Forced induction 100cc

[Crasherfromwayback]

As I was snowed in with work (as in real work, the kind that pays money) I had some jobs for the supercharger bucket done by others. I got craig from moto-metal to take care of the welding on my plenum and have to say I am really pleased with his work!

Here's a couple of pics of the mint welding job he did for me.



Yeah he's a good lad that does great work. Loving your work too mate! Most excellent!

[Sketchy_Racer]

Well after yesterday's startup and run I was wondering why my boost levels were not has high as planned, could it be that my charger is not as efficient as planned? The motor's flow is better than expected...

Nope, this dick-of-the-day left the tensioner bolt out of the supercharger cradle meaning the belt went slack and was slipping, I'm also going to take a punt and say the slipping is where a lot of the heat came from.

I haven't run it again to see the difference but I am sure it will be significant.

hopefully i'll get some mufflers to test out sometime next week and then we are in business!

[Ocean1]

hopefully i'll get some mufflers to test out sometime next week and then we are in business!

Is a KTM525 item any use to you?

[gatch]

Dude, maximum respect.

Even with no pipe on you can hear the blower. Sounds gorgeous. Most excellent work.

[Sketchy_Racer]

Is a KTM525 item any use to you?

Possibly, You wouldn't have a rough idea on the dimensions and weight of it by any chance?

Cheers

[Ocean1]

Possibly, You wouldn't have a rough idea on the dimensions and weight of it by any chance?

Cheers

It's at work, I'll have a measure in the AM.

[Sketchy_Racer]

Awesome, thanks.

[Crasherfromwayback]

Awesome, thanks.

Drop me an email at work too mate, and I'll have a sift about and see if there's something kicking around I can sort for you.

pmcdonald@wmcc.co.nz

[F5 Dave]

You know you should be doing it anyway.
You mean to get it back to legal size? Good point, do the right thing Rich.

[Ocean1]

It's at work, I'll have a measure in the AM.

Body is a 90x100 oval, it's 450 long, 550 overall.

In hole is nom 50mm Dia.

Weighs 2.1Kg

[Paul in NZ]

I'm insanely impressed.... Well done...

[Sketchy_Racer]

Body is a 90x100 oval, it's 450 long, 550 overall.

In hole is nom 50mm Dia.

Weighs 2.1Kg

Thanks for that, unfortunately too heavy for my application but thanks for taking the time to check it out.

Cheers,

Sketchy

[NordieBoy]

Thanks for that, unfortunately too heavy for my application but thanks for taking the time to check it out.

Cheers,

Sketchy

Maybe a SuperTrapp IDS? Very light and tunable.

[Drew]

Just make one. It's easiest way to make it nice and light. Use sheet instead of pipe to save on cost.

[Grumph]

Have a look at the $79 Chinese ones on trademe. VERY light, baffle pulls out to give 50mm straight thru and there's plenty of volume.
I've got one on a Z1 racebike at present and I'm happy with it. Just had to spin up a front flange piece.
They come in flashy colours too - just right for a bucket....

The last thing you need on a blown motor is any flow resistance in the exhaust...it's goodbye exhaust valve.

[Drew]

Have a look at the $79 Chinese ones on trademe. VERY light, baffle pulls out to give 50mm straight thru and there's plenty of volume.
I've got one on a Z1 racebike at present and I'm happy with it. Just had to spin up a front flange piece.
They come in flashy colours too - just right for a bucket....

The last thing you need on a blown motor is any flow resistance in the exhaust...it's goodbye exhaust valve.

Then it was pointless building the thing, because a 50mm free flow would make it so fucking noisy that it can't run at any tarmac track in the country.

[mossy1200]

I have the one I put on mine before I got a quieter one. It weighs 0.7kg but you would need to repack it to reduce the noise level.
Pick up at track tomorrow or Hataitai.

Even has bad weld work and is made of butter metal like all the cheap nasty tardme butter pipes.

[Grumph]

Then it was pointless building the thing, because a 50mm free flow would make it so fucking noisy that it can't run at any tarmac track in the country.

Pull your head out of your arse Drew...I've been building pipes and silencers for race bikes and cars since before you were in nappies...

I won't recommend something if I don't think it will work.

Our blown 500 twin used two 2 in bore straight thru mufflers and was well under 100DB - at a time when the regs asked for 102max.
this muffler I'm recommending has plenty of muffler volume - which is the main thing you need - and i'm confident it wil be legal.
The one I'm using now is on a full house Z1 racebike - big cams and compression - and is runnng at about 89 DB.
In my experience,noise on a 4 stroke is directly proportional to cam overlap. Also in my experience, most people have no fucking idea how to silence a race bike effectively.

[Kickaha]

Pull your head out of your arse Drew...
His head spends quite a bit of time up there

[Buddha#81]

but I wait for Drews well thought out reply with interest..........:lol:

[Drew]

Pull your head out of your arse Drew...I've been building pipes and silencers for race bikes and cars since before you were in nappies...

I won't recommend something if I don't think it will work.

Our blown 500 twin used two 2 in bore straight thru mufflers and was well under 100DB - at a time when the regs asked for 102max.
this muffler I'm recommending has plenty of muffler volume - which is the main thing you need - and i'm confident it wil be legal.
The one I'm using now is on a full house Z1 racebike - big cams and compression - and is runnng at about 89 DB.
In my experience,noise on a 4 stroke is directly proportional to cam overlap. Also in my experience, most people have no fucking idea how to silence a race bike effectively.Meh, I will concede.

[speights_bud]

Try this, dunno if its any good but it was for noise testing and was super nice and quiet, old 2T straight thru can hooked off a mx straight thru can, i was told it could be promising with dyno and a bit more design time.... more quiet = more supercharger noise :D http://a8.sphotos.ak.fbcdn.net/hphotos-ak-ash4/337592_10151290225580099_1610247627_o.jpg

[Grumph]

Try this, dunno if its any good but it was for noise testing and was super nice and quiet, old 2T straight thru can hooked off a mx straight thru can, i was told it could be promising with dyno and a bit more design time.... more quiet = more supercharger noise :D http://a8.sphotos.ak.fbcdn.net/hphotos-ak-ash4/337592_10151290225580099_1610247627_o.jpg

I'm sure that is quiet..I'm equally sure it's too restrictive for a blown motor. Refer what I posted earlier about ex valve temps..

If Sketchy has machined his gears correctly, there shouldn't be any blower noise. That's the advantage of a polyvee belt over a toothed belt...after all, when was the last time you heard belt noise from your car's alternator or water pump drives ?

[Drew]

.after all, when was the last time you heard belt noise from your car's alternator or water pump drives ?This makes a lot of sense, and is very disapointing!

Belt whine is the best part of supercharging! Except for the extra power.

[speights_bud]

I'm sure that is quiet..I'm equally sure it's too restrictive for a blown motor. Refer what I posted earlier about ex valve temps..

If Sketchy has machined his gears correctly, there shouldn't be any blower noise. That's the advantage of a polyvee belt over a toothed belt...after all, when was the last time you heard belt noise from your car's alternator or water pump drives ?

I told him he shoulda run a good 2" toothed belt but he just wouldn't listen....

I'd say your bang on about the pipe, as it was also too restricted for a std 145 with how it was setup.

[speights_bud]

This makes a lot of sense, and is very disapointing!

Belt whine is the best part of supercharging! Except for the extra power.

I'm guessing there will be some gear whine, almost always happens with straight cut gears to some extent, but with a nice finish and close fit they should be pretty quiet, it might just sound more like something with gear driven cams?

[Ocean1]

If Sketchy has machined his gears correctly, there shouldn't be any blower noise. That's the advantage of a polyvee belt over a toothed belt...after all, when was the last time you heard belt noise from your car's alternator or water pump drives ?

Mate, a straight lobed industrial roots blower direct driven by an electric motor absolutely screams. As in the cost of accoustic mitigation is a significant budget factor.

[Grumph]

Mate, a straight lobed industrial roots blower direct driven by an electric motor absolutely screams. As in the cost of accoustic mitigation is a significant budget factor.

Interesting...our 750cc straight lobed rootes blower was very quiet - even when revved to 13 grand. You could sit on it and rev it and literally not hear any noise from the blower. Straight cut gears too....

I remember the blowers pushing air through the yeast fermentation at DYC ChCh, ferkin big ones too, you knew when they were running but probably only around 90DB in the machinery room.

[Ocean1]

Interesting...our 750cc straight lobed rootes blower was very quiet - even when revved to 13 grand. You could sit on it and rev it and literally not hear any noise from the blower. Straight cut gears too....

I remember the blowers pushing air through the yeast fermentation at DYC ChCh, ferkin big ones too, you knew when they were running but probably only around 90DB in the machinery room.

Pressure differential makes a difference, they're often piggy-backed onto big vane vacuum pumps and they're quiet, (nothing to transmit the sound). On the other hand I've used them for fluidised transport, blowing, (sucking, actually) fibres around ducting, and when they're more or less unrestricted on the sucky side they howl.

[Sketchy_Racer]

I'm guessing there will be some gear whine, almost always happens with straight cut gears to some extent, but with a nice finish and close fit they should be pretty quiet, it might just sound more like something with gear driven cams?

Hey champ, Yeah there is plenty of whine, this is mostly due to the tooth count/pitch dia ratio is out of the recommended window. Interestingly is is only noisy at lower RPM and shuts up once the RPM come up.


Interesting...our 750cc straight lobed rootes blower was very quiet - even when revved to 13 grand. You could sit on it and rev it and literally not hear any noise from the blower. Straight cut gears too....

I remember the blowers pushing air through the yeast fermentation at DYC ChCh, ferkin big ones too, you knew when they were running but probably only around 90DB in the machinery room.

Yeah if the gears were perfectly designed and manufactured they should almost be quiet however housing design and oil also has a large influence on the gear noise, I could always try some banana skins to hide my poor gears. Ideally I would have gone with at least a 30+ tooth count but I didn't have the cutters for it so will see how the coarse 24T lasts. I have a fixture and program to make some more if I need to.

Out of interest did you guys ever create an efficiency map of your blower? As a bit of a side project (mainly for curiosity but also for performance) I am going to map the super charger and see where's sweet spot is in relation to RPM vs Pressure ratio.

To do it I am simply going to do some steady state testing at suitable RPM steps using a variable speed lathe, a flow restriction valve and a temperature probe and plot a graph as there will be a optimal point where I can get the best pressure ratio vs heat to get the optimum volumetric efficiency - sounds like fun!

[Sketchy_Racer]

Progress is being made on the bike, last night thanks to Kyle and Rich Ban for his pipe I got into the workshop and got an exhuast together. I have gone with one of the chinese mufflers as it is very light and looks like it will do the job. I have set the muffler up sort of like some of the Moto3 bikes with it mounted just under the right foot peg. Hopefully ground clearanc shoudln't be an issue. Unfortunatley I don't have any pictures at the moment so I'll get some later.

I have however started to put the bike thought it's weight loss program. So far I have managed to drop 650g off the rear wheel assembly which is a good start. to do that I have machined a new sprocket carrier and lightened the disc carrier. I have also through drilled a lot of the cap screws and turned the cap heads into tapers. Might seem crazy but that was worth 50g on the rear wheel alone. I am currently looking at changing to a 415 sprocket like the RS125s but need to sort out some sprockets. Might look at getting some water cut or just mill them out of some 4mm plate (which means I'll be able to make a cool looking design)

Next will be replacement rear sets that will be lighter and stronger than the current ones. I'm going to look at making a smaller subframe as the current one is designed to hold two people so I'm sure it can lose at least half a Kg there.

The aim with the bike is to get to 90KG which is going to be a mission! But a fun one.

Also here's a pic of the latest perk done in the CNC - a custom brake caliper mount for a mates Starlet with a turbo 4AGE

270182270184270185

[Skunk]

Next Project:
http://www.kiwibiker.co.nz/forums/showthread.php/152938-God-Help-you-lot-if-this-guy-takes-up-buckets

Two conrod V8.

[Grumph]

Hey champ, Yeah there is plenty of whine, this is mostly due to the tooth count/pitch dia ratio is out of the recommended window. Interestingly is is only noisy at lower RPM and shuts up once the RPM come up.



Yeah if the gears were perfectly designed and manufactured they should almost be quiet however housing design and oil also has a large influence on the gear noise, I could always try some banana skins to hide my poor gears. Ideally I would have gone with at least a 30+ tooth count but I didn't have the cutters for it so will see how the coarse 24T lasts. I have a fixture and program to make some more if I need to.

Out of interest did you guys ever create an efficiency map of your blower? As a bit of a side project (mainly for curiosity but also for performance) I am going to map the super charger and see where's sweet spot is in relation to RPM vs Pressure ratio.

To do it I am simply going to do some steady state testing at suitable RPM steps using a variable speed lathe, a flow restriction valve and a temperature probe and plot a graph as there will be a optimal point where I can get the best pressure ratio vs heat to get the optimum volumetric efficiency - sounds like fun!

Ours was a prototype small Martin blower, 750cc displacement. The company had changed hands and the new owner had got an engineer I knew to look at the design and do some more efficiency testing. He used a setup pretty much exactly as you describe except it was a datsun gearbox as a stepup on top of his lathe driving the blower...i was shown the results once and told it would have a flat efficiency curve up to about 10 grand. As it turned out I reckon we didn't lose efficiency over 12 grand either. The engineer did a redesign of the case and put a separator bar across inlet and exit which he claimed reduced backflow and churning losses. Worked for me...
He reckoned 80% efficiency at 10 grand.

