92-94 7-bolt VS. 2G 7-bolt...differences??

[Blk95gs]

I constantly read about crankwalk, I kinda understand what it is, but yet I've never actually heard why the 2G 7-bolt is more prone to CW than the 1G (92.5-94) 7-bolt. Is this true? Does CW depend on the driver or clutch components involved? I've also heard that CW isn't likely on DSM's w/ automatic transmissions. Is this true?

I've heard/read so many stories about it that I feel like there is such an inconsistency as to which cars may be likely to get it. Overall, I think that I just need a better understanding of the differences between the 6 & 7 bolt engines and what exactly contributes to such a catastrophe.

Feel free to discuss...

-Andrew

 

[andol469]

Crankwalk is caused by thrust bearing failure. I've read that DSMs made between 95-97 are most likely to have crankwalk. The most popular explanation for crankwalk is that Mitsubishi messed up on the crankshafts on affected 7 bolt engines. Improper machining of the crankshaft basically. So, it definitely is Mitsu's fault, although dealers might try to blame it on mods (especially a clutch upgrade.) The reason the 2g's are more suceptible (sp) to CW lies in the problems with their crankshafts. I think 1g (6 bolt) DSMs had stronger crankshafts and were machined consistently, which is why CW isn't a problem with 1g's. That's about all the info I'm good for, hope this helps.

 

[Blk95gs]

Alrighty...that helped define the problem for me, thanks.

Now...are there differences between the late model 1G's and the 2G's 7-bolt? Or does that also pertain to the fact that the crankshafts produced in 2G's were just crappy?

 

[Dieselboy]

Well, I know the '95 + 7 Bolts (2G) have different pistons, that I know isnt the reason. 1G's yield a 7.8 CR while 2G's yield an 8.5 CR. I believe the cranks are made slightly different, but as pointed out earlier, the thrust bearings are usually the fault.

 

[Sully944]

Well I've read up on CW a bit and what seems to be some of the professionals opinions is : The way the oil jets were installed in the motors caused them to stop working specifically in the main bearing housing so alot of block rebuilders are charging extra for installing better oil jets in the block housing before rebuilding. There are some links on this site pertaining to the problem can't remember where I read up on them. Do a search. One key piece of info though " Frequent oil changes are the best prevention to crank walk!

 

[rubbersidedown]

indeed. It appears another reason from CW are the piston oil squirters that Sully944 mentioned. If you want a complete in depth article w/ pictures and all then head on over to Magnus Motorsports's website. They dide an absolutely huge study on it and have pictures of how they cut the engine block up and everything. Its a good read.

 

[Blk95gs]

Thanks a lot everyone...now I definately understand it more.

 

[RamenPride]

plugged up oil squirters is just another theory. a lot of people report getting crankwalk even when the oil squirters weren't plugged up.
other theories:
a) cranks machined out of spec
b) mismatched bearings
c) clutch adjusted improperly
d) heavy pressure plate
e) oil feed line for the turbo coming straight off of the oil pump
f) blocks misaligned or machined wrong
g) block produced from weaker/inferior metals
h) crank produced from weaker/inferior material
i) poor thrust bearing design
j) location of motor mounts (three of them are on the tranny)
i) excess free play/misaligned cap bearings
etc., etc., etc.

 

[PogiTSI]

Basicly Mitsu F'ed up.

 

[pope]

Now...are there differences between the late model 1G's and the 2G's 7-bolt?

answer this i have a 7 bolt in my 1G and really dont want CW so is it just the 2G's that are more prone or is it both and all 7bolt motors?

 

[PogiTSI]

2g's are more prone to Crank Walk, I herd Only a Few in the entire history of a 1g 7bolt Crank Walked,