BONE STOCK 1969 383 4bbl piston

[Bad B-rad]

Anyone have photos of factory STOCK 383 4bbl piston(s) from 1969?
Installed is fine.
I believe 1968 and 1969 4BBL engines use the same piston.
Only 1968/1969 FACTORY 4bbl 383 pistons are what I am looking for.
Thank you.

 

[Nate S]

What are you trying to see?

 

[Demonic]

No pics, but when I had mine apart, they are very close to being a 0 deck.

 

[Bad B-rad]

What are you trying to see?

I have come across a 383 4bbl engine from 1969, "E" on the Id pad, that look to be untouched (stock bore, steel shim head gasket, plastic timing gears) and noticed the "notch" on the pistons is at the back of cylinder bore(toward rear of engine) and FSM claims it should face toward the front. (as most rebuilt engines have)
I know an old hot rod trick to flip the piston around for reduced friction, its even in the old Direct Connect/Mopar performance B/RB manual.
But from the factory?
So photos of unmolested engines will help.
Here is one pic.

 

[Bad B-rad]

My 1969 383 4bbl has notch in correct spot, as the FSM says it should be.

 

[Demonic]

Mine has the notch to the front.

 

[RJRENTON]

IMO...
I believe the OEM pistons were cast, the wrist pin boss is offset to the thrust side of the piston as it travels in its bore. There fore, wouldn't the pistons on the OPPOSITE side of the block be oriented differently? In addition, cast pistons usually have a steel expansion strut and are slightly elliptical in shape to control expansion and cast pistons are usually fitted with a tighter clearance, like 0.002" piston - wall, to accomodate the size change from cold to hot.
BOB RENTON

 

[Nate S]

IMO...
I believe the OEM pistons were cast, the wrist pin boss is offset to the thrust side of the piston as it travels in its bore. There fore, wouldn't the pistons on the OPPOSITE side of the block be oriented differently? In addition, cast pistons usually have a steel expansion strut and are slightly elliptical in shape to control expansion and cast pistons are usually fitted with a tighter clearance, like 0.002" piston - wall, to accomodate the size change from cold to hot.
BOB RENTON

Pistons on both sides of the block are the same and oriented the same. Think of it not as toward/away from the center of the engine but front/rear and direction of rotation. The connecting rods differ of course left to right. Notches always forward for stock, reversed for that old Direct Connection trick.

 

[RJRENTON]

Pistons on both sides of the block are the same and oriented the same. Think of it not as toward/away from the center of the engine but front/rear and direction of rotation. The connecting rods differ of course left to right. Notches always forward for stock, reversed for that old Direct Connection trick.

The reversed orientation, per the Direct Connection suggestion, is to move the thrust side of the piston to the opposite side of the bore to reduce the "drag" or horizontal force vector of the piston/bore interface at maximum rod angularity. Yes, the piston would need reoriented on the rod to maintain correct the piston-rod relationship. Was the reorientation worthwhile? When, racing, every little bit helps....the slight reduction in friction would result in, perhaps, 5 or more HP at max RPM....and that may be enough to win.....
BOB RENTON

 

[Nate S]

The reversed orientation, per the Direct Connection suggestion, is to move the thrust side of the piston to the opposite side of the bore to reduce the "drag" or horizontal force vector of the piston/bore interface at maximum rod angularity. Yes, the piston would need reoriented on the rod to maintain correct the piston-rod relationship. Was the reorientation worthwhile? When, racing, every little bit helps....the slight reduction in friction would result in, perhaps, 5 or more HP at max RPM....and that may be enough to win.....
BOB RENTON

The easier way to do it rather than pushing the pins in/out was to swap the 1 and 2 pistons, 3/4, 5/6, 7/8 This put the notches in the back and kept the oil holes up.

 

[PRHeads]

The easier way to do it rather than pushing the pins in/out was to swap the 1 and 2 pistons, 3/4, 5/6, 7/8 This put the notches in the back and kept the oil holes up.

Yup.

Back in the 80’s when I was re-ringing quite a few motors, I’d do it most of the time.