Conversion to thinner rings on an older engine

[PackardV8]

Greetings, speedtalkers,

We build mainly obsolete engines, including Studebaker and Packard. The Studebaker Champion was designed in 1939, a 3" bore x 4" stroke flathead, using 3/32", 1/8" and 5/32" piston rings. Yes, it's been suggested some of you Stock class builders use thin rings with spacers, but direct conversations with Grant and Hastings have not gotten any encouragement. Those to whom I've spoken disavow any knowledge of same. They just said get new pistons. It will require a substantial investment in new inventory to have pistons cut for today's thinner rings.

1. Any estimate of friction reduction which might be achieved and how it might affect horsepower and fuel economy?

2. Given the 3"/78mm bore range is shared with many smaller engines, most all current ring widths are possible. Any suggestions as to which width you'd choose and why?

3. Given an iron flathead is not as efficient at coolant regulation as an aluminum block with another seventy years of design science, is there any concern thin rings might not provide sufficient heat transfer from the piston to the cylinder walls?

Thanks in advance, as speedtalk usually can point to experience and not opinion.

jack vines

[ALKYAL]

Call Total Seal, They do this for Stock and Super Stock. Just got some Rings for a 3.310 bore 1.2 mm Top and Second

[bigjoe1]

Any of the real narrow rings are pretty expensive-- NOT WORTH the cost. The oil ring is the most drag-friction-- There is where you need to look



JOE SHERMAN RACING

[pamotorman]

used to clip the oil ring expander to reduce the oil ring drag before all these different oil ring expanders tensions were available.

[MadBill]

If available, I would think that modern materials and processes applied to the obsolete sizes would gain much of the potential benefits.

[Truckedup]

Jack ,the GMC 302 I built 15 years ago had Venolia forged piston with 1/16 inch compression rings. Since the old 6 has a 4 inch bore the ring choice was endless,..I was told by some guys the narrow rings wouldn't last 15,000 miles in the vintage engine for some unknown reason.. The pistons had .0055 clearance, it had 4 bbl , headers, hot cam and 9.2 compression....I sold the 37 Chevy truck to a guy in Florida 10 years ago that used it for a daily driver... with about 65,000 miles on the engine it was running just fine...

[digger]

Any of the real narrow rings are pretty expensive-- NOT WORTH the cost. The oil ring is the most drag-friction-- There is where you need to look



JOE SHERMAN RACING

In a motored engine this is true, in a running engine the top is comparable to oil according to the latest research

[modok]

Total seal will probably do what you want
As you know they make all kinds of ridiculous rings, but also can machine rings in just about any way I think
http://www.enginelabs.com/news/total-se ... e-grooves/

You could do a reduced radial wall top ring, and a napier second, surely would be an improvement.

[jed]

Jack, how big a bore are u willing to run??
Something around 3.050 to 3.100??

[mag2555]

x2 the most friction reduction comes from the oil ring and I would not waste my time going to anything less then 5/64" for the compression rings with the rpm these motors turn!

[PackardV8]

Jack, how big a bore are u willing to run?? Something around 3.050 to 3.100??

Hi, Jed, the one currently under construction will have a 3.068" finished bore.

[wyrmrider]

Jack youpick the finished bore before you have the rings in hand- you already have the pistons I would guess

[andyf]

We just got a set of Mahle pistons for a 427 Ford FE and they came with a 1,1,2 mm ring package. Pretty cool for an engine that has been out of production for such a long time. These Mahle pistons are super high tech for an FE engine with the X shape and the short pin and the various coatings that are on them. They only weigh 500 grams and the bobweight on this engine is around 2100 grams. Catalog item too, not a special order. So I know that an FE engine isn't as obsolete as a Studebaker, but a FE engine isn't nearly as popular as a Chevy SB or BB. So the aftermarket is providing some support out there for the older stuff.

[pamotorman]

Back around 1969 my first job in the machine shop was installing top ring groove spacers.

Not for thinner rings but to repair worn out pistons.

Must be all young guys at Grant and Hastings today.

Ramco "10 up" rings were preferred along with Hastings spacers.

Thanks
Randy

TOP GROOVE SPACER

Badly worn top grooves must be remachined before installation of new rings. A steel spacer is installed above the ring in a reconditioned groove to reduce the side clearance to the recommended dimension.

https://www.hastingsmfg.com/ServiceTips/piston.htm

that was called "GI"ing short for groove insert

[modok]

Even industrial small engines use far thinner rings these days, but they do not turn any higher rpms.
Not sure how much there is to gain. but I don't think there is anything to lose, putting a new piston in an old engine, as long as you also use modern oil, fuel, and air filter.