Going through some Ford iron pistons and found a set with holes drilled in the second ring groove. Another set has holes in the oil groove and another has no holes at all. Anyone have info on these holes?
I believe they are for any oil which gets into the ring groove to drain back into the crankcase rather than be drawn into the cylinder.
Thanks for the reply Norm. I've seen this on modern piston oil ring grooves but the holes in the second ring groove is new to me.
Early T pistons have no holes. Later T production had the oil groove holes added.
I suspect your pistons with holes in second groove were modified by an owner to try to reduce oil consumption and smoking due to worn rings/pistons.
They did a lot of stuff in the days of cheap labor and no money. My father used to tell about getting a few more miles out of a Chevrolet by stripping the pistons and setting them on a steel plate. Just the right strike on top with a ball peen hammer and the cast iron pistons would deform enough to tighten the wrist pin and swell the outside diameter to fit the cylinder bore better.
Too much and you cracked the piston! There was an experienced " mechanics feel" involved.
Holes drilled behind the second ring would have only made it worse not better for oil consumption, rings need oil behind them in order to assist in ring to bore pressure for compression seal.
View of holes in Ford iron piston.