Through-bolt failure 993 Supercup
#1
Rennlist Member
Thread Starter
Through-bolt failure 993 Supercup
We had the cup car out at NJMP last weekend to blow cobwebs out in hopes of doing the August Thunderbolt race.
fourth session I was watching from stands as Forrest lapped, and was horrified to see the car disappear in a massive smoke cloud entering T1. He pulled off right away but there was oil on the track and all over the engine bay. We went home.
He swore he didn't miss a shift, and I didn't hear anything untoward, so really a mystery. Diagnosis came back today: a thru bolt failed, dumping 70psi oil through an open hole into the intake. All in all we got off 'cheap,' but an interesting failure, no? Last engine refresh was '08.
fourth session I was watching from stands as Forrest lapped, and was horrified to see the car disappear in a massive smoke cloud entering T1. He pulled off right away but there was oil on the track and all over the engine bay. We went home.
He swore he didn't miss a shift, and I didn't hear anything untoward, so really a mystery. Diagnosis came back today: a thru bolt failed, dumping 70psi oil through an open hole into the intake. All in all we got off 'cheap,' but an interesting failure, no? Last engine refresh was '08.
#2
Rennlist Member
Was it one of the lower ones that have the O-ring between the case halves? My motor has RSR case and I was told they were there due to through bolt vibrations (RS case had'm too, and I'm assuming Cup also).
Crazy thing was they were definately not used (at least from last few rebuilds) as I didn't even know they were there when I built motor because they were completely filled with case sealant. I just happened to see that step in manual for RS motor and curiosity and a little scraping revealed them.
Crazy thing was they were definately not used (at least from last few rebuilds) as I didn't even know they were there when I built motor because they were completely filled with case sealant. I just happened to see that step in manual for RS motor and curiosity and a little scraping revealed them.
Last edited by JoeMag; 07-15-2012 at 12:45 PM.
#3
I was in the purple Lotus Exige exiting the Lightbulb when I saw the smoke. The flagger at the tower had the red/yellow flag out and i could see the sheen on the racing surface.
Kudos to Forrestt for immediately pulling off the track and into the grass! Made for much easier clean up...
Glad to hear she will live to see another day!
Kudos to Forrestt for immediately pulling off the track and into the grass! Made for much easier clean up...
Glad to hear she will live to see another day!
#4
Rennlist Member
Thread Starter
I was in the purple Lotus Exige exiting the Lightbulb when I saw the smoke. The flagger at the tower had the red/yellow flag out and i could see the sheen on the racing surface.
Kudos to Forrestt for immediately pulling off the track and into the grass! Made for much easier clean up...
Glad to hear she will live to see another day!
Kudos to Forrestt for immediately pulling off the track and into the grass! Made for much easier clean up...
Glad to hear she will live to see another day!