Modern_man

I'm worried about the "kife edging" that BIG NIPPER did on his crank, I thought about doing the same on mine (ABA crank), but I drew it on Auto CAD, as a solid and got that lightening the crank the way he did woud raise the center of gravite to de side of the rod journal, then the crank woud not get properly balanced. Although some shops only balance pieces considering them in two halfs, it would cancel the efect and the crank could be balanced, but taking it as indivudal cilynders it won't get balanced that way. I think that for such a powerfull engine, it would be better to left aome more material on the counterweights.
Any suggestions?
<img src="http://www.erichsueh.com/Images/BEAST/knifeedged.jpg">&lt;br /&gt;

Audi2ptzero

Oct 2002.

Modern_man

I'm jtalking about the way it has been done on the picture, it has been lightened way too much.....
I Understand as "knife edgeing" just reshaping the edge of the counterweight in a way it can easily pass through the oil.

Audi2ptzero

remove weight and so it can cut thru the oil with less resistance. But either way the shop will still have to balance it.

Modern_man

I know that, but I think I couldn't give a clear explanation.....
What a said is that the way it was done on the crank in the picture, it lightened too much of the counterweights.
Consider each cylinder separately, the counterweights are meant to balance the weight of th rod journals... What I said was that in a crank done like that, the counterweights will be lighter than de rod journals, getting each cylinder out of balance.
When you consider two cylinders at the same time, you wont fell this, because of the two rod journals balancing each other.
There are engines that don,t even have counterweights,the vw T1 was that way, so there were people who welded counterweights to them, so they could run smooth at high RPMs.
It sure would be heavier, but at least it wouldn't destroy itself at high rpms on a powerfull engine.
Audi2ptzero, is your crank done like that? Or did you left more material on the counterweights?

Audi2ptzero

Might even be a chance that the crank your looking at in that picture is my stock 1.8t crank that DRS had knife edged before we decided to go to a 2 liter crank for my engine.

Modern_man

I will remove less material on mine, and concentrate on a much lighter flywell (maybe even aluminum)