E: Engine Big End Replacement

Martyn Goodwin

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I seem to recall that Big Sid (Biberman, now deceased) recommended that Lanolin Grease - a by product of wool - was the best lubricant to apply to the pin to assist pressing it into the wheels

Martyn
 

Bill Thomas

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I checked and with new thrust washers and new big end, side clearance looks like it will be fine. Being a Comet crank it's easier to deal with. Pressed the pin into the drive side flywheel, which showed slightly less interference fit than the timing side. Quite happy with the amount of force it took to press it home.

Here I am thinking out loud again.... not having any sort of jig for aligning the flywheels, I'm thinking of putting the drive side into a chuck mounted to the bed of the mill, centring it with the quill, (using the centre in the inboard side of the mainshaft and confirming with running a dial gauge around the circumference of the flywheel) , mounting the timing side flywheel mainshaft in the quill with a collet, make sure it is running true, zero the DRO. Then lower the timing side down (going to try and set the quill up so it is totally neutral) and using a slightly modified puller, get the pin into the timing side flywheel as far as possible, then finish in the press. Feel free to rain on my parade or make suggestions. I think I can get as close this way as using some of the frightening alignment tools I have seen on the inter webs.
When I do mine, I am "thinking" of finding some tube or rod the size of some of the holes in the flywheels, Not too tight, Then pressing together.
I plan to do the same when I bore the new holes in the flywheels, For the 560, To keep them in line !!, I have been told that one bloke bored the hole in one wheel, Then did the other after, It did not work out well !!.
Just checked the outer bearing in the old rod, Which has been used, Before I take it out and fit it to my new Carillo
rod, And it's a few thou out of round, I don't think it will upset it too much ?, As long as it's not too tight.
Good Luck, Bill.
 

Chris Launders

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One method of putting the flywheels together fairly accurately with no special tools is to just start it in the press enough to hold and then use a set square at 90 degrees to the crankpin both sides to line the wheels up. whatever method you use it will almost certainly need trueing after. (I did a Bantam one yesterday and have an ES2 one to do today)

Bill, are you boring new crankpin holes with the shafts out, if so make a mandrill to go through the mainshaft holes and one through the existing crankpin hole, tack weld the flywheels together then knock the crankpin mandrill out and bore as a pair.
Chris.
 

Bill Thomas

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One method of putting the flywheels together fairly accurately with no special tools is to just start it in the press enough to hold and then use a set square at 90 degrees to the crankpin both sides to line the wheels up. whatever method you use it will almost certainly need trueing after. (I did a Bantam one yesterday and have an ES2 one to do today)

Bill, are you boring new crankpin holes with the shafts out, if so make a mandrill to go through the mainshaft holes and one through the existing crankpin hole, tack weld the flywheels together then knock the crankpin mandrill out and bore as a pair.
Chris.
Yes Chris, The shafts will be out, Not sure I can bring myself to Tack the wheels !, Is that not against the Vincent Law !!, Still it's only a box of bits !, Not worth much !, Cheers Bill.
 

BigEd

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Yes Chris, The shafts will be out, Not sure I can bring myself to Tack the wheels !, Is that not against the Vincent Law !!, Still it's only a box of bits !, Not worth much !, Cheers Bill.
They are your bits Bill so you can do what you like with them.:) I don't see that a few small tacks would do much harm as they could be dressed off easily afterwards. Not worth much? Maybe but that is until you need replacements and the "old spares" box under the bench doesn't have any.;)
 

Bill Thomas

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They are your bits Bill so you can do what you like with them.:) I don't see that a few small tacks would do much harm as they could be dressed off easily afterwards. Not worth much? Maybe but that is until you need replacements and the "old spares" box under the bench doesn't have any.;)
Thanks Eddy, But if I get stuck, I can always use these !!. I did them when I was young and Silly !, But they did rev high and pull Wheelies, Just when I didn't want to !!. Just a bit of Fun, Bill.
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chankly bore

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Non-VOC Member
One method of putting the flywheels together fairly accurately with no special tools is to just start it in the press enough to hold and then use a set square at 90 degrees to the crankpin both sides to line the wheels up. whatever method you use it will almost certainly need trueing after. (I did a Bantam one yesterday and have an ES2 one to do today)

Bill, are you boring new crankpin holes with the shafts out, if so make a mandrill to go through the mainshaft holes and one through the existing crankpin hole, tack weld the flywheels together then knock the crankpin mandrill out and bore as a pair.
Chris.
If you can get a mandrill to go through the holes you must have a F**&##@! big crank, can't even persuade a baby lemur to go through mine! By the way, at the Ballarat Rally a few years ago a chap tore down his A.J.S. single, took the flywheels in to a local garage and fitted a new big-end which he had in his kit. He then trued it up with a straight edge, assembled it all in the Caravan Park and rode it back to Queensland. What a HERO!
 

greg brillus

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Was that at the international.........I remember that bloke, and actually helped him at some point....... I remember he used the tow bar on a nearby van as an anvil............o_O................He was from Toowoomba.
 

timetraveller

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The way that I true flywheel assemblies as follows. It presupposes that the ends of the main shafts are in good order. If you do not have them then you should be able to use your lather to make a couple of centres. One centre in the chuck and the other in the tail stock. I fit the crankpin into the drive side flywheel, which already has the main shaft fitted. I then fully tighten the crank pin nut. I then assemble the big end, con rods etc. and then press on the timing side flywheel and loosely fit the nut to the timing side of the crank pin. Put it in the centres, making sure that they are tight, but not too tight, and then measure the out of round near to the flywheels on the main shafts as the whole assembly is rotated on the centres. You will now need a block of hard wood, oak is good but other woods might do, and an immovable object. I normally use the concrete foundation of any local structure but others might have access to a large anvil etc. This is when you do your body building exercises. Having worked out in what direction the timing side flywheel needs to move, pick up the whole assembly by the drive side main shaft, taking care to hold the small ends loosely, and hit the block of wood with the timing side flywheel. Go back to the centres and measure again. This will tell you whether you need to hit harder or more often. Start to tighten the timing side crank pin nut, but not fully, and then go back and do the body building again. If the neighbours see you doing this then explain to them that you had wood worm in the piece of wood and were trying to give the insects a headache. It might take a few goes but it is better to sneak up on the correct settings slowly rather than go too far and have to come back on it. Once you have it correct then fully tighten the timing side crank pin nut and go back and check again that nothing has moved. If this does not work then either the flywheels have different distances between the crank pin holes and the mains shaft holes or the faces for the crank pin to sit against are faulty. I have seen the former but never the latter.
To show how things have moved on; I have somewhere a 1940s or 50s motorcycle hand book which advises using a set square against one face of a flywheel and across the two circumferences of the flywheels. This was clearly considered good enough for bike used during the second World War or in the forties and fifties. In the hands of a skilled mechanic this might have been good enough. I'm pretty sure if I tried it then the bike would vibrate the flywheels to pieces very soon.
 
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