Subject: Pietenpol-List: 'A' pistons>What kind of pistons do you 'A' guys you when you rebuild?>>Richard>>My homepage: http://www.AirCamper.org/w3builder>....Oh that I had wings like a dove! for then would I fly away, and beat rest. -Psalm 55:6>--------------------------------------------------------->Visit www.AirCamper.org - A Low 'n Slow Online Community!>--------------------------------------------------------->____>Free instant messaging and more at http://messenger.yahoo.comRichard There are two choices for pistons of the Avariety. Fordalways used what are refered to as cam ground pistons. Theyhave asymetrical cam shape when cold and expand alond the wrist pin to becomecylindrical when at operating temp. Many old engines when rebuild used acheapersolution a slotted skirt. that allowed for theexpansion. Ifyou use the original style pison you should be alright. Some folks are now using pistons from modernengines.There are many to choose from,mostly from the small block chevy orfords. Youneed to know the bore size (3.875 stock) that will clean upyourcylinder walls and then check out the parts catalogues to find asuitable match.The slipper skirt used on the V8 pistons makes nodifference tothe application. Weight is a small problem but not at the slow speedsthe Aruns. Compression ratio however does matter. Be sure to check out thewrist pinto piston crown height. The piston should be flush to veryslightly abovethe cylinder head deck at TDC. Be certain it will not touch the head. Alittlemodeling clay placed on the piston and with the head in place turn theengineover. (no, not upside down
) remove the head and cut the clay inhalf andview the thickness. This will be your piston to head clearance. Wristpins sizescan be matched by using thicker rod bushings.Hope this isn't too confusing John Mc