Re: AM Rings?
 

Lee,

I'm sure you'll get some good input from Jerry and maybe he is consulting with Graham Beham and I don't know if there is better information out there than what would come from him. :cheers:

What I don't understand is why Total Seal did not just reproduce the specs from the stock rings if they are going to claim the application fitment. I felt the same way when I was going by FSM specs and their rings did not meet specs of GM/Lotus engineers.

Re: AM Rings?
 

My understanding(an I know "0" about piston ring manufacturing).....is that this is the widest ring that they can get, period.

Pistons can be shimmed to accept other rings with some minor piston mods, and probably cheaper than going 368.

Re: AM Rings?
 

I have made the following illustration to clarify what I am referring to, when I expressed concern about aftermarket piston ring side clearance combined with cross-sectional width issues.

1. I am not stating for fact that Total Seal rings are too thin and too narrow and should not be used with OEM pistons.

2. What appears to be fact from measurements made during LT5 engine work by individuals posting here who are/have been involved in such work, is the side clearance of Total Seal rings in an OEM piston is greater than an OEM ring in the same piston.

3. What appears to be fact from the same sources and others i have spoken with, is the cross-section width of Total Seal rings is less than OEM.

4. The dimensional differences may or may not have any detrimental effect on engine performane or durability. I simply do not know.

5. The amount of excessive back-clearance due to a narrower cross-section width, is not of concern to me, as much as the combination of a thinner ring combined with a decreased cross-section width.

However, given a couple of well known facts pertaining to the subject, such as

1. Piston ring grooves DO wear, i.e. rings DO move in the piston groove
2. Pistons do rock in the cylinder, i.e. piston slap
3. Pistons normally stay centered in the cylinder during operation

I think it is reasonable to assume (in a stock LT5 piston and all other factors being constant) that a ring that is thinner and has less cross-sectional width that a stock ring, will move more in the piston ring groove. Accordingly, I also think it is reasonable to assume that the ring and piston will wear with a resultant decrease in longevity. Attempting to quantify the decrease would, at best, be a wild assed guess. Obvoiusly, the greater the differences (increase in side clearance and reduction in cross-section width) the more effect.

Like any experienced engineer, always add a caveat. Here's mine. Nothing herein is to be construed or misconstrued as a detrimental statement, fact or otherwise, regarding Total Seal piston rings.

Empirical data always supercedes theoretical, so try 'em & see if you really want to know for sure.
http://i190.photobucket.com/albums/z...sAMRingDwg.jpg

Re: AM Rings?
 

Great stuff Jerry...I am waiting doing more research...as my intent is to potentially sell this motor......

I will say a worn pistion groove is not the issue here, as I have 3 sets and all are the same. I did note that the piston side clearance on a few other 5K pistons I checked was about .03...so we are talking about .01 difference. I also see that .04 side clearance is not abnormal by most standards. Given my choice, I would like to see .02, but options are limited. I am currently looking a shim options