VW VR6 balancing

Post by **Dave Koehler** » Sat Mar 08, 2008 7:20 pm

Bill,
Will get the numbers for you on Monday.
Dave K

Post by **Dave Koehler** » Wed Mar 12, 2008 9:08 am

Bill,
I think you meant to say subtract 70% to achieve the 30% factor.
(or multiply times .3 or 30%)

Here is what we had from the std bore oem test subject

piston/pin 408
rings 28
locks 2
big end 477
small end 175
rod brg 28
oil 5

613 recip
510 rot

693.9 bobweight calc @ 30% recip

The untouched oem std assembly with the above bobweight was 3gm heavy each end.

bill jones · Post by **bill jones** » Wed Mar 12, 2008 12:14 pm

-Thanks Dave----your info makes the situation much more clear.

-The stock VR6 I was working on needed a 702.5 bobweight stock and a 685.1 with the changes we made---figuring a 30% reciprocating factor.

panic · Post by **panic** » Wed Mar 12, 2008 8:04 pm

Silly me - here all along I've been laboring under the misapprehension that any data that appears not to be already known and is relevant to the question would be potentially helpful.
Since the comments prior to mine were in error regarding how the V angle was achieved, giving the journal offset angle (not given) would be progress, as was the fact that all the rod geometry would be strange due to double and opposing desaxe. Both of these factors strongly affect 2nd order vibration.
If I had an answer, you would have read it. I just assumed that you would understand how significant both of those factors are if attempting to adapt/modify an existing balance factor or method.

It appears that unless it answers your question, it isn't welcome. You don't want a discussion - you want someone to do your job.
But please feel free to berate me for trying to help.

bill jones · Post by **bill jones** » Wed Mar 12, 2008 9:17 pm

-excusssseee me?