Now that the sleeve drive crank is being made, we need the bearings to accurately size the component. The large diameter bearing is an American made imperial bearing, only available from a specialist importer.
I mailed them and duly received a quotation for £326. Plus VAT. Plus £10 postage. Total price £400.
How much? Feck me!
So, plan B. A quick search around the web showed no metric equivalent bearings, but a couple that were close. After marking those dimensions on the plans with Bob, we found an alternative that will work. Press a couple of buttons on my phone and it’s in the post.
£142 delivered. Result!!
Final adjustment to the flywheels to resolve a slight taper on the bore. The milling machine isn’t the first choice for this kind of work, but is giving good results. Setting it up was a bit of a faff though.
Measuring the distance between centres, we’re slightly over the planned 3.25" stroke at 3.3". It won’t matter but it does increase the capacity by an extra 46cc. The final capacity will be 2796cc instead of 2750cc.
I hope that doesn’t affect the insurance!!
It’s been a while since the last post, with life getting in the way of progress. But work hasn’t stopped, with most time spent puzzling over problems yet to be solved.
A minor issue is a slight taper on the flywheels. Only about 5 thou, but enough for concern so they’ve been re-bored on the mill with a boring head. That took a lot of setting up but with a final cut to go they should be finished. Again!
Meanwhile, just when I least expected it another barrel, sleeve and head turned up on ebay. Too close to miss, I picked them up from a very nice couple. The biggest bonus was finding the ball joint – still attached to the sleeve and quite serviceable!!
That brings the missing part list down to a piston and gudgeon pin. Happy Christmas!!
The flywheels are completed, ready for pressing to complete the bottom end. Less can be said for the other parts! The crankshafts and crankpin will need a carrier making, so they can be turned between centres. A little job to do in order to start a bigger job!
The blued areas on the flywheels is where they have been relieved to allow the bearing cage to spin, when everything else is pressed together. The inner sleeve for the main bearing wasn’t available oversized, so the wheels needed modifying. At least we thought of it now and not when it all went together!!
They certainly look the part. Bob has done a cracking job.
Lots happening at the moment. The big news is that the shed has changed hands! I’m now the legal owner on paper, though in practice nothing has changed. Bob and I are still working on project Hercules.
The flywheels have both been bored now, so they’re out of the big lathe and on the mill individually. Some of the thickness is being removed to create the counter balance for the weight of the piston and rod. The first wheel is nearly down to size.
Meanwhile, we’ve also had a trip down to Redhill to collect some tools from a late relative. Another trip required but the stuff is fantastic! If we get the two big machines the shed will really rock! Watch this space.
A fair mix of emotions yesterday when I found a Bristol Hercules cylinder on ebay. Great that parts are turning up, and I scored a barrel to compliment the Centaurus I already had.
But absolutely gutted to find the seller had a piston and sleeve, already sold!! That would have saved me some grief. I’m trying not to think about it. So close!!
Still, I have access to a complete engine in Donnington, a sleeve, barrel and a few heads so there’s a fighting chance of getting everything I need. Worst case, I’ll make a piston and get the sleeve I do have hard chromed and ground back to size.
They look like a pair of robots on the bench, almost have a personality if their own! Before anyone suggests it though, I’m not making a V-twin. It’s been done already!!
Quite a job setting this lot up and well done Bob, 10/10 for patience! The flywheels have been bolted together for machining as a pair, to ensure that the crankshafts and crankpin run true once assembled. A lot of weight to swing on the Churchill lathe, great stuff!