Calculating top speed on ice...

[Johansson]

Hi Bill,

You have a point there, do you know if the SNECMA engines were direct injected or used vapourisors?

I will try all three fuels to find the one best suited for this, I will also do some experimenting with the starting procedure so besides the propane preheating I will try a propane stinger inserted in one of the intakes that will get the engine humming before I start to feed the coil fuel.

[hinote]

You have a point there, do you know if the SNECMA engines were direct injected or used vapourisors?

Pretty sure they were direct. Of course there would still be ways to raise the temp of the fuel along the way--right? This would reduce the need for heat extracted from the interior of the engine. I tried a "stinger" type similar to Eric Beck's with some success; the long run of pipe inside the CC to get the injector to the correct location provided considerable preheating.

BTW another issue for you to deal with: The copper vaporizer coil is going to be subject to massive physical forces from the acoustic and general pressure fluctuations. It's likely to harden the metal quite rapidly and cause a failure. This scenario is also likely with stainless steel which work-hardens quite rapidly too. Watch your @$$ here (literally)!!

Mild steel may be your only salvation. OTOH my suggestion is to try an external vaporizer coil; this would capture some of the heat that is just wasted to the environment. I understand the reduced transfer rate this offers--but adjustments can be made.

Also BTW--DON'T use brake line! If you've ever tried to weld it you'll understand.

Regards,

Bill

[hinote]

HI again:

I just had a thought:

It would be pretty simple to modify that head-end plate into a sealed reservoir, which would absorb considerable heat from the combustion chamber. This would provide quite a lot of the necessary heat input for vaporization.

A couple turns around the outside on the way to the injectors, and you're done. BTW this would also allow convenient installation of a drain cock to remove fuel after shutdown--a necessary item (as you will soon discover) to prevent coking of your vaporizer from residual heat input to the now-stagnant fuel.

Word to the wise here!

Bill

[Johansson]

Thanks for the advice Bill, but I have been discussing this off-forum and am pretty confident that I am on the right track with this setup. (well now I´ve said it so most likely it won´t work tomorrow...)

[Irvine.J]

Wow this thread is still going, i have some catching up to do...


As you can see I been a little distracted.

[Johansson]

Oh boy am I jealous now, here it is -10°C and 30cm snow. I can´t wait until I can take my bike out for the first trip in the spring!

[metiz]

Oh boy am I jealous now, here it is -10°C and 30cm snow. I can´t wait until I can take my bike out for the first trip in the spring!

As if danger is a motivation point for you to not do something
A friend of mine rides motorcycles to - even with 20cm of snow and icey road surfaces. He's a madman, just like you!

[Irvine.J]

Is that a freaking busa you nutter?!

[Johansson]

Is that a freaking busa you nutter?!

Yup, a -99 with some minor engine mods (power commander, Yoshimura exhaust, large airbox mod etc.) but I am planning on turbocharging it when I find the time. This winter I have dropped it 1", rebuilt the clutch, geared it down a bit and added a quickshifter with shift light to get down to high 9´s on the dragstrip, all mods with drivability for 2000km weekend trips in mind.

One gets used to the power very quickly so when I rebuilt it I will aim for 350-400bwhp with some boost, a friend has turbocharged a Honda 900 and he finds it very amusing that a twist on the throttle can send the front wheel towards the sky in 240km/h...

[Barry]

Ghost rider number 2.

[Johansson]

I did the starting attempt a couple of days ago but the cold weather in combination with poorly made injectors was not a good combination. I have done some small mods that will make it easier to start (larger flares, fitted the old injectors that are proven to work) along with a better way of fixing the injectors. Earlier I used a piece of string to hold them in position and that was far from good.

I will also get a 19 kg propane bottle so I can try to start the engine on propane vapour and start feeding the coil once the engine is hot.

[Zippiot]

Wow missed a day and you already filled out anothr page...
Will you be using that old throttle valve for throttle or regulation? Its exactly like my fuel regulator for my car.
You can get stainless that doesnt work harden, cant remember the grade but its listen on mcmastercarr.

[Johansson]

Wow missed a day and you already filled out anothr page...
Will you be using that old throttle valve for throttle or regulation? Its exactly like my fuel regulator for my car.
You can get stainless that doesnt work harden, cant remember the grade but its listen on mcmastercarr.

Yup, the throttle valve will be used on the kick. Interesting info about the automobile fuel regulator, can you take a pic of it? It would be great if one of those could be used for future projects so I won´t have to spend 20h with the lathe again...

I used 304 grade since it was the cheapest available, a 2x1m sheet still cost over 200usd here so I figured that it would have to do.

[Zippiot]

Im using an Aeromotive Bypass Regulator, Ill take some pics tomorrow but its easier to describe how it works.
It was the cheapest bypass regulator which actually works differently from a "normal" fuel regulator.

The inlet is actually 4 female threaded holes around a spring loaded cone. The cone seals off the 4 holes from a 5th, this 5th hole is the bypass. One of the 4 holes is the inlet, the other 3 are outputs. When pressure overcomes the spring (adjustable and could be changed for a lever like you did) the cone moves up, unblocking thy bypass hole. So essentially when fuel pressure gets too high this output is revealed and sends fuel back to the fuel tank, relieving system pressure.
As an added bonus it has a vacuum refference port, so that when engine vacuum is low it takes less force to open the bypass. It can be plugged if it is producing undesireable results.

I got mine off Summitracing.com best price and shipped to me in less than 1 day flat rate!
The pic is a different style but functions the same.

[Johansson]

Zippiot: Ok, I have one of those on my old turbo-bike. From your earlier description I thought it was a throttleable valve.

I made an intake blocker and a removable propane stinger yesterday, now I have only a few finishing touches to do before I can do another starting attempt. I have also exchanged the old 11kg propane bottle for a 19kg so hopefully it will give enough vapour for the engine to start on. The stinger has a 4mm hole in it, I will bring a set of drills to open it up if it is too restrictive.