I havent heard any issues coming back from our machine shop. Not sure if they correct it and fail to mention it or we just havent had any problems.

Magnus has the 92mm made, OE has a 93, and the other aftermarkets are 94mm. The whole thing is kind of odd actually.

Not sure on which Manley it is. I will take a pic and show where it broke, like I said its definitely not in the normal place compared to an OE crank so I think it was a fluke. The Eagle that Buschur had problems with was one of the plugs used after the mainline is drilled. I believe it backed out on him and that was the issue but I am not 100% on my recall of that event. We threadlock them and then tap the edge over so it cant move.

 

To be very clear, I am not being negative on Manley. I think this is a freak accident, we didnt build the motor so I dont know the clearances or machine shop that did this. I have no torque specs either so I cant say what was going on there. This was either the original assembler/machine shop/bad luck that did this one. This could have started with oil starvation though the pan was full. We havent checked the pump yet but there was a lot of trash in the bottom of the pan so it is a case of which came first, chicken or broke crank.







That part number comes up as the Billet 4340 for whats it worth.

 

I used to work for sp crankshafts witch became pankl racing systems b4 they closed this year, we made highend crankshafts (wrc, nascar, le mans, prototype) when we manufactured a crank it gets heat treated multiple times( core hardend, stress relief, 1st grind cleaned nitrided 2nd grind ) then the remainder of the process, cracks or breaking can be caused by multiple issues, but on the manufacturing side there could be problems too, if it was made by 2xgrind the 2nd grind could cause cracks already nd the only way to see them is on a crack test machine, but even on those if the fluidsardaren't well maintained they won't appear, so that might be an issuse as well

 

I had my heart set on a 100mm Manley Billet crank for my 2.3L build. I thought that it would be good insurance....until I saw that failure pic.

 

Like I said this is NOT TYPICAL. Things break, people are idiots, and some people should never build an engine. This came to us from Arizona this way so I cant say what happened for sure. It wouldnt stop me from putting any aftermarket crankshaft in a 2.4L regardless of what brands I prefer.

I chalk this up to user induced failure rather than a part specific failure.

I havent even pulled the tune off the car yet to see what it looked like, so there are MANY variables that need investigated. Even if this was one failure in 1000, and I know there are more Manley cranks in service than that, we'd have a 99.9% success rate.

 

Thanks John Bradley great in and awesome pics that crank is the billet version and I wouldn't shy away from you using it. I'd rather the forged version because of price and the fact I think forged is just as strong. Billet is prettier and lighter due machining process but stronger I'm thinking not so much

 

This is why the Internet is bad lol. Like Aaron said, there was a lot of trash in the bottom end and pickup so most likely wasn't helping anything. I run a standard 88mm Manley forged crank in a 2 liter and I've been making over 800hp and 600 tq on a dyno jet for 2 years and haven't had any problems, last time I had the rod caps off everything looked great, but I assembled and measured all the clearances and know all my rod bolts are torqued and stretched accordingly. I'm sure the 100mm cranks see a bit more stress, but who knows what that crank in the pic could have been through. If we started hearing a bunch of people posting about broken manley cranks and issues with them that would be different. I am a little surprised it fractured off like that being a billet crank, but who knows what happened if it was oil starved with the right amount of heat and shock.

 

Wow, that crank is dun dun son son!

 

I'd be interested in finding out what off'd this crank, I just purchased the Manley Billet 94mm for my build.

 

Granted, I cannot see the journal surface very clearly from this vantage point, but at a glance this looks to me like the crank has fractured along a metallurgical fault.

 

I have a K1 forged crank used that was micro polished that I'm going to use in my 2.4 build do I need to have it nitrated or a good set of bearings will be sufficient? I was going to sell it to help fund my build because I have an oem 2.4 crank but I have changed my mind after researching.

 

It seems more related to the harmonics at high rpm and high power. Since this one broke we have had 2 more non billet (this time) Manley 100mm cranks crack in the same spot as this one broke. We are investigating the cause right now and coming up with some plans to change it. So far the shorter strokes in the K1 and Eagle have been fine, 94mm and down but we havent seen any Manley 94mm stuff.

 

I have a manley performance turbo tuff billet 100mm crankshaft for 4g63/4g64 for sale brand new. You will not break this one. Cheap doing new project 1000 and it's gone they are usually close to 1500.