Build a Racer

Hints and tips from a few years spent at the track:

> Make a list of what you need to bring to the track. My list is on my computer; easy to up-date, easy to print when needed. It's too easy to leave something at home. One friend left his race boots behind, and had to buy new ones at the track ... NOT CHEAP! Either that, or no race.

> Figure out what kind of race gas you need. I buy 110 leaded at $5/gal., then I mix it with regular unleaded, usually a 3:1 ratio. My compression ratio is 11.5:1 and I don't need 110 octane for that. Higher octane only burns slower, reducing HP at some point. My 3:1 ratio saves a bit of money too....

> Unlike Superbike, where a tire is lucky to last a race, I can get two seasons on mine. Some racers change tires each season regardless of wear, and you can sometimes get these tires for free! Right now I'm using the front tire from a 750 racer as my rear tire. Also use these tires on my street Guzzi.

> Racers are frugal in other ways too. I have a friend who uses (expensive) synthetic oil in his race bike. After a couple of races he drains it, but saves it to use in his truck! He figures the oil still has lots of life for his V8 or whatever....

> Dean turned me on to Honda "spray cleaner and polish". Very good for cleaning helmet visors and windshields. The small can (5 oz.) has lasted me at least a couple of seasons.

> If you're going to race in the rain, get some surgical latex gloves to put on under your race gloves. This will stop a lot of the dye from soaking into your hands. If you helmet doesn't have the click-stops to open the visor slightly, figure out another way to hold your visor open 1/2", otherwise you'll probably fog-up.

> Don't forget earplugs. Even at tracks that have a 105 dB limit, it's not hard for me to get a headache, or to have my ears ring into the next day. I'm even considering custom made earplugs. I can't imagine riding a MotoGP bike with the new 130 dB limit....

> Learning to race. If you're new at this, or thinking about Vintage racing, it's not about big balls and twisting the throttle more. Riding fast is about thinking and being sensitive to what the bike is doing. You learn to go faster in small increments. Riders who go fast "suddenly" usually have a big get-off, then go back and adopt the incremental approach. It's good to have a goal, or "focus" for each practice session, or race. For example, a more consistent line in turn 2, or dialing in the braking point for turn 5.

> The number one goal is always to "Bring it Home". I've seen too many first time racers crash, and never return. When you focus on your riding, the pressure to perform is lessened. When I started Vintage racing, I had absolutely no idea how I'd do. I didn't want to be last, and just hoped I could be somewhere in the middle of the pack. Well, I was towards the back of the pack, and sometimes I was last. But I was always learning, and kept on improving my bike. My lap times slowly came down.

> If you're having problems with a particular corner, talk to other riders that are faster than you. Learn about things like late-apexing. I learnt many corners by following the faster Honda 160 riders through them. I think a lot about my riding a lot and analyze many of the little details. On the track I try and translate all that into "flow". The good racers are all very smooth, and consistent. Racing is all about confidence. Work to build that confidence; it's a great feeling!

A lot of my inspiration to build an Aermacchi Racer came from the excellent article by Chris Kerber entitled, "Racing the Aermacchi Harley Davidson Sprint". Chris has raced Aermacchis for almost 2 decades, and is extremely knowledgeable about them. He's recently updated the information, and the best thing about it is that it's FREE! Just contact Leslie at Moto Italia, USA, phone 1 707 763 1982.

I'm a member of the Aermacchi Egroup, http://groups.yahoo.com/group/aermacchi and some time ago, there was a lot of discussion about "how to get the best bang for your buck", regarding building a 350 race motor. The general consensus was to use a 71/72 bottom end, with a 73/74 top end and 5-speed transmission. This means hunting down 2 motors (not impossible), to make one good stocker. I raced my first season with a stock motor, and it would pull an honest 100mph on the straights.

A stock frame can be used, if gusseted. I suggest not using anything later than a 1970; they got too long in the wheelbase and heavy after that. Thus, to build a racer, it's best to locate (2) engines and an earlier frame, as a starting point. Once you have these three things, approx. $2000 of parts (rims, tires, tank, seat, etc.), plus a lot of hard work will get you an Aermacchi vintage roadracer that is fun to ride, handles well, and makes you feel like a kid all over again!

If you have an Aermacchi racer, and want more HP, there is a lot of information available to that end. Using engine parts from Germany, I built my engine to specs provided by the Bladon Bros, in England. Chris and Paul (the Bladon Bros) were very generous in providing me with ALL the specs needed to build a racing motor, and I attribute a lot of my success to how well the engine pulls, with no flat spots. They have given me the OK to pass those specs along:

  • 39mm inlet valve
  • 34mm exhaust valve
  • Carillo connecting rod, 135mm
  • N6 cam
  • 1972 crankcases>best/strongest webbing
  • optimum inlet tract and carb size: 35mm
  • inlet manifold length: 100mm (measured along centreline)
  • sparkplug: NGK B10EV
  • compression ratio: 11.2:1
  • piston skirt clearance: .004" - .005"
  • timing advance: 32-35 degrees BTDC
  • ignition system: battery/total loss w/ Lucas Rita electronic modified for Aermacchi; 12 degrees of advance.
  • carb: 34mm Spanish Amal bored to 35mm
  • main jet 220/230
  • pilot 25
  • needle jet 105
  • needle 2C3 using bottom notch
  • 2A1 using top notch
  • slide #3

Flashback Fabrications Inc.tel 604-888-8785email
PO Box 401Lynden WA98264

[ excelsior ][ other projects ] [ aermacchi nw ][ brodie bikes ][ paul brodie ][ site map ][ home ]
Copyright © 2006-2010 Paul Brodie. All Rights Reserved.