Thursday, July 21, 2011

Robbins Pistons

Continuing from the last post. My Tiger came with .040+ Robbins M-1625 pistons. I'd never heard of Robbins pistons so I started doing some research to see exactly what I had, particularly because they are in pretty decent shape.

The first reference I found was Wes White talking about the '50s 500 he races at Bonneville on JJ:

I have not posted in a while because one thing has been holding me up. i have been waiting to get these piston blanks from an old racer guy I came across. These are probably 60 years old, made by Robbins in LA waaaay back. They are 11.5 to 1 or 12 to 1 compression, being way domier than my 10.5 to ones last years. They are what they called blanks, they are about .100 over right now and can be ground to any oversize. So down they go to match my standard bore. The skirts are unfinished. Unfortunately, piston grinding is one of those old world technology things that noone does anymore. Believe me I called them all and each and every big piston manufacturer was not helpful, one guy was actually rude. Then I found an old dude who knew Charlie Robbins (the guy who made these blanks) and he said he could probably help me out. Although he runs a new pistons making firm, he still knows how to do it up "old world." He said he would do it for the "Ghost of Charlie Robbins."

Those things just look angry...

Later I found the following on the American Hod Rod Foundation site:

A couple of years ago I met John Chambard through AHRF Pioneer Bob Mortan at So-Cal Speed Shop. We had a great talk and he gave me a pix of his old car at the time. I did a little photoshop magic and colorized it and e-mailed a copy of it back to him. Some time later he sent me his life story that included his dry lakes experiences. It was filled with all sorts of racing tidbits that just came into play. In the Gear Grinders Car Club Collection a pix of John's car surfaced. I re-read his story and put one and one together for John and you that goes with the next shot. The Robbins Piston Special showed up at the October '49 S.C.T.A. meet under Dusters colors. It normally ran at M.T.A. meets by the team Chambard, Tommy Hynes and Pierre Vawter flying RoaDuster colors. It got it's entry name because Charlie Robbins let Vawter cast and machine the pistons in his shop on the Friday before the meet. Power was from a 214" '33 Ford 4-banger with a Miller F-head. No speed is listed. See the Robbins Piston Special below.

Robbins apparently later offered finished pistons for HD's, Indians & Triumphs, mine are finished forged rather than cut to spec like Wes'. I've seen a few people selling them NOS and you occasionally see an old magazine ad. The following is a painting Mikey Hottman did based on an old Robbins ad.

I talked to Wes White about it all and he's pretty convinced my bike was raced at some point. Hot rod parts, nicely done shell bearing conversion, etc. Odds are it was deliberately bored .040+ because that's the largest you could go if you cared to be legal. Given the Robbins/JOMO parts it might have raced left coast somewhere.

I'll have to talk to Tom and/or Robbie about Robbins. I bet they know the whole story and have ads, catalogs, etc.


Nate said...

I get a kick out of every post you have on this bike. Every part has a really cool stroy of motorcycle history. The connections it leads you to is so awesome!!

Flathead45 said...

I'm with Nate on this one. I really enjoy the obscure history behind the parts you have.