Simes' FH Rebuild

[simon.holyfield]

Does this help? You can see a bolt in the flywheel. All I have access to at the moment...

[Vincent.vanGinneke]

Nice! Going to follow this.

[simon.holyfield]

So once again, thanks for all the advice and support! It's great to know that people are interested and ready to help , just for the asking.
Coming back to the pistons - yes, they are dished and yes, I have two sets of cases and one crank - actually, looking at the date codes I have a complete 1955 engine (LF prefix) and the original crankcases from the bike, CNLF prefix which match the brown registration document.

I was hoping to rebuild the LF engine into the CNLF cases and have a 'matching numbers' bike. As far as I understand the crankshaft change, this occurred in 1958 and affects the big end bearings only so I assume that my mission to transfer the 'LF' engine internals and top end to the CNLF cases should be successful?

I posted a picture of the view through the sump, showing a bolt in the periphery of the flywheel. Does this suggest I have the later crankshaft in the LF engine?

Steve, Simon, thanks for your ideas and offer on the belt primary. I've not really considered this yet; I've never deviated from a chain primary yet, but I will investigate that and any other mods that are available in 'A10 World'. I'd love to hear your suggestions - an Alton must be on the list?

You'll have read by now that I am at +60 thou, and I believe (though the pistons are still in) that the piston clearance will be borderline if not excessive. More later on that, when I have it all apart and properly measured.

If this appalling weather continues, there might be some workshop time tomorrow which might be for taking the barrel off or for starting on the timing case. There is a bit of a clonk when rocking the crankshaft which I think may be the dynamo chain or maybe the timing gears. I'd appreciate your thoughts on that:

https://youtu.be/BEXU9CVHxfE

[Simon.Gardiner]

Big-bearing crank has got 3 bolts holding the flywheel, equally spaced and with one over the crankpin (which extends to also retain the sludge trap tube). The heads of these are visible in the outer periphery of the flywheel.
The small-bearing crank has 6 bolts fixing the flywheel on its inside, the outside of the flywheel is unbroken - except for maybe some balance drillings, so if that hole in the photo has a bolt head in it I'm pretty sure there's a big-bearing crank in there.
Be interesting to see how that's been done, I can think of maybe 3 different approaches, some quite easy although possibly shockingly crude!

SG

[simon.holyfield]

Don't laugh...

https://youtu.be/i7WLWgPeIzQ

[Steven.Carter]

Don't laugh...

https://youtu.be/i7WLWgPeIzQ

I didn laugh, well maybe a bit
Did you get the barrel off ok? I struggled to get my one off last time

[simon.holyfield]

I did struggle with it, lots of rust in the unworn bit at the bottom of the offside cylinder.

The big & little ends are absolutely knackered, worse on the nearside. Unless someone has forgotten to put the shells in - thats what it feels like!

Any bets on the state of the sludge trap?

[simon.holyfield]

By the way, there is only a single balance hole in the crank - so it's a small bearing job. Can I put this in the 1958 crankcase?

[simon.holyfield]

And Simon, have a look at these:

The cams don't look too bad.

[Steven.Carter]

I wonder how many miles your engine has done, when I needed to change my pistons everything else was fine with 70,000 covered. I'm hoping that using an oil filter will have kept my sludge trap clean, I hope!