Forced induction 100cc

[carburator]

As Grump has put it, Ali mainfolds are a pain, mine are all stainless ( 304 )

there are certainly some tricks to making them hang together but also
careful planning yelds good results.

lots of lube and a 20 tonne press and the right dies you can do some interesting
transitions and flare's

[worm13]

Fair enough comment if you've got the composite experience...We were told that a layer of Kevlar would help.

2mm wall alloy, rolled corners, reinforcing ribs, beautifully TIG welded, presure tested to 45 psi....tell me that wasn't overkill.
On the other hand a quickly folded up 16G mild steel box, gas welded, held together...
By the time the alloy one had been fixed a couple of times and reinforced, it weighed pretty much what the steel one did but kept cracking.

Joys of using a epoxy resin! the room temp issue is what effects the epoxy from managing its optuim curing point, did a repair on a corvette carbon fibre bonnet, room temp was on the lower end of temp specs came in the next day epoxy had set but as soon as sand paper touched it you knew it was fucked! rule of thumb with carbon fibre to alloy is 1mm of carbon fibre is the same as 3mm alloy so on the base of what you said with the 2mm alloy do that in carbon and surely you would be more then safe and thats with a standard hand lay as well, if you can vac it bonus! even better if you can injection mould it!

[Sketchy_Racer]

It is damn awesome to be a part of. Also a pretty big time commitment on top of uni.

The V Twin is about the coolest thing ever, but still needs some sorting before it is ready for use in a car. Currently we run a similar set up with a 450cc single cylinder. Other engines have also included a supercharged r6.

All air must flow through a 20mm restrictor post throttle. It makes for some interesting tuning and intake design.




People on the team are highly skeptical about supercharging a single, although the old crankcases were set up for it. It will be very interesting to see how your engine goes.

Also is there any reason you made two separate blanks for gear cutting; rather than parting them off post cutting? Seems like more time involved in set up on the cutter.

20mm isn't exactly a lot of space! What sort of HP limitation is that going to give you guys? What are you studying at uni?


Interested to hear why the skepticism on the supercharged single? My worries are less about the fact that it is a single and more about the fact that it is only 100cc and if I can afford the drive losses of the supercharger. However if you look back at one of the earlier pages there is a video of a chap with a supercharged 50cc running on a dyno, his seems to run really really well!

Yes gears have been done this way as I will have to do multiple cuts to get the correct fit I am after, remembering I can afford no backlash so I will machine them "tight" then bring the sizes down slowly until desired fit. The beauty of a CNC is that I put it in a push the button, no pissing around with winding a rotary table handle.
In theory I could do it all by calc, but experience tells me that in theses situation, fitting the parts is much better than aiming for a measurement.

As Grump has put it, Ali mainfolds are a pain, mine are all stainless ( 304 )

there are certainly some tricks to making them hang together but also
careful planning yelds good results.

lots of lube and a 20 tonne press and the right dies you can do some interesting
transitions and flare's

Sweet glad to hear someone has done them with success out of SS. I will wait until I get the EFI kit and supercharger mounted before I bother with the plenum design.

[Grumph]

Why are the team sceptical about blowing a single ? You obviously haven't yet read the two books recommended to you on this thread...

Historiclly the biggest problem is throttling the intake satisfactorily. Given that most if not all attempts were suck - through, there was always a lag between opening the throttle and getting a response.Same shutting off too....Irving reports that a very long/large volume inlet tract with a secondary throttle close to the port can be made to work but some experimenting with lengths and volumes will be required.
With what's available now in injection, blow through becomes feasible which means the throttle point is close to the port. It also means that some form of pressure relief is needed when the throttle is closed....easy enough.
IMO you're going to need a regulated blowoff valve to keep plenum pressure down to running pressure at max when the throttle is snapped shut - and a safety blowoff valve for backfires. Irvings book has a drawing of a simple safety blowoff valve which is what I copied - dead easy. Just make it visible as trying to start a bike with the valve open unknowingly is one more frustration....

[Moooools]

20mm isn't exactly a lot of space! What sort of HP limitation is that going to give you guys? What are you studying at uni?


Interested to hear why the skepticism on the supercharged single? My worries are less about the fact that it is a single and more about the fact that it is only 100cc and if I can afford the drive losses of the supercharger. However if you look back at one of the earlier pages there is a video of a chap with a supercharged 50cc running on a dyno, his seems to run really really well!

