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Pinto piston ring orientation
lobsterissimus - 5/5/16 at 03:23 PM

Hi all,

I'm preparing to put my 2L Pinto engine back together with a load of new parts including piston rings.

I've gotten a set of Mahle piston rings, which don't come with any instructions on how to orient the rings.

I've had a search online but didn't find anything specific to a Pinto.

I've also got the Haynes Sierra manual which says to "fit the oil control ring sections with the spreader ends abutted opposite the front of the piston. The side ring gaps should be 25mm (1" either side of the spreader gap."

My best guess translation of the Haynes verbage is:
- fit the central (wrinkled) oil ring so its' gap is facing the rear of the engine
- fit the two support oil rings so their gaps are 1" either side of this

i.e.:


Can anyone confirm whether I'm right/wrong on this?

Ta, Mike


mark chandler - 5/5/16 at 05:16 PM

Piton rings turn on the Pistons in use, depending on if they are at the top, bottom or middle they go at different speeds, typically around 30rpm in normal use.

It does not matter, just clamp up where it's easy as after a few seconds running they will have all moved.


perksy - 5/5/16 at 08:56 PM

They should be free to turn after fitting and as said above they move anyway

Just me but I usually set the gaps 120 deg away from each other so they aren't all in line initially

Make sure the gaps are correct, they are correctly orientated and well lubricated & free to turn


There is a set of films of a chap re-building a Pinto from start to finish on youtube, might be worth a look ?


nick205 - 6/5/16 at 07:43 AM

When I rebuilt my 2.0 Pinto I was lucky enough that the company that did the clean up supplied new pistons already fitted with piston rings. IIRC the gaps were in different positions to start with and I assumed they were right. I fitted the pistons as received and never had any problems. On the rolling road the operator said the engine felt smooth and solid so I was happy. It didn't burn any oil either and the compression test looked good after 1k miles.


lobsterissimus - 9/5/16 at 08:47 AM

Cool, thanks for the replies.

Shouldn't take the Haynes manual as gospel I guess...