

| Subject: | Re: Fwd: Boston Bob on Connecting Rod Bolts |
| From: | Evan Mac Donald |
| Date: | Tue, 7 Sep 2010 16:46:28 -0700 |
I did not send my rods to Bob before he passed. Since the business has passed into other hands, the rebuuilding of rods as a service is not listed anymore.�Now, I need to find a different source for this job. Has anyone heard anything, good or bad about this outfit: http://www.thesamba.com/vw/classifieds/detail.php?id=931786 I hope to get�my rods out this time, before something bad happens again... ________________________________ <<Snip>> >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. >>snip<<
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