After going flag-to-flag for 2 races with my 95 tbird, I was feeling pretty good about my team's ability to field a car that would last this past weekend. As you folks can see from my Splitport DIY and other threads, I did what I thought was a pretty decent amount of testing. This included both high RPM runs down the hwy (it's still street legal) as well as even a 100mi rt commute to my office.
Well, life threw me a curveball here and after a mere 17 laps, one of my drivers came in with the engine "making popping noises like one of those kid's lawnmower toys". Nothing overheated and until the noises came up, we didn't have any oil pressure issues. All my datalogging had shown a nice safe ~11.5 AFR even had max engine load across the RPM band.
The engine had lunched itself.
- One sparkplug was completely lunched.
- We had oil being pushed into the intake via the PCV valve (massive blowby)
Upon removing the engine (we needed the oil pan for my spare), we found:
- one of the piston heads had been turned to little metal bits so one of the heads might be bad. [updated]
- The rings were thrown about and all over the crank like onion strings.
The lower engine was a goner. Well, we made the decision at that time to attempt an engine swap as I had the SC engine from the donor car that gave us the transmission with heads and lower intake manifold ready to install. We got the engine mostly put together with parts taken off the blown engine and got it installed. However, in the process of trying to mate it to the transmission, the transmission fell and pulled out of hydraulic clutch line. Well, that was a part I didn't have a spare of so our race weekend was finally over at noon Sunday.
Potential Causes of Failure:
- Only reason that the piston could die that way would be detonation.
- Block was bad to begin with. It came with my car and had a rebuilt tag on it. Someone decided it was a good idea to set the ignition timing at 30 degrees adv flat (jumper to tell the ECU to advance timing removed). Engine refused to rev beyond 4K. Perhaps something was out of spec and a mechanic for my friend decided this was the best way to keep this car running as a commuter car.
- Perhaps two of the injectors were dirty and the engine went excessively lean at the sustained high RPMs..
- Did we suck a valve?
We won't know more until I pull the heads. I'll post pics.
* Get a transmission jack.
* Get/keep a clutch alignment tool (this will help tremendously if we ever need to swap clutches)
* Get the injectors reconditioned before use
* If we are going to only race once a year, don't just bring a spare engine and expect to swap things over -- bring a fully dressed spare engine already mated to a matching transmission. With our skill level, we can swap an engine/transmission and still leave time to actually race but trying to swap/mate everything together at the track is beyond our team's current skill level.
* Beat the hell out of my co-driver to ALWAYS take the inside line around hairpins or they forfeit their session -- especially if these occur after a high-speed section. With 179 other idiots on the track, people WILL be playing bumper cars to make it around these corners and I'm sick of being the car they bump off of because we can actually hold our lines vs. skidding out drift style.
What's next for "Myopic Motorsports?"
Well, the judges liked our theme (Bozo Texino) and our shopping cart/snowboard rear wing so will probably keep it. It looks like I have a deal with a guy for a 93 Tbird with a 5.0L engine in it and a bad AOD transmission (don't care).
Since I won't be racing for another year, I plan to:
- Swap over to a 5.0. We can keep the 93's stock computer (doesn't control the trans) and the stock harness. This may cause further problems (like MadMikeyL's diff cooking and need for Cobra front brakes) but it'll be fun.
- Bodywork. Despite being on the track for only 17 laps, a punk driving a Pikachubaru managed to bang up our side. Sigh.
- Sell off my Splitport/V6 parts. This will be a great opp for you folks wanting a power upgrade to your V6 but not sure how to start. As you can see from my Splitport DIY (http://forums.tccoa.com/showthread.php?t=141039
), I've done a lot of homework here. According to my project log, 148.75 hrs (compared to 262 for my initial racecar prep and 130 for the manual transmission swap).
- Disassemble and sell off the non-engine bits from the 93 Tbird 5.0. The body/interior looks pretty nice so I'm hoping you folks can upgrade your existing cars and while helping me defray my racing expenses. Stay tuned.
- Fix the 2nd gear synchros in our M5R2. Why not? It's already out and we can replace that wonky clutch line that you couldn't remove.
- Acquire and refurb an entire spare V8/M5R2 engine/transmission combo. I'm totally serious here.
I know what I will be working on for the next year...