#6

[speedpro]

Isnt it about time you built a proper motor? stopped playing around with slow old Honda motors.

This is a real old comment, but I did finally get there. Best MB I built had decent horsepower and the current one dynos at 24.6 so that's OK as well. The FZR is finally making good horsepower as well. Both are great to ride.

[speedpro]

A meeting is coming up at Rosebank Road. There are severe noise restrictions at the track. The turbo should be OK. A turbo is good for reducing noise but we'll see. The MB despite not being all that loud will be too loud. I've decided to insert a tube between the start and end of the baffle cone. This will take exhaust gas from the centre of the expansion chamber where the pulse amplitude is much lower, rather than the very end of the baffle cone. The gas will then go through the stinger and muffler as normal. I've made a few pipes like this in the past which worked great. I cut a bit of .8mm sheet and rolled up a tube and welded the seam this afternoon. TIG welding mild steel is a shitload easier than aluminium. It'll be fun cutting the expansion chamber and cleaning it enough for welding. I might have to see my mate Kev about borrowing his gas set and brazing the supports inside. If I can cut it cleanly I'll be able to use sanding drums to clean the inside and outside edge and TIG it back together.

[TZ350]

This is a real old comment, but I did finally get there. Best MB I built had decent horsepower

The old MB100 was the first F4 Bucket two stroke to break 30 rwhp on the Team ESE Dynojet dyno.

[speedpro]

Off topic slightly but I was doing a bit of maintenance in the garage. I turned a piece of steel and wanted to run coolant. The pump was making noises but wasn't doing any pumping. Finally got round the back of the lathe, got access to the little tank and the pump and found the coolant had a custard-like consistency. No wonder the pump wasn't getting anywhere. After much pissing around I finally got the tank out, cleaned all the old goo out, and put it all back and added fresh coolant. Pumping a lot better now, and bonus, the floor behind the lathe is now waterproof.

[husaberg]

i seen a Vizard video with a zero HP loss strert legal muffler its pretty simple in concept.
i see no reason why it would not work on a 2t.
https://www.youtube.com/watch?v=J4w9fmb41Wc&t=41
His patent is also googlable.

[speedpro]

Good session on the ESE dyno today. #21, the MB/FZR, initially leaked fuel. I thought I'd sorted out the float valve but not so. I had a new one so went ahead and fitted it. It still had the bigger jet I wanted to try at Ruapuna and the timing was still backed off a couple of degrees how I set it for Ruapuna. I had taller gearing fitted to make sure it was getting loaded properly on the dyno. An all-gears run didn't show any problems and a top gear run resulted in a new personal best for this engine. Realistically it was a whisker under 25hp. Revved right out it would be getting close to 90mph. This motor is a real gem. The torque curve is near flat. I'm thinking the good hp number might have been helped by the Iridium plug I've put in. The motor is only just so big that I need to use a 24mm carb. I have a 28mm carb fitted but have a 24mm restrictor glued in. Initially it lost .1hp when I did it but with the other changes it's now making a bit more.

[speedpro]

I ran #6 as well. More just checking things as there are a few updates. I sorted out a leak from the seal on the exhaust cam where the cam trigger mounts to. No obvious leaks even after the runs. I also have a new tune that I wanted to try. There have been changes to trigger thresholds to try and eliminate the errors I was seeing. There was a bit of finessing of the fuel maps just to tidy up the AFR, and the same for the boost control. The log shows that the fuel is much closer to desired lambda and stable. The boost control is real smooth now, however the boost is very lazy coming up. In an all-gears run it pulled more boost in each gear and still didn't make as much boost as with the old setup. It's an easy fix, I'll just load the old boost control table. Power was down about 5hp which I'm putting down to lack of boost and warmer IAT due to lack of cooling air going to the duct on the dyno. I ran a taller gear, 15:60, like I should have fitted at Ruapuna. Top speed was something like 95mph which it'll pull easily. It was rev limiting with 14:60 for about 200m on the front straight. It might even be worth trying 15:55 which will have it doing a little over 100mph at 18,000.

A good day on the dyno