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Damn crank

Posted: Mon May 30, 05 5:35 pm
by Anonymous
OK,
I followed all the instructions and the crank wont turn when fully torqued.
Plastigauge showed all journals very close to .002".
the crank turns when layed in situ, but even pressure placed (by a mate) on either end of the crank tightens it up. When the end caps are torqued it closes right up.
Back to the machine shop tomorrow and another week lost!

Posted: Mon May 30, 05 8:04 pm
by Anonymous
Better to get it right than cost more money later on.

Posted: Mon May 30, 05 8:32 pm
by Anonymous
I know James, but its frustrating. Car was supposed to be back on the road by now :cry:

Posted: Mon May 30, 05 10:30 pm
by Dave-R
I thought you said Mustang Mike sorted it out for you?

Did you do the plastigauge check with the caps torqued right up? Did you check the full width of the journal for taper?

Posted: Tue May 31, 05 6:14 am
by Anonymous
Dave, yes and yes again. Plastigauge readings near identical.mike and i had crank at 60lbs torque at the time he declared himself satisfied.
when fully torqued it wont turn.
I give up, i'm going to have the machine job do it. i've followed all instructions given but to no avail. :cry:

Posted: Tue May 31, 05 7:08 am
by Anonymous
Crank could be bent I guess. I understand that this would not neccessarily be obviuos at the machining time.

Posted: Tue May 31, 05 7:48 am
by latil
Lets hope not most crank grinders will dial the crank before grinding and tell you if theres a prob before starting the job. Check and check again the mains alignment before taking anymore off the crank. Definately the right shells? Mains caps all in order,right way round? It'll come right don't despair :D

Posted: Tue May 31, 05 8:02 am
by Anonymous
Cheers Latil, everything is where it should be. the machine shop are pretty good. One if their guys is building a 383 Chevy stroker which requires specialist skills/knowledge so mine shoukd end up ok!

Posted: Tue May 31, 05 9:00 am
by Dave-R
I asked you if you knew how to do the plasigauge check and offered to give you the full instructions if you needed them.

You pick the journal you want to check and clean all the oil off it. Then you place a bit of writing paper on the bearings each side of the one you are going to check so that the weight of the crank is supported on the paper. On the end journals you shim the one next to it and the one at the far end in the same way.

Then you put your plastigauge on the journal and you tighten the cap down TO THE FULL SPEC.

I would guess that if you got a 2 thou reading without supporting the crank and without the cap fully torqued then the bearing has to be too tight.

In other words they have not taken enough off the journals which is a simple matter for them to put right and THE NUMBER ONE reason why you ALWAYS double check these things and never take anything for granted.

In other words always MEASURE! :wink:

Posted: Tue May 31, 05 11:07 am
by Anonymous
Dave, thanks for that, the readings I got were at full torque.
Anyway, heres the feedback from the machine shop
1) this a good one to laugh at over a beer! I may have over lubed the shells. I used a thick start up lube (cos it said so on the tube!) plus some engine oil. This might account for the varying aspects of different journals being tight at different times :oops:

2) the mains caps are being machined as it is suspected that they may not be properly round. I suspected this initially when i noticed a wear spot on the new bearing face

they are going to assemble for me.

Assuming it gets me to the nats i'll buy you a beer Dave for keeping me informed! :wink: