Cracked Crankshaft
Apr 12, 2011, 04:43 PM
#1
Cracked Crankshaft
So I'm in the process of getting my engine rebuilt. I'm getting parts from a very reputable sponsor on here and getting my block/crank machined by another local shop that specializes in evo's and another brand. The block is getting bored .020 over, honed, degreased, new freeze plugs, etc. I also had them magnaflux, micro-polish, and check for straightness my crank for piece of mind.
I got a phone call today from the machine shop telling me that my crank is cracked on a rod journal. I was then told that this happens quite often, especially on this cylinder. I'm not saying that I don't believe him, because he has done nothing to this point except be honest to me, but the conversation after that turned into an "upsell", which is making me think twice.
I've read that our stock cranks are relatively indestructible and that there hasn't been a lot of issues with this sort of thing...or maybe there is and you just don't hear about it.
I would like some input if from you guys and shops to see if this does happen, is possible, or if he's just trying to upsell me something.
It was funny too...the machine shop recommended one brand of crank and then the parts distributer (whom I trust more), told me that those cranks aren't great and to stick with factory crank. I'm not sure what to do here folks, please help put my mind at ease here. I wanna get this engine built once and built right the first time for the amount of money that goes into these things.
I got a phone call today from the machine shop telling me that my crank is cracked on a rod journal. I was then told that this happens quite often, especially on this cylinder. I'm not saying that I don't believe him, because he has done nothing to this point except be honest to me, but the conversation after that turned into an "upsell", which is making me think twice.
I've read that our stock cranks are relatively indestructible and that there hasn't been a lot of issues with this sort of thing...or maybe there is and you just don't hear about it.
I would like some input if from you guys and shops to see if this does happen, is possible, or if he's just trying to upsell me something.
It was funny too...the machine shop recommended one brand of crank and then the parts distributer (whom I trust more), told me that those cranks aren't great and to stick with factory crank. I'm not sure what to do here folks, please help put my mind at ease here. I wanna get this engine built once and built right the first time for the amount of money that goes into these things.
Apr 12, 2011, 06:47 PM
#2
So I'm in the process of getting my engine rebuilt. I'm getting parts from a very reputable sponsor on here and getting my block/crank machined by another local shop that specializes in evo's and another brand. The block is getting bored .020 over, honed, degreased, new freeze plugs, etc. I also had them magnaflux, micro-polish, and check for straightness my crank for piece of mind.
I got a phone call today from the machine shop telling me that my crank is cracked on a rod journal. I was then told that this happens quite often, especially on this cylinder. I'm not saying that I don't believe him, because he has done nothing to this point except be honest to me, but the conversation after that turned into an "upsell", which is making me think twice.
I've read that our stock cranks are relatively indestructible and that there hasn't been a lot of issues with this sort of thing...or maybe there is and you just don't hear about it.
I would like some input if from you guys and shops to see if this does happen, is possible, or if he's just trying to upsell me something.
It was funny too...the machine shop recommended one brand of crank and then the parts distributer (whom I trust more), told me that those cranks aren't great and to stick with factory crank. I'm not sure what to do here folks, please help put my mind at ease here. I wanna get this engine built once and built right the first time for the amount of money that goes into these things.
I got a phone call today from the machine shop telling me that my crank is cracked on a rod journal. I was then told that this happens quite often, especially on this cylinder. I'm not saying that I don't believe him, because he has done nothing to this point except be honest to me, but the conversation after that turned into an "upsell", which is making me think twice.
I've read that our stock cranks are relatively indestructible and that there hasn't been a lot of issues with this sort of thing...or maybe there is and you just don't hear about it.
I would like some input if from you guys and shops to see if this does happen, is possible, or if he's just trying to upsell me something.
It was funny too...the machine shop recommended one brand of crank and then the parts distributer (whom I trust more), told me that those cranks aren't great and to stick with factory crank. I'm not sure what to do here folks, please help put my mind at ease here. I wanna get this engine built once and built right the first time for the amount of money that goes into these things.
Apr 12, 2011, 07:18 PM
#3
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Apr 18, 2011, 04:26 AM
#10
They will crack, Ask any EVO engine rebuilding shop that has magnafluxed the crank.
I have a cracked one at a machine shop,I'll take a picture today if i can get over there. Stock cranks are good for about 400 torque, after that or abuse and they will crack. Most people don't know because it doesn't shut the engine down. Nobody ever talks about it because you can barely see it.
I have a cracked one at a machine shop,I'll take a picture today if i can get over there. Stock cranks are good for about 400 torque, after that or abuse and they will crack. Most people don't know because it doesn't shut the engine down. Nobody ever talks about it because you can barely see it.
Apr 18, 2011, 04:29 AM
#11
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That's news to me and I've built around 20 4G63's at this point and had a hand in helping build even more and never saw or heard of a cracked crank. That's over a 15 year period. The 4G64 crank is notorious for breaking but the 7 bolt Evo crank has put down very high HP and and torque without fail. I would check it first.
Apr 18, 2011, 05:17 PM
#13
I did see it in person... It's definitely cracked on #4 rod journal and near the thrust bearing area. These aren't huge cracks or anything, but cracked never the less. My trust is totally with the machine shop now after seeing it, receiving a tour, and getting very specific descriptions on the the engine's inner workings and such.
Apr 18, 2011, 05:37 PM
#14
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.