I'm having to replace the piston rods on the spare engine on my 740 roadster. I am looking at profile cutting them and then turning between centers. I'd like to use a material that doesn't require hard chroming. Any suggestions welcome.

Interesting question. I have also been this route and I tried buying hard chromed rod out of Texas for my throttle rod. Its hard chrome was about 0.005" thick. The hard chrome lasted about two years and became worn through. Apparently it's chrome was not hard enough.

I make a crosshead end of the piston rod from 80-55-06 ductile casting and the rod from 440C stainless
I have not used any as yet. The core for the connecting rod is made from W2 and harden and ground and a press fit into the casting before the cross head section is ground for the cross head.
Rolly

Thanks Rolly That is excellent information on materials. Have discussed this with my steam mechanician and he also wants to have the crosshead and piston rod as separate items. I'm drawing up the cross head and will probably go for a threaded and taper cross pin rod to the crosshead connection.
Do you have any advice on of the shelf bearing to replace the conrod big and little end (cone) bearings and also the crankshaft bearings.

Regards
Mark

I am not sure I understand your question.
I use a hardened and ground insert in the piston rod crosshead section of the piston rod made from W2 stock. I have a drawing somewhere for the angle to match the connecting rod. It’s then sent out to have it hardened, I then set it up in the lathe with my Dumore tool post grinder and finish it. Another rod material some have used is Hydraulic cyl shafting it is very tuff and has a ground chrome finish. When my friend Dick rebuilt his White he found a cylinder rebuilding Co and they gave him the two short pieces he needed.
My casting for the bronze cross heads are 70,000 tensile bearing grade bronze.
Rolly

Sorry I didn't word that at all clearly. I am looking at replacing the cones on the rods and the conical sections in the crossheads with a straight pin on the rods and a reamed hole on the crosshead sized to fit a needle roller bearing. I've seen it in one of the magazines, and I believe a couple of the Australian owners have done their engines that way.

A bit off topic do you know how Stanleys made the piston rod cross head assembly? Was it a one piece forging that was then turned between centers? just curious.
Regards
Mark

I think you’re talking two separate items. Both the piston rod Item #1 and connecting rods item #2 were forgings, your car the connecting rod is in two sections. My friend Richard made a pair of connecting rods cast as one piece in aluminum for David Nergaard, SACA-NE chapter President. As far as I know he has tried about every kind of crosshead pin. I think the last I’ve heard he was using a balljoint as used in a commercial rod end.
Rolly