
Former: 2003 S, 3.6 LN Nickies, ARP rod bolts, under-drive pulley, Fabspeed sport headers, Softronic tune, 987 airbox 987 motor mount, Function-First Sport motor mount insert, Ben's short shifter, Nine8Six projector headlights & center caps, ROW M030, stainless flexible brake lines, B-K rollbar extension & fire extinguisher mount, hardtop
|
|
|
05-15-2019, 11:46 AM
|
#6
|
Artist, 986S tinkerer
Join Date: Aug 2013
Location: Montreal, Canada
Posts: 1,821
|
I think that the problem was not caused by insufficient oil from the sump but rather blocked oil passages. I mention this in my previous video about the engine swap. See around minute 11:30. Threads of orange silicone sealant may have made their way into those little channels and holes that lubricate the crank. The extreme heat weakened the bolts and bang!
__________________
James now has: 2008 987S 6 speed
Crashed: 2010 987.2 pdk in speed yellow!
Sold to a cool racer chick: 2004 986 S
YouTube channel: the PORSCHE as seen by NewArt
www.youtube.com/channel/UCohdrH2xHTklM1thxk0KKOQ?
|
|
|
05-15-2019, 12:12 PM
|
#7
|
Motorist & Coffee Drinker
Join Date: Jul 2014
Location: Oklahoma
Posts: 3,665
|
Quote:
Originally Posted by NewArt
I think that the problem was not caused by insufficient oil from the sump but rather blocked oil passages. I mention this in my previous video about the engine swap. See around minute 11:30. Threads of orange silicone sealant may have made their way into those little channels and holes that lubricate the crank. The extreme heat weakened the bolts and bang!
|
I was wondering about that; blockage rather than an issue with a high G turn. Brad Roberts posted some data a while back that led me to believe that the high G starvation issue is not as relevant to the Boxsters as it is to the rear engine models. I may have misunderstood though.
Great videos, thanks for posting them.
__________________
I am not an attorney, mechanic, or member of the clergy. Following any advice given in my posts is done at your own peril.
|
|
|
05-15-2019, 04:49 PM
|
#8
|
Registered User
Join Date: Oct 2015
Location: Scituate MA
Posts: 870
|
Thanks for posting. You make it not so intimidating. I learned a bunch.
|
|
|
05-15-2019, 04:52 PM
|
#9
|
Registered User
Join Date: Oct 2015
Location: Scituate MA
Posts: 870
|
Quote:
Originally Posted by Gilles
Also, another related failure could be caused when the con rod bolts stretch, which leads to a spinning bearing, loss of oil pressure...
It is assumed that the connecting rod bolts stretch by continuous high rpm's (metal fatigue perhaps..?)
|
Can you elaborate on this please? Trying to understand. Thanks
|
|
|
05-15-2019, 05:17 PM
|
#10
|
Track rat
Join Date: Nov 2006
Location: Southern ID
Posts: 3,701
|
Quote:
Originally Posted by Gilles
Also, another related failure could be caused when the con rod bolts stretch, which leads to a spinning bearing, loss of oil pressure...
It is assumed that the connecting rod bolts stretch by continuous high rpm's (metal fatigue perhaps..?)
|
The fastest way to stretch rod bolts? Downshift over rev. Zing it past redline during heel/toe with no load on the motor a few times while entering a corner and rod bolts become stressed/stretched.
Clogged oil passages is another possibility especially if someone was *liberal* with sealant when replacing the pan or adding a deep sump. If that was the cause you could probably fish the oil passages and find it. Another telltale sign is the oil pickup screen completely jammed with excess sealant.
__________________
2009 Cayman 2.9L PDK (with a few tweaks)
PCA-GPX Chief Driving Instructor-Ret.
Last edited by Topless; 05-16-2019 at 10:26 AM.
|
|
|
05-15-2019, 06:24 PM
|
#11
|
Artist, 986S tinkerer
Join Date: Aug 2013
Location: Montreal, Canada
Posts: 1,821
|
Quote:
Originally Posted by Topless
The fastest way to stretch rod bolts? Downshift over rev. Zing it past redline heel/toe with no load on the motor a few times while entering a corner and rod bolts become stressed/stretched.
Clogged oil passages is another possibility especially if someone was *liberal* with sealant when replacing the pan or adding a deep sump. If that was the cause you could probably fish the oil passages and find it. Another telltale sign is the oil pickup screen completely jammed with excess sealant.
|
Possibly guilty of the first situation but definitely guilty of the latter. Many orange snakes found in the pickup screen and one can assume that there were smaller pieces that squeaked by! Did I mention how stingy I was with a better sealant on the new install?
__________________
James now has: 2008 987S 6 speed
Crashed: 2010 987.2 pdk in speed yellow!
Sold to a cool racer chick: 2004 986 S
YouTube channel: the PORSCHE as seen by NewArt
www.youtube.com/channel/UCohdrH2xHTklM1thxk0KKOQ?
|
|
|
05-15-2019, 07:29 PM
|
#12
|
Registered User
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,709
|
[QUOTE=Topless;595182][B]The fastest way to stretch rod bolts? Downshift over rev. Zing it past redline heel/toe with no load on the motor a few times while entering a corner and rod bolts become stressed/stretched.
This is the only reason I put aftermarket R&R rods in my rebuilt engine.
__________________
OE engine rebuilt,3.6 litre LN Engineering billet sleeves,triple row IMSB,LN rods. Deep sump oil pan with DT40 oil.
|
|
|
Thread Tools |
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is On
|
|
|
All times are GMT -8. The time now is 03:27 PM.
| |