I wanted to know since there aren't any up to date feedback.
Has anyone had pretty good luck with the Manley 100mm forged crank despite its negative history in the past for cracking/breaking? What are your current HP/TQ numbers on your Evo, thanks!

 

I have seen 3 Manley race ones crack and one 100mm billet crack.

 

Im happy to see that a billet one has cracked although I dont have that one, I have the forged one. Im leaning more onto install error or the fact that many people arent using the fluidampr harmonic balancer.. I also have a GSC balance shaft so I think IM gonna be pretty solid in terms of preventing cracking.

 

You don't want to try K1? Or you already bought a Manley and are looking for reassurance?

 

Go with Eagle or K1. Manley cranks like to break.

 

In terms of 100mm cranks:

Manley Forged < Manley Billet < K1 Billet

As mentioned earlier, the engine builder has a lot to do with the outcome of using these cranks, but it's much harder to break a K1 Billet crank. I don't know if it's because they use higher quality materials or their machining is just cleaner. I'm not speaking from personal experience here, just what consensus is on the forums.


That being said I'm running a Manley Billet with Fluidampr and have had good luck with it just like many shops around here thus far.

I believe the OEM 100mm crank from from the (4g64? or 4g69?) is more reliable than the Manley Forged.

 

I know there is quite the debate but I just really disbelieve the oem crank from a 4g64 is more reliable than a manley forged one that I have..
But as someone asked earlier I already have my engine built assembled and put together with a break in tune... but Im about to aim for 700 whp so need to see where my tq needs to stay at minimum or go all out as I planned.. I have nothing but high expectations of this crank lasting.
Mods are:
2.4LR:
O-Ringed block
87mm bore
Wiseco 9:5.1 compression
156mm Turbo Tuff Rods w/ ARP 625 rod bolts
Manley 100mm forged crank
Manley ARP main studs
ARP 625 Head studs
GSC balance shaft
Ported Cylinder head
GSC valves springs retainers
GSC R2 billet cams
Kiggly HLA regulator
etc etc you guys get the rest there isnt anything undone to the car except for the transfer case literally lol

 

I'd name the shops that built those engines but I'll leave them out. But they where all built by reputable shops. All cracked. The billet 100mm one cracked at low 500 whp on a mustang dyno.

 

Believe me or not. I had the same oem 100mm crank in 3 different 2.4 builds over the last 5 years. Last time it was tuned. It made 908 awhp 652 awtq. Put about 12k miles on the engine. Engine failed to an head gasket seeping coolant and detonating in one hole.

 

Yeah brother I believe the stories no doubt its just the reason for them breaking if that makes since... Thats why I need more up to date stories on these particular cranks breaking or cracking with having things like a fluidampr pulley, and an actual balance shaft (not the delete kit) as well as proper tq settings. and by balance shaft not the oem ones but the actual aftermarket (ams or gsc)

The reason I have a hard time believing an oem 100mm 4g64 crank will outlast a Manley Forged one is primarily due to the age and involvement of physics not design. No matter how well designed something is, the way these cars rotating assemblies move especially under high power applications can properly explain the direction Im going here: such as tension, clearance, and balancing, and heat produced. Good thing is I do have an OEM 4g64 crank just in case but again Im thinking it may not be needed as the reason for those who have broken are due to install error and no proper support mods.

 

Why is it hard to believe an OEM part is can last longer than an aftermarket one?

I bet the manufacturing requirements for the OEM crank are higher than the Manley forged.

 

I broke a Manley forged after 9000 miles in April last year at 430whp

 

What you quoted was my specific answer to your question (no offense).... again primarily age and the fact that the ones who are running these aftermarket (lightweight) compared to OEM cranks are not equipped with the correct supporting mods such as fluidampr pulley from increased vibrations including balance shaft deletes. also again as mentioned the proper install with respect to clearances and proper tq fastening specs etc etc. that plays a huge role in rotating assemblies especially my targeted focus (crankshafts). factor that with the heat generated + forces applied at extreme loads and failure is bound to happen...
I have yet to see anyone with lets say Fluidampr pulley and actual aftermarket balance shaft from AMS or GSC post with any issues. But im not doubting this crank will not crack/break, just believe its unlikely if done correctly. Plus I have an OEM 4g64 crank chilling just in case.

 

No offense but for that moderate power level... dont you think thats definitely a install error or at least support mod related?
I say thats moderate because there are people running 500 and no issue running the manley forged crank

 

I'm on 25k miles on my Manley billet, 500+ ft lbs of torque. No complaints here, it does crankly things like not break.