Can somebody tell me how to micropolish a used crank. And when it is need to be made? Plan to install new main bearings and I´m not sure about the polishing.

Thanks
Kevin

 

Meanwhile I found some interesting things:

http://www.babcox.com/editorial/ar/eb20232.htm

 

Get some 600 grit wet-or-dry sandpaper. Cut it to match the journal width. Wrap it around the journal. Get a string and wrap it around that. And just it back and forth. And lubricate the sandpaper with solvent.

 

# 30 micron - ~400 grit
# 15 micron - ~600 grit
# 8 micron - ~1350 grit
# 5 micron - ~1500 grit
# 3 micron - ~2500 grit

edit: i know nothing about micropolishing, didn't even know it was a "DIY"???.. was just interested in knowing why it was suggested to start with 600 grit (which seems too corse to me)


Modified by 2point2 at 7:34 AM 9/19/2005

 

wow i didnt know it should be done....

do i need to do this if i am gonna reuse the bearings?


edit: do i need to do this also for the camshafts?

 

contact earl, send if off to benson and call it a day...if you are not sure how to do it i would suggest you leave it up to the pros...better to spend the money and get it done right the first time around...

 

napa

 

Why do you micro polish the crank? Lets get some technical discussion in heeere

 

I would assume to get the crank as smooth as can be when rubbing against the bearings and to make sure of no imperfections.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by areyouasian &raquo;</TD></TR><TR><TD CLASS="quote">contact earl, send if off to benson and call it a day...if you are not sure how to do it i would suggest you leave it up to the pros...better to spend the money and get it done right the first time around...</TD></TR></TABLE>

I dont want to rock the benson bandwagon but I'm sure there are engine machine shops around you that are competent enough to micropolish a crank. I think I paid $40 to get mine done at a local domestic machine shop.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civicman86 &raquo;</TD></TR><TR><TD CLASS="quote">Why do you micro polish the crank? Lets get some technical discussion in heeere </TD></TR></TABLE>

I can't recall exactly who said it, maybe earl, but I think it was regarding an S2000 blowup (very badly cracked sleeve, IIRC) - he said roughly that Honda motors can always be fixed *unless* the problem lies within the crank area. The most important part is that spinning hunk of metal. The smoother it is, the longer it will hold lots of power. Obviously we all know even neglected stock motors can last a LONG time - its little things like this that make the 600whp street motors reliable.

 

it's $25 . here in spartanburg sc.