Crankshaft lightening

[Rusty]

Anyone knw how much a new 3B pulley is? Not too keen on fitting a secondhand one as it'll be a minimum of 16 years old...

[aelred]

I have a brand new 3B pulley. PM me if you are interested

[Albert]

I recommend http://www.pk-motorsport.de/ for the crank lightening

[Tommy200rs]

There are many stories of balancing the 5 cylinder engine. The dynamic zero balancing method with variations

- balance all eng. parts to zero separately and then add them together and fine tune balancing the package again to zero
- with/without the bobweight %-approach

etc.

Some googling:

http://en.wikipedia.org/wiki/Straight-5

Inline5 should have section here:

http://en.wikipedia.org/wiki/Engine_balance

Using balancing machines with modern SW and balancing station, but:

http://www.crankbalancer.com/

CWT Training video collection:

http://www.cwtindustries.com/Mutlt-Bal%205000.htm

http://www.youtube.com/user/CWTINDUSTRIES

Lecture for applying the theory later for inline 5 as homework:

http://video.aol.com/video-detail/module-4-lecture-3-in-line-engine-balancing/644282338

Inline 5-cylinder engines and their balancing:

http://www.autozine.org/technical_school/engine/smooth2.htm

" it generates end-to-end vibration like 3-cylinder engines, because piston 1 is not in the same position as piston 5, and piston 2 is not in the same position as piston 4. Therefore both ends of the engine will vibrate up and down with respect to the engine center. "

http://www.vibratesoftware.com/html_help/html/Diagnosis/Engine/first_order_engine.htm

http://www.vibratesoftware.com/

Article "The Balancing Act” Balance the design, or design for balance ?" tells more
http://www.tuev-sued.de/uploads/imag...08_smith_e.pdf
page 10
- dynamic balancing table approach
- section 4.3 5 cylinder case with measurements

Means and method of balancing multi-cylinder reciprocating machines
http://www.freepatentsonline.com/4545341.html

Balancing of the second order couple of a 5 cylinder in-line combustion engine
http://www.freepatentsonline.com/EP0462411.html
(use translator)

5-Cylinder Inline Design Project

http://sun-valley.stanford.edu/~hlj/projects/engine.doc

The article "Balancing act" has link to this company in UK

http://www.vibrationfree.com/

http://www.vibrationfree.co.uk/C&SC%20GG%20SPECIALIST.pdf

- most probably a good choice based on found articles

Is there some S2 forum experiences from vibrationfree company to Audi 5 cyl engine balancing ?

DE Balanced:

http://www.pk-motorsport.de/Gallerie_bilder/2,5l%20Kurbelwelle.JPG

http://www.bamotec-symt.de/motorenteile.html

a long feinwuchten story in Meckis forum:http://www.meckisforum.de/phpBB2/vie...welle&&start=0

PS.
googling also found the 5 cylider mega stroker: The 3.0 liter OM617

[dkw_dude]

Nice links!
Slightly o.t.: A 5 cyl engine with even more displacement here (3653cc 102mm stroke x 95,5mm bore ) GM LLR: http://en.wikipedia.org/wiki/GM_Atlas_engine#LLR

[Tommy200rs]

Balancing done in practice (no lightening) here:

http://www.s2forum.com/forum/showthread.php?t=43652

[QuattroFever]

to get the maximum weight off the crank, should the counterweights match the weight of the piston rod assy? or not relevant if the flywheel and front pulley is balanced to counteract the missing weight?

the flywheel has a much larger diameter than the crank so I'm guessing that drilling and adding heavy metal slugs on one side and just drilling the other would give enough balance on removing quite an amount of metal from the crank.

How could you even begin to work out how much metal is "safe" to remove before you've gone so far that it can't be balanced because the flywheel doesn't have the capacity to do so.

And which would provide the "smoothest" engine. balancing the rods and pistons to the counterweights or removing as much as possible from the crank and using the flywheel to balance?