#6

[Grumph]

At one point Mike was talking about simply swapping the EFI over from the turbo'd bike. He'd already got it rideable unblown and responding nicely.
So my question was effectively how much to duplicate the existing setup Vs cost of carbs.

This one is bored to 150cc and has an improved inlet cam so was intended to be run unblown. He's got it cos circumstances forced my downsizing.

Doesn't stop me commenting though - sorry Mike.

[speedpro]

EFI requires things that I can't be bothered making again. Carbs you bolt in, and after a bit of fiddling they're all good. The bike has a FZR250 2KR model ignition module and decent looking coils. I'm close to having done what I want with EFI and turbo on my bike and don't feel the need to do it again. I'd just like to get Greg's bike going. Carbs is the easy solution.

[Grumph]

I think I told you I was going to put a smaller tank onto the underside of that steel tank cover. The carbs on it now don't like pump feed and if it's going to be on kart tracks the alloy tank is too big. I was aiming it for BoB and other big track races down here.

[speedpro]

No sweat. If I try those carbs I'll make a small header tank the pump can feed, from which the fuel can fall into the carbs, and any excess simply recirculate back to the main tank. I had a similar system on my MB sidecar.

[speedpro]

Made a small endcap to fit the end of the shaft of the rolling road I built. The idea is to use a kart starter to turn the roller. Hopefully the alloy will be up to it. The end of the shaft already has a couple of threaded holes in it. Surprisingly and unfortunately the 2 holes aren't the same distance from the centre so I can't simply make 2 holes in this cap on a pitch circle. I'm makingt little pointy bits that can be screwed into the holes and which I will then tap the cap onto to leave indents marking the centres of the holes. Bit of a pain.

[speedpro]

Could there be a 4T single begging to be made using one cylinder from this head. Standard piston size is about 75mm I think so a bit small for Gary but big enough for most of the fast singles.

[Grumph]

The late Suzukis are lift limited by the small OD of the cam follower buckets. I've had engines with Yosh cams and the factory kit cams through the workshop.
The Yosh cams are as big as you can go with conventional cam profiles. The kit cams have effectively an extra "finger" on the tip of the lobes to reach down into the follower bores for an extra .020in of lift.
Pretty sure someone will have the Yosh profiles copied locally. I took the precaution of getting the kit ones digitally copied while I had them here.
The guy who copied them said he didn't know how he'd grind them as the transition from main lobe to finger is a concave curve.
Either CNC or a very small grinding wheel needed.

I believe the reproduction Patons being built for classic racing use GSXR1000 parts and the head is pretty much a copy too. 500cc twins.

[speedpro]

Seen in the museum at Mt Panorama, Bathurst. Note the extra fins welded on. This was done some time in 1995 or so. Some may remember from bucket racing from about 1985 or so, a Honda 125 ridden by Tonto and possibly others, which had fin extensions welded on. In the bucket case there was an air scoop that directed air across the rear of the cylinder as well. As usual, buckets are well ahead of other motorsports.

[Grumph]

Pretty sure Ballard was doing it earlier than 1995. When I was at Budget in ChCh a local MX guy was pushing for us to become agents for Ballard. That was pre 1989. The big finned barrels and heads were to come from oz and I was to assemble the kitted motors.
Neither Kirby nor i saw any great profit in it so it didn't happen.

[husaberg]

Pretty sure Ballard was doing it earlier than 1995. When I was at Budget in ChCh a local MX guy was pushing for us to become agents for Ballard. That was pre 1989. The big finned barrels and heads were to come from oz and I was to assemble the kitted motors.
Neither Kirby nor i saw any great profit in it so it didn't happen.

They as far as i know were doing them in the states 89ish also for the desert racing and for flat track.
the big xrs as factory never had the oil coolers the 250s did but they used the frame as an oil cooler.

[speedpro]

The moment of truth approaches.

