Crankwalk Sources

[niterydr]

I thought issues like this were already resolved, I figured this would be an informative post, not a summary of common knowledge. Any search of dsmtalk, dsmtuners, nabr private and public forums, any of the yahoo lists, any dsm related list in general, will list the 'monster clutch' theory of crankwalk. I know that besides a 'monster clutch' crankwalk has been linked to improper building techniques, improper block preperation (ranging from line hone, to clogged oil passages). The point is, fingerpointing on a public forum is useless. Crankwalk is as much of a 4g63 problem as spun bearings are to the 6g72. What saddens me is is the fact that it is always someone elses fault for a faulty rebuild. Fingerpointing gets people nowhere, lets turn this into a shared community thread of ways to 'prevent' crankwalk. Personally i've seen cases of nearly every tranny/motor/mods list out there crankwalking.
The things I personally believe that help fight against crankwalk are:
-line honing blocks w/torque plates still attached
-pinning caps
-proper assembly techniques (which I think is common knowledge, using plasti-gauge, etc).
-Making sure everything else 'attached' to the crank is in working order (from undampened pullys to improperly attached transmissions)
anyone have any other theories/ways to 'help prevent' crankwalk, please post them up.
Its unfortunate that this situation occured pubically once, and its unfortunate that it involves trusted members of the dsm community, but lets let by-gones be by-gones.

[TheBlizzard]

Doesn't the clutch only accelerate an already existing problem? I mean a ACT 2100/2600lb clutches are like stock clutches these days. I wouldn't think many people would put in a stock clutch when it goes bad unless the did know any better. I mean shit if they were that bad on motors they should put a warning label on the box just like a pack of cigarettes. :banana:

Another question has to be asked. Why is it then that crankwalking usually occurs after a rebuild? I have done searching and couldn't find that many that walked unless they have been worked on.

And Swanny all them steps up listed to prevent crankwalk are right on. But then you would agree then that skipping over any one of them steps could mean a certain death of a motor right?

And isn't a "monster clutch" is only going to make matters worse when something is not done right to begin with.

If somebody with valid proof of any of these questions can fill me in that would be great.

CRAIG

[Shane@DBPerformance]

100% stock cars with stock clutches that have never had the tranny removed have crankwalked. The whole way the tranny has to support the weight of the motor on a 2G might be part of the problem. You rarely have stock 1G 6-bolt or even 7-bolts crankwalking.

[JET]

Originally posted by niterydr@Nov 26 2003, 01:04 PM
The things I personally believe that help fight against crankwalk are:
-line honing blocks w/torque plates still attached
-pinning caps
-proper assembly techniques (which I think is common knowledge, using plasti-gauge, etc).
-Making sure everything else 'attached' to the crank is in working order (from undampened pullys to improperly attached transmissions)

This is the exact list of things that I have come up with. I have already talked to Mike about renting the torque plate when you guys get it. I am also installing the CRCO dowel kit. The only other thing I would add is the piece that John posted up from NABR that went over the alignment of the crank bearings, but that only matters if it is not doweled.

I have been toying with the idea of putting a torrington bearing in place of the clutch side of the thrust bearing. I know they will take a pretty good amount of force on them. For anyone that doesn't know, basically it is a set of needle bearings. I am thinking of machining down my dead crank and block to make room for the bearing. That is the major problem with putting a torrington in, I have not been able to find one that thin because that will decrease the surface area of the bearing which means it will hold less pressure.

The other issue with that is that the block is cast iron and I don't think it will like a needle bearing rolling around on it. To solve that the block has to be machined down even farther and a bearing surface mounted. .100" would probably work. Food for thought and I don't know if I will ever get to it or not, but it is interesting.

[MustGoFaster]

I have also thought of the torrington bearing idea. The biggest thing I hit was you can't just slip it over the crank, you would need a two piece bearing that bolts together around the crank. I don't know if they exist or not. Then I started wondering if it would be possible to add one somewhere else.

The other thing I encountered was a modification to the thrust bearing it self. It's on this page (http://www.aera.org/tech/tb1465r.htm) for those of you that haven't seen it. The idea is basically adding an oil passage right to the thrust surface.

[rick shindley]

I regret Jet's crankwalk problem. I have rebuilt about 20 or so 1G DSM engines over the past three years and several (I don't keep track) of them had ARP mains installed. No line boring was necessary and they are still running well today.

Claiming that using ARP main studs without line honing (not "align honing" as someone stated earlier) causes crankwalk is no different that claiming green paint causes crankwalk. If you want to claim something then provide the tech info to back it up! Opinions don't mean squat!


Dr ****

[rick shindley]

"Another question has to be asked. Why is it then that crankwalking usually occurs after a rebuild? I have done searching and couldn't find that many that walked unless they have been worked on."

I cut and pasted this from a previous reply in this thread. It is not a true statement. Crankwalk also happens after 50k! Actually, I found a stock 2G than had it at 43k! From my own experience I find maybe 30% of the 2G's I have worked on came in with some amount of non-spec crankwalk. I have seen only one 1G with it, a '93.

I helped a friend buy a clean, stock '95 GSX that was in a Mitsu shop at 106k torn down due to crankwalk. The car was a 1-owner and driven by a 30-year old nurse/single mom. (It was not abused whatsoever. She even had her car named... who could abuse a car with a name?) She explained that the car developed crankwalk at 53k and was repaired under warranty! Funny that at 106k (2 X 53k) it was in the shop again for crankwalk! Mitsu has a problem with that 2G motor design.

A big block engine builder told me that crankwalk was a problem for the drag cars with manual trannies back before auto trannies became popular in drag cars. He said that the thrust bearing in the big block engines had to be replaced after just ten runs down the track! Most Mitsu thrust bearings last a little longer than that now so maybe science has advanced a little?

Rick

[1Fst14B]

Originally posted by rick shindley@Dec 17 2003, 01:46 AM

Claiming that using ARP main studs without line honing (not "align honing" as someone stated earlier) causes crankwalk is no different that claiming green paint causes crankwalk. If you want to claim something then provide the tech info to back it up! Opinions don't mean squat!

Why does ARP say that it must be done?

There has to be a reason everyone, including the machine shop that rebuilt my engine, says that it should be line honed.

?? i dunno, ive heard enough horror stories just from watching the MNDSM list about engines grenading in the past, im not really sure what to think.
who knows how many people arent on the list, or on here, that get screwed and end up taking it elsewhere

Adam

[PSI2HI]

Blah, blah, blah............

It's fucked up, it needs to be fixed, it's my fault can this topic EVER end!!!!!!!!!!! Haha, errr wait no, not guilty....

Stock motor are the bomb!! I strongly recomend them.

Nick

[2003eclipse]

BUY A 3g you wont have the problem, cause you wont be fast enough.