2 bearing Ruby engine - Gudgeon Pins

[darcher121]

   

Any advice on removing the gudgeon pins and re-installing in new pistons?
Do I need the 2 vice clamps mentioned in the woodrow manual (see picture), or is there a “home workshop” method?

[Robert Foreman]

Two 6mm socket cap screws usually does the trick.

[Bob Culver]

The fancy stepped pieces are only to hold the gudgeon whilst attending the screw. The 1/2 inch part should be slightly reduced .The gudgeons must be supported to avoid twisting the rod. Short pieces of any metal just under 1/2 inch dia can be used. If cut with a hacksaw the ends can be trued in a drill press against emery paper, or pulled down stationary onto a file .
Cases of loose and broken bolts seems often traceable to gudgeons excessively tight in the pistons. These must turn freely at all temps., but should be no discernible play, It is unusual to swap gudgeons as the fits are very precise.
Do not attempt any lapping with abrasives as grit embeds.
(editted as initialy read to mean gudgeons to be swapped)

[John Mason]

When I did my engine I just wrapped the piston in plenty of soft rag and gentle held them in the vice. Just to tap the locking tabs back from the bolt heads then undo the bolt. I remove the pins by immersing the piston and rod in boiling water and then the pins just push out with a wooden loose fitting dowel. I reinstate in a similar manner.

John Mason.

[darcher121]

Much useful advice, thank you!
The new pistons should arrive tomorrow, complete with rings and pins.
Once the re-bore is done, Would it be wise to re-use the old pins, which seem to fit well with no play,
Or should I use the new ones that come with the new pistons?
Or am I worrying too much….

[Reckless Rat]

NO,
YES,
YES.

[darcher121]

Clear and precise!
I wish all instructions were like that!! ?

[Reckless Rat]

You're welcome.

[Hedd_Jones]

Another one here who uses the hot water method

[Bob Culver]

Unless there is a ring of varnish Seven pins should not be tight. Otherwise on a very cold start the pin tends to loosen. 
(Stephen Hainsworth covered this at length some time ago).Where are, and on other makes, I just sit an old household iron on the top for a while. You may not be popular using the good one.