I'm penciled in for Saturday to get the bike on a dyno to tune the Link ECU. The very helpful owner has already sent me a couple of different setups, 1 of which I've spent a bit of time on my rolling road making adjustments. The trick is to get the base fuel map correct and the ECU takes care of fuel calculation in areas not covered by the base map, such as on boost. I ran it with the wastegate open so it was not making boost except a very small amount at 100% throttle and with quite a few revs. At 12,000rpm it was managing 105Kpa and really wanting to get going. I needed to brake it a lot more once it started winding up. I think the dyno operator is pretty much onto it. His provided fuel map was a bit rich but only a bit. I took a bit of fuel out while I was testing. No power measurement was possible I was just going off the Lambda. His timing map seemed to work pretty well but I expect it's going to need a bit of timing removed off boost in the higher rpm ranges. On boost the timing is already conservative so we'll test and see.

It feels like it's going to be a little monster. Either that or I'll bring it home in plastic bins

[speedpro]

I've been struggling to get it starting nicely. Using the kart starter I can turn it over at 2000rpm and I can see the injector pulsewidth is not where it should be for a cold start. I know from the past that I should see a 4-5mS pulsewidth and it is only the normal idle pulsewidth of a bit less than 2mS. It does climb up if I keep spinning it. Initially I set all the cold start tables to "0" and then doubled the base fuel map values in the area around where it starts. Voila. It fired up instantly which proved that the issue was fuelling. There seems to be a delay before the enrichment kicks in. Possibly it's the post-crank which I thought it wasn't even using.

[TZ350]

I've been struggling to get it starting nicely. Using the kart starter I can turn it over at 2000rpm and I can see the injector pulsewidth is not where it should be for a cold start. I know from the past that I should see a 4-5mS pulsewidth and it is only the normal idle pulsewidth of a bit less than 2mS. It does climb up if I keep spinning it. Initially I set all the cold start tables to "0" and then doubled the base fuel map values in the area around where it starts. Voila. It fired up instantly which proved that the issue was fuelling. There seems to be a delay before the enrichment kicks in. Possibly it's the post-crank which I thought it wasn't even using.

At 2,000 rpm, is it spinning faster than the starting cranking speed the ECU is expecting for a cold start? The ECU could be thinking it has already started and is running fine. There should be a setting somewhere that defines at what rpm cranking settings are dropped.

[speedpro]

Anything over 400rpm, yes - "400", is considered "post-cranking" speed. I don't think it's configurable. Pulling on the back wheel to spin the motor can see the engine hitting 3-3,500rpm, same with push starting. It could be that the extra speed sees the ECU switch out of the post-cranking zone into post-start enrichment after which it goes to warmup enrichment. Post-start enrichment decreases on a timer until it reaches the value in warmup enrichment when it swaps over. Warmup enrichment decreases as the engine warms up. It works sweet but at the moment there is an issue with enrichment from the moment the crank turns. It did seem to go direct to post-start enrichment previously. Hopefully it will be sorted out tomorrow on the dyno when it's being tuned properly.

Looking forward to tomorrow and seeing what it can do. Something like the power of a stock FZR250 would be cool.

Loaded ready for a 6AM departure.

[speedpro]

Tuning went VERY well apart from being cold and miserable most of the time. Kris really knows his stuff and is a great guy, very happy to help, and not judgy that it's "only" a bucket. His eddy current dyno is a car dyno and the bike was only spinning the front rollers. His software assumes the rear rollers are also being spun and calculates the power produced by including the inertia of both front and rear rollers. The end result is a high reading. I think it's good even subtracting an amount to compensate but I'll do a test run on the ESE dyno to get an accurate figure before making any claims. The thing is that there is more to go. Tuning is still conservative, only about 11psi boost, fuel is rich, timing is a couple of degrees less than we know it likes, and if the boost goes crazy timing is pulled out and fuel is dumped in to kill it. There's also a fuel cut programmed if it goes really crazy.

HD National circuit next weekend is going to require stock FZR gearing. I've never been around that circuit so it's hard to calculate. If anyone with a fast bucket could reply with the power and speed on the track that would be helpful.