stunthanger.com

Engine basics => Engine set up tips => Topic started by: Terry Caron on March 17, 2015, 02:51:07 PM

Title: OK B-C class engine with ball/socket rod?
Post by: Terry Caron on March 17, 2015, 02:51:07 PM

Am I correct in thinking some of the old OK .29 or .35 had a ball and socket rod/piston assy?

Thanks.

Terry

Title: Re: OK B-C class engine with ball/socket rod?
Post by: Robert Zambelli on March 17, 2015, 03:28:24 PM

Hi, Terry.
Every OK engine I've owned had a standard wrist pin piston assembly.
Bob Z.

Title: Re: OK B-C class engine with ball/socket rod?
Post by: Terry Caron on March 17, 2015, 04:12:01 PM

Here's a pic of it - any idea what it's for?

Terry

Title: Re: OK B-C class engine with ball/socket rod?
Post by: Tim Wescott on March 17, 2015, 04:41:04 PM

I know that there were a few engines in that size class that used a ball & socket "wrist joint".  To the extent of my scant knowledge, this technique enjoyed a short surge of popularity right after WW-II.  There's no way I could even guess what engine your con rod might go to, however.

Title: Re: OK B-C class engine with ball/socket rod?
Post by: Terry Caron on March 18, 2015, 09:45:15 AM

Possibly Mohawk?
I know nothing about them other than that they exist, but I think were also an early Herkimer product.

Terry

Title: Re: OK B-C class engine with ball/socket rod?
Post by: Andrew Hathaway on March 18, 2015, 10:19:15 AM

The Mohawk .29 is just the early OK .29 with some cosmetic changes to the case, and no main bearing.  The rod is/was a typical piece with a normal wrist pin.

That's not a Mohawk part.

Title: Re: OK B-C class engine with ball/socket rod?
Post by: Terry Caron on March 18, 2015, 10:36:00 AM

Well, rats!
I'm sure someone could use this, if I could find out what it's for.
Just in case:
OAL 1.722"
Crankpin ID .218"
    "       width .214"
Ball diam .209"

Terry

P.S. - just found that I also have 2 unfinished .29 Mohawk con rod rough castings, typical as you said Andrew, PM if anyone could use one.
And a finished .29 Cub rod.

Title: Re: OK B-C class engine with ball/socket rod?
Post by: Andrew Hathaway on March 18, 2015, 01:15:34 PM

I could use the Mohawk 29 rods.  OK's idea of finishing the rod is to cut 90% of the way through the crank pin hole with a hacksaw for lubrication.  I think I've got about a dozen OK and Mohawk 29s, but I'm short a few rods since they like to crack at the saw cut.  I've been meaning to order a few of the castings from OK, but I'm pretty sure the last catalog I received from them was dated 2011.   n~