Discussion in 'Norton Commando Motorcycles (Classic)' started by concours, Jan 8, 2018.
As for the crank center section, I marked it prior to disassembly. The book mentions reference marks, but I see none.
My Q is, the drilled balance holes...
How do I KNOW they are oriented properly? (Toward the front, or rear) I’m thinking they are not arranged all the way to that end of the flat by virtue of casting irregularity..
You don't KNOW if you didn't mark the crankhalve(s) and the flywheel!
The only reference marks would be the ones you did before you disassembled it.
Those holes seem to be all over the place, my 850 crankshaft does not have that single hole at the upper part of the centre section and have pictures of other 850 crankshafts that are different again ?
Even if the crank had no cheek orientation marks for reassembly there will near always be tell tale stain type marks on the mating surfaces of the machined pads that you can match to each other.
I will suggest the T/S has the casting number on the inner face and the bigger recess to the machined pad (less on the D/S) and the drilled balance holes will also be offset in that direction.
If it does notwork out I would help you out by paying $100 for that nice looking drive side cheek.
I don't know if that picture up the page is before disassembly but you can see the offset I mentioned regarding the balance holes being away from the T/S cheek, the machined pad that the cheek bolts to is also offset (deeper to the counterweight) in the same direction. (as above)
Best to have the crank/conrods/pistons dynamically balanced anyway. Although you won’t probably notice unbalance (due to the isolastics system) it sure is worth it to give the associated parts easier life.
Crank end float measures .015”
Now, with two shims, and a coat of sealant, it's .011".
The longest nuts should be at the top, closest to tdc on the crank. Just saying. Check post #9 first photo. part number 15 here: https://andover-norton.co.uk/en/shop-drawing/56/engine-crankshaft-connecting-rods-pistons-camshaft-timing-gear
pay attention to stud length as well.
Thank you for that. Glad someone is keeping me honest.
That’s been remedied, moving forward.
Nice clean cases. Did you paint them? I believe some guys use a silver BMW paint? Been helping Art H do his MKIII engine...June rally?
I painted (daubed with a rag) the bottom, inaccessible portions. I had used the heated parts wash tank at work which left some etching. I'll do the top portions before building up the top end.
Off to my friends aircraft shop to borrow the safety wire...
Owning a brit bike without access to the airport shop....not a easy life!