7-bolt motor in 1g

[93-Katt-TSi-AWD]

I've heard a lot about 7-bolt motors having problems with crankwalking in the 2gs... but no one ever talks about the 1gs (93-94). Do they have the same problem? Does it seem to happen less in the 1gs? Thanks!

 

[coltboostin]

you dont here abotu it because it is a 2 g block problem, not a 7 bolt problem. I have been preaching this all along. I have a 93 7 bolt in my colt, no problems

 

[93-Katt-TSi-AWD]

so what's the difference in the two blocks?

 

[Gooberlog]

My 93 1g 7bolt has 149,000 miles on it and i push more than 18psi on pump gas, its running strong, but i think i'll get a 6bolt when the rebuild time comes around.

 

[MR2TuRbZ]

i am interested about this too, whats the difference between the 1g 7-bolt and the 2g 7-bolt?

 

[KeltonDSMer]

I have been studying cases of crankwalk for a while and this is what I have gotten from it so far:

1) Fact-the lack of lubrication on the thrust bearing causes the crank to move and "Walk"

2) The 2G 7bolts have oil squirters that are prone to opening under too low of pressures, there for taking lubrication away from the thrust bearing.

3)I think that the 1G 7bolts have the older style squirters found on the 6bolt motors (can someone attest to this?) and those do not open under low pressures, there for leaving enough oil to lubricate the thrust bearing.



All this makes sense to me, but it's all theory because I don't actually have a DSM of my own so I can't test any of this stuff out for myself.

I've never heard of a 1G having crankwalk either; I think it's all about the little piston oil squirters.

 

[dsmturboawd]

after opening my friends cw'd 2g, there was no oil squirters in it.

 

[RamenPride]

Originally posted by dsmturboawd
after opening my friends cw'd 2g, there was no oil squirters in it.

well that kind of kills the whole oil squirter theory, doesn't it? I personally tend to lean towards the misadjusted clutch pedal theory.

 

[coltboostin]

If your friend had no oil sqirters in his motor, then a prievios owner did some swap with a non turbo block,pluged the squirters, or something of that nature. Call mitsu and ask them what year 4g63t came without squirters.

Kelton is right and wrong. It is not that the 2g squirters stay open and 1g's dont. Im sure if a 1g squirter is dirty it would stay open at idle (the period in queston here) aslo.
The problem lies in the FEED for the squirters. In a 1g block, 6 and 7 bolt, the sqirters get their oil from the main oil galley (where the oil pumps into directly)
in a 2 g block, they get their oil from the main bearing oil passedge. Thus, if the squirter is open, that much oil is NOT getting to the mains, and thrust bearing

Make more sense?

 

[93-Katt-TSi-AWD]

ok... that makes sense... except I thought I heard that if you rebuild the 7-bolt (1g OR 2g) and if you replace the crank bearings you would pretty much be assured of having walking problems very soon... is this also ONLY true in the 2gs?

 

[coltboostin]

IF you replace the crank bearings?!?!
WHat are you suppost to reuse the old ones in a rebuild?!
ANY MOTOR, wether 6 bolt, 7 bolt, Honda, Ferarri, can walk. If it is rebuild or machined improperly, it can walk. If I had a 2g 7 bolt AND i was rebuilding, I hould be tempted to plug the squirter holes, as some peopel have done

 

[spoolinawddsm]

2g 7 bolts were built to american spec, 1g 7bolts were japan specs. so i hear stupid americans!