Hi,

I am putting my engine back together feeling sure if it is possible for me to get something the wrong way round- that's how I'll do it!

The Nanni pistons have ridges and arrows, but no side notch. I'm now realising that I may have got the right piston nearest oil pump orientated wrongly as the higher part is towards the plug and the arrow facing the flywheel:bang:. Can anyone confirm I have got it wrong?

Many thanks,

David

Forget about the patterns on the top of the Pistons. When you assemble the Pistons onto the conrods you must ensure that the 2mm offset on the gudgeon pin is towards the side of the big end rod caps that have the numbers stamped on them. Then when the Pistons and barrels are fitted the conrod numbers face the camshaft.

Thanks Toshi,

Nanni also said that the arrows should face the flywheel. I'll take it apart again and look for the 2mm offset . Many thanks.

Possibly a silly question but are you following a manual when you assemble the engine? I have lost count of engines assembled but still follow a manual each time just in case I forget something. I have got an older 540 Nanni kit and the piston crowns are cast rather than machined like the ones you have. If you can when you assemble the Pistons it is good practice to try and stagger the gap in the rings around the circumference. I will say hi for you to Auckland when I touch down there on Thursday