M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: Gunni on March 01, 2007, 04:00:42 AM

Title: Piston rings
Post by: Gunni on March 01, 2007, 04:00:42 AM
I can seem little blue smoke sometimes when Iīm on the throttle for a while,
and since the head has been checked thouroughly and recently put on,
Iīm suspecting the rings arenīt holding up that well, I havenīt done a compression test yet and really should get to that.
but in case they are bad
what do rings cost and wich ones should I be getting?

I figure when I remove the head again to install a MLS Iīll pop out the pistons
and replace the rings
Title: Piston rings
Post by: cecotto on March 01, 2007, 01:22:24 PM
Quote from: Gunni;20349
I can seem little blue smoke sometimes when Iīm on the throttle for a while,
and since the head has been checked thouroughly and recently put on,
Iīm suspecting the rings arenīt holding up that well, I havenīt done a compression test yet and really should get to that.
but in case they are bad
what do rings cost and wich ones should I be getting?

I figure when I remove the head again to install a MLS Iīll pop out the pistons
and replace the rings


I've seen quite a few M42 engines with worn rings, you might be right about this being your problem as well.

The donor engine for my stroker project had this exact problem. And actually my current engine has it too.

I recomend you have your cylinders given a light hone before installing the new rings. This will aid bedding in the rings, and give you good sealing.
Title: Piston rings
Post by: Gunni on March 01, 2007, 03:56:45 PM
I can get new pistons and rings for $240
Iīll see what new rings locally are and if getting these new pistons would be only just more exspensive, and they are not forged
just cast