Piston Rings

[hughicol]

Hi

Come across a bit of a problem. Decided to re-ring my 914 2ltr. First problem was that the rings I ordered when they arrived, although they were clearly marked 914 2 ltr., they were the wrong size i.e. the ones on my pistons were top 1.5mm, middle 1.75mm and oil ring 4mm whereas the replacements were 2mm, 2mm and 4mm.

Back to the supplier who ordered in another set which had to come from Belgium. They arrived and seemed ok till I noticed that the 2nd ring was slightly different in that the original had a step on the bottom of the friction edge of the ring(that which contacts the cylinder) but the new ones had a similar step but on the inside of the ring(which contacts the piston body). Does anyone know if this will be detrimental to my engine or will it be OK? The rings fit fine having tried them on one piston.

[davidppp]

Hello there.

The design of oil rings is very variable: I have often observed such minor variations when swopping old rings.

I would not worry.

Do make sure the cylinders are properly honed though, and that the side clearance of the top ring is within factory specs.

I do not have enough experience with the 2L 914 motor to say whether they wear fast, but the forged 911 pistons do usually wear out in this place and its not usually worth reringing them.

Kind regards
David

[hughicol]

Thanks for that info. I will certainly clean the pistons well, gap the rings and the barrels have been well honed.

Regards

Dave

[davidppp]

Hello Dave.

Sorry, I was not clear in my post.

Gaps are never a problem..its the side clearance which is critical to the survival and perforamance of the top ring..use a feeler guage at several places round the circumference of the piston..you can do this beofer fitting the new ring by just inserting a segement of the ring and rolling it round the piston..checking as you go..

Kind regards
David

[hughicol]

Hi

It's OK I did understand your point.

Dave