Diesel Crank replacement

[smithy010]

Anyone have a diesel and petrol piston out on the bench?

I think the old crank is grindable, i've just gotta decide whether a slight imbalance will not be a problem, so it doesn't cost me the cash for a grind.

[Golf Loon]

It all looks the same smithy. I dont reckon vw would have changed anything they didnt need to. Stuff it in and see how it turns.

[smithy010]

I thought about it a little more and realised that i have two pistons on one side of the crank and two on the other side, so the crank will be totally mass balanced. There may be some slight imbalances along the shaft... (negligible, according to my advanced mechanics course last year.)

All good.

Now to get some bearings, and get this baby running!

[Edison]

so the crank will be totally mass balanced.

Not really, your thinking on a different plane, it's wobble forces would be like one end of the engine up, the other end down. The mass of the piston sortof needs it's own weight balanced as close to the piston as possible, as you transfer it along the crank you get wobbles in other planes...don't you?

[smithy010]

That's what i meant by unbalance along the shaft. You're right in this way. I probably overstated it by saying it would be negligible, but the difference may not be much.

Hopefully the mass of the pistons will not be sufficiently different to upset the "wobble" along the crankshaft.

What do you think edison?

[Edison]

Stand back and crank it...

[Golf Loon]

Its not a high performance engine, I reckon it`ll work.
Get some bearings.

[smithy010]

Yep. 190 or so from tooleys for mains, big ends, and a bottom end kit.

Things are tough when you've gotta save up for something like that!

[Golf Loon]

Cheaper in the UK.
I can hook you up, or do some internet research.

[smithy010]

How about sharing your source loon?

I've found a pretty good place in the states... 100AU for Big ends, mains, gaskets, seals, and engine mount rubbers (left and right). Waiting for a quote on postage.