[koba]

Also in my experience, most people have no fucking idea how to silence a race bike effectively.

Got any tips for that?

Perhaps a new thread?

[Brian d marge]

Most people have no Idea how to silence a race bike , because they lack the knowledge of what "sound" is.

this also extrapolates to machining/engineering , many have no idea of load paths or or the loading on a material , or the dynamics of loading

When are we going to see this thing in action btw ?



Stephen

[Brian d marge]

Got any tips for that?

Perhaps a new thread?

take the energy out , look at motogp exhaust , yamaha, a couple of inches at the end , lets the volume flow through , ( little bit of turbulance ) BUT the engergy of the wave is ( a little ) absorbed

Stephen

ps from top of head just before bed ,,, so someone else can cross the t's

[Drew]

take the energy out , look at motogp exhaust , yamaha, a couple of inches at the end , lets the volume flow through , ( little bit of turbulance ) BUT the engergy of the wave is ( a little ) absorbed

Stephen

ps from top of head just before bed ,,, so someone else can cross the t'sYou mean, someone else can make a point. Have you heard a motoGP bike in the flesh? The muffler on them does little or nothing to silence them!

From 200 meters you still need ear protection.

[Grumph]

MotoGP and F1 cars, as I understand it have no noise restrictions at all...

Brian is onto it - you've got to take the energy out of the wave before it hits the atmosphere.

The problem here in NZ is unusual in a world wide sense in that we don't have a defined sound test.
The Euro/Brit test where the piston speed is the defining point for measurement is actually easier to meet as it is quite possible to tune a silencer for that specific frequency...and bugger any other frequency, I've passed the test...
Unfortunately, most of the pubished info - at least recent stuff - is about meeting specific frequency related regs.

Basically, you can't go wrong with plenty of silencer volume.

[koba]

Basically, you can't go wrong with plenty of silencer volume.

From my muddlings and observations of other peoples, I'd come to suspect that was the case. It's great to hear it from someone like yourself.

[NordieBoy]

Have you heard a motoGP bike in the flesh? The muffler on them does little or nothing to silence them!

From 200 meters you still need ear protection.

Meh. The same could be said for a stinger on a Kwakka classic mx 2 stroke...

The cops could use that for crowd control.

[Drew]

Ok, well that is all cometsly useless because Glen intends to build a light, functioning race bike. Heaps of volume flies in the face of that, so we're back to square one, and looking for efficient.

[F5 Dave]

Well the baffling material is light & ally tube is too.

[Grumph]

Ok, well that is all cometsly useless because Glen intends to build a light, functioning race bike. Heaps of volume flies in the face of that, so we're back to square one, and looking for efficient.

To turn one of your arguments back on you...if it doesn't meet the noise regs it can't be used anyway...

When anyone builds a bike now, meeting the noise regs is just one of the factors which have to be balanced.
The muffler I recommended and i think Sketchy has, I'd estimate is less than 1KG...

In this particular case, it's not like silencing an unsupercharged single - you couldn't care less about exhaust tuning, megaphone or length.
All you are worried about is getting the gas out with as little restriction as possible so as to keep the exhaust valve temp down.
For this application a large volume, straight through type will work well.

[DEATH_INC.]

it's not like silencing an unsupercharged single - you couldn't care less about exhaust tuning, megaphone or length.
? A supercharged engine responds to exhaust tuning just like a na engine does. Well...maybe not exactly the same....

[Drew]

To turn one of your arguments back on you...if it doesn't meet the noise regs it can't be used anyway...

When anyone builds a bike now, meeting the noise regs is just one of the factors which have to be balanced.
The muffler I recommended and i think Sketchy has, I'd estimate is less than 1KG...Are you talking about those shite Chinese ones? Because everyone I've heard talk about them, says they do little to quiet down a bike.


In this particular case, it's not like silencing an unsupercharged single - you couldn't care less about exhaust tuning, megaphone or length.
All you are worried about is getting the gas out with as little restriction as possible so as to keep the exhaust valve temp down.
For this application a large volume, straight through type will work well.Can a pipe be made of perf pipe, then second skinned the whole length with sloid pipe and a quantity of soft stuff between?

That way it only needs to be inch and a half pipe like a tiny motor needs (I don't care if it's supercharged, the gas output won't match that of a 250cc MX motor). This way length and tuning is still possible.

[F5 Dave]

. . .Can a pipe be made of perf pipe, then second skinned the whole length with sloid pipe and a quantity of soft stuff between?. . .
That sounds like my std Tiger pipe, except there are baffles leading back & forth inbetween, but there is a large volume with not that much inside it.

[bogan]

Can a pipe be made of perf pipe, then second skinned the whole length with sloid pipe and a quantity of soft stuff between?

I think you can get perf pipe where the holes are more directional, like a cheese grater, this may make for better air flow. Add a layer of steel wool right on the perf, then muffler pack for the rest, should contain the fury. Flatten the outside a bit, so it is slightly eliptical, makes for better sound reduction.

[Brian d marge]

You mean, someone else can make a point. Have you heard a motoGP bike in the flesh? The muffler on them does little or nothing to silence them!

From 200 meters you still need ear protection.

I think I have had a little experience with moto gp.... only a touch mind

Stephen

[Grumph]

Are you talking about those shite Chinese ones? Because everyone I've heard talk about them, says they do little to quiet down a bike.

Can a pipe be made of perf pipe, then second skinned the whole length with sloid pipe and a quantity of soft stuff between?

That way it only needs to be inch and a half pipe like a tiny motor needs (I don't care if it's supercharged, the gas output won't match that of a 250cc MX motor). This way length and tuning is still possible.

Well the one I've been using is very acceptable build quality and works very well indeed. IMO they're not suitable for NA singles though which is probably where people are having problems

The gas output won't match a 250 MX motor - close though - 100cc at 1 bar boost equals 200cc unblown so not a lot more boost needed to exceed the 250 output.

Exhaust tuning, again, is not needed or necessary or desirable on a blown motor...aside from the difficulty of geting a reverse wave at atmospheric pressure to pass into a combustion chamber which is above atmospheric pressure most of the time - certainly when any reverse wave arrives...the last thing you need is charge contamination with hot gasses at a critical point in the cycle. Carburation is easier to set too as there is no reverse flow whatsoever.

[Drew]

Well the one I've been using is very acceptable build quality and works very well indeed. IMO they're not suitable for NA singles though which is probably where people are having problems

The gas output won't match a 250 MX motor - close though - 100cc at 1 bar boost equals 200cc unblown so not a lot more boost needed to exceed the 250 output.

Exhaust tuning, again, is not needed or necessary or desirable on a blown motor...aside from the difficulty of geting a reverse wave at atmospheric pressure to pass into a combustion chamber which is above atmospheric pressure most of the time - certainly when any reverse wave arrives...the last thing you need is charge contamination with hot gasses at a critical point in the cycle. Carburation is easier to set too as there is no reverse flow whatsoever.Where I'm really struggling though, is why a supercharged engine is not making as much noise as an N.A motor. I know why a turbo motor is quieter, at least I thought I did, and it had nothing to do with the forced induction.

[DEATH_INC.]

.aside from the difficulty of geting a reverse wave at atmospheric pressure to pass into a combustion chamber which is above atmospheric pressure most of the time - certainly when any reverse wave arrives...the last thing you need is charge contamination with hot gasses at a critical point in the cycle. Carburation is easier to set too as there is no reverse flow whatsoever.
Lol...um the reverse wave is at less than atmospheric, that's why it works. It does not cause hot gas to pass into the chamber, it draws it out, and it certainly does not cause a reverse flow at the carb...that's caused in the intake tract....

[DEATH_INC.]

Where I'm really struggling though, is why a supercharged engine is not making as much noise as an N.A motor. I know why a turbo motor is quieter, at least I thought I did, and it had nothing to do with the forced induction.
Turbo's are quieter...until they make boost.
I also struggle with how a supercharged engine is quieter. How can a bigger bang be quieter? All the s/c engines I've ever heard are loud as f*ck.

[DEATH_INC.]

Basically, you can't go wrong with plenty of silencer volume.
This is true. The speedway guys at the springs discovered this when all the whingers made 'em silence down the cars/bikes. The same core with a larger capacity can was substantially quieter.

[pete376403]

Turbo's are quieter...until they make boost.
I also struggle with how a supercharged engine is quieter. How can a bigger bang be quieter? All the s/c engines I've ever heard are loud as f*ck.
Turbo is quieter because the energy it is using to drive the compressor would, in a normally aspirated engine, be released to the atmosphere as noise.

[Drew]

Turbo is quieter because the energy it is using to drive the compressor would, in a normally aspirated engine, be released to the atmosphere as noise.

Until it spools up and the waste gate is open. Then it would be noisier than an NA motor with the same displacement, because of the bigger bang.

[Ocean1]

Until it spools up and the waste gate is open. Then it would be noisier than an NA motor with the same displacement, because of the bigger bang.

Except the waste gate is a pressure-varied restriction, (as is the turbo exhaust rotor) a pretty good silencing trick in it's own right.

[Grumph]

I don't believe I've said at any point that a blown motor is inherently quieter than a NA one...what i will say is that silencing one presents an easier problem given enough room for silencer volume.
A NA motor - particularly a single - is reliant on exhaust resonances to make much of it's power. Get the pipe wrong and there goes a lot of power.
A blown motor does not need or want any exhaust resonances at all - period. It therefore becomes an easier job to build a pipe which won't lose power.

Turbos mufflers have an easier job too - the turbo takes a lot of the energy out of the exhaust gases before they reach the muffler.

[Brian d marge]

you can absorb the energy by either, expanding it (volume) or by absorbing it .. from memory the motogp are kind of like a kn filter but inverted , the gas has mass , and gets some boudry layer disturbance..so basically rockets on through , the energy contained in the gas..( sorry cant remember in what form or position ) expands out into the absorbtion material
now as motogp dont need a hell of a lot of absorbtion .....the muffler isnt so big ....or long...
stephen
sorry ...tapping this out on the phone on the train...so please excuse

[Sketchy_Racer]

Well the first exhaust has been made, it is completely non calculated and has been made just to fit.

Cheers to Richban for letting me tax his exhaust bends. (got new ones at work will drop em off soon)

It looks ok and combines parts of a CRF250 header pipe with a chinese muffler that I stole off the turbo bike. I will re-pack it but it does sound great at 11500 RPM

Thinking of exhaust designs I would believe that in the case that Grumph is explaining with a supercharged motor then I agree that exhaust is irrelevant and big is better but only is there is considerable valve overlap. This would mean that the positive pressure in the exhaust cycle would completely negate any form of scavenging.

However in a system where there is no valve overlap then sure I believe some sort of scavenging will have an effect. I plan on testing both methods so time will tell however I do believe that experience trumps pretty much all theory so have no doubt that Grumph is correct.

The next project that me and a mate are looking at is making a inertia dyno. More on that at a later date.


270370270371

[bogan]

The exhaust looks pretty exhaustlike, but I think we'd rather hear how it sounds :yes:


The next project that me and a mate are looking at is making a inertia dyno. More on that at a later date.

Skip the inertia bollocks and go straight to an eddy current dyno. Once all the other dyno costs are factored in I think the extra tuning ability would be well worth the budget increase.

[Moooools]

The exhaust looks pretty exhaustlike, but I think we'd rather hear how it sounds :yes:



Skip the inertia bollocks and go straight to an eddy current dyno. Once all the other dyno costs are factored in I think the extra tuning ability would be well worth the budget increase.

Agreed. Or even just a couple of old car brakes and a load cell. Especially for FI engines. Need a good amount of time at steady state to tune it up real nice.

How does the software work? I am assuming it is an array of cells for TP vs RPM?

[richban]

Agreed. Or even just a couple of old car brakes and a load cell. Especially for FI engines. Need a good amount of time at steady state to tune it up real nice.

How does the software work? I am assuming it is an array of cells for TP vs RPM?


One of these maybe. Looks simple enough.

http://www.mustangdyne.com/mustangdyne/products/chassis-dynamometers/cycle-atv/?prod=MD-ScooterDyne

[speedpro]

Some sort of power absorber brake thingy from trucks. They are an Eddy current type of brake but checking their specs they could draw a lot of current but I don't know what sort of power they would absorb at that current, or as stated a regular car disc brake and load cell on the cailper torque arm.

[Yow Ling]

a 60kw eddy current brake costs us$1400 fob china
a truck absorber will use one or two hundred amps at 24v depending on size
you can get 90 and180 volt ones as well

eddy current brakes or absorbers aren't that common over here, they are in Europe", hydraulic absorbers are more common here

the extra complexity of an absorber dyne does not make it very attractive, you need a closed loop control and just more electronics compared to an optical reflective or hall effect sensor for an inertia dyno

ese seem to manage ok with an inertia one

[Brian d marge]

im at those same crossroads......3d scanner , welder, or a very rare scotch whiskey

stephen

[gatch]

Hey champ, Yeah there is plenty of whine, this is mostly due to the tooth count/pitch dia ratio is out of the recommended window. Interestingly is is only noisy at lower RPM and shuts up once the RPM come up.


What gears are you after ?

I 'may' be able to help.

[husaberg]

Some sort of power absorber brake thingy from trucks. They are an Eddy current type of brake but checking their specs they could draw a lot of current but I don't know what sort of power they would absorb at that current, or as stated a regular car disc brake and load cell on the cailper torque arm.


Are you mean like a Telma electric brake?

