Notices
86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS
Sponsored by:
Sponsored by: DashLynx

Crankshaft turning

Thread Tools
 
Search this Thread
 
Old 01-31-2018, 03:43 PM
  #1  
Registered User
Thread Starter
 
FunkMaster88's Avatar
 
Join Date: Jan 2018
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Crankshaft turning

How far can a crankshaft be turned, i know there .010 .020 and .030...can it be turned .040?
Old 02-01-2018, 02:54 PM
  #2  
Registered User
 
gsp4life's Avatar
 
Join Date: Feb 2015
Location: Mogadore, Ohio
Posts: 858
Likes: 0
Received 13 Likes on 12 Posts
I think .030" over is the max for rod and mains. Mine are .030" over and a reputable local shop thought that was reground to the max. My machine shop couldn't find bigger bearings when I asked about it (for future rebuild purposes). 22re performance only sells bearings up to .020" over and they were skeptical about using .030" over bearings.

My cylinders are bored .040" also, so when this one dies, I'll just build up a new short block. Sounds like a new crank might be in your future if you need a regrind and are already at .030".
Old 02-02-2018, 12:10 AM
  #3  
Registered User
 
Thommo Thompson's Avatar
 
Join Date: Nov 2017
Posts: 331
Likes: 0
Received 0 Likes on 0 Posts
For toyota, of this era; bearings are available up to a maximum of 0.75mm undersize (0.295 inches)
so tgats it I'm affraid.
u can get sleeves but I've got no experience in them and no idea how they work.
Old 02-02-2018, 12:12 AM
  #4  
Registered User
 
Thommo Thompson's Avatar
 
Join Date: Nov 2017
Posts: 331
Likes: 0
Received 0 Likes on 0 Posts
Actually nah sleeves are for the oil seal of tge the shaft only. So forget that.
have u got bad knock?
Old 02-03-2018, 02:19 AM
  #5  
Registered User
iTrader: (1)
 
wallytoo's Avatar
 
Join Date: May 2013
Location: nh
Posts: 1,885
Likes: 0
Received 805 Likes on 528 Posts
Originally Posted by gsp4life
I think .030" over is the max for rod and mains. Mine are .030" over and a reputable local shop thought that was reground to the max. My machine shop couldn't find bigger bearings when I asked about it (for future rebuild purposes). 22re performance only sells bearings up to .020" over and they were skeptical about using .030" over bearings.

My cylinders are bored .040" also, so when this one dies, I'll just build up a new short block. Sounds like a new crank might be in your future if you need a regrind and are already at .030".
wouldn't that be 0.030 under, rather than over, as the new rod or crank journals will be smaller diameter than original?
Old 02-03-2018, 07:21 AM
  #6  
Registered User
iTrader: (-1)
 
Co_94_PU's Avatar
 
Join Date: Dec 2012
Location: Colorado
Posts: 5,433
Likes: 0
Received 554 Likes on 452 Posts
Originally Posted by wallytoo


wouldn't that be 0.030 under, rather than over, as the new rod or crank journals will be smaller diameter than original?
oversized bearings (they are thicker), for an undersized crank shaft.
Old 02-03-2018, 09:18 AM
  #7  
Registered User
iTrader: (1)
 
wallytoo's Avatar
 
Join Date: May 2013
Location: nh
Posts: 1,885
Likes: 0
Received 805 Likes on 528 Posts
Originally Posted by Co_94_PU
oversized bearings (they are thicker), for an undersized crank shaft.
right, i guess it depends on which part. the journals get ground -under, while the inserts are thicker than standard. i'd always seen rod/mains listed as undersize for the thicker inserts, even though the inserts are thicker.

fwiw, the pistons in my flathead dodge are 0.060-over, and there are both 0.080-over and 0.100-over pistons available for it, although the walls between the cylinder pairs are pretty thin at 0.100-over. i'd probably sleeve it rather than use 0.100-over pistons, though.

Last edited by wallytoo; 02-03-2018 at 09:22 AM.
Old 02-03-2018, 04:13 PM
  #8  
Registered User
 
Thommo Thompson's Avatar
 
Join Date: Nov 2017
Posts: 331
Likes: 0
Received 0 Likes on 0 Posts
Not quite guys. Undersize means, the back face of the bearing is std and the journal face is undersize. (for shafts that have been ground back)
oversize means the back face of the bearing is larger but the journal face is std. (for block that have been ground out)
if u have found a supplier who sais (advertises their products) otherwise, they have cocked up and need to realign themselves with industry std nomenclature.
and believe it or not, u can't get both and under and over. If u grind the crank and machine the block ur stuffed. Haha.

Last edited by Thommo Thompson; 02-03-2018 at 04:16 PM.
Old 02-03-2018, 04:17 PM
  #9  
Registered User
 
Thommo Thompson's Avatar
 
Join Date: Nov 2017
Posts: 331
Likes: 0
Received 0 Likes on 0 Posts
Here is a diagram.
https://lh3.googleusercontent.com/pr...w=w227-h647-nc
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dntsdad
3.4 Swaps
59
10-15-2021 04:17 AM
The_One
86-95 Trucks & 4Runners
2
04-25-2017 09:50 PM
kazuya2416
86-95 Trucks & 4Runners
18
03-31-2017 04:24 PM
Rock Slide
95.5-2004 Tacomas & 96-2002 4Runners
63
02-07-2012 08:05 AM
Rock Slide
95.5-2004 Tacomas & 96-2002 4Runners
37
04-03-2007 08:26 AM



Quick Reply: Crankshaft turning



All times are GMT -8. The time now is 06:47 PM.