Lots of assembly required.....

You have more experience than I but I figured that no matter what you do the inside of the fork will be in turbulent flow where there is a decent chance the the outside will still be laminar. If you are putting a fairing over the fork none of this matters.

Chris, good to see you posting here.

Al

Alan,

Howdy. I guess I'm not surprised to see you on here too. Definitely a similar crowd to the chassis design list.

First off, happy Labor Day, hope you are all doing some fun riding!

The last post ended on a high note, the bike was working well and no parts were breaking, yet I couldn't manage to drop my laptimes any further. I did have a parallel control experiment going on in that I was racing a box-stock 2004 Honda RS125 at the same time. Interestingly enough, my 125 lap times were at the same level as my single times. When I upgraded the RS125 to a TZ250 my lap times still did not show any improvements. Hmmmmm.

Taking the hint the universe was yelling at me I decided to try to find a faster rider who would be interested in a unique project. My close circle provided the answer in the form of Todd Puckett. I'd like to be able to post his facebook address or ADV username, or any list he posts too but unfortunately Todd wisely chooses not to participate in this experiment we are calling social media. He is truly a rarity these days in more ways than one. Todd was another Team Incomplete member who had a great run on 125s, getting a 2nd overall for the season in the competitive LRRS series and a regular podium finisher in cutthroat USGPRU events. On his clapped out RS125 Todd was regularly dicing with the fast 14-15 year olds who were on brand new machinery, definitely an achievement.

After a few seasons riding the same bike Todd was up for a change and willingly jumped on board to help develop the bike. Also, having a rider to do the riding duties freed me up to pay attention to all the tasks being neglected when I was the combined rider/wrench. After riding the nearly indestructible 2 stroke GP bikes for years I don't think Todd or I was quite ready for the fragility of a highly modified 4 stroke big single in the hands of a fast rider. The first months of his riding resulted in quickly decreasing laptimes married to quickly disintergrating engines! I looked for complex reasons behind the failures but the simple fact was that he was riding the bike much harder and faster than I was and subsequently loading the engine way past what I was able to do. Speed costs, how fast do you want to go? Damn fast.

Here's a shot of Todd on the air-cooled engine getting 52+ degrees of lean.



After backing off the tune a bit for longer life Todd got a good feel for the chassis and started being competitive with the modified Buell, SV650, and Ducati 1000 twins in the bump class. His split times in the tighter sections were always quicker than the bigger bikes but the advantage was completely lost once they got onto the straight. There is a lot of truth in the old racing adage 'there's no replacement for displacement.' Knowing a few more Hp would go a long way I looked for ways to bump engine output.

That is the road that led to more power and more spending but it has to wait for another post as I've gotta run now and make some parts for Kenny.

Chances are if you raced on the east coast during 2002-2008 you've seen/tech'ed/raced one version of the bike or another. I've met many people in the paddock who were stopping asking the same question with various punctuation: What is that?, What is that! and sometimes WHAT IS THAT?!?!?!?! I even have had the honor on several occasions of tech inspectors having to call for backup.

I feel bad that we have not been as present at the track these past couple of years as we'd like but this crappy economy does take its toll on such a tightly funded project like this. Once things start looking up and this new bike gets finished I hope to be making the rounds once again.

Outstanding

Yes, I know that tech inspection routine. Of course, my bike always looked pretty ratty, which never helped at tech inspection. My last season, I decided to clean up everything, and paint it all one color using proper, shiny automotive paint. Made tech go much faster - I deprived them of a reason to suspect poor preparation.

For some reason my rear brake was air-permeable and always needed to be bled. The tech guys loved to find something to make me come back and I was always getting caught out by the rear brake.

Just As Kirk was always bitching to Scotty how he needed more power, a roadracer is never satisfied with the power they have. Todd was adapting to the new chassis and suspension quite nicely but when up against bikes with nearly double the displacement there is only so much a rider can do through the turns without getting taken down the straights. In the search for more power we left no stone unturned. I massaged everything in the existing engine, 64Hp. We got a bunch of race parts from Ron Wood, 64Hp. Purchased a complete 75Hp engine that made.......64Hp. I was beginning to think that Peter's dyno maxed out at 64Hp. We tried big bore low revving engines, small bore screamers and everything in between. 42mm roundslide, 45mm flatslide, 48mm flatslide......64Hp.

I finally gave up on making the existing head make more power. The next avenue was to see what other non-Rotax options were available. At this point I walked into a friend's shop just after he bought a Ducati 999 engine off of ebay and was in the process of disassembling it. I saw the cylinder head and thought, that looks about the size of the Rotax head and they both have 4 studs. Could it fit? I was quite sure that a modern 4 valve head would flow more than the mid-80's design of the Rotax and proceeded to buy my own head from ebay and see what I could see. What I found out was that the head and cylinder assembly could definitely fit on the Rotax crankcases.



I needed to resize the cylinder spigot in the cases, bore new cylinder stud holes in the cylinder and head castings, and arrange for oil feed to the cams and oil drain back to the cases. Oh, I also had to design a camdrive system as the rotax is a single cam engine while the Ducati was twin cam. The chosen solution, with the assist of the engineers at Gates Belts, was a 1:2 reduction fron the crank to the exhaust cam and then a 1:1 from the exhaust cam to the intake cam. I was able to use stock belts but had to have custom pulleys made. After a bunch of work and money the engine was finally mechanically ready for testing.





The last item to take care of was to figure out how to run the fuel injection and computer. this was the first fuel injected engine I worked with so a large learning curve was ahead of me. After looking at the available generic ECUs and the contents of my wallet I decided to go with an Emerald M3DK setup from Emerald in the UK. The system and programming software was easy to understand and the ECU could be configured for nearly any engine type. A stack of cash and a few weeks later and I had all the electronics parts needed and only had to make a wiring harness to tie it all together.

Making the harness was a huge chore but its getting late so the rest will have to wait for another post.

that just might be the coolest thing I've ever seen. :

Bitchin'

(I have the feeling I'm gonna be saying that a lot more in this thread!!!)

Wow, I was there the whole time but hearing about it now I'm surprised you were ever ready to go to the track with us...

Gregor

Jesus, thecosman- I am in complete fear and awe. I dig your creativity and persistance!

My name's Len, and I'm subscribed.

Steve/Len, thanks, it's a huge effort but is quite rewarding when the bike does the biz.

Gregor, if I remember correctly I was rarely ready to leave for the track on time! Funny thing, at my recent Indy visit I realized that what I had made was a true GP bike. Every garage I looked in had a bike in various stages of disassembly. If Repsol Honda is tearing the bike down after practice then if I am doing the same thing I must be on the right track! I'll keep repeating that to myself......

I'm really amazed at your persistence to perfection cosman, this kind of ingenuity and commitment is what America has been missing for a while now.

When I first moved to Canada (yes we are in America too, just the colder part) I was truly amazed at the scale of things, along with how advanced it all seemed in comparison to my little home town back in Greece.
Fast forward 24 years later and my amazement has turned into discust as I'm realizing that this never ending need for cheap overseas crap has hurt not only our economy(ies) but also our pride.

This right here is something to make all of us proud that people like you put their life and finances on the line in order to reinforce what's been missing all along.

Thanks you for sharing this, really appreciate it

The Dutax engine is great. I love this type of thing. In for updates.

speechless

Absolute drool. That is fantastic. Thanks for sharing.

That is a thing of beauty, isn't it.

adiablolex, i think it's hard to balance having an easy life and still retain a sense of meaning and purpose besides 'consume'. we'll figure it out sooner or later. hopefully sooner.

saliah, I'll cherish that brass balls award right up there with all my race trophies!