Piston ring questions....

[bandit67]

Guys, assembling a 340 today and small block Mopar book says stagger ring gaps in alignment with the wrist pins, aka front and rear. I call that east and west. Ring manufacture suggests staggering gaps top and bottom, aka north and south. All my Chevy books show north and south. My two BB Mopar books do not address this as does not my other SB Mopar book.....what do y'all do. Seems what should be best would be best for all V 8s.

Next question, do you guys leave the plastic tits on the oil expander rings. Dad always took them off, saying they will end up clogging the oil pickup screen sooner or later. Ring manufacture says install the pistons with them on....hhhhmmmnnnn. The makers have spent big bucks on research and development as well as bucks to install them on the ring, seems they should know best.........thanks.....

 

[Fran Blacker]

No experience with your plastic tits. Maybe they leave them on while installing rings on piston and remove before install in cylinder?

 

[440Coronet500]

I stagger the ring gaps. 440'

 

[Ranger16]

I'm no engine builder, but common sense tells me stagger each one 180°. That said, they are going to rotate anyway so I'm not quite sure how important that is anyway.

EDIT:
I meant to say 180°, not 90° and edited it as such.

 

[HEMI-ITIS]

Rings come with directions,do as they say!

 

[Bighead440]

I personally don't sweat it too hard, as (stated above) they rotate anyway on their own when the engine is running. Make sure they are installed by the directions as far as top/bottom because of the relief or taper being important for compression sealing (top ring) and oil "scraping" effect (2nd ring). I install the top and 2nd ring gaps 180* apart front-to-back (aligned with the pin), and I put the expander (LEAVE the plastic ends on, if present) gap at the bottom of the cylinder (perpendicular to the pin) and the scraper ring gaps 90* apart at the top of the cylinder. To me, this leaves a "reservoir" of some oil between the scraper rings and below the drainback slots or holes in the oil ring groove for storage and break-in. Just for peace of mind, but if they are gapped properly and oriented properly as far as top/bottom (dots up, etc.), you won't ever know any difference.

 

[HEMI-ITIS]

I also install the pistons DRY!

 

[Bighead440]

I also install the pistons DRY!

Old timers used to soak the whole pistons in a coffee can full of 30wt-LOL. I always read to wet the skirts and leave the rings dry, and just lightly wipe the bores. Once when building a Ferd Cobra 4.6L DOHC supercharged engine, I had Total Seal make me some stainless steel top/ Napier second rings for ICON forged pistons. They supplied some powder (yes dust!!) and said wet the shirts and dust the bore and no liquid oil on the cylinders or rings besides what was on the skirts. Did it and it worked fine.

 

[turbine68rt]

This is how I installed mine. Worked out fine and runs great so far.

 

[bandit67]

Thanks Guys, turbine68, your diagram is the way Chevy books recommends but the Mopar A engine book shows that setup shifted 90 degrees , thats why my question. My last two ring sets instructions just show to stagger the rings but no orientation. I have always heard they 'move' but wonder do they ALL move equally or just some slightly. They say the plastic tits ensure the expander rail is not overlapped and to ensure that prior to installing the ring compressor. That tells me they intend them to be installed. Back in my Dads day, he dunked everything in motor oil prior to install....but his favorite were chrome rings....not sure they even make them anymore. I agree, "DRY" is the ticket. Thanks much for your patience....my knowledge of Mopars is limited, so I need the books...but you guys have experience ....

 

[turbine68rt]

I have seen diagrams suggesting to index the gaps with either the thrust or wrist pin side. Not sure what difference it makes from brand to brand since the 4 stroke principle remains the same. I'm thinking as long as the top and 2nd ring are 180° opposed it provides the least amount of leak path by the time combustion is completed. Maybe someone could explain the reasoning in greater detail, I've just experienced good results on my particular engine using that orientation, keeping in mind that over time the orientation will shift a certain amount.

 

[HEMI-ITIS]

No need to overthink this.Main concern is the final hone and ring gap.

 

[bandit67]

Good stuff....slugs going in today......