Club 80-90 Forums

Hi,

Does anyone know the actual piston/bore size for the 1.7D KY engine?

I'm looking for the correct match for the second repair oversize. That is 1mm oversize, I believe. I want to order the pistons from tornau-motoren.de and they say the size is 80.51mm. Is this the actual piston size, or the size of the bore?

https://www.tornau-motoren.de/kolben/ko ... iston.html" onclick="window.open(this.href);return false;

Any help or advice is much appreciated.

Thanks,
Andrei

I'd say it's the bore size.

Zylinderbohrung 80,51 mm / Bore size

https://translate.google.co.uk/?hl=en#a ... derbohrung" onclick="window.open(this.href);return false;

Hole based fit, clearance is allowed on the shaft/piston. When a hole/bore is machined it goes size to oversized. The piston manufacturer includes the running clearance.

That would be the bore size, as stock is 79.5mm, pistons are smaller and are not perfectly round.

As bigherb, cold, the pistons measure smaller in line with the small ends. When hot, the pistons expand/distort to become round.

Thanks a lot, it's clear now.

I have to start researching the crankshaft, or how to get it into the best possible shape