E: Engine Big End Replacement

Cyborg

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Well.... I chucked the flywheel and shaft into the lathe and it didn’t look all that promising, so I removed the chuck and then put it between centres. It’s indicating about .003 runout on the OD of the flywheel so will use it for a door stop and continue with the pair that came as one lump.... (at least until the pin broke). Could be that one of the centres is off, but don’t feel like spending any more time on it.
 

litnman

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If you are not sure your chuck runs true, lock the spindle in back gear to keep it from turning, then clamp the main shaft snug (not too tight) and rotate the part.
 

Bill Thomas

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This is the trouble with mine, If I can't get a good reading in the lathe,
With the old stuff, What chance do I have after welding and stroking !.
I see now it's been said the centres could be out,
This is why I sawed a mainshaft in half, To put the 2 wheels together with most of the balance holes,
also with bits of tubing, To try and set it up for welding the wheels together,
Ready for boring, Scared it will be miles out !,
But must give it a try, S--- or Bust !.
Looking at some youtube stuff, They seem to hold a lot of faith with the old ,
Straight edge across the outside rim.
Some of the youtube stuff with the H.D. s is rubbish,
One bloke bashing hell out of the wheels while still with the dials on !!.

I still have in my " Head " a view of a friend of Bob Dunn's,
Who worked in the next shop, Putting together a pair !! of flywheels,
Fully together they just spun in the hand, ie loose on the taper,
So would just rely on the nuts and bearings to hold them true :D ,
Wonder what happened to that bike ?, Not a Vincent, Thank God.
I will try John's idea of checking the chuck,
Good Luck, Bill.
 

Bill Thomas

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Talking of straight edges, I have just bought a pair of cheap Lidl ,
Right angle Magnets, Used for welding, I already had a few smaller ones,
Thinking it might help if I position 4 of them around the rims, Together with the tubes
in the balance holes, How could it go wrong :D .
 

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greg brillus

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Instead of welding up the holes Bill, Why don't you use an oversized big end, say one that is 1 1/4" diameter pin and then just offset bore the hole outward by half the amount.........Depends on what length rod you've got I guess........Cheers.
 

Bill Thomas

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That's what I was going to do Greg, But then I thought Alpha's wanted the conrod,
And it got to be more money, I don't like sending stuff out,
Alpha's messed up my Twin Bigend years ago, 1. 1/4" and it snapped !.
I have a short rod 1/4" shorter Carillo.
I don't ride fast now, Lucky to ride at all,
It's just something I always wanted to do, I may not ever do it,
Just a bit of Fun.
I have a spare pair of wheels and shafts, So could always do a 500.
 
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