Author Archives: Sophie Whiptank - aka Bart

About Sophie Whiptank - aka Bart

I'm just a bloke doing some stuff, the more interesting bits I post on my blog. Scroll down far enough and you'll see me riding from Melbourne Australia to Birmingham, England in 2014. But now I'm working on another project, a single cylinder motorbike engine at 2750cc!

Half moon rising.


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.

Double Barrelled!


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!!

Shed faries…


The shed faries have been busy while I’ve been in London this week. Bob has finished the second flywheel and it’s really starting to look like a big end. A BIG end!

It’s just a mock up at the moment, nothing has been pressed in. But you get a good general impression. The next step is to line bore the main journals and crank pin hole. That’s a fair job in itself, the tracing paper will come out again for that.

We’ll try the faceplate to start with, but it’s a heavy weight to mount and spin eccentricly. Counter weights will definitely be required. For now though it’s worth admiring progress, the steel is very tough and Bob’s taken the job forward well. Thanks Sir!

Flywheel 1 down to size


Bob and I have been busy and flywheel 1 is now down to size. The thickness and diameter are to the drawing so its out of the lathe to make way for the other wheel. Once we have a matching pair they can be bolted together.

Taking the half moons out in the miller will be slow going as it’s tough stuff, but little by little we’ll get there.

I held the conrod up to the wheel to get a sense of scale. It’s going to be a monster of a single!!

Finished baffle


A good day is when you make something. Or try to at least. As the sun sets the world is a difference place, as something exists that didn’t before.

So a good evening round Nicks ensued as we drew a baffle on the laptop and set the machine to cut it from perspex. (After a trial with some wood). The long suffering Emma provided Pizza and by the time I rode home the big Honda had a new baffle.

Does it work? I think so, but it was raining and dark. I haven’t ridden it since either! But I’m ringing the bell as it’s not my imagination, definitely an improvement. It may not be the final version as its a bit thick, but it will certainly do for now. 🙂