Over the break progress on the engine head been good. The drive side case is finished and the timing side well advanced. Attention now turns to the timing case, which will be quite complex. The first job is to get it bolted into the timing side, so we have a reference to work from.
The plan is to get the timing cover bolted on, then make a couple of mandrels to fit in the bores for the sleeve drive and main bearings. The mandrels will have a small hole in the centre, through which we can fit a bike punch. This will allow the centres to be accurately marked on the inside of the timing case.
In order to bolt the timing case on, the timing side needs to be drilled and tapped. 32 holes in total. Tap tap…. Starting tap, number 2 tap and finally plug tap. 96 operations! In the plus side, the second set of cases will then be ready to drop off at the frame builders.
Here’s a little project that’s been rumbling along in the background. I picked up an old pressure guage from John Collet’s place a couple of years ago. It was in the scrap pile and it just looked too nice to see going to waste.
I didn’t know whether it worked and the fittings weren’t compatible with my modern Chinese compressor of course! So it took a fair bit of fiddling with central heating fittings, some 8mm microbore copper pipe and a bit of soldering. Thanks to my mate Matt for helping with the soldering, much needed!
I thought about a full restoration on the gauge with a repaint in bright red, but I kind of like that patina – and it’ll only end up looking like this again in 30 years time 😁 Thankfully the gauge works just fine and that’s another thing saved for a while longer. Result!
A fair bit of work has gone on which I’ve put up on the YouTube channel. I’ll embed a few videos sometime.
Meanwhile, the heads and manifolds have come back from Sutton Soda Blasting and a fine job they’ve done of cleaning them up. You can see them side by side with the spare cases in the background.
Having a choice of manifolds is good, noting that the mounting flanges aren’t square so they can only fit one way. I can start to visualise the ancillaries now and get a clearer picture in my head. Quite exciting!
The main bearing on the timing side has been bored and that happened in no time at all. As per the YouTube videos, using the CNC control to start/stop the motor and feed the cut makes these bores quick to do. Even Bob was able to drive the machine and complete the operation.
All of the bores on the timing side are done now, so the next job is to fit the drive side without removing the timing side from the mill. The dowels will ensure that the cases go back together in the same place, so that the two main bores for the crankshaft to run in are completely concentric. (In theory anyway!).