Rings

[jaluhn83]

I've got a set of new old stock ducile iron rings for the truck but I've been debating if it's worth buying a set of moly rings for the rig. Any thoughts? The truck's getting new piston and a deglazing hone job, no boring or major machine work. I'm planning to run 20-25 psi boost (pistons are decked 0.015") and am trying for reliability and pulling power - not going to be racing or anything crazy. I'm willing to spend the money to get the right parts, but don't want to if what I've already got is fine.

Thanks,
~John

 

[Hydro-idi]

I would probably go with a new set of moly rings especially if you are planning on pushing that much boost. This, however, is just my opinion. I am sure that other members will chime in and give their opinions too.

 

[jaluhn83]

To make it clear, these are totally new never installed rings, it's just that they're plain ductile iron. (I think, certainly not moly or platinum)

My machinist thinks they're fine but I'd like a second opinion.

Thanks,
~John

 

[RLDSL]

Personally, I'd get teh best rings I could find if pushing that hard and strongly consider gapless. ( The gapless set gives you a gapless second ring )
Temember, if you push your boost that high, even if youve put studs etc on there, you are going to multiply your blowby with the increased cylinder pressure if you dont head it off at the pass.

 

[towcat]

how big are your balls and wallet? about ten years ago I built two 6.9's with Total Seal "zero gap" rings. both motors are nearing or have passed the 200k mark and have below normal blow-by. I'm into long term results, so it's finally now I can recommend the product after seeing how it lasted. the catch is the price and your machinist better be good at reading his gauges and have a ton of patience. every cyl needs to be hand fitted if you want best results.

 

[jaluhn83]

RLDSL - agree, but would moly really get me that much....?

Gapless would be nice, but out of my price range and probably too much of a pain for the benefits. I'm doing all the assembly work myself and I don't have the experience or tooling to want to mess with them.

Also, blowby in and of itself really doesn't concern me that much. As long as you've got sufficient ventilation to not get excessive crankcase pressure it doesn't really hurt anything other than maybe greater oil consumption and more of a mess.

I'm more concerned with ring strength and sealing.

20-25 psi is a max boost spec, I don't plan to run that high continually, maybe for a short period intermittently. I expect ~15 is the highest I'll hit in typical service especially with a stock injection pump. However, I'm trying to spec everything to where it can withstand that boost level should I wind up running that hard for whatever reason.

 

[hesutton]

If I had a machine shop that I trusted enough, I would have gone with gapless rings on my 6.9 build. I'm not planning on running high boost, but I too want longevity and another 300+k miles before pulling that thing again. I think I'd have a better chance of that happening if I had the gapless, but, like I said...... didn't have a machine shop I trusted enough to go that route.

Heath

 

[jaluhn83]

Here's the question though..... do gapless rings have any real effect on longevity or anything other than blowby? I can't think of any way they really would.... Still going to get cylinder wear, ring wear, valve wear, etc. Less carbon disolved in the oil I guess, but I don't think that's really a significant issue with proper oil and routine changes. Could also mitigate that issue with a bypass filter too if it's really a concern.

 

[racin460]

This is a very good thread. i've built plenty of alcohol sbc and bbc with total seal rings they're no different than a regular ring besides the extra sealing ring. Every time you put new rings in an engine you should check ring gap with a feeler gauge and file them accordingly. So now you have one extra ring to do. If you put your own engine together you already know how to check clearances and read micrometers. So you dont need a good machine shop to do the rings because they should be done per cyilinder even if its bored there are machine tolerances so each bore is different. JMO

 

[jaluhn83]

Honestly I've never looked into gapless much so I don't have any good personal experience.

I still stand on the point that it doesn't seem to buy anything for a diesel application.

Looking at the web page and the design of the ring it looks like the gapless are going to actually be weaker rings due to their design - the ring is thinner and thus weaker.

Just for kicks, what's the ballpark cost for gapless rings?