Cracked Crankshaft
Sounds like he's working with JAM (Jackson Auto Machine) in Hanover, MD. They're great people with state of the art facility. I remember getting a tour of their engine dyno room, good stuff. Had one of my heads resurfaced there.
I'm thinking of taking my long block there for their special on JAM 2.3 stage2...
They're like 2 miles from my folks' garage where my VIII is getting rest. Not sure what to do since she's running top shape but does have 151k miles on the stock block....
I'm thinking of taking my long block there for their special on JAM 2.3 stage2...
They're like 2 miles from my folks' garage where my VIII is getting rest. Not sure what to do since she's running top shape but does have 151k miles on the stock block....
i have personaly bought 4 stock cranks had them all magnafluxed every one was cracked in almost the same spot on the cylinder 4 journal. i ended up buying a eagle crank and everything is good now
You guys are correct...it is JAM. Great group of guys who really know the ins and outs of this engine. I will never doubt them again after talking to them for a while.
I am going to go with the stock crank again. They explained that it happens from heat and a few other factors, which can all be remedied during the build. They would have preferred me going with the Manley due to better material, but my whole build is already 'snowballing' past budget. Poop.
JB...you can see the cracks under the black light really well.
I am going to go with the stock crank again. They explained that it happens from heat and a few other factors, which can all be remedied during the build. They would have preferred me going with the Manley due to better material, but my whole build is already 'snowballing' past budget. Poop.
JB...you can see the cracks under the black light really well.
Last edited by lan_evo_mr9; Apr 19, 2011 at 03:02 PM.
We have seen micro-fractures in the drag car's cranks over 1100whp but we have never broke one. Luke broke a 6 bolt 4G64 crank (not the same as the 7 bolt 64) way back on a launch at only 480whp but we have yet to see the "Evo" 100mm crank break yet. GSC also has a 4340 100mm crank that will be on the market before too long.
aaron
aaron
When my OEM 4g64 crank snapped, it was in 2 peice in the same spot as stated above, where the crank counter weight(or w/e its called) meets #4 journal.
Here's a few pics of the piston damage... Don't have any of the block or crank, sorry.
The block was in amazingly good condition for what had happened and will be cured by a .020 over bore
The stock cranks can handle abuse, with the right prepping, bearings, oil flow, etc. But they are not indestructible like everybody thinks. I probably saw 5 other cracked cranks at the machine shop while I was there. Scary stuff. I do know it was mine because I marked one of the counter weights with a tiny pin punch. Sorry for the crappy cell phone picks...after I saw this, I couldn't believe how lucky I was that the whole thing didn't grenade.
The block was in amazingly good condition for what had happened and will be cured by a .020 over bore
The stock cranks can handle abuse, with the right prepping, bearings, oil flow, etc. But they are not indestructible like everybody thinks. I probably saw 5 other cracked cranks at the machine shop while I was there. Scary stuff. I do know it was mine because I marked one of the counter weights with a tiny pin punch. Sorry for the crappy cell phone picks...after I saw this, I couldn't believe how lucky I was that the whole thing didn't grenade.
That is the piece I removed and just set on the piston...just so happens to be resting on the wrist pin area. That piece does belong between rings 1 and 2. You are looking at the broken chunk, removed from broken area, resting on random position of piston. Sorry for the confusion- should have set it next to the piston or something.