piston rings
- Thread starter kurt v
- Start date
petehoovie
Well-known member
From 'Rumble Seat's' Flathead Tips - https://web.archive.org/web/20160318184559/http://www.flatheadv8.org/rumblest/intro.htm
RINGS: Ford originally came with 4 ring pistons to decrease excessive oil consumption. Rings contribute the most friction of any engine component. Check the drag on one piston in a cylinder using 4 rings and then again after removing 1 oil ring. Amazing! Increased friction causes a build up of heat as well as a reduction in hp. The added friction of the 4th ring causes an engine to run hotter.... something we really don’t need in our flatheads. To overcome friction requires hp...... hp I’d sooner be using for fun things. Why not change and run 3 rings which have 25% less drag than 4 rings do? Makes sense to me. Recent engines normally have only 3 rings and they last well past 100K miles.
RINGS: Ford originally came with 4 ring pistons to decrease excessive oil consumption. Rings contribute the most friction of any engine component. Check the drag on one piston in a cylinder using 4 rings and then again after removing 1 oil ring. Amazing! Increased friction causes a build up of heat as well as a reduction in hp. The added friction of the 4th ring causes an engine to run hotter.... something we really don’t need in our flatheads. To overcome friction requires hp...... hp I’d sooner be using for fun things. Why not change and run 3 rings which have 25% less drag than 4 rings do? Makes sense to me. Recent engines normally have only 3 rings and they last well past 100K miles.
tubman
Well-known member
I read on the H.A.M.B. that the fourth oil ring was added to solve an oil consumption problem that was prevalent with some of the very first Ford V8's. Over the years, piston ring technology evolved, but for some reason Ford never chose to take advantage of it, and Ford pistons were 4-ring until the end of the flathead era.
There was some concern expressed that leaving the fourth ring out would destabilize the piston in the bore, but when you realize that it is the piston that stabilizes the rings, that goes out the window.
Jack, how much does that fourth ring weigh? It sounds like reducing the rotating mass of each piston/rod assembly by the same amount doesn't make a lot of difference in overall balance.
There was some concern expressed that leaving the fourth ring out would destabilize the piston in the bore, but when you realize that it is the piston that stabilizes the rings, that goes out the window.
Jack, how much does that fourth ring weigh? It sounds like reducing the rotating mass of each piston/rod assembly by the same amount doesn't make a lot of difference in overall balance.