[carburator]

im at those same crossroads......3d scanner , welder, or a very rare scotch whiskey

stephen

Buy the welder, knock up some stuff, sell it then get the whiskey... pitty i don't drink as there are a couple of bottles
under the kitchen sink..

[speights_bud]

So hows it Going Mr Glen?, you dun gone all quiet recently, hows bout a video with the zorst on running?. Doc's given me another couple weeks off work until this tendon heals and I'm bored shitless

[Sketchy_Racer]

Yeah have gone a bit quiet, I have been busy with making the dyno the last few weekends and then got sick.

I have had the bike running and tried to dyno it, but found out that my battery is stuffed and was blanking the ECU so need to sort a new battery. Oh it made 9HP with it firing every second fire. The supercharger isn't working very well at the moment so I need to look into that. Got it upto 10 PSI then I think it nipped up because it has now dropped to 5PSI. I have some more 3 lobe rotors made up now so will try them at some point.

Might have a play in the shed tomorrow, the weather here is SHIT

[husaberg]

Might have a play in the shed tomorrow, the weather here is SHIT

If it make you feel any better, the weather here is also shit. Far shittier than normal

[Grumph]

If it make you feel any better, the weather here is also shit. Far shittier than normal

Highly implausible....it better get fine for next weekend.

On the plus side though, if it's like this I can jet the bucket down as it will be very effectively water cooled....

[husaberg]

Highly implausible....it better get fine for next weekend.

On the plus side though, if it's like this I can jet the bucket down as it will be very effectively water cooled....

its bloody cold too. So Bring the wet tires as well cause it has been crap since September..I will see ya there anyway.

[jasonu]

Any progress???

[TZ350]

I have had the bike running and tried to dyno it ... Oh it made 9HP. The supercharger isn't working very well at the moment so I need to look into that.

Hi Sketchy I love following your progress, it sounds like your on the right track as I have found that bikes invariably go ferrel before they start to behave. I am looking forward to seeing it all come together in the new year.

[Grumph]

Yeah have gone a bit quiet, I have been busy with making the dyno the last few weekends and then got sick.

I have had the bike running and tried to dyno it, but found out that my battery is stuffed and was blanking the ECU so need to sort a new battery. Oh it made 9HP with it firing every second fire. The supercharger isn't working very well at the moment so I need to look into that. Got it upto 10 PSI then I think it nipped up because it has now dropped to 5PSI. I have some more 3 lobe rotors made up now so will try them at some point.

Might have a play in the shed tomorrow, the weather here is SHIT

In my experience, blown motors are one step sideways, one step backwards, half a step forward....and if they ever run right for any length of time, paranoia is a normal state of mind....

At least ours was on Meth - when things got really grim, we could have drunk the bloody fuel....

[speedpro]

It all seems so easy when you talk about doing it. Heat is a killer as has been said, and making the head gasket a dry joint is very good advice.

My bike is turbocharged so shared a lot of problems. We only ever had it running "right" a few times and it still makes me smile thinking about those times. The sense of satisfaction makes it worth perservering. It's a shame the power your motor made was disappointing but hopefully it's a simple to solve problem. Excellent work so far.

[Sketchy_Racer]

Glad to see people are still keen on seeing how this thing is turning out, sorry it's gone so quiet end of year work has been getting out of hand.

I have done some testing with the roots charger and I am not happy with it's performance, so I am currently going down another route that is even more interesting (well, to me anyway)

I am going to make a centrifugal supercharger using a IHI RHB31 impeller and diffuser with my own design of the traction drive planetary gearbox. It's cool because there are no gears and I can run easily a 1:10 ratio.

Hopefully I can get some decent boost pressure and I have an idea on how I am going to control boost levels but more on that in the new year.

Hope everyone had a go christmas!

Cheers,

-Sketchy

[speedpro]

You do know RHB31s spin up to about 170,000rpm when they are working, or something silly like that.

[husaberg]

A little inspiration not that you need it. http://www.sherline.com/cncproj.htm
http://www.sherline.com/images/RosenTurbineM.jpghttp://www.sherline.com/images/superchargersS.jpghttp://www.sherline.com/images/RosenSC125as.jpghttp://www.sherline.com/images/RosenSC125bs.jpg


You do know RHB31s spin up to about 170,000rpm when they are working, or something silly like that.
i would have said 200000..........
i think i have a compressor map somewhere for the IHI's.

[ducatilover]

I like the new idea a lot, that wee bugger Husaberg posted is a very neat bit of kit

I may be able to help source RHB31 bits, I know a chap, or two :D
There are a few alternatives for that size, but the 31 is probably the most common thing you'll find and they flow about as well as you can manage out the box.

[Sketchy_Racer]

You do know RHB31s spin up to about 170,000rpm when they are working, or something silly like that.

Yep, that is the exciting part! I will most likely not have to get impeller RPM up to that point as the little 100cc motor is right on the surge line of the compressor. I still need to learn weather surge is going to be such an issue on a mechanically driven compressor wheel as surge is what happens to a turbo when the exhaust pressure is no longer enough to over come the generated intake pressure. Being mechanically driven makes me think that I will get away with being so close to the surge line.


A little inspiration not that you need it. http://www.sherline.com/cncproj.htm
http://www.sherline.com/images/RosenTurbineM.jpghttp://www.sherline.com/images/superchargersS.jpghttp://www.sherline.com/images/RosenSC125as.jpghttp://www.sherline.com/images/RosenSC125bs.jpg


i would have said 200000..........
i think i have a compressor map somewhere for the IHI's.

Thanks for that link, I have seen these on other websites where people had fitted them up to bikes, and unfortunately they don't work, well at least not in the applications I have seen where they tried to run them without a plenum. Beautiful piece of machining though! I am going the cheats way and using pre developed parts to save me time, the gearbox is going to be easy too.

[Ocean1]

the gearbox is going to be easy too.

Epicyclic unit out of an air tool?

[Sketchy_Racer]

Time to update a little.

I really haven't spent anytime on the supercharger bike since I got it running. I did 4 dyno runs with it after sorting power supply issues and managed to get a whopping 12HP out of it (running like a bag of spanners) however the dyno runs were more to test the charger performance not the motor and didn't really do any tuning with it, but the roots style supercharger just sucks balls. I have learnt I was excessively optimistic with the efficiency I was hoping to achive and the boost levels are much lower than planned and I don't want to increase the supercharger RPM as it will pre heat the intake charge even more.

So, in between work and holidays, I have been working on a gearbox layout a 1:10 + ratio which will help me achieve the RPM required for a RHB31 turbo impeller.

There is nothing new about this concept, it's called a traction drive planetary gearbox which is well suited to high speed applications. Rotrex use them in their superchargers which are really really nice units.

The only pain in the ass part about the layout is that I have to run a set of gears on the input to get the rotation the right way as the motor spins the wrong way for the turbine. (once it's gone through the gearbox.

Anyway here are a couple of screen shots from the solidworks assembly, I will make an exploded view at some point and explain to those interested how it all works.

276159276160

Cheers,

-Sketchy

[crazy man]

do you want a Rotrex houseing. l have a pile of them...ps kenny said he will teach you how to make one

[Kickaha]

So, in between work and holidays, I have been working on a gearbox layout a 1:10 + ratio which will help me achieve the RPM required for a RHB31 turbo impeller.

Why not put a pulley on the exhaust side instead of an impeller and drive it off the engine?

[Sketchy_Racer]

I'm guessing you're taking the piss Kick, :laugh:

but just in case; I wont achieve 100,000 RPM plus with belt drives and the center housing of the turbo wont support lateral loading from a belt.

It's either gears or a jack shaft and turn the charger around in the chassis to get it work, and I dont want two belts in there, one is enough.

[Kickaha]

I'm guessing you're taking the piss Kick, :laugh: no but I hadn't thought about how fast you'd have to spin it, seen some like that on car sites

[Sketchy_Racer]

do you want a Rotrex houseing. l have a pile of them...ps kenny said he will teach you how to make one

Yeah mate, I would love to take a look at one.

Haha I would love to see ken's design he's much better on solidworks than i am but not as much hands on experience

[Sketchy_Racer]

no but I hadn't thought about how fast you'd have to spin it, seen some like that on car sites

Ah yeah, the big compressors are ok to do that with but not this little baby.

[crazy man]

Yeah mate, I would love to take a look at one.

Haha I would love to see ken's design he's much better on solidworks than i am but not as much hands on experiencewill post a pic of what l have . looks like a turbo housing; have about 10 of them . so you worked out who ken is(-;

[husaberg]

Its a shame that you have given up on the rootes......the HP you were getting 12hp i think (is possibly twice that of the std pitbike anyway) did you dyno it first? i also assume it was without a inter-cooler as well?
I see it as the second best compromise.(The best for tight circuit racing being being screw...imo)
i see an issue with the power delivery with the centrifugal charger.....yes even with flirting with the surge line and mega drive speeds needed to obtain boost.(unless the drive can limit and maintain speed independent of the engine speed which maybe your drive can i can remember some one posting the the oil squeezed drive details on the ESE site i think maybe it can)
I know there will be suitable size screw compressor wheels.( lurking in commercial air cons) Also there is some interesting Wankel style rotary air con compressors for car aircons.
That said I certainly don't have anywhere near 1/1000's of your ability you possess to do scratch built housing or the rootes blower you did.

Maybe it your rootes could be tried on the Speedpro engine?

[Sketchy_Racer]

Its a shame that you have given up on the rootes......the HP you were getting 12hp i think (is possibly twice that of the std pitbike anyway) did you dyno it first? i also assume it was without a inter-cooler as well?
I see it as the second best compromise.(The best for tight circuit racing being being screw...imo)
i see an issue with the power delivery with the centrifugal charger.....yes even with flirting with the surge line and mega drive speeds needed to obtain boost.(unless the drive can limit and maintain speed independent of the engine speed which maybe your drive can i can remember some one posting the the oil squeezed drive details on the ESE site i think maybe it can)
I know there will be suitable size screw compressor wheels.( lurking in commercial air cons) Also there is some interesting Wankel style rotary air con compressors for car aircons.
That said I certainly don't have anywhere near 1/1000's of your ability you possess to do scratch built housing or the rootes blower you did.

Maybe it your rootes could be tried on the Speedpro engine?

First dyno run was about 6hp from memory, then I made up the rest with just adjusting the fuel trim on the map which improved peak HP but hurt lower rpm.

The boost characteristics from a roots is far more desirable than the centrifugal but the efficiency is terrible and with such a small motor I can't afford the parasitic losses.

From what I can figure, I will be able to over drive the centrifugal charger so that it makes excess boost pressure then bleed it off when the RPM comes up and still have less parasitic loss than the roots with about a 40 degree cooler intake charge temp.

Failing that, I have some really cool ideas on making an electronically controlled CVT but I will get the supercharger working before I waste my time with any of that.

The roots works well, it just needs some time and experimenting with rotors and the housing geometry. I never did try the 3 lobe rotors but it would be interesting to see how that works. If Mike is keen I will send it up for him to have a play with it but I'm hoping he will turbo his one.

[husaberg]

First dyno run was about 6hp from memory, then I made up the rest with just adjusting the fuel trim on the map which improved peak HP but hurt lower rpm.

The boost characteristics from a roots is far more desirable than the centrifugal but the efficiency is terrible and with such a small motor I can't afford the parasitic losses.

From what I can figure, I will be able to over drive the centrifugal charger so that it makes excess boost pressure then bleed it off when the RPM comes up and still have less parasitic loss than the roots with about a 40 degree cooler intake charge temp.

Failing that, I have some really cool ideas on making an electronically controlled CVT but I will get the supercharger working before I waste my time with any of that.

The roots works well, it just needs some time and experimenting with rotors and the housing geometry. I never did try the 3 lobe rotors but it would be interesting to see how that works. If Mike is keen I will send it up for him to have a play with it but I'm hoping he will turbo his one.

yeah re the drive i was think like the electric clutch on some fans and the 4ag supercharged engine i think the super turbo March also had something tricky.
Out of interest what psi were you getting with the 120?cc engine?.

i seem remember the fuel map for a twin (i think this came from the CHCH turbo Norton i posted with a link ecu) is way more complex than a 4 so i guess the single would be even more so .

[Ocean1]

Failing that, I have some really cool ideas on making an electronically controlled CVT

Sounds heavy. What's the hp requirement for the blower drive? How does a suitable AC generator/AC motor drive compare for mass? You'd get to accurately and easilly define motor/blower revs. Including on the fly, during a race. You also get to mount the blower wherever you want.

Can you organise an extra output from an ECU to control an AC drive?

[Sketchy_Racer]

yeah re the drive i was think like the electric clutch on some fans and the 4ag supercharged engine i think the super turbo March also had something tricky.
Out of interest what psi were you getting with the 120?cc engine?.

i seem remember the fuel map for a twin (i think this came from the CHCH turbo Norton i posted with a link ecu) is way more complex than a 4 so i guess the single would be even more so .

I was getting 7psi with a 100cc motor at a 1:1 drive ratio. It was running at 10psi until it got a little hot and scored up one of the rotors.


Sounds heavy. What's the hp requirement for the blower drive? How does a suitable AC generator/AC motor drive compare for mass? You'd get to accurately and easilly define motor/blower revs. Including on the fly, during a race. You also get to mount the blower wherever you want.

Can you organise an extra output from an ECU to control an AC drive?

