Date: Mon, 6 Sep 2010 19:09:10 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Fwd: Boston Bob on Connecting Rod Bolts
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very interesting.
then the only 'good' 2.1 rod is a fully and properly rebuilt one.
----- Original Message -----
From: "David Beierl" <dbeierl@ATTGLOBAL.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, September 06, 2010 6:05 PM
Subject: Fwd: Boston Bob on Connecting Rod Bolts
> >Date: Mon, 4 Sep 2006 10:50:11 -0400
>>Reply-To: ROBERT DONALDS <donalds1@VERIZON.NET>
>>Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
>>From: ROBERT DONALDS <donalds1@VERIZON.NET>
>>Subject: Re: Connecting Rod Bolts
>>Comments: To: Evan Mac Donald <macdonald1987@SBCGLOBAL.NET>
>>To: vanagon@GERRY.VANAGON.COM
>>
>>Evan
>>1.9 and 2.1 rods are the same casting and are interchangeable with the
>>exception of the bolt. The longer stroke 2.1 cranks in combination with
>>the
>>1.9 rod bolts can but do not always hit the camshaft
>>The 2.1 rod bolt work well for 150K and I have seen these stretch to yield
>>bolts reused with failing.
>>2.1 rods distort over time by this I mean the big end is no longer round.
>>The cap shifts and the big end gets smaller opposite the parting line.
>>Another way to say that is if you draw a line down the rod from the small
>>end threw the beam of the rod threw the big end the circle is smaller at
>>that point. So just replacing the bolts is not the cure for the 2.1 rod
>>problem. The big end needs to be resized to do this I have a cap grinder
>>it
>>trims a few thousandths off of the mating surfaces of both the rod and
>>cap.
>>After deburing the hole and installing new non stretch to yield bolts and
>>reassembling the rod I torque the nuts and resize the big end with a
>>sunnen
>>rod hone. Machine shops have spec books to provide dimensions for the
>>finished size.
>>I take the next step and that is to install rod bearings torque and
>>measure
>>difference between the size of the ID of the big end with the bearing in
>>place The size of the rod journal this is clearance to the crankshaft. The
>>difference influences the warm oil pressure.
>>used rods with the 150K measure as much as .004ths bearing clearance this
>>is
>>enough make oil light come on at an idle. My engines have a rod bearing
>>clearance of .0015ths. and I can say that because I have invested in the
>>right equipment to properly measure clearances and restore dementions.
>>
>>you CANT just replace the bolts unless you only want 6k out of the engine
>>
>>my rebuilt rods are $140 exchange with news bolts ready to install
>>Rebuilding is about restoring clearances
>>assembling is about adding parts
>>at Boston engine you get more than parts
>>
>>Bob Donalds
>>Boston Engine
>>
>>all rights reserved
>>
>>
>>----- Original Message -----
>>From: "Evan Mac Donald" <macdonald1987@SBCGLOBAL.NET>
>>To: <vanagon@GERRY.VANAGON.COM>
>>Sent: Monday, September 04, 2006 8:51 AM
>>Subject: Connecting Rod Bolts
>>
>>
>>>I have heard that the bolts for 2.1 l con rods are not the greatest, and
>>>should be replaced on a rebuild with 1.9 l bolts. I don't have any 1.9 l
>>>engines around I could steal them out of, and would also worry about
>>>re-using "tired" bolts in an upgraded rebuild, anyway.
>>> Does any body have any suggestions? I haven't had much luck on my own,
>>>but I also have no idea what other bolts may be a usable substitute.
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