Wednesday, June 30, 2010

Let's talk about my fat ass

    Can we talk about my out of control obesity? Certainly, the years have ravaged my once boyish figure; but it was still to my surprise that I all but bottomed out my suspension when I first sat on Plan B with the new subframe. I built the subframe around a shock I've had laying around for a while, a spiffy Malossi RS24 shock (by Paioli) originally designed as the front swingarm shock for an Italjet Dragster.  I suspect  the difference in geometry is to blame, and my addiction to transfats and sweet, empty carbs.

    Regardless, I needed to find a beefier shock with similar dimensions to the one I had, but that was a bit tough, and most quality shocks of this sort go for around $400, even a good spring for a motorcross application retails around $120, and the dimensions would still be a rough fit. Luckily, I was able to get a couple of random industrial springs with appropriate specs for not very much money. The thinner one is rated at 470lbs. and the thicker at 790lbs. Both springs match the outer diameter of the original and are 8in. long.
HELLO LIZ!

    But that's where it gets complicated, as the shock will accept a spring of a maximum 5 3/8" long and has a travel of about 2". I'm having a tough time staying in front of the math on this one, as I'll have to cut off some length to allow the shock to fit, but also compress the shock enough to keep the sag within a usable range. So, I'm willing to accept a fair bit of trial and error through this process.

   I headed down to Naz & Phil's shop to use the press to get the spring on, but it was a smidge more involved. After trimming an inch off each spring, I cooked the coil top with a torch to flatten it out. Ultimately, I need to fab up a tool to help rebuild the shock. This process had a few false starts and took nearly all day. After the tool was done, the spring installed easily. Knocking an inch out of it's length reduces the spring's max load to 347lbs, but that will hopefully prevent my massive girth from dragging the motor across the asphalt.














Wednesday, June 2, 2010

I luv my Obnoxious Subframe

A few shots of the newly powder coated subframe. Thanks Responsible Jon!

Saturday, May 8, 2010

To Boldly Go ... Waaay Off Topic.

    Enjoy 'em while you can: Friday, May 14th, The space shuttle Atlantis STS-132, will blast off for the second to last ever Space Shuttle launch. The final launch of Endeavour in November 2010, STS-134, will be the final launch of the space shuttle program, effectively ending the manned spaceflight program in the United States. ...Indefinitely. Given the rate at which aerospace programs develop, it could seriously be 30 years before another U.S. spacecraft breaks the surly bonds and sends men & women into outer space.
        Is this news to you? Allow me to recap. The first ever Space Shuttle (Columbia) was originally delivered to the Kennedy Space Center on March 25, 1979, coincidentally the same day I was born. The first launch of the space shuttle was in April, 1981. Given the stresses involved in leaving and returning to Earth's atmosphere, the service life of the typical shuttle was estimated at 30 years. (A timeline sealed by the 2003 destruction of Columbia)  NASA & US Air Force chose to develop a new craft rather than request funding to build a larger Shuttle fleet. This new craft was proposed to place a low-cost orbiter within the reach of private corporations, while simultaneously developing frontier technologies and drastically reduce overall mission costs for NASA. The new experimental ship was called the X-33, with a larger production version follow-up called the Venture Star. X-33/Venture Star was planned to be active by the time the original space shuttle fleet was retiring. -but that was before Narloy-Z.
The reason the X-33 could be so cheap and still get the job done is because it doesn't require a large external fuel tank or solid rocket boosters; not to mention eliminating SRBs makes space travel much, much safer. The reason the X-33 didn't need the external periphery is because it was to use a RS-2200 Linear Aerospike engine. The conventional rocket engine uses a bell-shaped thrust nozzle. The design of the thrust nozzle greatly determines the amount of power it's capable of producing. Just as a two-stroke expansion chamber exhaust performs optimally at a specific RPM, rocket nozzles perform optimally at a specific altitude and air pressure. Thing is; rockets aren't supposed to stay at specific altitude, they're supposed to shoot through them. As a result, traditional rocket engines spend most of their lives outside the powerband. 

