Thread: 1955 S1 rebuild

Originally Posted by shamirj

took another pic of the top of the piston after a quick clean up and found some numbers stamped. it looks like its a 40 thou oversize not sure what this actually means guessing the bore has been made bigger by 40 ??? something...

will clean out the bores and inspect closer to see if there are any damage to the walls still cant believe the piston finally came out

Means that the bore has been overbored, to correct the fact that it had worn oval, by .040 inch, referred to as "forty thou". The piston needs to be the same size as the bore (well, not actually the same size, but the same amount oversize).

John

Give the bore a light hone and then measure the play between the piston and the bore, the method is described in the book. This will tell you if you can reuse the pistons. Hopefully you are within tolerance, can get away with a little more. 40th is normaly it but people do go bigger not sure where you get the bigger pistons.
Dennis

just cleaned all pistons today and soaking in oil mix to lubricate the rings for removal and inspection. have not had a chance to inspect the bore yet. needs a clean. bolted up the brackets (some) for the seat backs some of the rings are tight as and dont even rotate around the piston due to the gunk around it. prob needs another better clean. water pump cleaned as well.

piston is 40 thou oversize not sure of the other numbers though...

After soaking the pistons in light oil mix my father has assisted in removing them and has found them to be very stuck and useless. rings have jammed and are full of muck.

i think some have even broken upon removal. so now Im after a set of piston rings. quick call around $126 for 3 ring set but mine is 4 rings per piston from Melb. no other leads yet for 40 thou oversize. ebay in uk nothing listed either. anyone been down this path and where did they get their rings from. how much should a complete ring set cost ? cheers

Hi,

the place you called in Melb was that Automotive Surplus?\
heres there contact details anyways

Automotive Surplus Online

cheers, Chris

Hi shamirj

Cox and Turner Engineering in the UK would be you best bet. They are slow via email best to call.

John Cox

Phone/Fax
+44 (0)1425 652627

If you give them a ring tonight (Monday) that's morning UK so you should get them ok.

Give them your engine number as we want to make sure you get the right ones.

I'm in UK currently will give them a call as well just to see the price(Local call) if you have not done already by then.

They post really quick and you should have it by the end of the week.

Auto Surplus online quoted $120 for piston ring set and have available. $126 from Melb 4wd was the mob i tried who provide a 3 ring set not 4. Not sure of the UK mob but will try later. cheers

Joe,
Have you tried JP pistons in Adelaide? That is where I got mine. They do pistons and rings.
JP Pistons Home Page 08 8261 7222

Still suggest you get a new 40 thou piston or a full set if you can afford. David Chilton (Chilton Engineering 07 3391 1672 can hone the gudgeons for you.) Paul