Gas Nitrided Piston Rings

[Zal3v]

Hi I’m building up my 4.6 3v forged bottom end for centrifugal boost via Paxton 2200sl. I have all the parts for assembly except piston rings for my Manley -6.5cc .020 pistons. After reading and doing my research, it seems like the Total Seal AP stainless is more of a headache and possible nightmare to seat as well as the oil consumption. I was thinking about plasma moly rings and it all sounds like it would be best but I do plan on running between 15-21 psi. All the sources including Manley are saying that I would need stainless. I’ve seen several also saying I’ll be fine with moly. Bear in mind this is not a daily driven car nor a race car either. With all that being said, I came across Modmax’s gas nitrided rings that are supposed stainless but claim to provide instant seating. Does anyone have any experience, feedback or suggestions for me because the rings are the only thing holding me back ATM.
Thanks,
Z

 

[Midlife Crises]

Moly rings are typically iron rings with a band of molybdenum in a groove around the face on the ring. They work very well in stock applications and seat quickly. They are not designed for boost.
Steel or stainless steel top ring and Napier second ring properly gapped for boost will hold up to the pressure and temperature you are suggesting. Especially with the modern narrow low tension rings common today.
They are no more difficult to fit to the cylinder than any other style ring. Same process. The cylinder finish is very important.

 

[Zal3v]

Thanks Midlife, I remember you telling me about this last week in our PM. This is one of the reasons why I started to explore stainless and found these gas nitrided rings. Here is the link:

ModMax 4.6 5.4 STAINLESS STEEL File-Fit Rings 1.5/1.5/3MM

ModMax Stainless Piston Rings 4.6 and 5.4 1.5/1.5/3mm

www.modmaxracing.com

What appeals to me is the “instant” seating they are advocating but still not sure about them and looking for someone with personal experience with them.

 

[Midlife Crises]

If your pistons have 1.5-1.5-3mm ring grooves then that would be a good set of rings to use. You mentioned you are 0.020” over so order the 0.020” over set. They will have to be filed to fit with extra clearance so the ring ends don’t butt together when they expand from heat. The clearance recommendation usually comes with the rings.
The instant sealing will depend on the cylinder wall finish.
Question; Doesn’t Manley offer a steel or stainless steel, Napier, stainless steel ring pack for the pistons you have? I bet they would work just fine.

 

[Zal3v]

If your pistons have 1.5-1.5-3mm ring grooves then that would be a good set of rings to use. You mentioned you are 0.020” over so order the 0.020” over set. They will have to be filed to fit with extra clearance so the ring ends don’t butt together when they expand from heat. The clearance recommendation usually comes with the rings.
The instant sealing will depend on the cylinder wall finish.
Question; Doesn’t Manley offer a steel or stainless steel, Napier, stainless steel ring pack for the pistons you have? I bet they would work just fine.

Well, Manley uses Total Seal for their specific rings. They are offered in two types:
1. Plasma moly
2. AP stainless steel (which I’ve heard the horror stories about)

 

[Zal3v]

If your pistons have 1.5-1.5-3mm ring grooves then that would be a good set of rings to use. You mentioned you are 0.020” over so order the 0.020” over set. They will have to be filed to fit with extra clearance so the ring ends don’t butt together when they expand from heat. The clearance recommendation usually comes with the rings.
The instant sealing will depend on the cylinder wall finish.
Question; Doesn’t Manley offer a steel or stainless steel, Napier, stainless steel ring pack for the pistons you have? I bet they would work just fine.

Well, Manley uses Total Seal for their specific rings. They are offered in two types:
1. Plasma moly
2. AP stainless steel (which I’ve heard the horror stories about)
Aside from the seating, I’m also concerned with the wear on the cylinder walls and cross hatch hone. I’ve heard that stainless will require frequent tear downs and also they tend to consume a lot of oil. I’ve been advised that stainless should only be in a race motor. This is all just talk but what do I know? That’s why I’m here asking away.

 

[Midlife Crises]

The ModMax rings you listed have everything you need. They are similar to the Wiseco rings I’m using.

 

[Zal3v]

The ModMax rings you listed have everything you need. They are similar to the Wiseco rings I’m using.

Awesome, what was your initial break in procedure? Have you noticed over the time any excessive oil consumption? I’m starting to think that the people who complain about these rings just didn’t have the cylinders honed correctly.
Here is the Manley/Total Seal rings and I might just get these, could you kindly review them and let me know what you think? BTW, thanks for all the help!

Manley 46620ST-8 4.6L / 5.4L Stainless Steel Piston Ring Set (.020 Over)

Manley rings provide minimal blow-by and increased horsepower while maintaining cooler, cleaner oil resulting in longer engine life. Top Ring: Premium steel with Chrome Nitride face coating. Second Ring: Reverse twist cast iron. Oil Ring: Three piece, standard tension, full oil return.1.5 mm x...

www.lethalperformance.com

 

[Midlife Crises]

The steel alloy top ring is a must for a supercharger. I like the Napier type second ring because it removes oil from the cylinder walls.
Break-in was very simple. Normal street driving for the first 100 miles or so. Nothing over 5,000 rpm and boost down around 8 lbs max. Always warm the engine before driving. Break in oil was 5-30 Mobile 1 full synthetic. I changed the oil around 100 miles and it was clean. Refilled with 10-30 Mobile 1 full synthetic and a new Ford filter and began the tuning process. Boost up to 16 psi and up around 7,000 rpm. Never used any measurable oil. Put in 6 quarts and drain out 6 quarts annually or at 3,000 miles. I have drained a few ounces from the catch can at oil change time. The last time I checked compression all the cylinders were at 180 psi +- 5.