honeybadger
Just don't care
- Thread starter
- #1
Hi all,
Creating a new tear down and build thread for the motor. For those unfamiliar, while pulling the oil pan 2 weeks ago to see if the FPC vibrations had cracked the GT500 oil pickup tube (surprise, it did!), I found a main stud in the bottom of the pan. I decided to put the motor on a stand and do a full tear down to check all bearings, caps, rings, pistons, etc. Ultimately, I found a pair of cracks in the crank snout, so it's trashed. Plan is to replace with a CPC, drop in new cams, and re-pin the harness and send it. This thread will detail that process.
Please keep discussion educational/constructive around the swap, analysis of findings, etc. Would like to keep this thread informational for everyone vs. arguing over FPC vs. CPC, 5.2 vs. 5.0, GT350 vs. GT, etc. With that out of the way, let's jump in!
I have been taking video and that will share the step-by-step process, but wanted to start the conversation regarding some of the findings.
First up, the findings that triggered the tear down. Main stud in oil pan. Looks like the nut loosened up and it backed itself out.
From the #5 cap. Builder thought it might be because of a bad clutch/flywheel balance issue. Who knows.
Stud where the oil pickup tube broke off.
Broke right at the bend, just like the FP350S one did
Okay, further in. First thing I noticed is that my secondary tensioners are showing excessive wear on the top. Passenger side has almost worn all the way through
These have the FP GT4 pieces. They were replaced about 44 track hours ago. The set before ran 52 hours without issue. Only difference is I ran E85 exclusively this time vs about 80% in the previous refresh. I reached out to FP to see what they say.
Cams are beginning to show a bit more wear. Nothing particularly outrageous that I can see, but it's definitely got my attention now. Lobes still look good from my POV.
Heads off and I noticed some inconsistency in the way fuel appears to be burning. On one head, we have the intake valves two different shades - one gray and one black. However, on the other head, the same pattern appears to be limited to just one of the cylinders. Thoughts?
Piston tops like good from what I can see. Head gasket patterns looked good, I didn't see anything blown out or evidence of water/oil leaking
Flipping it over, here's some info on the bottom end. Bearings look great. We have that one gouge on #5 main, but it's not deep. Thinking maybe from a cold start?
#5 below
#3 cap and journal
Rod bearings and journals all looked like this. Still need to remove one to look at bottom
I don't have a good shot of the combustion chambers, but they all looked pretty good--much better than the previous refresh
Unfortunately, here's the big one
And here's where we sit now. Anything ya'll want to see before I remove the crank/pistons?
Creating a new tear down and build thread for the motor. For those unfamiliar, while pulling the oil pan 2 weeks ago to see if the FPC vibrations had cracked the GT500 oil pickup tube (surprise, it did!), I found a main stud in the bottom of the pan. I decided to put the motor on a stand and do a full tear down to check all bearings, caps, rings, pistons, etc. Ultimately, I found a pair of cracks in the crank snout, so it's trashed. Plan is to replace with a CPC, drop in new cams, and re-pin the harness and send it. This thread will detail that process.
Please keep discussion educational/constructive around the swap, analysis of findings, etc. Would like to keep this thread informational for everyone vs. arguing over FPC vs. CPC, 5.2 vs. 5.0, GT350 vs. GT, etc. With that out of the way, let's jump in!
I have been taking video and that will share the step-by-step process, but wanted to start the conversation regarding some of the findings.
First up, the findings that triggered the tear down. Main stud in oil pan. Looks like the nut loosened up and it backed itself out.
From the #5 cap. Builder thought it might be because of a bad clutch/flywheel balance issue. Who knows.
Stud where the oil pickup tube broke off.
Broke right at the bend, just like the FP350S one did
Okay, further in. First thing I noticed is that my secondary tensioners are showing excessive wear on the top. Passenger side has almost worn all the way through
These have the FP GT4 pieces. They were replaced about 44 track hours ago. The set before ran 52 hours without issue. Only difference is I ran E85 exclusively this time vs about 80% in the previous refresh. I reached out to FP to see what they say.
Cams are beginning to show a bit more wear. Nothing particularly outrageous that I can see, but it's definitely got my attention now. Lobes still look good from my POV.
Heads off and I noticed some inconsistency in the way fuel appears to be burning. On one head, we have the intake valves two different shades - one gray and one black. However, on the other head, the same pattern appears to be limited to just one of the cylinders. Thoughts?
Piston tops like good from what I can see. Head gasket patterns looked good, I didn't see anything blown out or evidence of water/oil leaking
Flipping it over, here's some info on the bottom end. Bearings look great. We have that one gouge on #5 main, but it's not deep. Thinking maybe from a cold start?
#5 below
#3 cap and journal
Rod bearings and journals all looked like this. Still need to remove one to look at bottom
I don't have a good shot of the combustion chambers, but they all looked pretty good--much better than the previous refresh
Unfortunately, here's the big one
And here's where we sit now. Anything ya'll want to see before I remove the crank/pistons?
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