This past week has been a very eventful one, to say the least.
The week prior to Branson, the car came together and I was able to take it on a few test runs and really run her with the new Holset HY35. I have a regular straight away I use to do tuning, which is tucked away in the corner of my small home town of 4,000 people. Last Wednesday, I took the car out while VE Analyze Live was enabled. This is a very useful feature in Tuner Studio that automatically adjusts my VE table bins according to my air to fuel ratio. Of course, you must set up your desired AFR target table beforehand, but from there, it’s cake.
I was pretty conservative with the car until I slowly started to work my way up the RPM range and the Holset started to work it’s magic. This particular turbo doesn’t really kick in until approximately 3800 RPM, so it takes a little while to spool the thing. One mistake I made was running without a boost gauge of any kind, nor did I make an effort to monitor the boost in Tuner Studio. Once I got a small taste of the power the Holset generated, I couldn’t get enough. The car had a small hesitation at mid range, but pulled like a freight train up top. Remember, I’m not monitoring boost and I do believe I performed a hand full of wide open throttle pulls down my small tuning strip.
This went on for a couple trips down this stretch of road until I was satisfied. I took the car home and upon pulling in the drive way, I noticed my small valve cover catched can filter was puffing out more smoke than I had remembered. I kept watching to see if it would die down and asked for others’ opinions, but it didn’t seem to show any sign of improvement. I ignored the issue and continued with a few more pulls. I, once again, monitored the smoke and it showed no improvement.
Upon creating a thread over at HybridZ, I was reassured (based on a video I had posted) that the smoke was normal. Unfortunately, my video didn’t capture the magnitude of smoke and I had informed them that the compression test showed all cylinders within spec. However, I performed the compression test prior to my last run that evening.
Come Friday, it was still bothering me, so I went ahead and did another compression test. I started from the back and worked my way towards the front. I will admit, I was quite nervous I would find something I didn’t like, but crossed my fingers. I tested up to cylinder 3 when my luck turned South. All cylinders were testing at about the 126 mark up until cylinder 3. I strapped on my gauge and cranked the motor.
I freaked out. I couldn’t believe it. I had always thought the bottom end was invincible considering all the punishment we had put it through, but I was wrong. I couldn’t believe what I was seeing, I was sure I wasn’t making it to Branson the following Wednesday. This wouldn’t have been so bad had I not worked on the thing for the past 6 months to have it ready, specifically, for this event. I immediately sent a text to my club president to make him aware that I may not make it to the event. Upon turning the motor to TDC and shining a flash light into the spark plug hole, I discovered this:
I couldn’t believe it, I had cracked a piston. I am almost certain this was a result of running high boost. I looked back at my datalog and the MAP sensor recorded a max of 26 pounds of boost. This, combined with a premature tune, did it in.
My club president immediately called me to talk about the situation. I spoke to him about what happened, why it happened, and what I should do. The conversation came down to the conclusion that either way, before or after Branson, the motor will need to come apart. Fortunately, I have an extra junkyard motor, gasket set, and rings that were sitting on my shelf. I told him this and he said I have two options.
1. I could push the car into the garage and drive my Subaru down to Branson and have a good time without the car.
2. I pull the motor and tear into it, replacing the cracked piston if the cylinder wall isn’t too scored and trailer it down to Branson.
I hmm’ed and haw’ed for a while and realized that I can’t stop now. I’ve come too far and worked too hard, too many sacrifices had been made to let this stop me now. The decision was made to pull the motor that night. So that is what I did.
Prior to pulling the motor, I pulled off the head to check things out and this is what I found:
The cylinder wall did have scoring, but it was so minor that I knew a new set of rings would seal and I could make this happen.
About two hours after the discovery, this is where I was:
I was making good time, and broke the motor down that night. I ended up find these little critters in my oil pan!:
I did not expect this, and started to get scared. I initially thought I had just cracked the piston head and that was that, but I was clearly wrong. These pieces actually originated from pistons 3 and 4. It looks like the pistons were subjected to so much force that they not only cracked but broke into pieces and barely held together.
As you can see, the piston cracked all the way through the ring lands and everything! Those rings were actually broken as well, I’m really not sure how this piston didn’t just grenade in the motor. It’s funny to think that I was still doing 26 lb pulls and didn’t notice any loss of power.
It turns out two pistons were actually severely damaged.
Once I did a good inspection of everything and removed all remnants of metal pieces/shavings that I could see, I installed new rings on the pistons to replace the broken two and re-used the bearing that were in the original connecting rods. I did this because I knew these bearings were already ‘seated’ to this crank journal.
Once these were in, I began the reassembly process.
On Friday night I discovered the problem and broke the motor down to the short block. The following day, I replaced the pistons in the morning and had the car running at approximately 1:00 A.M. I was very thankful to hear the motor fire after I realized I had my distributor 180 degrees out of phase.
So, moral of the story is: Don’t run boost until you have a boost gauge and keep it on the low side!
That was memorial day weekend, so luckily, I had Monday to do additional test and tune sessions with the car. The car ended up dying on me Monday night on my way into Omaha due to a bad alternator connection. I had my mom limp me back home by charging my battery every 15 miles. I was in bed at 3:30 AM the following morning (Tuesday). I was able to perform a compression test post-rebuild. Luckily, the numbers turned out in my favor this time:
On Tuesday night, we loaded the car and prepped the truck to tow the car down to Branson. The car was very well for the most part. I couldn’t seem to control my boost levels, but that was something I could work around.
The following day, we were on the road. Woohoo!
The drive down was great! The weather was perfect and everything was smooth sailing on the way down. I traveled with a group of 6 or 7 cars from the club, which worked out very well.
Branson Z Fest is something that everyone should experience. There is something very unique about the people that surround these cars. I personally have never met such great and helpful people in my life. These people are willing to do anything for you to ensure you have a great time and enjoy the experience. Many people experienced car issues (which were expected), but it really wasn’t an issue due to the fact that there were so many experienced individuals that there wasn’t any problem they couldn’t fix. It was amazing, to say the least. I wasn’t able to snap a ton of photos, but here are a few from this amazing trip I was able to go on. There is no question that I will return to Branson for the Z Fest for years to come.