            Now, a linear aerospike engine doesn't have that problem. The RS-2200 uses a pair of variable geometry ramps to maintain optimum explosive pressure regardless of altitude. The new engine is 30% more fuel efficient than the older engine, and as a result, all fuel tanks could be internalized. As you can imagine, even with liquid hydrogen cooling from within, the stress on the ramps directing a river of exploding rocket fuel is quite tremendous, and the original material was insufficient for the task. X-33 engineers reluctantly selected Narloy-Z to build the ramps, which was tougher albeit significantly heavier. In doing so, this altered the flight characteristics and the weight difference had to be accounted for elsewhere.  The engineers spent a lot of time and money developing a composite tank for the liquid hydrogen fuel, but met with repeated failure. The traditional Aluminum-Lithium tank worked flawlessly, but required a revision of the entire frame to meet the needed power-to-weight ratio. At this point, despite numerous NASA & USAF challenges, the off schedule and over budget X-33 was canceled,  but mostly to make way for Constellation

            Rather than support a high-technology, low unit-cost vehicle that could open up private spacecraft enterprise, the Bush Administration favored a robust, far reaching, long-term approach to space exploration. The plan was to return men to the moon, but rather than just planting the stars & stripes and collecting rock samples, Constellation would also deliver modular units to be assembled as a semi-permanent base on the moon. With the larger orbit of the moon and its low gravity, the moon in many ways makes for a superior 'jumping off' point for missions to Mars and the other planets in the solar system. But... with the War on Terror, Operation Iraqi Freedom, and the publics' general lack of confidence in all things Pres. Bush, the idea of a "Moon Base" seemed ridiculous. Regardless, NASA engineers progressed with plans to return to the Moon in a similar fashion to the Apollo missions. The last few years have seen the current crop of NASA Scientists and engineers scouring for resources to essentially create a high-tech Apollo sequel with early missions in the late 2010's and moon landings in the early 2020's.

         With 9 Billion invested, President Obama terminated Constellation across the weekend of April 15, 2010. Obama's new plan relies on the rise of (as of yet non-existent) commercial spaceflight providers to fly astronauts to the International Space Station, with the Russian space program filling the interim gap of... an unknown duration. The other initiatives set aside funding for research on a mission to land on an asteroid, earth based astronomy and emphasis on earth-centered exploration, with particular focus on climate change. In escence we will go from the clear global leader in manned spaceflight, to relative nobodys with zero experience overnight. The private leader in which Obama has placed his trust is Elon Musk, co-founder of PayPal and owner of SpaceX, a company which to date has launched 1 of their primary rockets. -Compared to the thousands of launches and the hundreds of manned spaceflights NASA has successfully and safely conducted. Killing Constellation to force NASA to sit on its laurels, waiting for amateur hour to play catch-up will cost about 6,000 jobs at Cape Canaveral. Most of those jobs are highly technical and specific to spaceflight; it will also cost another est. 14,000 jobs in the greater community. This in a time where job creation is allegedly a priority, where we hand out vast fortunes to down-on-their-luck bankers, auto-giants and nearly any yacht owner with a frowny face.


           The biggest bummer for me is that at one time as a kid I fantasized about being an astronaut; and now as a grown man I get to learn that even if i ate my Wheaties, and did my push-ups, and studied real hard to be an astronaut, it wouldn't have mattered. A lot of people ask, What's the point? Why spend all that money? There's a lot of poetic, soul-searching responses that you either already get and don't need to be told, or that you will simply never understand. So I'll provide a practical answer: Look at the computer in front of you, or your cellphone, or thisisphotobomb.com. NASA is the benevolent arm of an innovation machine. We live in an 'information age' whose economy all hums along on microprocessors. Think about how much we use computers in our daily lives, if you're old enough, think about life before the internet or before you owned a computer. Microprocessors are the direct descendants of the Integrated Circuit, which was developed purely because vacuum tubes couldn't withstand the violent shaking and G-forces of a rocket launch -one of the first ever integrated circuit computers was the Apollo Guidance Computer. Obama wants to create a 'Green Ecomony'- he has a industry legend at his fingertips; Silicon Photovoltaics (Solar Cells) were invented by NASA. NASA has been using Fuel Cells in satellites and spacecraft for decades. If anything, that is NASA's value: huge life-altering innovations.

