1969 440 Piston ID

1970FuryConv · Apr 9, 2015

For a 1969 440 that I am disassembling in prep for a basic rebuild: rings, bearings, gaskets, valve job, cam, lifters, timing chain: I found that the cylinders are stock bore diameter at 4.32". I found that the pistons have 7 D stamped on the top of the piston head. F is cast into one side of the piston pin area and other symbols are cast on the other side (these symbols seem to vary). Piston rings look almost new. Rods are press fit onto the pins. The rod bearings have no markings. Piston deck height is .045-.050" as measured with a dial caliper.

Based solely on the cast F, I am guessing that the pistons are Federal Mogul replacements that were used to up the compression in a C-body non HP motor. I suspect from the few documents that came with the car that the last engine rebuild was done around 1995-2005. Does anyone recognize these pistons?

70bigblockdodge · Apr 10, 2015

I have never seen rod bearings without a.size and date on the back side. Compression height is measured from centerline of the pin to the top.

1970FuryConv · Apr 11, 2015

I looked at all 16 rod bearing halves. They have no markings. They are light gray. They are damaged (scored/grooved) from dirt that came between them and the rod journals. My guess is the damage came from whatever dirt was not cleaned out of the engine when the new pistons were installed. Fortunately, the engine was not run very long, probably because the trans gave out, so the rod journals are OK, except #7, which has a tiny groove and which I think I can polish out.

By contrast the crank was probably not removed. Main Bearings 1,2,4,5 are stamped 8 and #3 thrust bearing is stamped 11 68.

As far as clearance from the top to the piston head to the block deck at TDC, maybe we have a difference in terminology.

The long and the short is that I have these pistons that are stamped 7 D on the head, but have little or no manufacturer marking. I tried to find them using a Google search, but came up with nothing. I was trying to figure out what they are and whether they are worth reusing, since condition is good. I hoped someone on this website was building engines 15 years ago and might recognize them.

Of note in trying to Google old part numbers, "Chrysler Piston 7 D" brought up all kinds of useless info, even Detroit Pistons basketball info. I have the same type problem with the cam I removed from this engine. The cam is stamped 454 directly in front of the rear journal. Even though I searched with Chrysler as key word, everything came up Chevy. At least I know I'm getting rid of the cam.

70bigblockdodge · Apr 11, 2015

I think those are stock pistons I have a set of stock 70 pistons loose and will take a pic when I get out to shop today.

Yah your deck height measurement made sense after I posted that:busted:

Big_John · Apr 11, 2015

I believe that is a stock Chrysler piston, not aftermarket.

Deck height is about right for a 69 that hasn't had the decks cut. Spec is actually .027" (IIRC) and we always hit about .030-.035" with the NHRA legal stock engines after decking the blocks. BTW, they used the same pistons in all the engines in 1969. The HP engines had the same compression as the regular engines so the deck height is the same.

The markings on the top are for size at the assembly line. Pistons are measured and stamped and then matched to block bore sizes. I can't even begin to tell you what the number corresponds to.

I just so happen to still have an ash tray on my bench.... Stock Mopar piston removed from an engine 30+ years ago.

1970FuryConv · Apr 11, 2015

Ah, the cryptic F on the side of the piston. So they're original Mopar with rings and bearings replaced. At least my pistons are in better condition than your ash tray.
I finished cleaning the piston heads: Piston Head Markings: Pistons 1,3,5,2 stamped 7 D on top of head. Pistons 4,6,8,7 stamped 7 C on top of head. You & 70BigBlockDodge are right, original pistons and 7 D cannot be the part number. Pistons 5 and 7 pictured. It's interesting that sometimes the stamping is at the forward mark and sometimes 180 degrees away.
Thanks for the info about the same pistons in all 69 blocks. I took deck height measurements at the low point and high point of two different cylinders, #3 & #6. In coming up with .045-.050", maybe my measurements were just 1/100" off. Oh well, now I get to go back to the fun of block cleaning. I used POR 15 engine cleaner to take the grease off. Time for 3M Safest Stripper to at least rough up the old paint.