Crank polishing

Marvin Robinson · 05-27-2014, 11:20 AM

Got a crank that needs polishing to get another .001-.0015 on the rod throws. Anyone have a method for doing this in house, or is a machine shop the ONLY way to get this done... trying to meet a deadline.

carl hinkson · 05-27-2014, 11:30 AM

You should never try to polish crank to remove material for clearance as you will not have flat journal in the end.

Ed Wright · 05-27-2014, 12:40 PM

Can't find +.001" bearings?

john corcoran jr · 05-27-2014, 01:23 PM

Marvin,
You could just "polish" the bearings instead. After all, aren't they made of a softer metal than the crank? I'm JUST KIDDING. Just call the crazy Ukarainian and I'm sure he will get the right parts for you before you even get back out to the garage.

Marvin Robinson · 05-27-2014, 05:09 PM

Bearings are already .001 oversize and coated so I can't polish them, no .002 available. Looks like a trip to the machine shop, I don't have access to a lathe.

okieracer · 05-27-2014, 06:32 PM

You can't polish what you need in the crankshaft. Get the bearings you need undersize and have your crankshaft grinder set the clearance with the crank grind. If you try to polish the journal will be swaybacked.

MAURICE BLENDHEIM · 05-28-2014, 09:33 AM

Quote:

Originally Posted by Marvin Robinson

Got a crank that needs polishing to get another .001-.0015 on the rod throws. Anyone have a method for doing this in house, or is a machine shop the ONLY way to get this done... trying to meet a deadline.

Marvin…Do it right, the crankshaft grinder will finish it for your desired clearance. No point meeting a deadline with questionable clearances. MB.

05-27-2014, 11:20 AM	#1
Marvin Robinson Member Join Date: Jun 2005 Location: Gary, IN Posts: 139 Likes: 0 Liked 0 Times in 0 Posts	Crank polishing Got a crank that needs polishing to get another .001-.0015 on the rod throws. Anyone have a method for doing this in house, or is a machine shop the ONLY way to get this done... trying to meet a deadline. __________________ Marvin Robinson 3188 STK/SS

05-27-2014, 11:30 AM	#2
carl hinkson Member Join Date: Feb 2007 Location: NORTHEAST Posts: 287 Likes: 1 Liked 18 Times in 10 Posts	Re: Crank polishing You should never try to polish crank to remove material for clearance as you will not have flat journal in the end.

05-27-2014, 12:40 PM	#3
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Crank polishing Can't find +.001" bearings? __________________ Ed Wright 4156 SS/JA

05-27-2014, 01:23 PM	#4
john corcoran jr Junior Member Join Date: Oct 2003 Location: darien, il Posts: 53 Likes: 0 Liked 16 Times in 10 Posts	Re: Crank polishing Marvin, You could just "polish" the bearings instead. After all, aren't they made of a softer metal than the crank? I'm JUST KIDDING. Just call the crazy Ukarainian and I'm sure he will get the right parts for you before you even get back out to the garage.

05-27-2014, 05:09 PM	#5
Marvin Robinson Member Join Date: Jun 2005 Location: Gary, IN Posts: 139 Likes: 0 Liked 0 Times in 0 Posts	Re: Crank polishing Bearings are already .001 oversize and coated so I can't polish them, no .002 available. Looks like a trip to the machine shop, I don't have access to a lathe. __________________ Marvin Robinson 3188 STK/SS

05-27-2014, 06:32 PM	#6
okieracer Junior Member Join Date: Jul 2002 Location: Durant Posts: 8 Likes: 0 Liked 0 Times in 0 Posts	Re: Crank polishing You can't polish what you need in the crankshaft. Get the bearings you need undersize and have your crankshaft grinder set the clearance with the crank grind. If you try to polish the journal will be swaybacked.