      Some food for thought. The Over-Budget & Off-Schedule X-33's entire program budget was 1.3 Billion dollars. That equates to 5 days of occupation in Iraq at the height of the occupation, or 2/10ths of 1 percent (0.002) of the bank bailout. It's still a chunk of change, but we've spent far more money in far less effective ways.

           The way I see it, the biggest threat to manned spaceflight is the meddlings of the President of the United States. If not for Bush's far-off vision, and Obama's complete lack of vision, we would not be in this situation right now. The X-33/ Venture Star was supposed to be the torch that NASA handed off to the private sector, to initiate private spaceflight. If it hadn't been canceled, the technical issues could have been sorted out - for a fraction of the cost of Constellation- without damaging the livelihoods of the average NASA engineer, and without US Astronauts having to cross their fingers on a rocket ride with Captain PayPal. In November or whenever the last launch ends up being scheduled, I will make the trip (pilgrimage?) to see the final Shuttle launch. I will raise my Mai Tai or Corona to the heavens and offer a salute to the life and death of a beautiful and truly inspired era known as "The Space Age".

Friday, April 30, 2010

Quick Preview...?

    So my subframe is almost done, minus some adjustments and of course some powdercoat. I fitted it up to see what it actually looked like together for the first time. I also got to sit on Plan B for the first time in a while. The new subframe adds about 4-5 inches, which kinda looks ridiculous at the moment, as if I'm going down to the Quaker Steak to drag race some dudes on their hayabusas. I think when the bike is finished, it will look less goofy.

Saturday, April 17, 2010

Welcome to the Ditch.

    Its been a really long time since I posted last, but lots of stuff has been happening.  The biggest thing to happen would definitely be an email received by T.N. from someone Extra Awesome who took notice of my last blog post. Quite the Honor & Wow! is all I will say on that. 

    Several weeks ago, I am ashamed to say that I was grifted out of a dollar by a juggalo in front of my corner grocery. Yes. Please friends, take a moment and spend some quiet contemplation on that one. The 'how' this occurred isn't that important or interesting really. I like to think of myself as a nice person. I usually 'Chip-In' when someone gets runned over, I'm kind to animals or I would help a friend move to a new digs. If say, you, dear reader, were bleeding in a ditch somewhere, I would act as expected: call the paramedics, get you out of the ditch, apply first aid, etc... But as a man of principle as well, there are people that I would allow to remain in the ditch, people who simply don't need to exist -who have through technology or the manipulation of civilizations' principles have dodged the darwinian thinning of the herd. Take notice, fans of Insane Clown Posse, you are now in the ditch.    

    I have prepared another graph to illustrate this concept:



So yeah, I don't like juggalos. Moving on...

    I've been working primarily on two projects of late, my smallframe's engine and Plan B's custom subframe. If you recall from the Polini Cup season finale, I built my bike unwittingly with a warped subframe, and even if I was comfortable riding/racing a bike with an off-camber rear wheel, it created clearance issues with the rear clutch pulley that had to be addressed for the bike to fully function. I'm also a big believer in good ergonomics as a performance gain, since the bike can only go as fast as you can ride it. Everything I've read on ergo stuff says that the average mopeds' center of gravity is way too far back, especially since I weigh almost twice as much as Plan B. Lastly, my carb location makes having pedals difficult and I liked the idea of getting pedals back on the bike. All these reasons resulted in the new subframe being longer than stock by several inches. The subframe isn't done yet, but pretty close. Hopefully in time for the next race??

 Back in 2004, I realized that Horsepower is great for racing, but only in a RPM range that you can access. At the time, the 'King of the Hill' of smallframe cylinder systems was the Zirri MR2000, rocking a reliable 25+ hp at 12K. Not bad for a sand-cast, air cooled, cast iron jug.  But racing the small tracks that we did, the bike rarely rose above 6K rpms. I then schemed up a conversion that would get around 25+ hp but at 7K. Afterwards, life/school/girlfriends stepped in and the idea was shelved for years. I have now finally started to work on that idea. In my last post I had reamed out my Con-Rod to fit the new gudgeon pin for the new jug, I have also now welded on the 13mm decking plates necessary to span the difference in cylinder sizes. I then machined off the excess so the cases will fit together. I need to bore the cases to the proper spigot dimension: 70mm, and fab the reed intake for the new, much larger reed block. Overall, the engine will gain about 30% more capacity, from 136cc's to 168cc.

