Need source for original pistons (396)

[Joe L.]

Re: Need source for original pistons (396)

Dick,


The pistons sets are matched weights but they don't match the factory weight which requires another engine balance.



DOM

DOM------


Anyone that rebuilds an engine, including using all NOS internal engine parts, is nuts if they don't have it balanced. And, if this is done, it's a moot point whether the replacement pistons (or any other reciprocating parts) are the same weight as the originals.

[Joe L.]

Re: Need source for original pistons (396)

It was my understanding that Alcoa did the forging of the blanks for all the manufacturers of those pistons.

Dick-----


I would not be surprised, at all, if that was the case. When it comes to aluminum forging, it's pretty much a "big guy" kind of operation.

I believe the C4 forged aluminum suspension components were forged by either Alcoa or Kaiser. I expect the C5 and C6 forged suspension components are done by Alcoa.

[Clem Z.]

Re: Need source for original pistons (396)

DOM------


Anyone that rebuilds an engine, including using all NOS internal engine parts, is nuts if they don't have it balanced. And, if this is done, it's a moot point whether the replacement pistons (or any other reciprocating parts) are the same weight as the originals.

YES and you get a much smoother running engine because the factory balance had a broader spread than a good auto machine shop balance. good shops balance to within the weight of a dollar bill !!!!

[Joe L.]

Re: Need source for original pistons (396)

YES and you get a much smoother running engine because the factory balance had a broader spread than a good auto machine shop balance. good shops balance to within the weight of a dollar bill !!!!

clem-----


YUP!

[Domenic T.]

Re: Need source for original pistons (396)

DOM------


Anyone that rebuilds an engine, including using all NOS internal engine parts, is nuts if they don't have it balanced. And, if this is done, it's a moot point whether the replacement pistons (or any other reciprocating parts) are the same weight as the originals.

Joe,
I was talking about the old days, but there are a lot of NUTS people that do this every day that are smart enough to use the weights that the manufacturer uses.
I balance EVERYTHING and sometimes it is on and off the scale and back in or on.

When you bur a new car it is NOT personally balanced as you know. If you tear it down and install the same weights you assume the factory balance.
If you take a virgin engine down that ran smooth and rebuild it with the same weight it will still run smooth.

When I twisted a wrench for a chevy dealer back in the 70's virgin rebuilds were not ballanced because the weight of the parts (crank/pistons/rods/and pins) were controlled at production as to save space and reduce error which makes perfect production sence.

The race guys did ballance but my grand mothers car wasn't.

DOM

[Domenic T.]

Re: Need source for original pistons (396)

YES and you get a much smoother running engine because the factory balance had a broader spread than a good auto machine shop balance. good shops balance to within the weight of a dollar bill !!!!

Clem,
It was the weight of a 100 dollar bill.

DOM

[Clem Z.]

Re: Need source for original pistons (396)

Clem,
It was the weight of a 100 dollar bill.

DOM

i was posting about my days i forgot about allowing for inflation.

[John H.]

Re: Need source for original pistons (396)

We built the Viper V-10 from the bare castings up, in-house, at the Viper assembly plant; the piston/pin/rod/rings came from Mahle as an assembly - we just installed the rod bearing inserts. The forged crank (fully-machined on all surfaces) was pre-balanced based on the specified rotating/reciprocating weight of the Mahle piston/rod assembly plus the bearing inserts. No additional balancing of the rotating assembly was done during engine assembly. Part of the daily ISO-9000 conformance audit procedure was weighing the Mahle assembly.