When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Coming out of turn 5 at VIR during DE, i hit the Rev limiter in 2nd gear. Shifting to 3rd I immediately hit it again, the into 4th and the engine just felt low on power. I limped around to the south paddock exit and came back to the trailer. Check engine light on, plenty of oil pressure, temp at 180. It didnt behave badly on return, but I was taking it slowly. I shutnitndown andd.let it sit for a 1/2 hour. Went to fire it up ant it wouldn't start. So I winched it on and headed home.
I got nit to start after taking it off the trailer only to hear the telltale sou d of what in a normal car would be lifter ping. But I'm pretty sure this is goi g to be dreaded bore score. Interestingly, I had done a cam deviation reading after each of my first 2 run groups and got 0 and .2, well within spec. But I have been throwing CEL regularly lately since going to 200 cel cats.
This week ill dump the oil and pull the pan and see if it is scored. If it's I'm pretty sure I'll go the renn27 swap. I can't see dumping another 30k into a standard LN rebuild just to still worry about oil starvation, AOS, IMS, etc.
From the scenario you gave my guess would be oil starvation/thermal runaway resulting in a spun rod bearing......To late to worry about oil starvation , AOS deficiency ect now...
Just wondering what preventive measures if any were done, what oil and weight, how many miles on the engine.....
A good Cub Scout always prepares for the worst but hopes for the best....
It could be a rod bearing, I'll find out this weekend. Regarding the motor prep. Oil change the day before the event 8.5q of 5w--40 mobil1, new factory AOS within the past month along with a new water pump and all new antifreeze. I had just completed a tip to manual swap and did a lot of maintenance while the engine was out.
“Oil change the day before the event 8.5q of 5w--40 mobil1, new factory AOS within the past month”
Well there you go! Skip/PT3 seems to be on the right track… as he often is.
Porsche newby here... but, are you saying his choice of motor oil stands out as the obvious reason for this gentleman's problem. Thanks for taking a minute to educate me.
Porsche newby here... but, are you saying his choice of motor oil stands out as the obvious reason for this gentleman's problem. Thanks for taking a minute to educate me.
He is making assuptions on the system as a whole and taking it on the track. Its been shown that running the stock aos and the updated lower oil level can allow for oil starvation. A deep sump can help but most data shows that having the Uaos systsm in place allows u to run up to 2qts more then stock without hydrolocking the motor. At this level the oil pressure drops around turns was significantly reduced in frequency and severity.
I too have a feeling he hurt the bearings on the bottom end.
Agree with the guys. I run 12 qts of oil in my 3.6 on the track and street. That's 3.5 qts more than your standard 8.5 qts.
+2 qts from a 2qt deep sump
+1.5 qts from the UAOS track
Not only do you get more oil to mitigate oil starvation and oil pressure drops, but the UAOS Track can effectively process all this extra oil without the fear of hydolock.
Whereas a brand new oem AOS can't even process 8.5 qts effectively. Hence the issues that develop from the oem AOS on the street and track.
Porsche newby here... but, are you saying his choice of motor oil stands out as the obvious reason for this gentleman's problem. Thanks for taking a minute to educate me.
^^Not in so many words, but yes - DeJeeper articulates it well. Obviously you never really know 'til you tear the engine down but these guys have enough experience to make educated guesses...
He is making assuptions on the system as a whole and taking it on the track. Its been shown that running the stock aos and the updated lower oil level can allow for oil starvation. A deep sump can help but most data shows that having the Uaos systsm in place allows u to run up to 2qts more then stock without hydrolocking the motor. At this level the oil pressure drops around turns was significantly reduced in frequency and severity.
I too have a feeling he hurt the bearings on the bottom end.
Originally Posted by dporto
^^Not in so many words, but yes - DeJeeper articulates it well. Obviously you never really know 'til you tear the engine down but these guys have enough experience to make educated guesses...
Forensic Failure Analysis of engines and their related systems has been my forte for 50 years for manufactures like FoMoCo, Mitusishi,and Porsche ....and on multiple Racing Categories......Studying the avenues of Forensic Failures will correlate to the avenues of avoiding the failures...I've gotten to the point that i don't need to examine the failure in person I can do it on the Internet or by phone....lol
Hindsight is 20-20 .....
Most all of these failures can be avoided by a few simple bolt-ons and following guidelines, 100% can be avoided by Instrumenting and Logging conditions and taking the necessary steps....
OP Im sorry for your failure, I hope you don't mind us using it as an example of what not to do.......
Last edited by Porschetech3; Nov 13, 2024 at 08:51 PM.
Sorry to disappoint you guys. But the car being g hard to start and thr ticking noise seem to be related to the crank position sensor and interfacing with the flywheel. Waiting on sir tools to ship me the engine support to pull the granny out and figure out why is happening. But the CPS isn't supposed to have a groove in it.
this was a used flywheel I installed for rhe tip to 6mt swap.
Sounds like borescore
