anglia4

I'm happy with all of the above. I was leaning towards not coming for coronavirus reasons. Duke Blackwood, Dad Blackwood and myself have planned a 270km daytrip of insanity around Taranaki back roads to satisfy our nanging needs.

For the gravel or for gisbourne?

I have so much adoration for that CRM.

I’ve started doing a wee bit of prep for bush nangs in case I end up going lol. The more I look at this bike the more I find half arsed So today I added split pins and lock nuts to all the places that should have them, like the brake rod and chain adjusters which were only finger tight. The brake rod was nearly wound right off, it needed resetting on the spline. i had to add some extra spacer nuts to the chain adjusters for some reason. It’s within normal axle adjustment but at the limit of the threads... weird... I’ll call this 3/4 assed now I also added a bit of tire tube to keep water from the tire out of the carb. I also rotated the bars up to a normal position cos I’m a grumpy old man these days.

Ah I see. Not a matching numbers shirt

Cool tee shirt.

I got lucky enough to be able to spend a whole night in the shed on Friday. So I kept welding until the pipe was finished... It was a massive effort. Severely underestimated. It was race day on Sunday, so I took both pipes along to back-to-back test them. I knew vibration was still going to be a big issue so was gonna run each pipe in one session and then ride an FXR for the rest of the day. The new pipe was good, the power band is a little wider and smoother, from ~9000rpm to about 11,700rpm, and I can tell its got a wee bit more power because now I get it to top gear before the end of the straight. Unfortunately it only got about 3 laps into the test before I could hear it getting louder, and as I pulled into the pits it got VERY loud. The vibrations had made the bolts come loose in the past, so I had tie wired them (loctite and spring washers wasn't doing it). Being tie wired, rather than rattling out, they have vibrated and pulled and stripped all the threads out of the barrel Time to balance that crank! I'm happy that the pipe has made a gain though. Now I'm going to do some research about nozzles to increase the stinger size and deal with its length.

Spacer: So after all those drastic mods I was at this stage running the final version of the bastardized random unknown pipe and now on a 24mm PRC Maikuni Flat Slid Carb. After a chunk of trial and error tuning I observed a massive increase in power, and the rev limit went from topping out at 7k to zipping past 11000rpm (where I sook out and change gears). Unfortunately, these are only balanced for 6000rpm... so now your hands go numb and every bolt on the frame comes undone in seconds. Its also still painfully slow compared to the stadard FXR150's. So for now its back in the laboratory while I finish welding up the pipe and pull the crank to balance it. While I've got it apart I will take some more off the barrel to get the squish down, and if funds allow, I'll re-bore it and might look at fitting a new piston to get better ring options, RG500 thingy's look like they might be a good fit. That's the whole story up to date now. Edit: you can see in this photo how pissed the piston is sitting on the barrel. This is because of the 10mm cut from the skirt on the inlet side with my precision 5" grinder.

Reed valve hole that I filled: After a bit of a hone to take the worst of the marks out: Freshly skimmed barrel:

The last piece of the puzzle to date has been the engine itself. My search for that elusive horsepower led me down the rabbit hole of port timing. I raised the barrel 1.5mm Raised the exhaust port roof 6.6mm (+ the 1.5mm) Lowered the floor of the inlet port 10mm Cut the inlet side of the piston skirt 10mm This theoretically results in port timings of 195°Ex/128°Tr/185°In, however I haven't checked it with a degree wheel yet. Originals were 155.5°Ex/118°Tr (didn't bother to measure inlet because of the reeds). As well as taking the 1.5mm back from the top of the barrel, I machined the head about 1.1mm and used a thinner gasket to get from 17.5cc to 13.7cc (8:1CR to 10:1CR - Uncorrected) This gave me a squish band of about 1.8mm, which is about 0.8mm higher than I would like it to be. These engines have a bizarre piston port/reed inlet system that suzuki trialled in the 70's. Basically it just ends up being shit at both. So I've blocked up the reed port and massively adjusted the piston port to make it a piston port engine only. Comparison of before and after inlet port sizing: Have you ever seen someone precision machining their piston with an angle grinder? You have now!

Its always easy to push haha thats why I didn't notice

And then, this one time at band camp... I pushed it around and around and around the dummy grid wondering why it wouldn't start, only to get back to the pits after watching the race and find this sitting on my toolbox...

I also made it look heaps better, cos if its gonna be slow its gotta look good doing it.

Now I just have heaps of welding to do...

3D scanned with an xbox kinect 3D camera and then modelled using solidworks sheet-metal