Tom... you may wanna go ahead and invest in an aftermarket crank... cheap insurance with quite a few stock 2.4L cranks breaking. I would hate to see you get it back together and the crank fail...

 

hmm, aftermarket it is for me then..............

 

By no means am I saying the stock crank will break, but in the long run I think it would be cheap insurance considering the ones I have seen that have cracked have all done it in the same spot...

 

Hi Fred,

crank failures are pretty rare though. this crank that was in the car was new, and looks to be 100% untouched (still might be bad structural wise). there's not a single scratch on the journals though. ill have the machine shop spin it and check it for balance and so forth. definitely wouldn't hurt to throw in a manley though.

yes that would suck if the crank broke right after i got it back together.

 

Agreed, when looking at the total cost for a build, a crank isn't that expensive to do upfront.

 

if you do a forged the crank does not add much cost the billet cranks are fairly expensive for not much of a weight loss unless you go with something like buschurs ultra light or winberg.

 

Ah my exact combo! To the T.... Now just strap on that 6466 and do some real work!

 

here's what the stock 4g64 crank weigh's. this is also with the crank bolt at the end with the washer. so deduct another 1lb id guess. stock crank is not really that heavy.
i think the major benefit to the aftermarket cranks are knife edging + better oiling.



ya im def doing the LR 2.4 now. i was thinking about doing a 88mm crank with a 162mm rod for a 2.1L so i can rev it to the moon, but then i thought.. how often is it going to need to rev that high? and a 2.4LR is going to be so much funner on the street then a 2.1. then there's a 2.2L which i believe is a 94mm crank with 162mm rod. the 2.2 seems like the best of both worlds. good displacement + can still rev out high. IF i needed a new crank i would probably just go 2.2L.

i believe from what i read the safe limit to take a 2.4LR is like 8250RPM (this being super safe (way safer then taking a 2.3 to 8500) - i think ultimately they are capable of 8850 with less piston side load / friction then a 2.3 is physically capable of).

i am still reading and learning, so if i say anything stupid, feel free to correct me lol.

 

Tom its mot the weight of the crank... you will do what you want in the end but I wish I had put an aftermarket crank in mine now... just one less thing to worry about... Good Luck

 

I believe Crank failures have more to do with the owner than the actual Crank. Because the Crank is inherently weaker than a 2.0 Crank people must adjust. You can two step and launch all the time plus doing 3rd gear clutch drops to spin tires from a roll. Those shocks will kill it fast. A friend of mine killed 2 cranks in less than 1k Miles. I have driven lots of 100mm Crank cars for many thousands of Miles and never had a Crank failure.

 

Also as added info my cars made more power than the car that was breaking cranks on a regular basis. So the failures were not power related.

 

It is really luck of the draw with the stock cranks period...

 

i know its not related to the weight, but i wanted to show the stock crank isn't that heavy like others think it is. its not light, but its certainly not that bad.

i think seeing threads of cranks breaking is as rare as cams breaking. i don't think its going to happen easily. i don't think any rpm limited engine under 9k is going to be breaking cranks. as long as the rotating assembly is balanced i just don't see it.

 

hmmm map made over 1000 hp on a stock crank, and I know others who have ran stock ones with higher hp cars as well so I don't buy it one bit. It had everything to do with their builds. I mean if you get a crank from a motor from a junk yard and throw it in your motor and it breaks omg its a terrible crank. How about doing it the right way and have it checked out to make sure nothing is wrong with it in the first place. I mean I am not saying his to you personally or nothin but thats the mind set on alot of people. They see one failure and omg it is the worse thing in the world. I mean they have been doing that in the dsm world for years with the whole nt block and crank over the years and its all a bunch of crap.

 

The next time you speak with Aaron ask him about it Tom... the two that I know that broke were both checked out and both under 600hp... both built by top shops so when I say it is luck of the draw I am not joking...