The CVT isn't for the supercharger it is for the engine gearbox, so I can hold the motor at peak power and fix the supercharger RPM for desired boost pressure and efficiency point. The CVT will run in the original engine gearbox housing with a sliding selector fork driven by a stepper motor that will be controlled via a computer to aim for a target engine RPM and adjust the selector fork position to chase that target.

[Ocean1]

The CVT isn't for the supercharger it is for the engine gearbox, so I can hold the motor at peak power and fix the supercharger RPM for desired boost pressure and efficiency point. The CVT will run in the original engine gearbox housing with a sliding selector fork driven by a stepper motor that will be controlled via a computer to aim for a target engine RPM and adjust the selector fork position to chase that target.

Ahh, makes sense. How did you plan on driving the blower, multiple gears off the crank?

[Sketchy_Racer]

Ahh, makes sense. How did you plan on driving the blower, multiple gears off the crank?

Nah just a belt like the last one, the charger has it's own gearbox inside for gaining the RPM

But, like I say first I want to achieve building a good supercharger capable of good boost pressures and efficiency. Then, I will see how hard I push this little chinese motor before it shits itself.

[husaberg]

I was getting 7psi with a 100cc motor at a 1:1 drive ratio. It was running at 10psi until it got a little hot and scored up one of the rotors.



The CVT isn't for the supercharger it is for the engine gearbox, so I can hold the motor at peak power and fix the supercharger RPM for desired boost pressure and efficiency point. The CVT will run in the original engine gearbox housing with a sliding selector fork driven by a stepper motor that will be controlled via a computer to aim for a target engine RPM and adjust the selector fork position to chase that target.
Sounds like you can whip it up in your smoko break:laugh:
I had set this to (mike i think) ages ago.
The drive looks remarkably like a fish tank filter where it is driven without mechanical contact.
I have a site saved somewhere with an electric supercharger (one that actually works) i think it had about 6 beefy electric engines and was good for like 1 minute. imagine the alternator drag to power it.(bloody can't find it )

PS if anyone know's why the highlighting of text always moves please let me know.

some intersting links
http://www.ty4stroke.com/viewtopic.php?t=29536
http://www.rbracing-rsr.com/waterinjection.html
http://www.rbracing-rsr.com/turbotech.html
http://pdf.directindustry.com/pdf/ogura/super-charger-model-tx04-tx07-tx10-tx12-tx15-tx20/14328-153977.html
http://www.axialflow.com/products.htm

[Ocean1]

Nah just a belt like the last one, the charger has it's own gearbox inside for gaining the RPM

OK, sounds fairly straight forward, anything fancy required to keep the blower case pressure from invading the blower gearbox?

[Sketchy_Racer]

OK, sounds fairly straight forward, anything fancy required to keep the blower case pressure from invading the blower gearbox?

Nope, I am just using a oil slinger (like what they used to use on old car engine rear seals) to keep the oil in the supercharger. There will be very little oil in the charger, just enough to keep the rollers lubed but not enough to create drag on the outer annulus drive ring.

When I get home I will make an exploded view of the pictures I posted earlier and explain which part does what as it is hard to see from the cross section photos.

[speedpro]

I never did try the 3 lobe rotors but it would be interesting to see how that works. If Mike is keen I will send it up for him to have a play with it but I'm hoping he will turbo his one.

I already have a 2-lobe/rotor supercharger from a kit for Suzuki Cappucinos. It's only 300cc/rev so if I go for supercharging I'll use that. Lobe wise it's in good nick but I had to replace all the bearings and file the gears clean as I think it had been run low on oil. My problem will be where to put it and the drive system. I don't have the gear or skills to fabricate anything to fancy.

[speedpro]

Regarding electric drive for the blower. I think the power requirements will put paid to that idea. Check out the size of say a 2hp motor, make it 12V and then consider the current needed - lots. Intermittently it could come from a battery, especially something like a LiFePO4. I suppose model aeroplane gear could be adopted as they use variable speed electric in their models now. Anyone who went to Tokoroa a few years ago would have seen a few good examples.

[Sketchy_Racer]

I already have a 2-lobe/rotor supercharger from a kit for Suzuki Cappucinos. It's only 300cc/rev so if I go for supercharging I'll use that. Lobe wise it's in good nick but I had to replace all the bearings and file the gears clean as I think it had been run low on oil. My problem will be where to put it and the drive system. I don't have the gear or skills to fabricate anything to fancy.

Sweet, yeah the AMR300 will work well with your motor. If you need any machine work done from drawings let me know, I can make stuff and mail it up for you.

[husaberg]

Sounds like you can whip it up in your smoko break:laugh:
I had set this to (mike i think) ages ago.
The drive looks remarkably like a fish tank filter where it is driven without mechanical contact.
I have a site saved somewhere with an electric supercharger (one that actually works) i think it had about 6 beefy electric engines and was good for like 1 minute. imagine the alternator drag to power it.(bloody can't find it )

PS if anyone know's why the highlighting of text always moves please let me know.

some intersting links
http://www.ty4stroke.com/viewtopic.php?t=29536
http://www.rbracing-rsr.com/waterinjection.html
http://www.rbracing-rsr.com/turbotech.html
http://pdf.directindustry.com/pdf/ogura/super-charger-model-tx04-tx07-tx10-tx12-tx15-tx20/14328-153977.html
http://www.axialflow.com/products.htm


Regarding electric drive for the blower. I think the power requirements will put paid to that idea. Check out the size of say a 2hp motor, make it 12V and then consider the current needed - lots. Intermittently it could come from a battery, especially something like a LiFePO4. I suppose model aeroplane gear could be adopted as they use variable speed electric in their models now. Anyone who went to Tokoroa a few years ago would have seen a few good examples.

yes (highlighted) i think it was all up 12 kw electric motors for a very small boost for a very small duration) i was before that, mentioning electromagnetic clutch for engagement only. The attachment i posted "is only a spool up motor" so very little power is actually required. because it doesn't produce any real pressure at those rpm's(threrefore requires very little power) but it would certainly reduce the lag of turbo designed for a 660cc engine on a 100cc engine.


this is the one i was thinking of not practical obviously i actually thought it had more electric motors but it drains the battery in mere seconds.
http://image.turbomagazine.com/f/8570777+w750+st0/0406tur_knight02_z.jpg
http://www.turbomagazine.com/tech/0406tur_knight_turbo_electric_supercharger/

[ducatilover]

I've been playing with the elec blower idea in my head for yonks, always thought an RHB31 would work well in the application. Probelem though, I don't think my charging systems can handle the load (maybe on the DR600-GN?)

[Sketchy_Racer]

Electric will work, but it will add significant weight and complexity, the only gain would be control. You could use an electronics package to control the boost curve.

As for power requirements you need to look at the energy draw of a mechanically driven supercharger which lets say is 20% of the engines total output at peak power. So a boosted motor making 20Kw at the crank will be loosing 4Kw to drive the charger. In an electric driven one, the draw would be theoretically the same if the charging system and electric motor were 100% efficient, but they aren't so what would be a 20% parasitic loss would suddenly become much more, probably closer to 30% depending on the setup, not to mention the extra mass needed for a good size alternator and a 4000W electric motor which would have to be made from a multi setup like the one pictured earlier.

The only way it could work which would be very difficult, would be to create a system such as KERS (Kinetic enercy recovery system) that is used on the formula 1 cars. The system uses an generator/motor set that is used as a generator under braking conditions which charge battery then when needed the generator is then turned into a motor to help drive the motor. The other system uses a flywheel which is spun to store the kinetic energy.

All really interesting but very hard to make practical on a bucket bike

[ducatilover]

Great info thanks.

I know there have been several drag cars that successfully run elec chargers, but they're big scale with big, big motors. I'd love to have some forced induction on my DR600 motor, but a Turbo won't cut it and I'm not smart enough to design a blower set up.

I think I'll just keep reading this awesomeness whilst collecting the bits to get an RHB5 on the ZX6 :niceone: (one of these days...140hp will be mine)

[husaberg]

I've been playing with the elec blower idea in my head for yonks, always thought an RHB31 would work well in the application. Probelem though, I don't think my charging systems can handle the load (maybe on the DR600-GN?)

Mass air storage would be an easier solution........................




The only way it could work which would be very difficult, would be to create a system such as KERS (Kinetic enercy recovery system) that is used on the formula 1 cars. The system uses an generator/motor set that is used as a generator under braking conditions which charge battery then when needed the generator is then turned into a motor to help drive the motor. The other system uses a flywheel which is spun to store the kinetic energy.

All really interesting but very hard to make practical on a bucket bike
i thought the KERS uses the stored flywheel inertia to directly propel the actual engine with a one way clutch.

the Telma electric eddy current (Used on Dumpers etc)is another more direct option which use a eddy currents generator to dispate speed they as far as i know dissipate the energy to heat directly rather than friction, but that could be another form of co-generation.(that is turning breaking force directly in electricity rather than heat)
but as you say impractical solution at the moment.

Actually it could make a nice dyno.

seen this one which is intersting
hydraulic accumulator capable of holding hydraulic fluid at pressures of about 3000-5000 PSI (these are baked).

You can use this pressure to assist the spool-up of a slightly modified turbocharger incorporating a small turbine on the coupling shaft. Some jet engines use a hydraulic starter in a similar fashion.

This idea seems like it would work well, for a few times at least. What happens when the pressure is gone? There in lies the beauty of the system. The car's movement over bumpy terrain would cause the shocks to generate the pressure needed. Using a series of check valves the flow of hydraulic fluid leaving the turbo would enter the shock absorber and then be pumped under pressure back into the accumulator (http://www.halfbakery.com/idea/Hydraulic_20Boosted_20Turbo#1083171600).

[ducatilover]

Mass air storage would be an easier solution........................
A hose from my mouth to the carb would work a treat then

[speedpro]

A hose from my mouth to the carb would work a treat then

You'd need an intercooler

[ducatilover]

You'd need an intercooler
And a 38mm wastegate

[husaberg]

A hose from my mouth to the carb would work a treat then

Nitros............................................ ...
http://www.nitrous.info/images/motorc1.jpg
http://www.nitrous.info/motorcycle-nitrous-injection-system.htm

[ducatilover]

No thinks, I'm familiar with nitro and can't be fucked unless it's premixed in my tank :rolleyes: boost and boost everywhere is where it's at

[jasonu]

And a 38mm wastegate

and a filter to catch the dribble...

[ducatilover]

and a filter to catch the dribble...
More like a bath tub.

Anyway, get back on topic, moar awesome engineering please!

[Sketchy_Racer]

Well as promised here is an easy explanation of the gear box layout.


http://www.youtube.com/watch?v=Hnrr4cOjUbc&feature=youtu.be

The input shaft will spin at engine speed (or what ever ratio up to a 1:2 ratio in order to achieve desired boost levels)

Then that shaft transfers through a set of a gears which are there only to reverse drive direction

Then the second shaft drives the outer ring gear (which has no teeth, it is a traction drive gearbox so relys on friction to transfer drive) It is not a fixed drive it has 4 engaging dogs that keep it floating.

The Outer ring the transfers drive to the Planet gear which is 28mm dia which is a 4.44:1 ratio to the outer ring (for each rotation of the outer ring the planet gear spins 4.44 times)

Finally, the center shaft or Sun gear is captured by an arrangement of 6 of the 28mm Planet gears which has a ratio of 2.49:1

This means that the final ratio comes in at 11.06:1 which is great for achieveing 100,000-200,000 RPM for the turbine whilst keeping all the bearing within their designed operating range.


Again when it comes to manufacture, this system is actually far easier to make than the Roots system (if we ignore the compressor housing and turbine stolen from the turbo) but the heat expansion and inertial expansion of the outer ring will be critical as that is what maintain the friction between all the rollers.

[bogan]

Interesting on many points.

The floating ring gear, I'm guessing the 'floating' tolerances have to be very tight anyway to prevent excessive wear?

And here


Finally, the center shaft or Sun gear is captured by an arrangement of 6 of the 28mm Sun gears which has a ratio of 2.49:1

You mean 6 of the 28mm Planet gears right? and these hole the shaft captive so you only need one bearing on the shaft itself to contain end float, or do they do that too?

[Sketchy_Racer]

Interesting on many points.

The floating ring gear, I'm guessing the 'floating' tolerances have to be very tight anyway to prevent excessive wear?

And here



You mean 6 of the 28mm Planet gears right? and these hole the shaft captive so you only need one bearing on the shaft itself to contain end float, or do they do that too?

The floating tolerance are not to great, It is to make sure there is no mechanical binding as the outer ring expands with heat and velocity.

Wear will be expected, and the unit will more than likely only live 4-5 hours operating before an inspection will be required. But ya never know.

And yes, you are right the 6 Planet gears not Sun gears. End float is via a shoulder on the turbine shaft (which is not shown in the video) The shaft is held fully captive via the Planet gears.

[Sketchy_Racer]

Making progress.

I have finished the base plate, bearing posts and the outer ring. I am not totally happy with the fit of the outer ring but I will test this one out and may make a spare one with greater pre-tension.

I have also spent a lot of time researching traction drive fluids which are what make the whole gearbox work efficiently. They are a synthetic hydrocarbon oil with elastohydrodynamic properties. A bit of a mouth full.

The principle behind these fluids is that under extreme pressure they go though an almost instantaneous phase change to create pseudo pads between the contact points enhancing mechanical drive transfer without a great losses.

I have sourced a couple of supplies but this shit aint cheap! Rotrex charge $100 per litre and HKS $350!! I hoping I will managed to find another supplier that isn't a brand so it wont have that extreme mark up. Mobile DTE heavy oil has these attributes but not to the same extent and I have a heap of that at work so I may give it a try, if it doesn't work it wont cost me anything.

