Let's hear all the gory details about your car and how it became alternative fuelled.
Post Reply
Posts: 90
Joined: Sat Nov 09, 2013 4:53 pm
Location: Pump handle Saskatchewan


Post by geraldm » Mon Nov 11, 2013 1:25 pm

The Dragon to date has been a 3 year project , the first year was mostly a mock up build with the engine running inline with and auto trans to jack shaft to rear honda shaft drive , rear wheel .
The second year is when Bumpstart stepped up and started offering his knowledge of the Mazda Rotary which is vast to say the least . I put together a cross mount version with a rebuilt 13b for the second year . heavily modified 500 Holley with manual enricher ( no high jets ) . self built single fire direct fire ignition on leading plugs only . ( no cap and button or rotor ) .. Used 2 HEI GM modules from the early 70's upward . one for each rotor , using magnetic pick up for the pulse from 1st gen mazda . No exhaust to speak of 18" long header pipes . primary drive consists of Polaris VSD from a Polaris sportsman 500 .. primary is polaris secondary is a team clutch . onto a jack shaft to deliver wheel power via # 50 chain to rear wheel . front end is Honda Saber , wheels from Harley v rod with 1 inch axle . Rear brakes Harley 4 piston caliper with home made brake disc and hardware . NO FRONT BRAKE ,, Oil pump mod , pressure 30 psi hot idle to 80-90 psi 4000 rpm hot which keeps his blood circulating and cooling at a good rate . The third year out ( Summer of 2013 saw the dragon in the winners circle EVERY TIME HE RACED and has never been beaten by anyone in any class .

Bumpstart's comment to that was ( and he's not even breathing hard yet ) so after a very short thought process decided to make him breath not to his maximum but to a level he calls moderate of 12 to 15 lbs boost with a propane conversion that should bring him to somewhere around the 300 HP area maybe a tad more .

WHY do a conversion like this when the dragon is already a winner , because he is running at his lowest possible rates and that somehow just doesn't seem right . http://www.youtube.com/watch?v=plw0ZOez ... dPafoT2Zng so that is why were here to seek out info that will make the conversion go smooth and give me a good understanding of the physics and application of propane . thank-you and please feel free to comment Gerald m.
Now how the hell did that happen ?

Posts: 132
Joined: Wed Jan 20, 2010 9:09 pm


Post by bumpstart » Sat Nov 16, 2013 10:58 pm

welcome! .. ive pointed gerald here as this is the place to ask the curly questions

the choice to look hard at LPG is simple..
this bikes mechanical systems have been built with high simplicity in mind so as to achieve a high level of reliability in a dusty and vibrational environment
the fuel itself in the rotary engine is very tolerant of a wider range of mixtures , especially in the lean scale,,
so gives us more margin to get things wrong without a disastrous result

the impco blow through mixer systems very simple
and offer a much safer ( in the result of an accident or potential petrol spill on the bike and rider )
, reliable yet better result than the equivalent blow through petrol carb system
and better yet, evolves on his current ignition setup and inlet manifolds
will strap on easily ..and mimics a similar and successful path i have taken with a couple of daily driven street cars

his only other option would have been to reverse a lot of engineering
and learn a steep curve for a much more complex, expensive and potentially larger mechanical package method with aftermarket EFI
,, with not the same payout in reliability or rider safety
( however the aftermarket efi has more potential to take the engine further though im hinting his driveline is not so durable at those HP levels )

so ,, here we are ,, advice needed ...
,, particularly around finding a suitable but small tank

i have hinted at indian scooters and bikes,, and possible china and italian kits and the need to incorp electric and excess flow lockoffs
we need input from experienced members on the ins outs... whos and wheres of these tanks
maybe something long and narrow like front pannier tube style around 10L usable
.. but open to other suggestions, please look at the vid ,, its an impressive bit of gear and lateral thinking is the name of the game

and also guidance for the interlock system, that whilst the dragon is unrestricted competition vehicle , needs addressing as it can be done simply

ideas discussed range from the full ignition switched controller (at some expense ) to perhaps a safety interlock through the seat like modern lawn mowers
( being most effective in the event the rider comers off and protects the bike the rider and the crowds )

system wise ,, since space is premium ,,and the impco system proven under boost..
is to use an impco 200 on the holley base as it will fit immediately on existing manifolds, and a model E or L chosen to keep up to it, decided either way by the needs of the location it fits in ( L vertical. E flat )
ducting will be direct from the turbo and intercooling will be a simple single stage water injection setup pre turbo

geralds location is canada and he is a can do .. old school ..sort of guy
im hoping some of the original crew here that is local to him get on board to assist with the finer things especially in view sourcing of the right parts and tips for the safety aspects
when the going is hard, don't retard, remember your lubrication

Posts: 90
Joined: Sat Nov 09, 2013 4:53 pm
Location: Pump handle Saskatchewan


Post by geraldm » Sun Nov 17, 2013 2:01 pm

WOW ! that is quite a introduction Bumpstart , I do appreciate the confidence ! He's right we do have the basics pretty much figured out , like what were using for sizing and application . Just looking for opinions of how to make things work smoothly and maybe bypass a glitch or two . As far as components I feel the the Model 200 carb is a good choice as well as the e or l depending where we might need to fit and we will be following along those proven applications .

The Dragon is totally my own build but Bumpstart has helped me engineer some good ideas into the little engine during last winters rebuild for possibly just this project in mind ( He seems to have the ability to know what i'm thinking before hand )

I have done considerable searching on the fuel vessel with really no results other than the available rv type of tanks that I feel are not the right application . I know they are out there somewhere but so far have had little luck finding .

Please feel free to comment , that's why were here . Although we might not use all your suggestions I do read and ponder over all replies ,, Please don't be offended if we don't use all of them . Gerald m.
Now how the hell did that happen ?

Post Reply