T100R

[Rex]

Sounds like you're all good to go to me.

[Duppy Conqueror]

Duppy

It's a strange fact of life but when a hard and a softer metal are rubbing together it is always the hard metal which wears.

A good example is the Gudgeon pin or wrist pin as our American friends call them, the pin always wears before the little end.
 True Rex we have were going to replace the small ends but the same guy in the machine shop told us the wear was on the gudgeon pin so we are waiting for them now.

[Rex]

They "usually" come as part of a piston package. Are you reboring too?

[Marky]

Hi - no rebore deemed necessary at this stage !  The bore,rings and pistons all look ok so probably going to build it up and see how she fairs once I get the crankshaft finished .  New bearings/bush all round amongst other parts which came up - seals,spindle,gudgeon pins,sludge trap, valve guides(+seat cut),stator....cams polished, just waiting for crankshaft to be ground and may need big ends which the workshop is going to sort before I get it back.  Few other minor issues still to sort but nearly there now!

[Duppy Conqueror]

No planns to rebore at the minute the bore looks fine its already bored out to +30. The whole bottom end is new bar the big ends but that may change depending on what things look like when the con rods are taken off to grind the crank, Question if things look fine is it a good idea to replace the big end shells anyway or leave well alone?  

[Revband]

If the big end journals are in good order and unworn and the shells are also undamaged and unworn then they will not have to be replaced just ensure that they are refitted in the same place as they are now, but correct measurement is essential as no wear is acceptable here.

The big end bolts should be replaced as a matter of course, these are fitted and tightened to a measured amount of stretch and should only be used once.

[Rex]

The big end bolts should be replaced as a matter of course, these are fitted and tightened to a measured amount of stretch and should only be used once.

Hmm, in the ideal world when Meriden was still extant, maybe.
Obviously check the bolts for waisting and other damage, but a used genuine Meriden bolt is still a far better bet than a Taiwan sweat-shop bolt of uncertain metallurgy.
I have fitted newies from a reputable Midlands TriBSA parts dealer and the nuts were as soft as butter. Unless you envisage afternoons on the  Santa Pod strip I'd advise refitting the old bolts and nuts if at all possible.
I'd also advise reusing the big end shells (obviously if they're not worn) in the SAME locations, rather than regrind as a matter of course, too.

As you may discern, "tried and tested" beats "new pattern" with me every time.

[Revband]

Rex

Wilemans in Derby still have a supply of original bolts, I can see your point regarding inferior bolts but thankfully in the years I have been working on these 350/500 twins I have only ever known one big end bolt fail and that was a reused original, waisting is difficult to detect on these bolts as they are made with a waist.

[Duppy Conqueror]

Ok assuming all bearings and such has have been replaced and the rebuild is starting anything in particular to watch as reguards oil leaks just the bottom end at the moment, new oil seals will be put in all round. The drain plug on the chain case has about 2 good threads left so that needs to be sorted, so tap it out or is there a heli coil or modern equivelent.

[Rex]

Personally I would helicoil it to use the original plug. Normally there's cheap helicoil kits on the Bay of Fools, and also firms like Tracy Tools do cheap kits too.

[Duppy Conqueror]

Rex I think we would just get the same firm to do it for us with a heilicoil one cant keep retaping casings