Anyway here are some photos of the parts so far, all this is has been manually turned and milled. This gearbox is so simple I don' t need fancy CNC gear at the moment.

276433276434276435276436276437276438

[Sketchy_Racer]

Oh so close!

It'll be running tomorrow. I have to machine the shafts and finish the gears off and the last piece will be to put the end float collar on the impeller shaft, that'll be the hard part.

Anyway, I pulled the old Roots blower out of the bike to give a side by side comparison. These photos make the new blower look larger than it is, and the mass will be the same as the old one coming in at 1.6kg.

Who wants to take a bet on how much boost it will make? I recon 20psi will be achievable (but for how long....)

276474276475276476

[Ocean1]

Looks good mate. You looking at a similar manifold volume for this one?

[Sketchy_Racer]

Looks good mate. You looking at a similar manifold volume for this one?

Yeah will be using the same plenum as the last one which is just over 1000cc.

[Ocean1]

Yeah will be using the same plenum as the last one which is just over 1000cc.

Look forward to hearing it spool up!

[Kickaha]

I recon 20psi will be achievable (but for how long....)

I think you're aiming low, F1 Turbo era they ran 60lb use that as your benchmark

[NordieBoy]

I think you're aiming low, F1 Turbo era they ran 60lb use that as your benchmark

They were also slightly bigger than 100cc per cylinder too...

[Sketchy_Racer]

I think you're aiming low, F1 Turbo era they ran 60lb use that as your benchmark

Haha, maybe but I don't think the compressor map of this turbo housing will achieve that no matter how fast I spin it! Those sorts of pressures are where the power is at though

[ducatilover]

I think you're aiming low, F1 Turbo era they ran 60lb use that as your benchmark
The BRM V16 ran even more... a long time before.

Where do you live Sketchy? I'm going to steal that blower.

[Yow Ling]

I have sourced a couple of supplies but this shit aint cheap! Rotrex charge $100 per litre and HKS $350!! I hoping I will managed to find another supplier that isn't a brand so it wont have that extreme mark up. Mobile DTE heavy oil has these attributes but not to the same extent and I have a heap of that at work so I may give it a try, if it doesn't work it wont cost me anything.

Anyway here are some photos of the parts so far, all this is has been manually turned and milled. This gearbox is so simple I don' t need fancy CNC gear at the moment.


We use a traction oil in a Graham drive on a machine at work $US128 for a quart plus about US 85 to ship it, pretty cheap when you consider the price of a new Graham drive , but bloody expensive for oil.

[koba]

We use a traction oil in a Graham drive on a machine at work $US128 for a quart plus about US 85 to ship it, pretty cheap when you consider the price of a new Graham drive , but bloody expensive for oil.

What is a Graham drive?
What is a quart?

[Sketchy_Racer]

We use a traction oil in a Graham drive on a machine at work $US128 for a quart plus about US 85 to ship it, pretty cheap when you consider the price of a new Graham drive , but bloody expensive for oil.

Got any spare? :bleh:

Upon further research CVT oil offers similar properties, not as great as proper traction oil, but good enough for me to give a try. It appears that ALL forms of this traction fliud is extreemly expensive which is pain because I only need about 100ml, hopefully the CVT oil will work.

On another note, all the machining is finished for the charger so it's time to put together, but that will be tomorrows mission.

[Yow Ling]

What is a Graham drive?
What is a quart?

http://cvt-ivt.tripod.com/id1.html

quart is quarter of a us gallon about a litre

[Yow Ling]

Got any spare? :bleh:

Upon further research CVT oil offers similar properties, not as great as proper traction oil, but good enough for me to give a try. It appears that ALL forms of this traction fliud is extreemly expensive which is pain because I only need about 100ml, hopefully the CVT oil will work.

On another note, all the machining is finished for the charger so it's time to put together, but that will be tomorrows mission.

Try the cvt oil first, it lubricates a metal belt on a metal pulley so kinda the same and only $200 for enough to fill a car transmission, if you have no luck pm me

[husaberg]

I think you're aiming low, F1 Turbo era they ran 60lb use that as your benchmark


They were also slightly bigger than 100cc per cylinder too...

I know Warwick was joking but anyway the F1 fuel was 84% toluene.
I know Honda ran up to 43psi high a rather high Comp ratio too
the "M power BWM" life span for a qualifying engine was 7 minutes.
re the oil holey shit, i wonder how long it lasts LOL

[Kickaha]

the "M power BWM" life span for a qualifying engine was 7 minutes.
Around 100hp per 100cc out of some of Turbo era cars so what would you expect, maybe if Glen only aimed for 50hp per 100cc he could get 14 minutes

[Grumph]

Around 100hp per 100cc out of some of Turbo era cars so what would you expect, maybe if Glen only aimed for 50hp per 100cc he could get 14 minutes

So what lifespan were you aiming for at the last BoB ?.....15min at about 15hp ?

Jeez W you left yourself open for that one....

[Kickaha]

So what lifespan were you aiming for at the last BoB ?.....15min at about 15hp ?

Jeez W you left yourself open for that one....

Plus the practices and races before it, i reckon I got at least 20-25 minutes, thats longer than some have lasted

[Sketchy_Racer]

Its together,

It all went together perfect, my solidworks skills are improving as all the parts were made from a drawing to a specified tolerance to allow the assembly to work and it all dose!

So far on the end of the battery drill at 2000 RPM it has managed to make 1PSI :) But it will have to wait until tomorrow to test it out on the bike. Im still not convinced that the CVT will be suitable so I will still look at getting some traction oil. I am also going to buy a optical tachometer to measure the turbo RPM to engine RPM so I know the slip and try different oils.

On the end of the drill, you can't hear the turbine at all, just a whur of the gears. It'll be interesting to see if It will make a racket once it is spooled up

It is mounted in the bike and tomorrow once I finish putting the exhaust and stuff back on I will fire it up and see what it does. It's geared at a 1:1 ratio to start with so at 10,000 engine RPM the turbine should be doing 110,000 rpm if there is no slip. The maximum RPM is 250,000 for this turbo but I will limit my one to 200,000 rpm, more because the gears will far exceed the design.

276626276627

[Sketchy_Racer]

Try the cvt oil first, it lubricates a metal belt on a metal pulley so kinda the same and only $200 for enough to fill a car transmission, if you have no luck pm me

Sweet, cheers mate.

I will try scrounge some Rotrex oil before I harrass you though as I only need 50ml of it which is probably the left over from a top up for a rotrex owner.

[Sketchy_Racer]

Well, it was on the bike and running, and it was totally silent! Couldn't hear it at all over the sound of the engine.

Running at 1:1 gave me the planned boost of 5psi at 8000 engine RPM, now that I know everything is working well and nothing bad happend I have made new belt pulleys to ramp the RPM up. The boost curve is exponential to RPM increase so at 200,000 RPM it should have a pressure ratio of 2.5 which give me about 22psi boost at 75% adiabatic efficiency (according the compressor map I found on the net)

Anyway here's to hoping.

One thing I do think I am going to have to do is run an oil pumo system. 15 minutes of running saw the gearbox temp rise to 60 degrees and climbing which isn't really that great, and would suggest that I am getting quite a bit of slip on the rollers however upon pull down after 30 mins of running there is virtually no marking on the bearings so who knows. I Am going to need to get some traction fluid I believe. Either way so far everything is working well and if it does perform as hoped then a full re-desgin will happen and I will try get rid of all the bugs in this "mock up" version.

Tomorrow I will get the new pulleys mounted up and see what we can manage, I have the option to one step further to get a 2.5:1 pulley ratio which would put me into 250,000 RPM at the turbine, this shit excites me!

Cheers,

-Sketchy276722276721276720

[Paul in NZ]

Phark - I feel less worthy and more ham fisted every time I read one of these threads....

Awesome stuff....

[NordieBoy]

Phark - I feel less worthy and more ham fisted every time I read one of these threads....

Awesome stuff....

I replaced a broken spoke and felt proud :woohoo:

[jasonu]

I'm sure this is all against the 'spirit of the rules'<_<
Maybe I will ask the MNZ to make an emergency rule clarification...:laugh:

[Sketchy_Racer]

I'm sure this is all against the 'spirit of the rules'<_<
Maybe I will ask the MNZ to make an emergency rule clarification...:laugh:

As long as in the same rule change 80cc MX engines are introduced :laugh:

[Sketchy_Racer]

No cigar!

Just tested it at 2:1 over drive which should have given me a 200,000 RPM shaft speed at 10,000 engine RPM and 22 ish psi boost gave me nothing more than 5psi so it's obvious that the magic behind these types of traction drives is in the magic fluid. Luckily I am lucky enough to be getting some to test from Yowling so hopefully it will cure the problem. I also believe that the pretension of the annulus (the outer ring) on the planet rollers is not enough, so if the traction fluid doesn't solve the problem then I will also increase the fit of that.

Oh well, all pretty basic problems to solve

[speedpro]

No cigar!

Oh well, all pretty basic problems to solve

So basic I've decided to make one in my lunch break. Geeez!

[Grumph]

No cigar!

Just tested it at 2:1 over drive which should have given me a 200,000 RPM shaft speed at 10,000 engine RPM and 22 ish psi boost gave me nothing more than 5psi so it's obvious that the magic behind these types of traction drives is in the magic fluid. Luckily I am lucky enough to be getting some to test from Yowling so hopefully it will cure the problem. I also believe that the pretension of the annulus (the outer ring) on the planet rollers is not enough, so if the traction fluid doesn't solve the problem then I will also increase the fit of that.

Oh well, all pretty basic problems to solve

Make the bastard solid drive with a starter clutch in there to take care of the over run loads....

WE WANT MORE BOOST.

[Yow Ling]

Hurry up Sketchy, you must have been home for at least 20min !

[Sketchy_Racer]

No time to work on it tonight, so it will have to wait until after work tomorrow. I hope it works, but history tells me not to get excited just yet.

[Sketchy_Racer]

Well, I wasn't going to post my failures, because it is rather embarrassing, but the supercharger still doesn't work.

I got the oil from Yowling and put it in with no modification of the charger and got LESS boost, was only getting 2psi and it was making 5 with CVT oil. I though to myself, surely I am not applying enough pressure to activate the phase change of the traction fluid to for the elasto-solid to transfer torque, so I made another outer ring (3rd time) with even more pre-tension and had to heat it to 150 degrees to get it on. I put it all together and ran the bike up, and managed 5psi which was a little more promising but after 2 minutes the oil inside boiled and blew all the sealer out and literally dropped it's guts. Luckily no damage to any of the supercharger parts.

So I left it for a day as I was pissed right off with it, but today I spent my lunch break researching traction fluids. I can't make out what brand exactly traction fluid I have (Yowling put MSI alpha traction fluid) but that returned no information on google. So I looked up all the alternatives and found that the major supplier of traction fluid is from Santolube from USA and their Santotrac 50 (http://www.santolubes.com/resources/tds-msds/TDS-SANTOTRAC-50.pdf) is the most common traction fluid that is usually re-branded. It was thoroughly tested by NASA when they were designing the mars rover gearbox along with many other traction fluids and surprisingly there is a LOT of information on the web about it. It turns out that the traction fluids are very sensitive to the loading they are put through achieve the dynamic phase change. Not enough pressure and it wont work, but also to much pressure and it will fail equally.

If you imagine that the fluid contains these long thin polymers that in most situations lubricate by preventing metal to metal contact (as most oils do) in a traction fluid when the right amount of pressure is exerted the polymers will align and grip each other and create traction (note: not friction) between the two surfaces, but if the pressure is to great the polymers are squeezed out and can't achieve this condtion.

So, in terms of pressure, all the fluids are the same sort of level within 5% and are asking for around 907Mpa (mega pascals) this equates to 92.5 Kgf/mm2 which when worked out to the contact patch of my outer ring on the rollers equals 4.628 Kg which is really not that much! Well, certainly a lot lot less than what I currently have.

I am going to the best of my ability try to achieve this loading upon my rollers. Upon dissasembly I have also learnt of machining tolerance failures so that the rollers were not contacting the shaft correctly so it seems that it may have been a combined effect of this failure.

So once again, no good news but I have learnt even more which is always fun, and still have enough oil for 2 more attempts so I hope I can manage it! I have emailed Santolube to try and source some oil also.

I will post in tomorrow to let you know how it all goes.

[bogan]

Knowing very little about traction fluids, but 4.7kg force sounds like bugger all, I assume the force goes up if you have a bigger contact patch? Is the problem perhaps your contact patch is too small? Mind you, stands to reason if you were getting 5psi with far too large of a force, the correct force might bump it up enough. Be intersting to see how it goes with the better force anyway. Good perseverance btw!

[Farmaken]

And here I am getting excited about grinding some more holes in my cylinder liner :facepalm:

This is very clever stuff indeed :Punk:

[TZ350]

Sketch, thats a realy interesting post ......

[husaberg]

silly question, but has you tested the supercharger by it self to see what it produces.

http://www.coordsport.com/blog/wp-content/uploads/2010/12/page2-300x170.jpgmissed the HKS one myself


i can't remember where i seen the schematic,(not the one above) but i swear one i seen had 2 oil coolers pre and post the oil pump?

this is some impressive shit you do Glenn

[Yow Ling]

Google ALPHA traction oil

http://www.chemcas.com/msds112/cas/2356/68049-42-3_128-37-0.asp
above is the MSDS

We use it in a Graham drive which is a common usage for it

Im sticking with the FXR route for now

[Sketchy_Racer]

Sketch, thats a realy interesting post ......

