Forced induction 100cc

[Grumph]

FFS - don't worry about pressure spikes yet - you're only dealing with a 100cc cylinder and a relatively small volume of pressurised air.
I ran a 1200cc plus plenum full of wet mixture at 18psi with quite big and uneven pressure spikes (in theory anyway) Never had a problem and never saw any variations on the boost gauge...she'll be right mate.

Drive, we used a polyvee about 25mm wide on a blower with 750cc displacement which was quite heavy,,,,never had a drive problem even when revving to 13 grand. The original and only belt is still on my wall. When you machine your pulleys just remember to take the tips off the pointy bits...Glen Smiths TQ had a reputation for shredding belts until they brought it South and I had a look at it. The pulleys still had points....Any V belt is supposed to bear on the sides of the V not the tips.
The polyvee run a tad slack will allow a small amount of slippage on the overrun - easy and uncomplicated.
15mm should be fine.

[ducatilover]

That's a bloody good price on the injection set up, have you considered running the mechanics of that with a micro-squirt ECU? I reckon that'd fuel beautifully.

[Brian d marge]

FFS - don't worry about pressure spikes yet - you're only dealing with a 100cc cylinder and a relatively small volume of pressurised air.
I ran a 1200cc plus plenum full of wet mixture at 18psi with quite big and uneven pressure spikes (in theory anyway) Never had a problem and never saw any variations on the boost gauge...she'll be right mate.

Drive, we used a polyvee about 25mm wide on a blower with 750cc displacement which was quite heavy,,,,never had a drive problem even when revving to 13 grand. The original and only belt is still on my wall. When you machine your pulleys just remember to take the tips off the pointy bits...Glen Smiths TQ had a reputation for shredding belts until they brought it South and I had a look at it. The pulleys still had points....Any V belt is supposed to bear on the sides of the V not the tips.
The polyvee run a tad slack will allow a small amount of slippage on the overrun - easy and uncomplicated.
15mm should be fine.

and no great angle changes ..... be nice to the poor wee thing

Stephen

ps I looked for the cam software ,,,,,,,, how did u get the older one on ur computer ??

[Sketchy_Racer]

and no great angle changes ..... be nice to the poor wee thing

Stephen

ps I looked for the cam software ,,,,,,,, how did u get the older one on ur computer ??

it's the first software our company used so we still have the disk, I just can't create code from it because I don't have the security dongle

[carburator]

just go old school.. 30 degree tip plunged works well..

i have floating around a cad file for it, used 3mm raduis at the peak
works very well for me..

[Brian d marge]

it's the first software our company used so we still have the disk, I just can't create code from it because I don't have the security dongle

I use Linux and ,,yes well the CAD, CAM scene is ...yes limited ..There are alternatives ( good sometimes to ) such as Calculix , and Salome but the CAM side of things ......

Stephen

[Sketchy_Racer]

The EFI kit turned up today. Super happy with it so far it's all as it was advertised and fits together well.

I had to make an adapter to allow me to bolt the throttle body down. It also let me orientate the injector to get the best angle (i think) into the port. The injector pretty much aims directly at the intake valve.

Then it was wires, i've now got

Throttle position sensor
Manifold absolute pressure
Engine temperature
Intake air temperature
O2 sensor
crank position sensor

All the cool stuff to keep an eye on what's going on.

I'm so far really impressed with the software and how many parameters it lets you adjust. A lot of it does not need adjusting such as enrichment factors relative to altitude where the values stay the same.

So hopefully I'll look at getting it plugged into the computer and get it talking on the weekend. Can't start the engine even if I wanted though as the barrel is at work getting the sleeve swapped out for the smaller one to get me under 100cc

Also on the supercharger front, I have finished the two lobe rotors and made a second set of gears, fits together great and have gone with 0.1mm wall to rotor clearance, 0.08 endplate clearance on both sides and 0.1 rotor to rotor clearance.

The gears have a total of 0.03mm back lash (putting the dial gauge on a tooth) so I think that will be fine relative to the clearances inside the housing.

I still need to get a belt and make some pulley and some intake and outlet fittings for the supercharger.

