Clearance and end play issues

[Knoxes]

We checked the crankshaft end play and came up with 0.008. According to the FSM, this is just a bit out of spec. I've searched all over the forum, and it seems like the consensus is that this is a pretty significant issue - not to be overlooked. Do I have any options other than returning this crank? Also, the mains were measured by the machine shop at .0028 - also out of spec.

Not sure how to proceed here.

[dwg86]

Where did you get the crank? I wouldn't run it.

[Knoxes]

Rock Auto. I think it's a Standard Crankshaft. They also sent the wrong bearings, so I could potentially ship the whole thing back to them. Not easy to do, though.

Is it possible to get a larger thrust bearing?

[dwg86]

Rock Auto. I think it's a Standard Crankshaft. They also sent the wrong bearings, so I could potentially ship the whole thing back to them. Not easy to do, though.

Is it possible to get a larger thrust bearing?

I've never heard of a oversize thrust bearing. I wouldn't try to find on. It may be a pain to send the crank back, but you paid for a serviceable part. You shouldn't have to pay for machining and trying to find a thrust bearings to make it work. I say it's out of limits, so send it back. You don't want to use questionable parts in your new engine. Rock auto should repay for the return shipping. Check your local part stores for a rebuilt crank. If there are any problems its easier to return. Check craigslist for a whole 258 engine or parts. I've bought a whole engine for $50.00 before. If you can't find a good machineable used crank, scat is making new cranks. But beware a few of them have been out of tolerance. I have a used 12 wt crank in my basement I can sell you. Its a standard main/rod crank, but it had a spun rod bearing on number 1 rod. So it needs inspected. I wouldn't sell it without having it turned and inspected (I don't want to sell a bad crank). The machinist I use charges $130.00 to turn a 7 main 6 rod crank. I would need to get $100.00 for it. So now its up to $230.00 without bearings or shipping, so it's probably not worth it. For a little more, you could have a new crank.

One more thing. The main bearings that you get with a 258 crank "kit" won't work in a 4.0 engine. You will have to buy 4.0 main bearings. The lock tabs are in different places.

[Knoxes]

Thanks, dwg. I spoke with the machine shop - they're not concerned with the variances. But I have some time to deal with this, so I'm inclined to take your suggestion and send it back. RA is a PITA on returns. And yeah, the bearings didn't fit either the block (expected) OR the crank (WTH??).

And I appreciate the offer, but it's a 232 crank. And since I already have the dished pistons, I'm sticking with this formula for now.

[Knoxes]

Another machine shop just agreed that both the variances were fine.

hmm....

[awbrown]

http://www.ebay.com/itm/111122043852?it ... m=&vxp=mtr The factory manual lists .003-.007 end play for a 2.00 - 2.750 main journal crank .. as long as the rods and mains came in under .0028 I would consider it usable , that being said ,bearings vary in thickness and blocks vary as far as bearing bore sizes ,so unless everything is blueprinted or at the least done by a reputable machine shop then you are pretty much dealing with factory clearances that could be as the book says .0006 or so to .0034....... Adney Brown Performance Crankshaft Inc. 586-549-7557