Yes gears have been done this way as I will have to do multiple cuts to get the correct fit I am after, remembering I can afford no backlash so I will machine them "tight" then bring the sizes down slowly until desired fit. The beauty of a CNC is that I put it in a push the button, no pissing around with winding a rotary table handle.
In theory I could do it all by calc, but experience tells me that in theses situation, fitting the parts is much better than aiming for a measurement.

We get 42kw (apparently) out of the 450cc single. But the current map isn't the best it could be. I have only talked briefly to people who were around when the crank cases were set up for a blower, but they were jabbering on about having too much dead time between power strokes.

I am studying engineering.

You obviously haven't yet read the two books recommended to you on this thread...

Supercharging is not something I want to actively peruse. It was more of a passing comment. We have enough other stuff to deal with and enough custom in the car as it stands. Plus team budget is limited and so on.

[Grumph]

We get 42kw (apparently) out of the 450cc single. But the current map isn't the best it could be. I have only talked briefly to people who were around when the crank cases were set up for a blower, but they were jabbering on about having too much dead time between power strokes.

Supercharging is not something I want to actively peruse. It was more of a passing comment. We have enough other stuff to deal with and enough custom in the car as it stands. Plus team budget is limited and so on.

The comment about not having read the books was aimed at Sketchy......

I admire the projects you guys get to play with now but when I look at some of the parameters you have to work inside, I reckon they're too artificial. Maybe it's just to get you into thinking outside the square, I don't know.
In my day.....too long ago now....you just bought an old race bike and learned as you went along, and if you kept at it you could make the spares you needed and any trick bits to develop it further.

[Sketchy_Racer]

Why are the team sceptical about blowing a single ? You obviously haven't yet read the two books recommended to you on this thread...

Historiclly the biggest problem is throttling the intake satisfactorily. Given that most if not all attempts were suck - through, there was always a lag between opening the throttle and getting a response.Same shutting off too....Irving reports that a very long/large volume inlet tract with a secondary throttle close to the port can be made to work but some experimenting with lengths and volumes will be required.
With what's available now in injection, blow through becomes feasible which means the throttle point is close to the port. It also means that some form of pressure relief is needed when the throttle is closed....easy enough.
IMO you're going to need a regulated blowoff valve to keep plenum pressure down to running pressure at max when the throttle is snapped shut - and a safety blowoff valve for backfires. Irvings book has a drawing of a simple safety blowoff valve which is what I copied - dead easy. Just make it visible as trying to start a bike with the valve open unknowingly is one more frustration....

Yeah I am hoping that the fuel injection system is going to make the fueling control much better, I am looking forward to the kit turn up as I can't really design the rest of the intake system until that arrives. I know I am going to need a blow off valve but though I wouldn't need a safety dump valve with the fuel injection, as even if the intake had a back fire there would not be enough fuel in the air to create conditions for a ignition, thoughts?

I am planning on going to the library this weekend to have a look at those two books, hopefully they are returned on time.

We get 42kw (apparently) out of the 450cc single. But the current map isn't the best it could be. I have only talked briefly to people who were around when the crank cases were set up for a blower, but they were jabbering on about having too much dead time between power strokes.

I am studying engineering.

Supercharging is not something I want to actively peruse. It was more of a passing comment. We have enough other stuff to deal with and enough custom in the car as it stands. Plus team budget is limited and so on.

Yeah I guess that would be right in regards to dead time, but I suppose that is where having the right sized supercharger for the motor is important. Also plenum volume will be important, the bigger the beter is guess for cylinder filling but if it is to big i may experience lag from low rpm. However part of the beauty of supercharging is that it will be making boost even with the throttle shut, it will just be dumping it to atmosphere instead of the motor.

Cheers,

-Sketchy

[Sketchy_Racer]

Got most of the charger finished today, made the bearing plate for the drive side and also the gear cover. Cocked up the gear cover but luckily it wont be seen and wont affect the operation of the charger.

When setting up a datum edge in the mill, I use a 10mm diameter touch probe which is awesome as long as you remember to include the 5mm radius of what ever you zero an edge at, otherwise it will machine everything with a bloody 5mm offset. Of course only noticed it after the first cut. Never rush jobs during lunch breaks haha.

Got the shafts pressed into the rotors and will finish the rotors to length tomorrow as well as turn the gear nut threads.

Then it's time to mill some gears, going to write the program for that tonight, easier to do by hand than use the CAM software.

Also the oil cooler kit turned up so I can look at getting that mounted over the weekend, and I will look at getting a blowoff valve and intercooler to hack up tomorrow. Planning on going to pick a part and stealing some suitable parts from there.

[Moooools]

The comment about not having read the books was aimed at Sketchy......

