So I'm putting together my A15 & am trying to figure out the ring gap placement. the instructions on the ring box say to not align the gap with the wrist pin or the thrust side of the piston and for the oil rings it says to place the top & bottom cap rings @ 45 degree's to the oil ring. I assume this means place the gaps on the upstroke side of the piston but I'm curious how you experienced A series builders align your gaps.

I'd think it'd make sense to place them on opposite sides but hey, I haven't completely assembled a motor in 20 years so what do i know!

any helps appreciated!
Thanks ,Evan

The FSM only says: "Install piston rings at 180 degrees to each other, avoiding to fit them in the thrust and piston pin axial directions."

There is no photo. My guess is 30 degrees from the piston pin direction.

Also note:
* Fit "F" mark of pistons toward front of engine

Here's a SBC diagram:



Subaru:

Hmmm.. i see that every repair manual I have just repeats wording and diagrams/photos from the Factory Service Manual. But none are as complete as the FSM

The exception is the newest Chilton's specific manual (B110/B210/B310), which has their own wording and photos. It also has a lot of good general information with generic pictures.

It has a ring gap alignment position diagram. It shows all gaps at 45-degrees from the pin.

Be sure not to place the rings upside down!

Even in honda motorcycle manuals they have it the same as the subaru diagram and thats how I always do it and had no problems yet. Good luck

thanks for all the digging, I couldn't even find what you found in the FSM, I have the same manual in your pic, 71 version.

Just so I'm clear, the thrust side would be the downstroke & if you don't want ring gaps on that side how can one avoid it? Your going to have to end up in this area a little bit aren't you? It also looks like they've stacked a gap in one of the diagrams which I thought was a no no.

Thrust side is perpendicular to the piston pin. Both sides really...