Thanks Rob,

Probably out of reach but will still be of interest to you is a traction drive CVT


http://www.youtube.com/watch?v=hgl7IBmUj8o

If you google Nuvinci they make a CVT for a bicycle which is really neat, not sure how they control the gear ratios but it is a nice little unit.

There is a lot of different designs of traction drive CVT but the one in the video has to be one of the best out there.

[Sketchy_Racer]

Google ALPHA traction oil

http://www.chemcas.com/msds112/cas/2356/68049-42-3_128-37-0.asp
above is the MSDS

We use it in a Graham drive which is a common usage for it

Im sticking with the FXR route for now

Thanks for that.

If I knew it was all going to be this much work I probably would have never given it a shot, but I am to far in to give up now, gotta keep trucking!

[Sketchy_Racer]

Knowing very little about traction fluids, but 4.7kg force sounds like bugger all, I assume the force goes up if you have a bigger contact patch? Is the problem perhaps your contact patch is too small? Mind you, stands to reason if you were getting 5psi with far too large of a force, the correct force might bump it up enough. Be intersting to see how it goes with the better force anyway. Good perseverance btw!

Yes you are right, the force goes up with area, in my case my area is 0.05mm/2 and the oil is asking for a pressure of 92.5Kgf/mm2 and the area of my contact patch is 5% of 1.0mm2 so I need 5% of 92.5Kgf/mm2 which results to:

92.5 * 0.05 = 4.625

which is the force required on my contact area. I think, Im open to correction that I understand the force application correctly.

[Moooools]

Yes you are right, the force goes up with area, in my case my area is 0.05mm/2 and the oil is asking for a pressure of 92.5Kgf/mm2 and the area of my contact patch is 5% of 1.0mm2 so I need 5% of 92.5Kgf/mm2 which results to:

92.5 * 0.05 = 4.625

which is the force required on my contact area. I think, Im open to correction that I understand the force application correctly.

That does all look right. My question is how you obtained the 0.05mm^2 given you have two tangential surfaces. Is it just an approximation or are you taking the area where the two surfaces are within a certain distance of each other. i.e. doe the traction fluid take effect when 2 surfaces are 'x' close to each other?

[Sketchy_Racer]

That does all look right. My question is how you obtained the 0.05mm^2 given you have two tangential surfaces. Is it just an approximation or are you taking the area where the two surfaces are within a certain distance of each other. i.e. doe the traction fluid take effect when 2 surfaces are 'x' close to each other?

Thanks for the confirmation,

The contact patch is a semi calculated approximation drawn from the elastic modulus of the steel outer ring (annulus) and how much interference I will require to achieve the 92.5kgf/mm2 and at the given interference of 0.023mm on diameter (according to solidworks) I will see a interference area of 0.05mm2 which I have taken as a estimation of the contact patch on the rollers.

So really, it is just a guess but it is a figure to work with that I can measure from depending on the success or failure of the next attempt.

[jasonu]

Well, I wasn't going to post my failures, because it is rather embarrassing, but the supercharger still doesn't work.

I got the oil from Yowling and put it in with no modification of the charger and got LESS boost, was only getting 2psi and it was making 5 with CVT oil. I though to myself, surely I am not applying enough pressure to activate the phase change of the traction fluid to for the elasto-solid to transfer torque, so I made another outer ring (3rd time) with even more pre-tension and had to heat it to 150 degrees to get it on. I put it all together and ran the bike up, and managed 5psi which was a little more promising but after 2 minutes the oil inside boiled and blew all the sealer out and literally dropped it's guts. Luckily no damage to any of the supercharger parts.

So I left it for a day as I was pissed right off with it, but today I spent my lunch break researching traction fluids. I can't make out what brand exactly traction fluid I have (Yowling put MSI alpha traction fluid) but that returned no information on google. So I looked up all the alternatives and found that the major supplier of traction fluid is from Santolube from USA and their Santotrac 50 (http://www.santolubes.com/resources/tds-msds/TDS-SANTOTRAC-50.pdf) is the most common traction fluid that is usually re-branded. It was thoroughly tested by NASA when they were designing the mars rover gearbox along with many other traction fluids and surprisingly there is a LOT of information on the web about it. It turns out that the traction fluids are very sensitive to the loading they are put through achieve the dynamic phase change. Not enough pressure and it wont work, but also to much pressure and it will fail equally.

If you imagine that the fluid contains these long thin polymers that in most situations lubricate by preventing metal to metal contact (as most oils do) in a traction fluid when the right amount of pressure is exerted the polymers will align and grip each other and create traction (note: not friction) between the two surfaces, but if the pressure is to great the polymers are squeezed out and can't achieve this condtion.

So, in terms of pressure, all the fluids are the same sort of level within 5% and are asking for around 907Mpa (mega pascals) this equates to 92.5 Kgf/mm2 which when worked out to the contact patch of my outer ring on the rollers equals 4.628 Kg which is really not that much! Well, certainly a lot lot less than what I currently have.

I am going to the best of my ability try to achieve this loading upon my rollers. Upon dissasembly I have also learnt of machining tolerance failures so that the rollers were not contacting the shaft correctly so it seems that it may have been a combined effect of this failure.

So once again, no good news but I have learnt even more which is always fun, and still have enough oil for 2 more attempts so I hope I can manage it! I have emailed Santolube to try and source some oil also.

I will post in tomorrow to let you know how it all goes.

Sounds like some typical Bucket issues...

[Drew]

I bloody hate it when these threads get too clever for me!

All I'm reading now is that you won't ne able to help me with my bucket when I get round to finishing it.

[Sketchy_Racer]

I bloody hate it when these threads get too clever for me!

All I'm reading now is that you won't ne able to help me with my bucket when I get round to finishing it.

Haha, ignore the tech talk, basically the spinning thing doesn't spin because I'm a muppet and didn't build it right, today i'm going to try fix that

What are you doing with your bucket? it should be finished already, stop pissing around with that gay side car thing and get onto the real race bike.

[Drew]

Haha, ignore the tech talk, basically the spinning thing doesn't spin because I'm a muppet and didn't build it right, today i'm going to try fix that

What are you doing with your bucket? it should be finished already, stop pissing around with that gay side car thing and get onto the real race bike.

Oh right, that's my kinda language.

Bucket is on the back burner till we have our own garage. Sidecar is more fun to ride than a bucket...trust me on this. Come to the have a go day and have a ride on ours, you Will giggle so much you'll shit!

[Bert]

Haha, ignore the tech talk, basically the spinning thing doesn't spin because I'm a muppet and didn't build it right, today i'm going to try fix that

What are you doing with your bucket? it should be finished already, stop pissing around with that gay side car thing and get onto the real race bike.

Right I get it now.:innocent:
Good luck with today's attempts; great work by the way. (knock sensor is on its way)....


Oh right, that's my kinda language.

Bucket is on the back burner till we have our own garage. Sidecar is more fun to ride than a bucket...trust me on this. Come to the have a go day and have a ride on ours, you Will giggle so much you'll shit!

Great days; we might have dig out stinky and come play too.

[Drew]

Great days; we might have dig out stinky and come play too.
Is stinky a proper Sidecar or a bucket?

[crazy man]

Is stinky a proper Sidecar or a bucket?stinky is a play sidecar like yours a bucket one is a real one

[Sketchy_Racer]

Still nothing, It just doesn't want to work. I installed a oil pump to make sure that the oil supply was correct, it worked very well. I also measured that all rollers were getting even contact which they seemed to be (as best as I could test them) The outer ring seemed to have a reasonable amount of pre-tension on it, But here's the intersting part,

It makes 1 psi of boost at idle which sounds like it should make heaps once RPM comes up, but as soon and I mean as soon as the rpm rises the pressure drops and so does the flow to a point where it is really noticeable. So the only thing that can be happening is that the outer ring is expanding and creating slip.

Still got a couple more ideas, otherwise I am going to go down a different style but more on that later.

[Moooools]

Still nothing, It just doesn't want to work. I installed a oil pump to make sure that the oil supply was correct, it worked very well. I also measured that all rollers were getting even contact which they seemed to be (as best as I could test them) The outer ring seemed to have a reasonable amount of pre-tension on it, But here's the intersting part,

It makes 1 psi of boost at idle which sounds like it should make heaps once RPM comes up, but as soon and I mean as soon as the rpm rises the pressure drops and so does the flow to a point where it is really noticeable. So the only thing that can be happening is that the outer ring is expanding and creating slip.

Still got a couple more ideas, otherwise I am going to go down a different style but more on that later.

Huh. That confuses me. Originally I was going to suggest that the planetary gears were not getting even contact because they are in single shear. But the sun gear supports them so they shouldn't really get on the piss. I suppose they could be bending tangentially to the outer ring but you would see pretty clear wear marks. And you have checked for this so probably not that.

The ring heating up and expanding? What sort of temperature is it getting up to?

The bearings in the planetary gears outside their designed maximum velocities?

Only other thought is that your calculation for pressure is out for the sun gear. The planetaries are in single shear so probably have shiteloads of compliance compared to the strain on the outer ring. So they are probably deflecting inwards so that reaction force is present between the sun and planetaries that is close to equal to the force from the ring gear. The contact patch of your sun gear is going to be significantly less than your ring gear with pretty much the same force on it. Thus a much higher pressure and may not be in the correct range for the oil.

Other than that I have no clue what could be upsetting it. Sounds complex.

[Flettner]

Good on you, haven't heard one of those in ??? I don't know maybe thirty years or so.
I found that using a single was a problem, you need a large plenum ( intercooler ) but that give delayed throttle response. So I made a throttle valve at the cylinder head and a blow off valve in the plenum chamber, super charger was blowing all the time. Plenum chamber had an air to methanol inter cooler inside it, external radiator, I'm not sure how well it worked. My injection was a mechanical / electrical cross ( just like a dog too ).
Decided if I ever built another one, I would build a fourstroke tamdem twin, even induction pulses and some balance , and lots of revs!!!
That is soo ooo cool, thanks for sharing it.

Neil Hintz

[speedpro]

Come on Neil. You know you want to build another one, or two.

[Flettner]

E90 fuel allowed?

[husaberg]

E90 fuel allowed?

nope..........


http://www.gull.co.nz/fuel-products/
http://www.gull.co.nz/assets/Uploads/Gull-Force-10.pdf
its not an additive, because that is how it is sold from the pump.
i agree with the relevance in regards to F4 and F5 but the fuel regs missed them. big surprise which is also ironic.
http://www.mnz.co.nz/regulations/rules/general-rules
F4 and F5 must conform to 10.17.1 which is the AVgas or FIM unleaded.
As Ethanol is not listed ad being a component of the FIM unleaded Fuel even though the rest of the ingredients are fine.

So Greg you Are right the FIM fuel Fuel that covers F4 and F5 plus the other classes not listed under 10-17.2 and 10.17.3 .................

[Ocean1]

Still nothing, It just doesn't want to work. I installed a oil pump to make sure that the oil supply was correct, it worked very well. I also measured that all rollers were getting even contact which they seemed to be (as best as I could test them) The outer ring seemed to have a reasonable amount of pre-tension on it, But here's the intersting part,

It makes 1 psi of boost at idle which sounds like it should make heaps once RPM comes up, but as soon and I mean as soon as the rpm rises the pressure drops and so does the flow to a point where it is really noticeable. So the only thing that can be happening is that the outer ring is expanding and creating slip.

Still got a couple more ideas, otherwise I am going to go down a different style but more on that later.

You'd be getting those symptoms if the drive was slipping badly, but you'd also be getting them if it was simply under-geared. Any way you can get a digital tacho onto the impeller.

[Flettner]

Glad to see " the munter " is still alive and well in NZ motor cycling::laugh:
Change the rules to allow E85 ( that will do ) and I'm in!!

[Flettner]

Or perhaps I'll just haul out the Uniflow and remake that?? ( speaking of munters ).

[Yow Ling]

Or perhaps I'll just haul out the Uniflow and remake that?? ( speaking of munters ).

Seeing as that is one of the pinnacles of NZ bucket racing development , could you post a bit about it, even a few black and white pics would be cool
thanks

[koba]

Or perhaps I'll just haul out the Uniflow and remake that?? ( speaking of munters ).

I'm with Yow, I've heard about that and want to know more!

[speedpro]

It's really boring and not that clever. I remember being reasonably bored with the whole uniflow thing.

[Kornholio]

It's really boring and not that clever. I remember being reasonably bored with the whole uniflow thing.

One man's boredom is another man's jizzfest....

[Sketchy_Racer]

Show me Uniflow! What is it and how does it work?

I'll hopefully have some more news from tomorrows tests to see if the supercharger works. If it doesn't i'm going to design version 2!

[Yow Ling]

Show me Uniflow! What is it and how does it work?

I'll hopefully have some more news from tomorrows tests to see if the supercharger works. If it doesn't i'm going to design version 2!

its kinda like this but smaller
http://www.oldengine.org/members/diesel/Rootes-ListerTS3/TS3.htm

[speedpro]

I remember brushcutter conrods were bigger sellers than usual one year. I presume that 100cc uniflow is still lying on the shelf covered in dust and dirt. Do you still have the 500cc one as well? I know you are too modest to do it but a new thread with a few pics of the stuff you've built including the microlight and autogyro stuff would be plenty interesting to lots on here. Many are interested in the engineering side of things.

