Date: Sat, 27 Oct 2001 20:10:14 -0400
Reply-To: Robert Donalds <bostneng@FCL-US.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Robert Donalds <bostneng@FCL-US.NET>
Subject: Re: B. Bobs 2.1 main bearings, one more question
Content-Type: multipart/alternative;
----- Original Message -----
From: Kenneth D Lewis
To: bostneng@FCL-US.NET
Cc: vanagon@GERRY.VANAGON.COM
Sent: Thursday, October 25, 2001 2:44 PM
Subject: Re: B. Bobs 2.1 main bearings, one more question
Bob;
OK. I measured the bearing ID( in the case) and the crank's OD. Subtraction should give me the clearance. What is tolerance here? How about differences in orthaganol ID measuments i.e. out-of-round?
Anybody know of some good WEB sites with this info?
TIA
Ken Lewis
86 Crewcab,60 356
http://Neksiwel.20m.com/
Ken
I looked in the VW without guesswork book for out of round (orthogonal) dimensions for the crank rod and main journals it says the cranks on the type 1 and 4 engines can be out of round as much as .0012 ths
I dont often see that kind of wear on 2.1 cranks they are for the most part mint or junk. I would say that the crank is ok if its less than .0005 ths small or out of round more than that I would consider not using it. Regrinding has not been an option until the past few weeks I now have in stock some .010 mains for a std case
The 2.1 blocks tend to shift and also get smaller at the center main bore. The 2.1 main bearings are made with an huge oiling depression at the case seam. While thats great for feeding the crank oil that makes it realy hard to get a good reading at the parting line of the case with a bore gauge. I have not found specs on the 2.1 cases in any of the crank spec books or the VW info. The 2.1 case is often out of round as is the the 1.9 and the type 4 case due to the cases alignment dowel pins (not the main bearing dowel pins) gaining some play over the years I have found that a block of wood and a wack of the hammer can realign the case halfs so the measurements can be taken. The main bearings can help (not cure) align the case as the case is closed with the bearings in place. I have more than once seen the bearing measurements show that the main bearing bore is still not round due to the case shift. I would say that if you measure the main bearings in the case with it torqued and they do not go lower than the minimum clearance in any one place you are good to go. I would add to that statement that it is realy hard to measure less than .001ths and be consistant every time so check it more than once then check it the next day again.
Bob Donalds
http://www.bostonengine.com
as always all rights reserved
I
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