I've been spending a lot of time down at Naz's workshop, big thanks to him for all his help and letting me use his tools. 

 Naz and the hellfire glue-gun.

   

 










Monday, February 22, 2010

Wind beneath my wings

           Everyone has an inspiration, a goal, something they want really badly, or want to be with every iota of their being. When I get coffee, I see dudes that are definitely attempting to become Johnny Depp, or Demetri Martin or that really, really want to fall into an Ocean Pacific T-shirt design from when I was 12. When I was 12, I wanted to be Chuck Yeager. I wanted to shoot down Messerschmidts with my Mustang and test-fly rocket planes. Now that I've done all those things, I think I want to be Jan Thiel. Why? Because Mr. Thiel designed probably the blindingest most amazing race engine to date. Now, its possible that he has some competition by way of Yamaha's direct injection boat engines, but I can't find anything with wheels that holds a candle to the RSA. Even the Boffins at HRC & KTM are struggling to match this beast. 

           Some years back the arms race in MotoGP 125 was a dead heat, with bikes from a handful of marques pretty evenly matched. Piaggio / Aprilia was getting feedback from the riders that they wanted an engine with more torque in the upper midrange. Tuning possibilities exhausted with the current RSW engine, they sought to develop a different style of engine, and recruited legendary 70's 80's GP engine tuner/designer Jan Thiel, who happened to be alive and interested in the project. With his genius and Piaggio's resources, the results were unconventional and powerful. The RSA is a 125cc Transverse Rotary valve engine that makes a blistering 56.5hp, with more torque and 3.5 hp more than its reed valve predecessor. Without a new material (carbon this, silicon that) having been invented, a 3.5hp gain is pretty significant in a race class where the blood has been squeezed from the stone for decades. 

              Like many, when I first got into bikes I presumed that the stock rotary systems on my Vespas were garbage and that aftermarket reed valves were the only way forward. The truth as I'm learning is that reeds are the easiest way to access 97% of available horsepower, but that at the tip top, rotary is still the Hp King. Why? Because when a rotary valve opens there is no obstruction (like a reed cage) between the crankcase and the carb, optimizing intake charge velocity. And that miniscule difference in intake velocity is what gives rotary the narrow edge. A transverse rotary is even better as it dumps the incoming charge between the crank webs, just behind the cylinder transfers.  Combine all that with the knowledge that a rotary valve can be independent of piston position, and therefore successfully manage backflow and low-end issues, and you have a very spicy meatball.  Alas, the ship has sailed on all of my current bikes, they will all be reed valves. But now I'm thinking that for future efforts, I'll try to build a rotary bike. 

         I can find very little info on this motor, lots of pictures on complete bikes racing, but very little on the engine itself, or its 250cc brother. I made a graph to illustrate what an efficient powerplant the RSA is. Basically, the total power of the motor, divided by the capacity. As an example, the Yamaha R1 is rated at 172hp. If it were as efficient as the RSA, it would have 280 MORE hp. I realize the logic is kinda flimsy and my numbers are not all official, this graph is more a visual aide than anything. Not pictured: as it didn't fit on the graph is the pokey Harley Sportster 883 with a rating of 19.2. 

   
          In other news, I made another batch of Tomos/Polini/Daelim type intakes and tree'd them up. As I'm writing this, the wax is being cooked out of the mold in my oven. Probably this week I'll cast the mold and see if things are improving. I altered my mold design based on some suggestions from fellow engine nerd / metal caster Graham. Elsewhere, I used a bore bar to enlarge the small end on my Vespa PK crankshaft to fit the new piston for my smallframe racer. I originally bought a 20mm reamer to do this, but after setting everything up, the Adamantium or whatever the con-rod is made of actually dulled the blades on the reamer. The new piston is about 8mm wider than the old one, and should produce a big improvement in capacity.

Friday, February 19, 2010

Quick Update: 2/19/10

Lots going on, no time right now, GO:

PK Crank + Bore Bar = win! 















Original Piaggio Si shock, meet Paoli hotness:



















Engine I'm obsessed with and can find almost no info on: