Two different tests with the 1/1, 1/16, 3/16rings generated about 15 degrees hotter water temperature and nearly 20 hotter oil temperature compared to the .7mm, .7mm, 2mm ring set.
The results confirm piston ring to cylinder wall friction as a meaningful contributor to engine operating temperature and identifying friction as the source of the heat was quite easy. The standard 1/16, 1/16,3/16 rings reduced engine power by nearly 20 lbs. feet of torqueand over 15 HP compared to the gas ported .7mm, .7mm, 2mm ring set.
In fact, the 1/16, 1/16, 3/16ring set generated so much oil temperature that the label on the oil filter began to “shrink” from the heat!
In a “real world” comparison, Joe Gibbs Racing Engines built the new JD-1 desert off road racing engine using Total Seal Diamond Finish .7mm, .7mm, 2.0mm rings. While many other off-road racing engines use traditional 1/16, 1/16,3/1rings and struggle to keep engines from overheating, the JD-1engine runs remarkably cool. In fact, it nearly ran too cool during BAJA 1000when overnight temperatures dropped to nearly 40 degrees F.
Elaborate on heat transfer through the oil to prove that the heat wasn’t “trapped” in the piston.
All of these dyno and race results point to the same thing, piston rings rubbing against the cylinder walls generate friction, and that friction produces heat and robs power. By going to thinner piston rings, friction can be significantly reduced, and the benefits are two-fold - increased horsepower and reduced operating temperatures.
Add used oil analysis data that shows the reduction in cylinder bore wear between the two ring sizes.
So, before you decide to buy a bigger radiator for your hot running engine, you might want to consider trying a set of thinner piston rings first.