[Flettner]

I need to read through the forum and see what happened to the roots style supercharger? Why sketchy are you using a centrifugal super charger now, what have I missed?
Well the uniflow is boring now, sitting under the bench, in bits. Best place for it.
For those that are interested I'll see if I can find some pictures of it. Pre digital, pictures cost money so there wasn't many. Here is a video of the next version in a jet boat, still uniflow scavanged Unfortunately you have to wait until the end to see the engine go best. http://www.youtube.com/watch?v=uiXsPkP9jvw&feature=share&list=UUoYhqhrdK9On_IfKGD31hGA
http://www.youtube.com/watch?v=uiXsPkP9jvw&feature=share&list=UUoYhqhrdK9On_IfKGD31hGA

[Flettner]

Yes I'm going to have to get a bigger bench, to store all the shit projects under :laugh:
I haven't given up on the concept, I've got a 650cc version now ( still being built ). This time nikasil bores EFI with a programable ignition. I had a lot of trouble with the cylinder castings, but now no problem casting twostroke cylinders. http://http://i1056.photobucket.com/albums/t380/uniflow/IMG_0515.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_0516.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_0514.jpghttp://http://i1056.photobucket.com/albums/t380/uniflow/IMG_0510.jpghttp://http://i1056.photobucket.com/albums/t380/uniflow/IMG_0505.jpg
Is this the right way to post these pictures?

[Flettner]

It would seem not. http://i1056.photobucket.com/albums/t380/uniflow/IMG_0505.jpg
Here we go, one half of the 650 uniflow block

[Flettner]

http://i1056.photobucket.com/albums/t380/uniflow/IMG_0504.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_0515.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_0514.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_0516.jpg

[Flettner]

That last pattern is for a 360cc cylinder, used on the microlite engine but now also being used on my new project. 360cc two stroke engine in a YZ250F frame, EFI, reverse cylinder, vairable rotary valve induction running on E85. Sorry yes I'll post else where, I don't want to rail road the thread.

[Sketchy_Racer]

Cool images and concept. I have seen these around before, just hadn't taken much notice.

The roots blower works, it is sitting on my bench awaiting a couple of new parts to try make it more efficient, and the centrifugal one is more of a engineering challenge than for the bike to be honest, but I do hope once I get it working I will be able to get some really good efficiency out of it.

One thing I can say is that making boost, and high levels of it with small light weight units is not easy!

[Grumph]

Cool images and concept. I have seen these around before, just hadn't taken much notice.

The roots blower works, it is sitting on my bench awaiting a couple of new parts to try make it more efficient, and the centrifugal one is more of a engineering challenge than for the bike to be honest, but I do hope once I get it working I will be able to get some really good efficiency out of it.

One thing I can say is that making boost, and high levels of it with small light weight units is not easy!

It's not that bloody easy with big, heavy units either....and when you do finally achieve enough boost to be useful, then you will find the weak points of the base motor....Carry on.

And I repeat...solid drive the bastard with a starter clutch in the drive to let it overrun....

[speights_bud]

And I repeat...solid drive the bastard with a starter clutch in the drive to let it overrun....

Also known as a 'Sprag' Bearing or 'Sprag' clutch

http://www.youtube.com/watch?v=QjR7dimpSJA

[Flettner]

Sketchy, would you be talking about teflon tip seals? I used those in mine and they certainly helped. You fit them to interfere with the housing and lobes ( just a little bit ) and they machine / smudge them selves in. My super charger had helical gears so they could be shimmed against each other to move one rotor against the other for clearance adjustment. Roots chargers are good for that bark off the mark, out of corners etc. 14 psi is where you want to be. Hey I'm not trying to tell you how to suck eggs.

[Sketchy_Racer]

It's not that bloody easy with big, heavy units either....and when you do finally achieve enough boost to be useful, then you will find the weak points of the base motor....Carry on.

And I repeat...solid drive the bastard with a starter clutch in the drive to let it overrun....

Yeah, that is what i'll do if I cant get any success from this one soon. But even that will have it challenges it's hard to find bearings that will be happy at 200,000 RPM

A toothed belt drive is another option, Powerdyne use them on their superchargers, admitedly not very reliable but for me if a $10 belt lasts a day of racing that'll be good enough. Again an overrun clutch will be compulsory

[Sketchy_Racer]

Sketchy, would you be talking about teflon tip seals? I used those in mine and they certainly helped. You fit them to interfere with the housing and lobes ( just a little bit ) and they machine / smudge them selves in. My super charger had helical gears so they could be shimmed against each other to move one rotor against the other for clearance adjustment. Roots chargers are good for that bark off the mark, out of corners etc. 14 psi is where you want to be.

Yep, I need to make new rotors that will accept tip seals and also want to try putting a guide in the outlet port of the charger.

The gears on mine are taper locked and I have a jig that holds everything in place while I tighten things up, but It lets me set the clearance where I like.

[Flettner]

Sketchy, what fuel pump are you using? How big is it, what flow, what amps draw, can it handle E85?
I'm using a Bosch car unit on a Kawasaki I have but it's sucking up 4.5 amps all the time. Charging system can't keep up under four to five thousand revs. I'm getting the stator rewound for better charge at lower rev's but it would be nice to find another pump that's smaller and lighter.

[husaberg]

Yeah, that is what i'll do if I cant get any success from this one soon. But even that will have it challenges it's hard to find bearings that will be happy at 200,000 RPM


Plain.................

[Brian d marge]

http://i1056.photobucket.com/albums/t380/uniflow/IMG_0514.jpg

Hi there
Who did your casting ?

and ps , can someone give a short update of whats happening !!! the bike now has a turbo?

Stephen

[Sketchy_Racer]

Plain.................

Yeah, but then I need a high pressure oil feel, It could be done I suppose. I'll look into that some more later though, I think I am on the verge of getting this to work.

[Sketchy_Racer]

Sketchy, what fuel pump are you using? How big is it, what flow, what amps draw, can it handle E85?
I'm using a Bosch car unit on a Kawasaki I have but it's sucking up 4.5 amps all the time. Charging system can't keep up under four to five thousand revs. I'm getting the stator rewound for better charge at lower rev's but it would be nice to find another pump that's smaller and lighter.

I'm running the fuel pump that came with the EFI kit at the moment, it draws 2 Amps, runs 3Bar and 25L/H. I'm running total loss and plan on using a Lithium battery once I get everything working so I can have a reasonable amount of power to run the bike without the weight.

I will be binning the fuel pump for an in the tank one so I can get rid of all the hoses running around the place.

[husaberg]

Yeah, but then I need a high pressure oil feel, It could be done I suppose. I'll look into that some more later though, I think I am on the verge of getting this to work.

Adapting a hp oil pump or feed is something you could whip up over smoko Glenn You know it true.(not for me though) i actually have a have 2x volume Takikawa one here for a CRF50 any good to you? should be easy to mount but there will be easier ways the stuff for the LCR150 slat flat bike modded the oil feed and pump for a xl125 quite simply from memory. you could mount in direct of the stator if you wanted too not rework the whole oiling system.Actually there is a few turbos with self contained oiling isn't there? can't remember what they are though?

[Sketchy_Racer]

So,

As mentioned earlier the supercharger was working at low RPM making boost pressure at idle. However when the RPM rose, the boost and flow dropped off significantly.

I removed the traction fluid and tried some other oils. I had a Elastohydrodynamic oil from Omega oils to test and also re tried the nissan CVT and honda CVT oil. As soon as the other oils went into the charger, it completely lost all flow and pressure, showing how important the traction fluid is!

So I pulled to down to inspect the charger for signs of slip, and I found them. It has marked the outer ring considerably. This means that under the RPM rise the contact pressure is no longer enough to keep the traction fluid working. I have 3 more outer rings to try all with slightly different interference's to see which is best, but I do believe that i'll finally get it working soon!

I gave myself a chronic headache in the shed from exhaust fumes so have to have a nana nap for a hour or so :sick:

[Sketchy_Racer]

Hi there
Who did your casting ?

and ps , can someone give a short update of whats happening !!! the bike now has a turbo?

Stephen

Hey Stephen,

The bike now has a centrifugal supercharger, a belt driven turbo if you want to call it that.

The roots blower is currently getting some new parts to make it work better but I'm hoping I can get the centrifugal blower working as it will be more efficient.

[Flettner]

So there will be a pump up for sale soon?
I'll give you an address to send it to.

[Grumph]

Couple of things arising...

Don't use a toothed belt - we've discussed this before. Use a polyvee about 20mm wide with plenty of wrap around the pulleys. Cheaper and more reliable too.

Stephen as a Royal Oilfield owner and believer will tell you all about the floating bush plain bearing - may even be able to tell you how much oil it needs. Mr Turbo and ohers blew roller bearing motors successfully with low pressure and not a lot of oil volume coming through....

It appears to me as though all the traction drive is good for is headaches of one kind or another.....

[Sketchy_Racer]

Couple of things arising...

Don't use a toothed belt - we've discussed this before. Use a polyvee about 20mm wide with plenty of wrap around the pulleys. Cheaper and more reliable too.

Stephen as a Royal Oilfield owner and believer will tell you all about the floating bush plain bearing - may even be able to tell you how much oil it needs. Mr Turbo and ohers blew roller bearing motors successfully with low pressure and not a lot of oil volume coming through....

It appears to me as though all the traction drive is good for is headaches of one kind or another.....

Yeah, I can accept the criticism towards the traction drive, but it's cool and intrigues me which is why I will continue for now with it.

I assembled the blower for it's last attempt tonight, but the bloody engine wont run, seems to have shit a pickup coil or the ECU, not sure but it is not sparking and the pickup sensor is not triggering the ECU.

For the last outer ring I got some assistance from one of the mechanical engineers at work to give me a hand with the calcs and worked out how much interference I needed for the correct loading. This worked out to be 0.12mm interference over a 62mm ring to achieve the 92.5kgf^mm2

So I made the ring and then also took the advice from Dave Griffifs to achieve and accurate round surface with an excellent surface finish which was to make a cast iron lap and used diamond paste to lap the surface. It worked out well and I got a very straight and flat surface.

To assemble it I used a 300 degree temperature difference and it slotted together easily. Once cooled it still rotated smoothly which is key!

So once i get the damn engine to run I think it'll be good to go.

[Brian d marge]

Couple of things arising...

Don't use a toothed belt - we've discussed this before. Use a polyvee about 20mm wide with plenty of wrap around the pulleys. Cheaper and more reliable too.

Stephen as a Royal Oilfield owner and believer will tell you all about the floating bush plain bearing - may even be able to tell you how much oil it needs. Mr Turbo and ohers blew roller bearing motors successfully with low pressure and not a lot of oil volume coming through....

It appears to me as though all the traction drive is good for is headaches of one kind or another.....


Can do if needed , have some old calcs somewhere on the enfield floatind bush ....I still use it in me race bike

Stephen

[F5 Dave]

heck there's 2 weeks till the next meeting, heaps of time. Start work on the cosmetics for a break & get into it the night before,

[koba]

I still use it in me race bike


I'd like to know more about this, have you posted details before? Where?

If not you should crack some storytelling out.

[Brian d marge]

I'd like to know more about this, have you posted details before? Where?

If not you should crack some storytelling out.

I have an enfield fetish as you know , the bullet runs a floating bush, it has better load carrying characteristics in some areas for the size etc

I was involved in the bonnieville attempt may moons back to try and get an Enfield to win its class ( won the AMA plate but not the salt flats ), as part of that we needed to know the engines boundries

So I did. from fins to oil etc ( MEGA respect to those old engineers , bang on the money were they)

I have some docs that may help if anyone cares, the calcs for the bearings are not so hard , ( use the Sommerfield number , old but,,,,,)

Stephen

277894
ps I aint in this photo......( I am young and slim and far too good looking)

[husaberg]

I have an enfield fetish as you know , the bullet runs a floating bush, it has better load carrying characteristics in some areas for the size etc

I was involved in the bonnieville attempt may moons back to try and get an Enfield to win its class ( won the AMA plate but not the salt flats ), as part of that we needed to know the engines boundries

So I did. from fins to oil etc ( MEGA respect to those old engineers , bang on the money were they)

I have some docs that may help if anyone cares, the calcs for the bearings are not so hard , ( use the Sommerfield number , old but,,,,,)

Stephen

277894
ps I aint in this photo......( I am young and slim and far too good looking)

I read somewhere that the floating bush came about because they couldn't get flat alloy cadges for the bearing? (Classic Bike i think with an exert of a interview the designer) something about the riveted cadges not being up to the increased forces on overrun.
i have posted those yummy light MMC rods that run direct on the Crankpin somewhere.

ps bowling shirts LOL

[Flettner]

http://i1056.photobucket.com/albums/t380/uniflow/CCF05022013_00000_zps46367768.jpg

The final solution.

[Flettner]

Husaberg, have you got your stuff yet?

[Flettner]

http://i1056.photobucket.com/albums/t380/uniflow/CCF05022013_00001_zpsf28b6302.jpg

A picture of the 440 Uniflow, boat testing. The chambers have their bleed off from the mid section. These do look like missiles and in fact as we pulled up to the the boat ramp to run the boat we were set upon by three police men, wanting to know what we intended to do with these rockets. It took quite a while to explain that they were connected and would not fire off!! If I had known they were going to be at the boat ramp I would have painted them yellow with red tips, just to make it more interesting.
These days you would probably be locked up !!

