APS-G-50 attempt

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weezilco

APS-G-50 attempt

Post by weezilco »

Hi, name is Brian Stokes, located in NW Sydney vicins.

I've been building bicycles and small motorcycles for a while. The techniques I've been using for those things should help me work out a 50cc lake bike.

I'm going to try to have a go next March at APS-G-50cc and A-G-50cc motorcycle classes. I'm still sketching the frame at the moment but the engine has been procured.

Found a Yamaha DT50 engine which has water cooling and reed valve to cylinder induction. I'm scoping all the 2-stroke trickery I can find on the net in search of 10-12hp. Hopefully someone will have leads for a tuner who can do my cylinder porting; I ain't brave enough for that job yet. I'm tearing down and cleaning the motor this week and looking for the necessary replacement parts to get this scrapyard motor back in respectable shape.

This bike will have a feet-forward rider posture. I'm hoping that the FF arrangement as well as a 10" front wheel on a leading link suspension with hub-centre steering that I can minimise the nose height & frontal area. Planning on partial streamlining with a fairing and a tailbox to simplify my first effort at a lake bike. I'm hoping also to be able to remove the bodywork at the salt so I could run in A-G-50 as well. I'm aiming for 100mph with the bodywork on.

I'm looking for suggestions, favourite links for tiny 2-stroke performance or frame design stuff from the seasoned folks.

thanks,

-Brian
hawkwind racing
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Post by hawkwind racing »

I only know of two M/C and one car effort LSR attempts all in the states , the m/c's are both streamliners as is the car so you are pretty much on your own ( I will try to remember the sites or you can do a google ), much like myself building a twin engined sidecar streamliner and a APS/F 1000 from scratch as well as my highly modified bussa
best of luck in your quest as personally I recon you have choosen the hardest class (50cc ) to try and break a record :D
Hawkwind
fastest busa in Captains flat pop. 200
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Post by DLRA »

This year there was a record set by Paul Broughan in your engine class.
PP-50 36.255 MPH so there's your benchmark

Having a look at the Bonneville Records for streamliner;
S-BF H. Muller NSU ' 56 121.700 MPH
SC-F Walter Grether Honda 10/03 52.690 MPH
SC-G Iron fairy Honda 8/03 57.527 MPH
S-G Costella-Nebulous 4 Honda 8/03 47.353 MPH

ElMirage
SC-G Dugan / Pichel I.F. R. Dugan 11/02 60.708 MPH

Muroc
50-APS-G Cummings & Strahm I D. Cummings 96 79.183 MPH

Good Luck

By the way have a look at Bob Prior's Profile page. He's building a streamliner motorcycle. http://www.dlra.org.au/profiles/205.htm
Keep the shiney side up........
DLRA WebMaster / Editor
weezilco

Post by weezilco »

There a guy running a modded production Aprilia RS50 at Bonnie doing 75mph.

http://home.earthlink.net/~spidergrips/falknerlivingstonracing/

From what I read, there's cubic dollars in that motor.

If I have a motor that moves a lot of air and has a strong bottom end, 12hp might not be madness. I'm hoping that 12hp along with the long-n-low approach will give me the aero efficiency to get to 75... but I'm aiming for 100. :)

Thanks for the encouragement, Gents.

-B
weezilco

Post by weezilco »

gregwapling wrote:have a look at Bob Prior's Profile page. He's building a streamliner motorcycle. http://www.dlra.org.au/profiles/205.htm


Thanks for the research, Greg.

I've been admiring Bob's chassiswork for a while. I don't think I'm going to build a fully enclosed bike thids time, tho. Roll cage, fire system, 5 point, sealed firewall and so on would seem to be required. Sounds heavy.

I think I'm just going to thieve some of the efficiency tricks used in recumbent push bikes. The human power land speed record is 72.74mph, held by Canadian Sam Whittingham in a full streamliner.

http://www.speed101.com/now/fastest_0127_6.htm

A very fit cyclist can make about 500W (bout 3/4 HP). If that's so, seems to be sensible that with good air mgmt that 100mph could be doable with a 50cc motor making ~10hp.

