Dubai944

You could use my old ones..they are proven..haha.

I didn't bother with rebalancing. Getting anything done properly in Dubai was a nightmare so I just put it together myself with as much care as possible.

67King

Planar cranks (I-4's and Ferrari V8's) can be balanced all individually. So there's no problem with balancing only the pistons and/or rods.

Wossner makes good stuff. Will be going in my 3.0L 16V turbo if I ever get my race car back together. Wossneronline sells them for I think $860 or therabouts, so they are a more affordable option than the ebay ad you linked.

Laust Pedersen

The balance shafts and the crank counter weights will not be optimized as they were from the factory, but people have tried extremes for other reasons (no balance shafts and knife-edged crank) without disastrous consequences. Although I personally found that the engine was shaking too much, when briefly running with a broken balance belt.

To assess how far you are from the factory balance, just calculate the relative weight change in % (piston + con-rod) between OEM and you intended configuration.
I suspect this is a small number and not worth a re-balance.

Laust

blade7

?.

Eric_Oz_S2

I'm leaning towards just replacing the rods and rod bearings and checking the piston rings when the pistons are out.

LUCKY DAVE

We use Carrillo rods in our supercharged/nitrous land speed Aprilia "The Punisher".
We're making 380 rwhp with a twin cylinder 1060cc engine, and so far are the only twin to go 200 on a high speed mile.
Carrillo - when only the very best is good enough.

George D

Under $999 with shipping? If this is the case, worth consideration. Forged rods from Wossner are best of the parts bin.

Eric_Oz_S2

steve (or anyone)

What is the normal life (when max gap is exceeded) of piston rings in this engine. I know it 'depends', but in general do they tend to exceed tolerance after 100,000 miles? If they are still in tolerance is it worth changing them, or will this risk other issues with bedding new rings into the 'worn' (but still in tolerance) bores ?

Dubai944

Have you done a leak down test on your engine? I am still getting less than 3% on all four cylinders with new rings in the old untouched S2 block bores.