I admire the projects you guys get to play with now but when I look at some of the parameters you have to work inside, I reckon they're too artificial. Maybe it's just to get you into thinking outside the square, I don't know.
In my day.....too long ago now....you just bought an old race bike and learned as you went along, and if you kept at it you could make the spares you needed and any trick bits to develop it further.

It seems artificial because it is artificial. You are given an artificial brief to design a car for. Some of the rules are designed around safety, like the 20mm restriction to keeps speeds low. Some are to make the engineering less about money and more about design.

It isn't motorsport really, it is an engineering challenge.

[crazy man]

very nice job Sketchy

[bogan]

Yeah I guess that would be right in regards to dead time, but I suppose that is where having the right sized supercharger for the motor is important. Also plenum volume will be important, the bigger the beter is guess for cylinder filling but if it is to big i may experience lag from low rpm. However part of the beauty of supercharging is that it will be making boost even with the throttle shut, it will just be dumping it to atmosphere instead of the motor.

Be a lot of waste with the throttle between the charger and engine? I thought they usually put them in front of the charger. Or is the lag reduction worth a little bit more fuel consumption?
Or dual throttles, one behind controlling what goes into the engine, and one in front to control manifold pressure.
Maybe I should get a copy of those books too, this shit is interesting!

When setting up a datum edge in the mill, I use a 10mm diameter touch probe which is awesome as long as you remember to include the 5mm radius of what ever you zero an edge at, otherwise it will machine everything with a bloody 5mm offset. Of course only noticed it after the first cut. Never rush jobs during lunch breaks haha.

Looking pretty bling dude! Done the offset one once of twice myself, worse one is getting tool heights muddled up

[Sketchy_Racer]

very nice job Sketchy

Cheers mate

Be a lot of waste with the throttle between the charger and engine? I thought they usually put them in front of the charger. Or is the lag reduction worth a little bit more fuel consumption?
Or dual throttles, one behind controlling what goes into the engine, and one in front to control manifold pressure.
Maybe I should get a copy of those books too, this shit is interesting!

Looking pretty bling dude! Done the offset one once of twice myself, worse one is getting tool heights muddled up

The throttle body will be mounted just before the intake port of the head pretty much replicating the fuel system lay out of a modern EFI bike.

Haha, I'm lucky enough to have over 100 tool holders which I keep a library of tools setup in, means when I program a job I can call up any tool in the library and it has the associated tool length offset to avoid collision, basically if the CAM software simulates it, she's good to go. Only time it fails is if I put the tools in the wrong position in the tool holder. However I have once replaced a worn tool and forgot to reset the tool length.... the vice was not so happy about that and neither was the boss

Crashing CNC machines isn't a mater of "It it will happen" it's more of a case of "when it will happen"

[speights_bud]

worse one is getting tool heights muddled up

When i started my new job i found they'd written a macro to try monkey proof setting tool lengths, now its just into MDI, M101 T#; the machine gets the pot/tool, then just handle feed down onto height block, flick back to auto, push go. Machine inputs its own tool length and Z axis rapids home. works quite well, is in a victor mill. the Haas mill we have has buttons for tool measure and next tool which is even easier.

Crashing CNC machines isn't a mater of "It it will happen" it's more of a case of "when it will happen"

And with some operators how often will it happen today....

[bogan]

Crashing CNC machines isn't a mater of "It it will happen" it's more of a case of "when it will happen"

Yeh, unless you want to sacrifice production by triple checking everything everytime. Those solid carbide ones make a hell of bang when they let go at full noise though!

When i started my new job i found they'd written a macro to try monkey proof setting tool lengths, now its just into MDI, M101 T#; the machine gets the pot/tool, then just handle feed down onto height block, flick back to auto, push go. Machine inputs its own tool length and Z axis rapids home. works quite well, is in a victor mill. the Haas mill we have has buttons for tool measure and next tool which is even easier.

We use a mitoyo height gauge, just measure them up on the bench and input the data. Saves fucking around with height blocks and datums in the machine, especially good when you're mid job.

And with some operators how often will it happen today....

haha, had to teach 3rd year engineering students for two summers, so I know that feeling (they were fine when I was there, but tried shortcuts when I fucked off). One of them even managed to demolish the wiggler (noisy edgefinder).

[Brian d marge]

[QUOTE=Sketchy_Racer;1130364405]
QUOTE]

Well done, most project dont get of the ground , you will go far young skywalker ,,,,,

Stephen

ps can I use that machine centre , I ll be real careful with it honest gov !