Thanks mate, well I'm neither a machinist or a woodworker, I'm a soldier, and not surprisingly, I'm a far better soldier than I am a machinist or a woodworker, ha ha.
But I do love machines, and machinery, so today I soldiered on. First thing I did was remove a couple of the APE studs, so I could measure the outer sleeve once I lifted the cylinder. If the cylinders weren't so close together I'd remove all the studs and when I pull the block, leave the pistons in their bores Harley style, i.e., pistons in the bores, with the wrist pins pulled. Works great on a VTwin, but not so much on anything else.
1428 spacer plate 11 Jul 2020 2 by
Terry Prendergast, on Flickr
Anyway, the outer sleeve OD apparently measures 87mm. I say "Apparently" because the jaws on my caliper weren't quite long enough to give me confidence that I'd reached the middle, so I intentionally cut the holes in the spacer to 88mm, just to be on the safe side. Considering that the pistons are 83.5mm, that only makes the cylinder walls 2.25mm thick, which sounds about right, the sleeves are understandably quite thin.
1428 spacer plate 11 Jul 2020 by
Terry Prendergast, on Flickr
Due to my current diet, I've been having baked beans with my eggs and bacon for breakfast and I've been admiring these little tins, then putting them in the recycling bin. Yesterday I was looking for a container to store all my small slotting drills and was using a lid from a rattle can, but had a lightbulb moment this morning, so cleaned the can and took it out to the garage to re-purpose as a drill bucket.
1428 spacer plate 11 Jul 2020 3 by
Terry Prendergast, on Flickr
But back to the spacer. I thought about what I could do to allay Frank's concerns about the boring tool, sadly using the horizontal tool hole wouldn't have worked unless I could run my mill/drill backwards, but I can't, so all I could do was use a nice short cutting tool with the thickest shank, and I had no issues at all.
1428 spacer plate 11 Jul 2020 5 by
Terry Prendergast, on Flickr
I did notice though, that as I'd removed so much material from the middle of the plate, the centre was sitting slightly "proud", so the cutter was cutting the high spot on one side of the sleeve hole for a few revolutions before it started to cut on the other side, which pissed me off. I decided to pull both the spacer plates off the machine and once separated, there was aluminium swarf-a-plenty betwixt them, and also the self tapping screws I'd used to hold them together, and just drilling the holes for the cylinder studs had caused "high spots" which needed to be sanded down. I spent the next 30 minutes of so getting the plates deburred. I made a little hold down plate to pull the centre down, and also to avoid swarf getting back in there. It worked well. I ended up with 8 of these that I couldn't bring myself to throw out, anyone need a really big washer?
1428 spacer plate 11 Jul 2020 7 by
Terry Prendergast, on Flickr
Anyhoo, I then had to line up the first hole again before I could take it out to 88mm, which involved much farting around changing chucks, refitting the hole saw until it was cutting the same track in the timber below, locking both axis, etc to ensure that the hole was exactly where it should be. Once I was happy with it, I cut the other three. Took over 1 hour per hole on average, not that it took anywhere near an hour to cut a hole, just a lot of setting up. It reminded me of when I was the QuarterMaster of the Army Engineering Agency back in 99 when I was fascinated watching a CNC mill doing a magnificent job of making something all on it's own, while changing the cutting bits as necessary, once again on it's own.
Once all the holes were bored, I traced the outline again with the base gasket. Using a hole saw and "The death of 1000 cuts" treatment from my bandsaw I roughed out the shape, then after trying a few different things to smooth it out, I settled on my favourite old 4 inch angle grinder fitted with a flappy sanding wheel to lightly smooth and shape it, then my electric die grinder fitted with a porting "cone". I then gave it a sand on a flat surface with wet and dry sandpaper on a block, with some WD40 to lubricate it. All in all, it came up pretty well.
1428 spacer plate 11 Jul 2020 9 by
Terry Prendergast, on Flickr
Of course, looking good and fitting good are two different things, but as I haven't lifted the block yet and it was getting late anyway, I laid it on top and was happy to see that everything looked to be lined up.
1428 spacer plate 11 Jul 2020 9b by
Terry Prendergast, on Flickr
And that dear reader, was how I spent my first Lockdown Saturday. Tomorrow I'll lift the block, put the spacer in place, machine up those piston blocks and hopefully put the head on, do the cam timing, and see if I have enough clearance. We'll see.........