darkcambria

iTrader: (2)

Running Summit Point Shenandoah I had the engine let go. At the time it didn't seem too bad but I finally got the engine torn down. This was an untouched msm longblock with similar to a FM big enchilada on it. 57k miles total.

Here's the video of it happening on my warmup lap at 2:40. Not terribly exciting.

First thing I noticed when I pulled the valve cover was that the intake cam was just sitting there. The cam bolt was snapped. That hadn't been touched since the belt was done 20k miles ago (About 300 race miles as well).



Rod exited the bottom


Not much left of it



Put a hole through the intake side also


Wiped out the turbo housing



Head





Bottom end






So now its time to move along. I have a spare bottom end that's at the machine shop getting ready. Planning to build that and add an efr6758.

DeerHunter

Ouch! How much boost are (were) you running? Estimated torque?

darkcambria

iTrader: (2)

12 psi. I'd estimate around 210 lbs of torque or so, not crazy excessive.

borka

iTrader: (1)

that is some impressive carnage.

most all engine failures i see here are rods letting go. a $200 set of ebay rods would have prevented this.
Can be done in a weekend and $300 including new seals.

sshamrockk

Watching back the video, im willing to bet you over-revved it a bit. sounds like your keeping your foot to the floor between shifts letting it slam the limiter. Very bad habit as it doesnt shave time off your laps, just causing un-needed wear on the clutch, trans, and in this case, im willing to bet your motor. Probably stretched a rod and it got weak.

darkcambria

iTrader: (2)

It let go at around 6800 or so. I don't discount that the rods were likely already starting to go since this has seen a couple seasons of hill climbs and track days. I have my flat foot shift map set to 80% fuel cut and 60% timing cut which provided a very soft redline when flat foot shifting. I did log at a few events when I set that up and measured just about 4 tenths reduction in shift times. So for some of our hills where I shift 12 times or so it was providing a measurable drop in times.