Monday, August 9, 2010
Wow, what a whirlwind weekend!! We haven't posted in a long time as the wrenches have flying at Team StimPack's new adopted HQ! We got the engine running on a craigslist turbo just before the event but after diagnosing bad turbo bearings, we replaced them and got glorious boost for 30 seconds! :-( Turbo bearings again... While we were rebuilding it we saw that it was damaged inside, but hoped it would last longer!
We had decided to switch to E85 fuel and when the turbo didn't work out we ran with it anyhow. How bad could it be?? Our theme was corn based this time to go with it. Subsidizes put to good use!
We had a good engine in the car that was running strong, and another as a spare heading into the race weekend, but it didn't work out as planned...
Drivers this time were Bill, Dan, Martyn, and Salah. Darryl, Cody, Bob B, and Tim C showed up to spectate and help. The details are as follows:
Our first engine was our low compression version that we had built to be turbocharged (but the turbo had failed last week). We were running E85 fuel with 440 cc/min injectors. I went out on track and the car was running pretty well but not as strong as normal (top speed was ~85 vs ~100). The car lost power badly after 20 min and I pulled in to find rod knock. Pulling the oil pan off we found the crank and rod bearings were toast. We decided our used spare bearings weren't good enough and ordered some from the part store. Engine swap #1 begins...
We finish the swap in 3 hours, go through tech and BS inspections, then head out on track with an hour or 2 left in the test session.
The car ran rough and overheated. In troubleshooting we switched to the stock 240 cc/min injectors. That didn't help and the car seemed to run rougher and rougher. After much deliberation we replaced the bearings in engine #1 and installed it 1/2 way that night before the lights went out.
On a positive note the theme is a huge hit! We boiled up dozens of corn cobs and gave them away, and popcorn and corn whiskey (Jack Daniels).
We arrive at the track at daybreak (6:00) and finish the swap by the 8:00 drivers meeting. Race starts at 9:00 and the car is running badly. It only liked being @ 4200 rpm at first, and soon overheated.
The head gasket had leaked at cyl's 2 and 3 and the engine had consumed it's water. This head was known to have questionable flatness (aka out of tolerance) so we pulled the other engine's head and installed that.
We changed the split oil pan gasket and tried push starting again.
This time the car lurched, spit something out the back, and barely ran. We told Salah to try to do some laps, but he got pushed back to our pit... Diagnosis: a valve retainer had let go and the rocker arm flew and dislodged the adjacent cylinder's rocker. Two bent valves and dented pistons.
So we then take the bad head over to the on-site machine shop and with Darryl's help get it machined flat. We rebuilt that engine and completed swap #3 last night. As a last step, we pumped out most of the E85 and filled the tank with gas.
More corn, popcorn, and 2 liters of Jack was dispensed and shared.
The car started really strong but 20 minutes in, bearing failure again. Total race laps logged: only 9! With 3 engines!
Dejected we packed up and most of us left after lunch. It took some restraint to not have the car crushed!
But, at the award ceremony, Dan and Tim C (visiting), we won the "Most Heroic Fix" award for our efforts! (picture at top of post)
Here's the full collection of Martyn's pics and video clips:
click here: Picasa photos