Seeya,

-B
weezilco

Post by weezilco »

hawkwind racing wrote:best of luck in your quest as personally I recon you have choosen the hardest class (50cc ) to try and break a record :D
Hawkwind


Thanks much. I agree that 50cc will be challenging. It's a bit like a puzzle, finding and putting together all the little efficiency tweaks until you squeeze out the very last drop of speed.

I recall a guy I knew from my drag racing days in my youth in Indianapolis, who ran a '68 302 Camaro with a 2-speed Powerglide. A 302 is a fairly small V8 as we all were concerned in Indy. With his limited budget, if Kirby wanted to keep up with the 350 & 427 guys, he had to dial in the rear end ratio on the day and pay close attention to aerodynamics- including a full belly pan. He kept a notebook of all the silly little 5hp upgrades he could find. Kirby figured that 10x 5hp tweaks = 50hp and that hp wasted by inefficiency was hp you had to buy. Kirby drove the car to Raceway Park and took the mirrors off in the pits every weekend. He finally invented the 'quick disconnect mirror'. :D None of us knew exactly how much faster QD mirrors actually made Kirby go, but when you can get a fairly standard Camaro/Chev 302/Powerglide into the low 13's at ~120mph, there's little doubt he was on to something.

I think my experience with recumbent bicycles will be helpful in this effort. You get painfully familiar with efficiency issues when the power source is you!

seeya,

-Brian
DON NOBLE ... DLRA # 281

Post by DON NOBLE ... DLRA # 281 »

50 CC hey . WELL i should bring out my bigblock 1967 YAMAHA YL1
its got a thumping big 100 cc twin cylinder 2 stroke . i had one of these in 1968 as my first set of wheels . about 2 years ago i found another one in great registerable condition so i bought it . i just start it up every now and then and ride it around the yard .
in 1968 remember it used to do 70 mph , lying flat on the tank and i was only about 55 kg wringing wet . i wound it out to 80 + mph down a steep hill once and boy you should have seen the smoke trail .
i have seriously thought of bringing it to the salt the last 2 years , so maybe next year and run it in production class
weezilco

Post by weezilco »

DON NOBLE ... DLRA # 281 wrote:50 CC hey . WELL i should bring out my bigblock 1967 YAMAHA YL1
its got a thumping big 100 cc twin cylinder 2 stroke . i had one of these in 1968 as my first set of wheels


I remember those. They revved to about 8500-9000 & were wicked fast with a good pair of chambers on. I think we knew them in the USA as the "Big Bear" model.

DON NOBLE ... DLRA # 281 wrote:i have seriously thought of bringing it to the salt the last 2 years , so maybe next year and run it in production class


Why not? Sounds like fun!

seeya

-Brian
gnomester
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Post by gnomester »

50 CC hey . WELL i should bring out my bigblock 1967 YAMAHA YL1


Hmmm .. maybe I should take another look at my Suzuki TS125 A 1976.
Not as old as your YL1 Don, but I did buy it new and it was also my first form of transport.
Too many parts missing for a P/P 125 and it is bored to the max so I would need to run in 175cc class maybe :?

And good to see your 50cc bike project is moving ahead Weezilco.
I look forward to seeing the bike on the salt :D

Gnomester
weezilco

Post by weezilco »

Yep, moving forward in drips & drabbles. I have a fortune cookie message taped to my monitor: "Perseverence is not a long race- it is a series of short ones."

I'm trying to apply that wisdom by doing little bits every day. If there's no building or designing to be done, there's always cleaning and phoning around for parts.

I have to apply effort in small measures as well. Unfortunately, I got collected by a drink driver while I was on a motorbike in Indianapolis some years back and I don't move around so well anymore. That's OK- I'll get there, but just in small nibbles.

seeya

-Brian
Chris Hanlon
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Post by Chris Hanlon »

G'Day Brien
I could'nt agree more, but how come each time I go racing it always ends up teararsebust in the last couple of months before March. This year I'm not going to make to many changes and am trying to do a little each day even if its only deep thought.
Seeya Chris
Home of the Worlds Fastest Ute

Endeavour to Persevere
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