3.7L down for the count again
First off...after adding up all the money in the car (you would NEVER believe how much!) there's no way I can just sell it for what I could probably find a buyer for. So breathe easy...I'm keeping it and I apologize for scaring you guys. :) I'll give whatever time I have but it's just going to move down the priority list a little.
So...shortly after this awesomeness:
http://www.3sgto.org/showthread.php?...-lbft-15.8-psi
...I am yet again stuck with a hurt car. I lost 14-15 psi of oil pressure at 2000 rpm after a pull. This isn't the first time either. Last time it happened at just 19 psi and hardly any timing (before I even started advancing it). I pulled the pan down and found the center mains had wear all the way around (but weren't smashed). The crank journals were fine. I replaced all the main bearings with ones that were tighter for more support (I went to stock 6G74 clearances), switched from 0w-40 to 5w-50 oil for more film strength, dropped the rev limiter from 8340 to 7100 (I thought maybe the high RPM was the issue), and dropped the boost from 19 to 16 psi to start tuning. After getting it back together I took note of the oil pressure at 2k (64-68 psi at 2k) so I could watch it very closely. I thought I was out of the woods and was pretty psyched after hitting 600 tq but obviously I wasn't. I'm sure this time once I pull the pan again I'll find center main bearing wear again.
Now I was thinking that maybe the 6G75 cranks are weak and it was flexing from power. On the other side...in the back of my mind I was thinking that Italo Grasso did 774 tq on the same crank so WTF.
I talked to Ray P just now and he had a good point. He's wondering if maybe my old school machine shop didn't balance the assembly properly. It makes sense since it's 360 degree bearing wear and not just wear/smashing at the bottom.
So where to now? Well...obviously this crank is probably cracked all to hell. I could have the balance checked by another reputable shop and just get another (properly balanced) stock crank if it checks bad. Or I could just go with a custom 4340 grade forged steel crank made by one of our pioneering vendors that will be announced soon. Stay tuned! :)
