Folks, I'm rebuilding an R53 - "stock". I marked the pistons when I took them out, and I noticed they have an "F" marked on the piston skirt. All the pistons "EXCEPT #1" have the "F" mark towards the forward side of the engine (front of car), But #1 was reverse...... After installing the rings, should I reverse the "F" mark to face forward?? These are stock, original pistons as best as I can figure?? I'm not building a race engine, just a reliable, get around town engine that won't burn oil. HELP!!

 

Ignore the F. There should be a small arrow stamped on the top of the pistons. All arrows should point towards the timing chain.
Do not mix up the bearing caps - they are a matched set with their respective con rods.

 

The piston skirts have cut-out on one side to accommodate oil squirters when pistons are at the bottom of stoke. The F or arrow markings are to ensure alignment of cut-outs with squirters. A mis-aligned piston (F or Arrow pointing toward flywheel) will collide with its oil squirter and cause damage.