Compression rings

[sw2dude]

So whats the consensus on the upper compression ring? Whats the better choice 1.20mm or 1.50mm?

I should add, Im planning a rebuild on a 95 dohc. It seems like you can go either way with this year. Your thoughts?

[OldNuc]

Depends on where you live and if you have emissions inspections. The secret is to check the dimension of the piston crown to the top of the top ring grove and go with the one with the greatest dimension. If they are identical then the 1.5mm is considered a stronger ring. The minimum top dimension and thin ring is the lower emission setup.

The manufacturers catalog for the pistons has these dimensions. I am jumping to the conclusion that you are looking at the Federal Mogul Sealed Power pistons.

[sw2dude]

Sorry for not being more detailed in my original post. Yes, thats correct, sealed power wh845cp .50mm have a 1.2mm top ring and the wh846cp .50mm have a 1.5mm ring, these will both work for me I'm just not sure of the benifit of th 1.5mm ring. The mid 94 and later models all have 1.2mm top rings, did saturn figure something out in 93-94 and make design change to the thinner ring for a reason maybe??? I have read that the distance from the top ring land to the top of the piston is beefer on the 1.5mm pistons. Also I'm going for a mild build maybe a 2nd intake cam. Its going to be a DD. This is why I'm not sure which ones to go with but I'm leaning towards the h846cp 1.5mm pistons.
RING KITS: wh845cp .50mm=E933K wh846cp .50mm=E932K

[sdowney717]

thinner rings equals less friction.
I would use chrome moly anytime i can get them.

http://www.hotrod.com/techarticles/e...ech/index.html

The impetus for these changes has been OEM requirements to reduce friction for improved gas mileage and better sealing for emissions reduction

chrome moly are really good rings last and last.

[OldNuc]

The thinner ring allows decreasing the crown height and this reduces the amount of unburned fuel that is exhausted. It is an emissions issue. The thinner ring reduces the stress on the thinner top of the piston. I have the cam mod and like it and I used the 1.5mm rings. As long as you do not have the tail pipe Nazis to deal with then build it up a bit.

Originally Posted by sw2dude

Sorry for not being more detailed in my original post. Yes, thats correct, sealed power wh845cp .50mm have a 1.2mm top ring and the wh846cp .50mm have a 1.5mm ring, these will both work for me I'm just not sure of the benifit of th 1.5mm ring. The mid 94 and later models all have 1.2mm top rings, did saturn figure something out in 93-94 and make design change to the thinner ring for a reason maybe??? I have read that the distance from the top ring land to the top of the piston is beefer on the 1.5mm pistons. Also I'm going for a mild build maybe a 2nd intake cam. Its going to be a DD. This is why I'm not sure which ones to go with but I'm leaning towards the h846cp 1.5mm pistons.
RING KITS: wh845cp .50mm=E933K wh846cp .50mm=E932K