I just recently come across gas ported pistons rings. Didn’t know it was a thing, until the other day and let me explain why. It’s been two years having a boosted motor and it’s been a blast. Truck started running like crap and went to do some maintenance. Replaced the head gasket on the passenger side and started getting blow by like I’ve never experienced before. Compression tested every cylinder. Each one was at 180 except for cyl#5 and it was at 50 psi. Motor is a 6.0 bored .030 over with hyperutectic pistons and basic rings. Most likely going to have to sleeve #5 so while I’ve got it apart wondered if gas ported rings are worth the money? I’m leaning towards yes but wanted to hear from someone who has experience and unbiased opinion on them. I hate that I’m going to have to tear my motor apart and spend money at Christmas but I want to do right once…again haha. Merry Christmas to all!

 

yes, They were designed for applications where the piston being used does not have gas ports.

 

Thanks for looking. I’m wondering if I should invest the money since I have confirmed that I am indeed getting pressure past the rings? Have you had personal experience with these? That’s really all I’m looking for is unbiased opinion and or real world experience. Thanks

 

I have not. But based on what I read, I would like to try a set.

 

What does this cylinder being “clean” say? Should I just go ahead and pull the motor or am I reaching to think replacing the head gasket will fix this?

This is a cheap Chinese gasket. What would make it bubble?

 

You say the cylinder is clean. No cross hatch?

You need to check the block surface for flatness. No GM block I have ever checked has been truly flat. They usually have twist in them, however I have seen some with low spots in them.

As for the Cheap Chinese gasket... the word Cheap defines your issue with it.
They are knock off of the OEM part. They are not designed for the boost and if the block is not flat, eventually it's going to find the weak point. The heat and the pressure is what cause the distortion or "bubble" as you put it.

 

OP, get yourself a machinist straight edge to check the block deck flatness, they are not that expensive. Get a set of feeler gauges as well.

I bought the 24" OEM brand from Summit and checked main housing bores alignment and the block deck on an engine I'm building. There's a way to check it: parallel to the crank axis, perpendicular and each diagonal. I can't recall what the specs are, but it's a few thousands every 6" measurement IIRC.

I guess check the head as well or take the heads to a machine shop so they can check. They may need milling? Or what does the head for that cylinder look like?

Why would you use a chicom no name head gasket, though? I would not use that even on a stock rebuild. A new set of head bolts alone ain't worth it (if you are using one-time use TTY bolts obviously.)

 

To further illustrate my point about the factory decks on the LS block not being flat... This goes for both Aluminum an Iron blocks.

 

The plugs looked all the same, like they’re getting good spark even #5. But cylinder was wet, oily. The technical stuff I’ll leave it to the machine shop to do. But I bought cheap Chinese because it’s my first turbo build and I thought I could get away with it, and maybe watched too many YouTube videos 😝! Learning as I go and I appreciate the feed back. Oh and I’ve got ARP head bolts. Been running it for two years and it’s been a blast.

 

Looks like blown head gasket steam cleaned it for you.