VW VR6 balancing

[Dave Koehler]

VW VR6 (15 degree banks)
Anyone worked on one of these yet?
Looking for a balance factor.
Been screwing around reverse engineering it and nothing makes sense yet.
Thanks

[Keith Morganstein]

VW VR6 (15 degree banks)
Anyone worked on one of these yet?
Looking for a balance factor.
Been screwing around reverse engineering it and nothing makes sense yet.
Thanks

[Dave Koehler]

That's kind of what we are thinking with a but.....

Working down to 30% so far and nothing apprciably changes. This would indicate that bobweights are not needed. Here is the BUT.... Without bobweights it is out 80 grams. We will drop down some more percentage wise to see what happens. I am beginning to wonder if there is a countershaft with a similar setup to the Detroit Diesel or this one is just bad or VW screwed up or didn't think it mattered. Lot of ORs at the moment.

This crank spit a rod. Crank was straightened, welded and ground. Stroke matched up fine on the welded journal.

[Keith Morganstein]

That's kind of what we are thinking with a but.....

Working down to 30% so far and nothing apprciably changes. This would indicate that bobweights are not needed. Here is the BUT.... Without bobweights it is out 80 grams. We will drop down some more percentage wise to see what happens. I am beginning to wonder if there is a countershaft with a similar setup to the Detroit Diesel or this one is just bad or VW screwed up or didn't think it mattered. Lot of ORs at the moment.

This crank spit a rod. Crank was straightened, welded and ground. Stroke matched up fine on the welded journal.

You're right, they do have a balance shaft.

[bobqzzi]

That's kind of what we are thinking with a but.....

Working down to 30% so far and nothing apprciably changes. This would indicate that bobweights are not needed. Here is the BUT.... Without bobweights it is out 80 grams. We will drop down some more percentage wise to see what happens. I am beginning to wonder if there is a countershaft with a similar setup to the Detroit Diesel or this one is just bad or VW screwed up or didn't think it mattered. Lot of ORs at the moment.

This crank spit a rod. Crank was straightened, welded and ground. Stroke matched up fine on the welded journal.

You're right, they do have a balance shaft.

VRs don't have balance shafts

[SchmidtMotorWorks]

Without bobweights it is out 80 grams.

Are both ends out the same?

Are the rod journals single or offset/split?


If they are single (not split) I'm thinking there would be a bob-weight but it would be small something like 100% rotating plus 10% reciprocating (just guessing), I'll look in some books that might have some clues about this tonight.

[panic]

[Adger Smith]

Call Hines
I had a outboard that I couldn't figure out & they sent me the info. They might have the VW info.

[gem]

AERA info lists a 50% reciprocating factor in TB1896. In their Prosis software under crank specs it is listed as 30% reciprocating.

ABS Products claims a balance factor of 38% reciprocating and 100% rotating. They claim their info comes from an OE source that says this is the value used in production.

I have used 50% reciprocating successfully in the past before I had the conflicting information. Now I'm unsure of what I would do. I would probably split the difference between AERA's two values and go with the 38% of ABS.

[panic]

[Dave Koehler]

Thanks everyone. Fun, ain't it?

Panic
Please say what you are getting at and where you are going with it.

[Dave Koehler]

Update: Rounded up another untouched assembly and 30% matched up on the button so that's what we went with on the problem child.

Interestingly enough after enough digging I finally found the 30% figure in some old notes....after the job was done.

[panic]

Sorry if accurate data breaks your concentration.

Oh wait - was it my job to solve to solve your problem?
my bad.

[Dave Koehler]

Panic,
All you had to do was expand on your one line comment. Oh wait.. you didn't have an answer.

Actually, I solved my own problem without your high and mighty attitude.
You might as well delete your response since you delete all of your other one line comments throughout this forum.
Since you are on a higher plane why do you waste your valuable time here?

[bill jones]

-Dave---could you post the weights of the stock components and the final bobweight number you used to get your balancing to come out right at 30%.

-Was the first engine you started out to balance lightened up in any way---to where it was balanced different than stock?

-Did you add a few grams for oil?
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-the one VR6 I have dealt with had 630grams reciprocating and 513.5 rotating of the stock components.

-when we had it balanced to the new components we had 617 reciprocating and 500 rotating.

-I assume that you use 100% of the rotating weight and then subtract 30% from the reciprocating weight---and add those numbers together for the bobweights?

-If this is right the stock VR6 I had should have balanced out at 954.5 bobweight--and the rebuilt VR6 should have been balanced with a 931.9 bobweight---is this correct to your way of thinking?
---------------------------------------------------------------
-I thought that I had asked the same question here on Speedtalk about balancing the VR6 about a year ago----can't seem to find that thread anywhere-----but I never found any joy.

-So I sincerely appreciate your effort in finding out and then displaying your findings for this engine.