Boxster piston ring end gaps?

[Homeoboxter]

Originally Posted by marsheng

The ring gap will seldom change down the bore. The ring wears and opens up the gap. If there is wear in the bore, you will feel a lip just above where the ring stops at the top. No step, bore ok.

Yeah, I checked that, I think the bores are fine, there`s no lip. It`s possible though that there`s some ovality, and the wear may be different along the bore due to the different piston speeds at different heights. So I`ll measure this just in case. BYprodriver also had a fair point when suggested that if the wear is substantial I may have a better seal with the original rings in the same position than with new ones. But most likely it`ll be fine with a fresh ring set once I find one. I think I`ll just go ahead and order a set for the 2.7 and send it back if it doesn`t fit, but I doubt that.

[marsheng]

Originally Posted by Homeoboxter

BYprodriver also had a fair point when suggested that if the wear is substantial I may have a better seal with the original rings in the same position than with new ones.

Rings can rotate during their life so there are no original ring positions. Always give a light hone before installing new or old rings to help bed them in. .

Cant find the link on running in a motor but if you are using old pistons, a few squirts on the accelerator with a back of is all that is required.

Have you ever see race cars do 10000 miles as slow speed to run them in ?

New pistons, new hone, 2 - 3 heat cycles and pedal to the floor.

Quite and old video of mine.

https://www.youtube.com/watch?v=PsEFKYULNDc

Cheers Wallace

[Homeoboxter]

Originally Posted by marsheng

Rings can rotate during their life so there are no original ring positions. Always give a light hone before installing new or old rings to help bed them in. .

Cant find the link on running in a motor but if you are using old pistons, a few squirts on the accelerator with a back of is all that is required.

Have you ever see race cars do 10000 miles as slow speed to run them in ?

New pistons, new hone, 2 - 3 heat cycles and pedal to the floor.

Quite and old video of mine.

https://www.youtube.com/watch?v=PsEFKYULNDc

Cheers Wallace

Thanks Wallace,

Yeah, I meant the same rings to go back to the same cylinders.
What do you use for honing? Just a honing tool in a drill or you take it to a machine shop?

12500 rpm is not bad for a 4T single . What can the CB125 twin do, if the singe can be spinning like this?