[Flettner]

The 100 uniflow engine. Early development.
http://i1056.photobucket.com/albums/t380/uniflow/CCF05022013_00002_zps5cf754dc.jpg

[husaberg]

Husaberg, have you got your stuff yet?

Its in Auckland awaiting customs documentation will have it sorted today and i guess i will then expect another gouge from NZ tax department before delivery new to the importing stuff.
I will probably hit you up tonight for some info if your available.

[Flettner]

No problem.

[Sketchy_Racer]

That's right all 15psi of it, nice efficient cool boost. Intake air temp was 35 degrees in the plenum Ran bike for 20min, no boost loss, if anything it got better. Still no idea on shaft RPM

I knew I would get there eventually

Now the concept is proven it's time to make the real deal! with a proper oil pump and proper rollers.

Might try the larger housing and impeller next, see if I can get more than 20psi. And also try one more gear step up to get more boost at lower RPM. It makes 5psi at 3000RPM and 15psi at 5000RPM and holds 15psi to 8000RPM (didn't take revs past that)

Surge does not seem to be an issue even when flow is chocked off so running larger impellers than turbos is possible it seems as the blower is no reliant on exhaust vs intake pressure ratios.

So happy it works!

[koba]

That's right all 15psi of it, nice efficient cool boost. Intake air temp was 35 degrees in the plenum Ran bike for 20min, no boost loss, if anything it got better. Still no idea on shaft RPM

I knew I would get there eventually

Now the concept is proven it's time to make the real deal! with a proper oil pump and proper rollers.

Might try the larger housing and impeller next, see if I can get more than 20psi. And also try one more gear step up to get more boost at lower RPM. It makes 5psi at 3000RPM and 15psi at 5000RPM and holds 15psi to 8000RPM (didn't take revs past that)

Surge does not seem to be an issue even when flow is chocked off so running larger impellers than turbos is possible it seems as the blower is no reliant on exhaust vs intake pressure ratios.

So happy it works!

Brilliant!

Was this from changing the fit of the rollers?

[Sketchy_Racer]

Brilliant!

Was this from changing the fit of the rollers?

Yep, a complete re-design on the outer ring and it's interference on the rollers. Seems to have worked a treat. I will run it up on the dyno for a few loaded power runs on the weekend then pull the charger apart to check wear. In theory there should be none.

[koba]

Yep, a complete re-design on the outer ring and it's interference on the rollers. Seems to have worked a treat. I will run it up on the dyno for a few loaded power runs on the weekend then pull the charger apart to check wear. In theory there should be none.

Cool, keep us posted; this is really interesting.

[Yow Ling]

well done Sketchy, I would have hidden it in a secret place in the shed by now, maybe even earlier

[Ocean1]

Nice!

Where's the video?

[husaberg]

Yep, a complete re-design on the outer ring and it's interference on the rollers. Seems to have worked a treat. I will run it up on the dyno for a few loaded power runs on the weekend then pull the charger apart to check wear. In theory there should be none.


well done Sketchy, I would have hidden it in a secret place in the shed by now, maybe even earlier

Impressed I wouldn't have got past the talking it up stage:yes:

But does it deserve a better motor to drive it now?

[Sketchy_Racer]

Thanks guys, yeah it has definitely tested the patiences but I knew it wasn't going to be easy or everyone would do it.

I will go into the details of the design on the weekend once I pull it down.

The best part is once the gearbox is sorted a RHB31 compressor housing is $10 USD and a impeller $15 USD so if I can manufacture the gearbox cheap enough I am hoping to be able to sell them for less than $500 as a complete unit that can be bolted onto anything 250cc or less.

In terms of manufacturing, once production processes are added there are not many parts and they are simple in shape, even cast materials could be used.

[ducatilover]

The best part is once the gearbox is sorted a RHB31 compressor housing is $10 USD and a impeller $15 USD so if I can manufacture the gearbox cheap enough I am hoping to be able to sell them for less than $500 as a complete unit that can be bolted onto anything 250cc or less.



I like this very much.
I'd love to have on on the DR motor, just for the penile extension factor

[Sketchy_Racer]

The *chhh chh ch ch ch* of surge when I shut the throttle nearly made me pass out with coolness. May sound even cooler once the blow off valve is connected ;)

[ducatilover]

It's not compressor surge doing it is it? I'm not clued up on these set ups

[Sketchy_Racer]

It's not compressor surge doing it is it? I'm not clued up on these set ups

Yep, it's completely normal if the throttle is shut and there is no blow off valve to relive pressure, so it surges back down the compressor. It's not bad unless it is surging under load. (and is really only an issue for turbos, not superchargers)

[TZ350]

That's right all 15psi of it, nice efficient cool boost. Intake air temp was 35 degrees in the plenum Ran bike for 20min, no boost loss, if anything it got better. Still no idea on shaft RPM

I knew I would get there eventually

Congratulations ...... very impressed

PS I would like to try one, please let us know when you are ready to make one or two.

[ducatilover]

Yep, it's completely normal if the throttle is shut and there is no blow off valve to relive pressure, so it surges back down the compressor. It's not bad unless it is surging under load. (and is really only an issue for turbos, not superchargers)

Thought so, comp surge does sound great (memories of a Mazda BFMR with cruise control, would back off going down hills, pe-tow-tow)

[Sketchy_Racer]

Congratulations ...... very impressed

PS I would like to try one, please let us know when you are ready to make one or two.

Thanks Rob

Once I get the final design done I will get a couple of interested people to test the units for me and tell me what breaks and what can be improved. Of course these test units will be free. So i'll be in touch.

Cheers,

-Sketchy

[Drew]

Make one for my RF900 and a tidy box to go round the carbs so it doesn't push fuel out the overflows, and I'll TEST THE SHIT out of that bitch!

[ducatilover]

Because I'm a nice bloke I'll take the burden of testing one :innocent:

[pete376403]

Yep, it's completely normal if the throttle is shut and there is no blow off valve to relive pressure, so it surges back down the compressor. It's not bad unless it is surging under load. (and is really only an issue for turbos, not superchargers)
Um, why would it be bad on a turbo but not on your setup? from your description, they are both centrifugal, non positive displacement superchargers that vary in the method of drive - exhaust driven turbine vs mechanical drive. Surge, if it's bad enough, will knock the blades of the compressor wheel. You probably don't want that. The preferred way to avoid surge is to match the compressor and turbine to the air flow requirements of the engine.
Also I understand the primary purpose of the blow off valve is to dump pressure from the inlet plenum when the throttle is closed in order to keep the turbo revs up, so when the throttle is opened again there is less lag waiting for it to spin up again.
Still very impressed by your metalworking skills.

[Sketchy_Racer]

Um, why would it be bad on a turbo but not on your setup? from your description, they are both centrifugal, non positive displacement superchargers that vary in the method of drive - exhaust driven turbine vs mechanical drive. Surge, if it's bad enough, will knock the blades of the compressor wheel. You probably don't want that. The preferred way to avoid surge is to match the compressor and turbine to the air flow requirements of the engine.
Also I understand the primary purpose of the blow off valve is to dump pressure from the inlet plenum when the throttle is closed in order to keep the turbo revs up, so when the throttle is opened again there is less lag waiting for it to spin up again.
Still very impressed by your metalworking skills.

Surge, unless very severe (under load surge with massive boost loads) usually only hurts the thrust bearings in a turbo, as they are only designed for small loadings.

In my case the impeller shaft is running on 6 deep groove ball bearings that will easily handle any sort of thrust the turbines tries to chuck at it.

Mine is surging when the throttle is closed at the moment because the blow off valve is not connected. Centrifugal superchargers don't suffer lag like a turbo as the turbo RPM rises with engine RPM, regardless. They do however suffer from the exponential boost curve of a centrifugal compressor.

Either way, surge is naughty and I will in the long run connect the BOV back up. :innocent:

[Grumph]

Well done and congrats on your perseverance...

Now get the bigger stepup on to the sucker and get the boost up to 20lb plus....

i note that there's a big Rotax triple used in jet skis which is centrifugally blown.
I'm told the blower is about 6 inch dia....

[Sketchy_Racer]

Well done and congrats on your perseverance...

Now get the bigger stepup on to the sucker and get the boost up to 20lb plus....

i note that there's a big Rotax triple used in jet skis which is centrifugally blown.
I'm told the blower is about 6 inch dia....

Cheers mate,

I'm starting the re-design now the new one will have a 20:1 drive ratio which will allow me up to 300000 shaft RPM if I want it and 30PSI boost (although efficiency dropps off considerably) with a internal oil pump (probably off a scooter)

The current unit is a bit shit and needs a decent oil pump.

I need to source a supplier of precision gears? Anyone know where to get some?

[Sketchy_Racer]

Video as promised


http://www.youtube.com/watch?v=RSLMCN4TUpQ&feature=youtu.be

[ducatilover]

Would you be using an electric oil pump, or one like a bike runs? If it's one like a bike, I've got one or three floating around

[Sketchy_Racer]

Would you be using an electric oil pump, or one like a bike runs? If it's one like a bike, I've got one or three floating around

One of the star wheel style ones out of pitbike and scooter motors like mine, mechanically driven

[ducatilover]

One of the star wheel style ones out of pitbike and scooter motors like mine, mechanically driven

Got a DR/GN250 one, would that work? Haven't split it but to my eye looks to be good. 278142278143

[speights_bud]

I need to source a supplier of precision gears? Anyone know where to get some?

If you want real precision, consider getting them wire cut. Not likely they will understand the fine precision tolerances you actually require at We-can, seems like Keith just decides 'he knows best' on your application these days... They also have a wire cutter but they are 2x more expensive than the Auckland machine shops were when we quoted some square holes...

[Drew]

One of the star wheel style ones out of pitbike and scooter motors like mine, mechanically drivenWe've got a friggin enormous one for a ZX12r in the spares container.

Edit.

I also have a pit bike motor that's dropped a valve (I think), as a spare for my couple of those.

Welcome to either.

[Yow Ling]

Printing presses use gears, we pay AU$1 per tooth on 1/8CP gearing, other machines use helical gearing , some module (?). If the gears are shit the print is shit.
Seeing as you have traction oil in the supercharger case , why not make the input gears into rollers

[Moooools]

Thanks Rob

Once I get the final design done I will get a couple of interested people to test the units for me and tell me what breaks and what can be improved. Of course these test units will be free. So i'll be in touch.

Cheers,

-Sketchy

I would more than happily take one off of your hands. :D
Even if I had to pay.

Top fucking effort getting that thing going man. Looks truly excellent. That is some top notch engineering.

[Moooools]

I need to source a supplier of precision gears? Anyone know where to get some?

AH gears. Or BOP gear cutting.

Both are good if you want them custom cut. Need to get them hardened afterwards though.

[speights_bud]

Printing presses use gears, we pay AU$1 per tooth on 1/8CP gearing, other machines use helical gearing , some module (?). If the gears are shit the print is shit.
Seeing as you have traction oil in the supercharger case , why not make the input gears into rollers

Made some tiny gears for the ink pumps once, prick of a job without the specialized tooling for it. But the Boss insisted so i carried on and yea they worked in the end but it wasn't very economical.... Sounds like the aussies have it sorted :)


AH gears. Or BOP gear cutting.

Both are good if you want them custom cut. Need to get them hardened afterwards though.

Yep BOP Gears are good, there is also a firm in Pram that do gears which i can't remember their name. We used to borrow Gear cutting hobs between the 3 of us for special/oddball pitches etc. A deep Cycle nitriding should do the trick for heat treatment if you want to go steel, or hard anodize some 7075 if heat & expansion etc play nice.

[Moooools]

or hard anodize some 7075 if heat & expansion etc play nice.

Hell yes 7 series. I know where a nice big bit of round stock is living too. :shifty:

[Ocean1]

Yep BOP Gears are good, there is also a firm in Pram that do gears which i can't remember their name. We used to borrow Gear cutting hobs between the 3 of us for special/oddball pitches etc. A deep Cycle nitriding should do the trick for heat treatment if you want to go steel, or hard anodize some 7075 if heat & expansion etc play nice.

Bettany Gears is the one in P'ram. And I suspect best practice might see gears running at those revs ground. Or lapped, if you can find anyone who know how nowadays.

[Sketchy_Racer]

Yeah, and custom parts are expensive.

Because I can design the geometry of the outer housing around exisiting parts, I am going to try find common parts that are cheap and easy to find. Alibaba is a perfect place to find parts.

This morning I have asked for a quote on 20 Oil pumps ($1-2 each) 20 compressor housings ($10-20 each) and 20 impellers ($5-10 each)

I hoping to get that as a small inventory so I can have a stable supply of more parts than I anticipate using but without much financial investment.

At the moment I am just looking through gears and different options.

The biggest pain is that the gears really do nothing for the supercharger apart from make it spin the right way, and adds complexity and weight to the unit. The reason I have the gears is because I am driving the supercharger off the left hand side of the engine. If I drove off the right hand side, I wouldn't need it, however it's a pain the ass to drive it off the right hand side.

So I am going to use the gears to help with the step up stage, hoping to get a 2:1 ratio at the gear set and then a 10:1 in the planetary gearbox giving a 20:1 ratio, which gives all levels of boost control.

I am thinking that the gears out of motorbike gearbox or the likes would be a supply of easy to find gears failing that I have found 2 suppliers of Spur gears

https://sdp-si.com/

http://www.wmberg.com/

hoping to have some luck there.

Once I get all the parts that I will no be manufacturing I can then design around them to create the best possible supercharger for cheap!