Project Fuel Injected Turbo FZR250, half

The mill is a Rexon round column type with a 2 speed 1hp 3phase motor. I've added a 1phase to 3 phase VFD to the input so it's now variable speed. It still has the belts and pulleys on top. I have spent a bit of time tramming it as best I can. It's near perfection on the Y-axis and is only a couple of thou out for full end to end travel on the x-axis. The column is mounted on a 4-bolt flange. A 3 bolt flange would have made things a lot easier. A mate in Wellington gave it to me.

 

The Z travel hasn't been a big problem so far which is to be expected given the smaller size of the work I do. I have a friend with a Bridgeport mill which I'm allowed to use if I ever do need a bit more. So far the only time I've needed it was when I was using either a rotary table or the universal dividing head. I have found that a bit of chatter happens sometimes and it sounds like it's from the belts/pulleys. I found I need to clamp down the middle pulley hard which helps. Normally it has spring loaded bolts holding it so it can slide when you change pulleys. The motor is only ever going to be 1hp but that's heaps for what I do. You do lose a bit with the VFD, probably due to the waveform not being ideal. Supposedly you end up with about 80% of whatever the rating is. It's still plenty.

 

I managed to stop the lathe again today. I think the belts slipped. I was getting enthusiastic with the parting tool on a bit of mild steel, or maybe it wasn't so "mild". turned out to be a good example of making decent depth cuts and getting a much better finish. 1mm depth and turning at a decent rate and a mild feed rate gave a shiny finish. Less depth and it was nowhere near as nice. At 1.5mm depth it made really nice chips which were farkin hot.

 

Yeah, blue chips. The deep cut was with a standard carbide tool rather than the parting tool. Finished a "kit" of washers and spacers to fit the 2nd R6 shock to the other chassis. The new dogbones are slightly thinner than the stock dogbones so 1.4mm thick washers are needed to make sure the bolts clamp the dogbone to the sleeve going through the bearings. The shock top mount is only 30mm wide but the chassis has a 40mm gap between the mounts. I made steel washers that are 16mm diameter at the shock and 25mm where it fits against the alloy of the chassis. A small step and a 45degree taper and they came out looking great and also spread the load when it's all clamped tight. The alloy was already dented where the original shock had been jammed in and tightened.

 

I have a couple of different types of carbide inserts. Pretty standard ones that came with the lathe are OK on steel and alloy but I bought carbide insets that are sharpened and polished for alloy. You can really peel the alloy off with them. I've been spinning 30-50mm lumps at 1000-1400rpm and using faster feed rates. I also bought a carbide boring bar that uses slightly pointy carbide inserts at 45degrees. The standard boring bar is OK but this one lets you start with a much smaller hole. The parting tool inserts say you can spin a 20mm bar at over 1000rpm and use a good feed rate. I've tried it and it works a treat. I also bought a small stack of cheap end mills for the mill. Supposedly 70HRC. So far they are pretty impressive and go through steel fast and clean. I even tried machining tool steel. Initially it wasn't so crash hot but I tried pushing the feed rate and it came right and mowed a flat in the round bar I was testing on. Those chips came off really really hot. I'm gonna try machining an old cheap carbide tool. I might wear a bit of PPE for that test. My mate Kev machines carbide now and again using CBN(I think) inserts. No shape to them, just a flat triangular bit. A small molten ball forms on the tip of the CBN insert. Not sure if that is technically correct but it seems to work OK. Edit - boring bar is not carbide, only HSS. I looked at the carbide one but didn't really need it.

 

There's "tool steel", and then there's "tool steel". I have a quality 14mm tool steel end mill. It's 8% cobolt similar to the one in the link. Typically the cheaper tool steel is only 5-6% cobolt.

14mm PLAIN SHANK ENDMILL Co-HSS LONG SERIES (carbidenz.co.nz)

I have machined the outer race of the bearing for my scooter starter clutch. That was interesting holding it and getting it clocked up.

I have a "kit" of parts ready to fit the R6 shock to my turbo twin. I'll try the stock spring but will reduce the preload which is something like 10mm standard.

The 7kg spring with about 1-2mm preload allows the bike to sag about 10mm without the rider.

 

I went out looking for Threebond sealant. The local Repco were helpful but didn't have any "1215", which is the typical sealant I think. I drove up the road to Partmaster and a guy working there used to work for ThreeBond in Australia. After a bit of a chat he told me that "1215" is not rated for use in contact with gasoline. Obviously a problem for 2-strokes and possibly the cause of the air leak which caused the latest siezure as I used it to attach the reed cage and adaptor to the cylinder on the MB100. The stuff to use instead is ThreeBond "1104 NEO PLUS" which is rated for use in contact with gasoline. The data sheet says it can be used on the flange surfaces of fuel pumps which is pretty definite. The good thing is that it's lots cheaper than "1215".

This might be a consideration if you like to put a bit of sealant on the carb manifolds. I've seen "1215" swell out of the joint.

 

I have the R6 shocks fitted to both bikes. The MB/FZR has been run on the dyno and the chain rubbed the reservoir a couple of times. I have had a look and the MB engine can be dropped about 20mm but I think the clearance will still be tight. The turbo has the standard bottom end with the sprocket in the standard location. The rear sprocket is 60T versus the original 55T and the chain looks a bit close to the shock as well.
For anyone who has fitted an R6 shock to a FZR250 have you experienced any issues with the chain contacting the reservoir?

 

My son and I went to Tokoroa Kart track over the weekend. It was wet on Saturday when I was looking to have a ride on the turbo twin so I didn't get to try the shock. On Sunday it was fine and sunny and my son was getting round nicely on the MB/FZR using the R6 shock with the 7kg/mm cutdown spring. I had the damping adjustments set to about mid-range. There weren't any complaints so nothing was touched. The bike was handling better. There is at least one place where he had been standing on the pegs to let the bike move around and there was no need do that now. He was also getting his knee down in places where before he hadn't been. I thought I could see a bit of movement creep in later in the GP(40 laps) so I will consider a bit of shock maintenance. Fresh oil won't hurt. One place in particular he looked to have a bit of an advantage, the left-left down the back. The camera showed him making a bit of ground over others going through there. Previously he's mentioned the back stepping out under power but I think he said it only happened once this weekend. The GP was won by Rogan Chandler who's a very good rider. Watching him pile into the hairpin into the back straight was a lesson in bike control, or bike out-of-control.

 

I don't think contact will be a problem. The MB/FZR had no problem and although I haven't measured it I think the turbo twin chain is actually slightly further to the left so has more clearance.

Short video of the start and first few laps of the GP looking back from the MB/FZR.

 

I have purchased an intercooler core and have been looking at how and where to mount it. I was thinking of mounting it on the intake plenum with a flange and running ducts to it for the cooling air. It's getting complicated real fast, My latest thought is to remove the current plenum and build a new alloy plenum that the intercooler core is welded to. The intercooler core would form the roof of the plenum, more or less opposite the throttle bodies. The turbocharger will feed the bottom of the intercooler to the left into a seperate chamber. This compressed air will flow up the left, to a chamber across the top, then down the right to the plenum over the throttle bodies. I'm not really looking forward to the fabrication work given my TIG welding skills. There's cables and hoses all around that area so they'll either be re-routed or built around.

 

I don't know what temp drop to expect. The log shows it hitting about 100C at times so there does need to be a reduction in temp before adding more boost