Date: Sun, 29 Dec 2002 11:32:32 -0500
Reply-To: Bradley Flubacher <flub@ADELPHIA.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bradley Flubacher <flub@ADELPHIA.NET>
Subject: Re: diesel rods weights
Content-Type: text/plain; charset=us-ascii; format=flowed
John,
Thanks for your notes. I was very careful to punch numbers in all caps
and rods as I was taking the engine apart. This was a "factory rebuilt"
engine not many years ago. The vanagon was parked for six years before I
got to it.
I haven't noticed that the numbers stamped onto the caps were different
though. I'm not sure how reputable the rebuilder is that had done it
previous to me.
I've made the decision to remove the pistons and throw them on a scale
at my local post office. If nothing else, it will give me peace of mind.
I am sure that I've matched all the caps with their rods, as well as
the main caps.
It's looking like a nice little smoker!
Brad
jbclem wrote:
>Brad,
>
>On gasoline engine VW rods, the numbers are to make sure you keep the rod
>caps matched up with the other part of the two piece rod. Since the two
>circular holes(eyes) in the rods are resized(honed) with the rod pieces
>bolted together, when you take the rods apart to replace the bearings you
>need to have a way to reassemble them so that the individual rod caps are
>mated with their original partners in the same orientation that they were
>honed. When you have four sets of rods (8 pieces) laid out on a table and
>you're cleaning them and moving them around, it is possible to mix up these
>matched pieces. So you should have two pieces(rod and rod cap) with the
>nunber 64 on each piece, two with the number 74, etc...and when reassembled
>the numbers have to be on the same side, ie right next to each other when
>the pieces are bolted together. If you marked the rod pieces before you
>disassembled them that'll work as well. As I remember, the convention was
>that the numbers were on the same side as the knotches(that designated which
>way was up when the rods were laid out on the crank in a certain horizontal
>manner). This was for gasoline VW engines, and looking in a Bentley vanagon
>manual at the diesel engine there is no mention of the numbers but you are
>told to mark the rod and the cap before removing them for the same reason.
>Orientation-wise, for diesel connecting rod installing, the Bentley
>mentions this: "casting marks and retaining lug for bearing shell face
>toward intermediate shaft", along with a picture showing the casting marks.
>I hope you have a Bentley manual, these things(rod orientation and rod cap
>matching) are important both for the balance of the engine and future rod
>bearing wear.
>
>Sorry I can't be more specific, I've rebuild many gasoline VW engines but
>not one diesel. But given how much more stress is going to be on the
>crankshaft system in a diesel engine, I'd say these things are even more
>important. What do you do if you overlooked all this? Get out a bright
>flashlight and a mirror and look real hard to see if you can spot any marks
>that make sense, and hopefully you've got the numbered caps assembled
>correctly. As for the rods without numbers, if there are no marks at all
>and you have no idea if they are assembled correctly, then you have to find
>someone who has rebuilt enough VW diesels to know what exactly how important
>this is, and what you can get away with. If you used a set of rebuilt rods,
>they probably came assembled correctly, so if you put them back together the
>way they came then you might be ok, but call the machine shop that did them
>and find out how they mark them. In my case, in rebuilding a gasoline VW
>engine, if I somehow found out I have put a rod cap on backwards, even if
>the engine was all together I would take it apart again. I'm so paranoid
>about things like this that I don't think I even had this particular
>problem.
>
>Let us know what happens.
>
>John
>
>
>
>
>----- Original Message -----
>From: "Bradley Flubacher" <flub@ADELPHIA.NET>
>To: <vanagon@GERRY.VANAGON.COM>
>Sent: Thursday, December 26, 2002 11:33 AM
>Subject: diesel rods weights
>
>
>
>
>>I just finished assembling the bottom-end of my engine that I'm
>>rebuilding and noticed numbers stamped on the connecting rod caps. Are
>>these weights? Do I have to take out the pistons again and weigh them
>>each to make sure I have the weights correct? I saw one had the number
>>74, one had 64, and two had no numbers on them.
>>
>>Brad
>>
>>
>>
>
>
>
>
| 