Lots to do, but it's looking like a bike now!

Cheers,

-Sketchy

[Grumph]

I appreciate that you may well want to integrate boost pressure into the ignition and maybe fuelling curves, but I'd really recommend also fitting a mechanical boost pressure gauge. One fitting on the plenum and a pipe, not hard, and it gives you a check on what your electronics are telling you.

[Sketchy_Racer]

I appreciate that you may well want to integrate boost pressure into the ignition and maybe fuelling curves, but I'd really recommend also fitting a mechanical boost pressure gauge. One fitting on the plenum and a pipe, not hard, and it gives you a check on what your electronics are telling you.

Of course mate, we couldnt run forced induction without a gauge! Yeah I have a small one from my turbo 250 that i'll steal.

Cheers for the feedback as well mate, it's good to have someone with experience help out and save me some aggrivation when I cock stuff up.


-Sketchy

[Sketchy_Racer]

Now as I understand I am going to need a good strong spark for running boost. The ecu is powered by a battery and I am still to figure if I am going to run a charge system, will figure out how long the battery will last
The ECU lets me run a compensation for voltage drop to maintain correct injector and spark timing which is cool.
I have a old coil off god knows what that I used on the MB100 motor for years but I am better off getting something new fit for the purpose?

Cheers,

Sketchy

[Drew]

Were I you, I'd get a plug top coil from something modern.

[Grumph]

Of course mate, we couldnt run forced induction without a gauge! Yeah I have a small one from my turbo 250 that i'll steal.

Cheers for the feedback as well mate, it's good to have someone with experience help out and save me some aggrivation when I cock stuff up.


-Sketchy

You Hope.....

Ignition - I've no idea what the Longshit uses as stock but you're obviously going to have to have a battery so any 12V coil OF THE CORRECT RESISTANCE should do. The plug top coils are in my experience, very low primary resistance and may not match whatever ignition you use. We used std Kawa 500 coils with an ER&D box which just had more agressive advance curve and higher rev limit.
No probs firing meth at high pressure. Plug range is going to be interesting - on meth you run the hottest plug you can get away with but you're going to have to start at around NGK 12 IMO....

[F5 Dave]

well it will be interesting to see this go, I've been at this bucket lark for well over 20 years & never seen an F4 super before. Heard of one that was rubbish, seen Diesels 'thing' & Mikes pics, but looks like you've done some great work as usual.

. . .so where's my old H100 engine at? Have to look at building a 125 version at some stage.

[TZ350]

I'd really recommend also fitting a mechanical boost pressure gauge. One fitting on the plenum and a pipe, not hard, and it gives you a check

The few things I remember from playing with superchargers, was that a mechanical boost gauge in the inlet manifold after the throttle plate could tell you when things were going wrong in the valve train like a kissed valve or weak valve spring as the boost would start to blow straight through. And then there is the heat, supercharged engines produce a great volume of waste heat in the cooling system and exhaust that needs to be accomodated. Although only standard cams were needed for good power the exhaust note was much louder and the ignition timing was 10 deg plus 10 advance, that and no choke was needed because of the churning action of the rotor lobes on the suck through setup. And the shreek of the belts slipping on full boost and max revs. And instead of reving it right out, short shifting and driving it on the torque curve was the go.

Your bike is Bucket history in the making, when you have it running I would love to come to Kaitoki again just to hear and see it out on the track.

[Moooools]

The EFI kit turned up today. Super happy with it so far it's all as it was advertised and fits together well.

I had to make an adapter to allow me to bolt the throttle body down. It also let me orientate the injector to get the best angle (i think) into the port. The injector pretty much aims directly at the intake valve.

Cheers,

-Sketchy

You really want to have that injector spraying down before the valves. That way when it is picked up in the air stream it gets diverted onto the valves.

You also might want to to some spray pattern testing. Just apply fuel pressure and hook the injector up to 12V. If the spray is conical then no need to worry, but if the spray is flat then orient the injector so it sprays a horizontally. Injected machines can be quite picky with this; especially when starting.

Otherwise looking really good. Very impressed.