Can the 7 bolt problem be fixed?

[Grinder5]

The site won't let me use the search feature, so I can look for any posts on this though I know there are some. My question is this. I have a 94 7 bolt block, completely stripped, and was thinking of having machine work done to it to rebuild it. Can the 7 bolt blocks be align-honed to make uniform crank journals to eliminate the crankwalk problem. I think I remember reading that the crankwalk problem has something to do with the crank and block journals being out of round or something like that, allowing the crank to have play in it. I found a shop that will do an align-hone fairly reasonable, but wondered if this would solve the problem without buying a new crank, trying to do a budget build if I can.

 

[gthompson97]

The "crankwalk" problem was blown way out of proportion. Only a small number of people actually get "crankwalk." And if memory serves me correct, crankwalk happened the most on the 2g models instead of the 1g.

 

[ChvyKc]

The site won't let me use the search feature, so I can look for any posts on this though I know there are some. My question is this. I have a 94 7 bolt block, completely stripped, and was thinking of having machine work done to it to rebuild it. Can the 7 bolt blocks be align-honed to make uniform crank journals to eliminate the crankwalk problem. I think I remember reading that the crankwalk problem has something to do with the crank and block journals being out of round or something like that, allowing the crank to have play in it. I found a shop that will do an align-hone fairly reasonable, but wondered if this would solve the problem without buying a new crank, trying to do a budget build if I can.

Just thought that I would throw this link up here for you to read. A buddy of mine told me about it after he was done building his 7 bolt. I have not read it entirely since I have no reason to (6 bolt in my car), but Magnus basically cuts two 7 bolt blocks in half and gives you a run down on their theory to why they crank walk. I believe that they basically get down to believing that it is the oil squirters pulling oil away from the bearings. Hope this helps.

The majority of the crank walk issues were in the 2G with 95 being the worst and 99 being the best (probably just because the newer models will obviously have fewer miles on them so you will see less failures).

http://www.magnusmotorsports.com/crankwalktheory.htm

 

[daveyfx]

Starting in 98, the 7-bolt 4G63 supposedly received revised thrust bearings to try and cut down on the crankwalk problem.

 

[talondude4]

It's said if you remove the clutch switch that it will help prevent it. I don't know how reliable it is. Just drive it, if it goes then just rebuild it or get a 6bolt and hope that don't walk.

 

[gsxtacy]

Its already been done. Fixed and warrantied.

The problem is the 7 bolt CRANKSHAFT. Check out www.overbore.com

The guys' name is Mark, and believe me, this guy is sharper than your average pencil.

The hardness of the crankshafts differ between the 6 and 7 bolt 4g63's.

Mark quoted .015" hardness depth on the 7 bolt and .040" on the 6 bolt cranks.

He also said that the oil tempature AT the thrust bearing differed. Something about 190* at normal load on a 6 bolt, and 215* on the 7 bolt at normal load.....I don't know for sure though.

He has a Engine Dyno at his facility to test this kind of stuff so contact him and ask him straight up if you want.

I personally myself would NOT rebuild a 7 bolt. I may however in the future give one of Marks' engines a try. I haven't heard anything bad about any of his stuff yet. He drives a DSM himself and is on this board sometimes. Chime in if you find this post, EngineMan.

 

[Crawl]

I bought a 7 bolt from overbore.com had engine profesionally installed. Engine crankwalked at 178 miles. Oh yeah thats fixed .