Going to be installing the pistons in my 305 this weekend. Ring package box only has minimal instruction about the oil ring. Rings are Hastings with a moly top ring.

Do you have a prefered method of clocking the rings, putting the gaps of certain rings in certain positions ? How much does it matter ?

Thanks

 

I do 180* offsets on the compression land rings. I've heard if you do 0* offset you can have excessive blowby. I also did 180* on the oil rings, because I planned on 75 psi pressure. I've also heard 90* on oil rings is good.

 

I think clocking them is kinda a waste of time. I suppose offsetting the gaps is a good idea, but I never really worried about it much.

getting the oil ring on was kinda tricky, unless you put the lower backup ring on, then put the wavy ring on 90* offset, then the top backup ring on 90* offset again. otherwise it just keeps popping out. dip the pistons in a coffee can of oil before installing in the block (IMHO).

 

several manuals have the diagram of what ring goes where. off the top of my head i don't remember but i'm thinking it's something like the gaps at 10, 2, 5, and 7 o'clock positions. you don't want a gap over the wrist pin

 

I believe this is very important especially for forged pistons since the clearance at the top of the piston when cold can be as big as .040". The ring gaps are positioned differently for pistons on each side (bank) because when the engine is under load the piston is against the thrust side of the cylinder wall. This leaves the gap at the top of the piston predictably on the opposite side of the cylinder. Oil consumption and blowby are controlled best when the gaps are both: A. totally inside the piston groove under load and, B. spaced away from the corresponding "next" ring.
Click this picture.
(and it costs nothing to do this)