Forced induction 100cc

[Sketchy_Racer]

And you go tell everyone about the secret parts i've put in my Loncin Engine.... damn you... i saved over 1200g's of rotating mass!

Haha sorry bro. You should make a mission and come down for a bucket meet here some, once I get the superbucket running of course so you can take it for a thrash

[speights_bud]

Haha sorry bro. You should make a mission and come down for a bucket meet here some, once I get the superbucket running of course so you can take it for a thrash

The Hawkes bay guys have started getting together and organizing a trip down, trying to get a few things done on mine this week, maybe on the dyno if i get a chance just to see where its at. but definitely gotta come down and try your track out

[TZ350]

Most interesting thread on KB in, well - ever?

A handbuilt supercharged 100, yes thats very interesting, its become the first thread I read each day.

[Paul in NZ]

Are you SURE you want to go forced induction?

http://www.telegraph.co.uk/news/pict...July-2012.html

[Grumph]

DON"T use a welded alloy plenum....been there cracked that repeatedly. Did ours in 2mm alloy initially but it wouldn't stand the pulsations and cracked. The replacement in 16G mild steel was a quickie but held up well. Had we continued we were looking at moulding one in carbon fiber as everyone we spoke to said it had no natural resonant frequency and they swore it wouldn't split....
Being a single yours will pulse worse than our 180deg twin...
I'd think even if you use large dia tube as the plenum body it will still crack the ends and seams.

Sorry, it ain't easy....

[Moooools]

Had we continued we were looking at moulding one in carbon fiber as everyone we spoke to said it had no natural resonant frequency and they swore it wouldn't split....

Sorry, it ain't easy....

Ha. Made me laugh.

Don't use composites. It will pulse just like any other material. Except it will be shitty to make. And you will be wet laminating at room temperature. Which will make it want to fall apart under any sort of vibration. Also the material is not isotropic which makes it very hard to apply any sort of maths to it. Just do it in ally but give it a safety factor of like 10.

[bogan]

Yeah I guess if you wanted to get really serious then angular contact would be the way, however in this case I think she'll be sweet mane

My gear understanding is also very basic, and yes as far as I know there is a recommendation for the tooth count and module relative to the Pitch circle but the addendum and dedenddum is fixed to your module and your module selection is just your pitch circle / tooth count. Strictly speaking I should need a 1.6 module but 1.5 is close enough

I think the 24 tooth gear will work , got some bronze for it and the blanks turned up so will just make a set and see how we go.

I think the most common deep groove have angular contact in the same size anyway, so an easy upgrade later if required. Start cheap, learn as much as possible, then upgrade where required, always a good plan!

[andrew a]

Hi Glen you mention PIT BIKE thats not legit for a bucket motor. Sorry

[Grumph]

Ha. Made me laugh.

Don't use composites. It will pulse just like any other material. Except it will be shitty to make. And you will be wet laminating at room temperature. Which will make it want to fall apart under any sort of vibration. Also the material is not isotropic which makes it very hard to apply any sort of maths to it. Just do it in ally but give it a safety factor of like 10.

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.

[speights_bud]

I haven't done much with gears, but it was my understanding that a given number of teeth of certain modulus will have only one optimum pitch circle diameter. Or can you just cut deeper/shallower as required?

Yes gears do have an optimum pitch circle diameter, which allows the gear to run most efficiently. however the specified standard diameter can't always be used when setting up multiple gears fixed on one shaft as per the pic of the gear cluster i made below. The Diameters can be fudged to a certain extent, but it changes the shape of the tooth and as you'd expect larger diameter makes the tooth wall flatter as it rises to the point.

For those who may be interested....

I Made 6 of these gear clusters, all in manual machines & kept this one because the guy turning it in the CNC lathe balls-ed up the bore so used it as a setup piece. which is kinda good when you are fudging diameters for fixed centre gears.
You might be able to see the tooth width on the 3rd from top gear on the cluster has narrower teeth than the mating gear. This is because if we cut the mating gear to the standard depth it would become too weak. so seeing how the diameters are fixed and there is a specific ratio required, there was some fudging done to make everything fit properly.

It is only using certain gear cutting methods you can do this though. I think Glen is using the 'standard form' method for cutting his gears, which as far as i know (never done too much of this type) won't generate the desired tooth shape if the diameter is changed from standard, it would only result in the teeth being crammed into each other or spread further apart.
This method done in a manual mill. video bit boring at first, (skip ahead to milling) but quite in depth:
http://www.youtube.com/watch?v=VHTXaU7GZC0


If the teeth are Rack generated, as i did for the bottom 2 of the gears on the cluster. Using a designated gear hobbing machine the tooth shape is formed via a series of gears & ratios etc. you setup the gearboxes from some charts, some magic happens and you get the tooth shape you wanted.
http://en.wikipedia.org/wiki/Hobbing
A poor video making a helical gear using a manual style hobbing machine and a poor cutting method:
http://www.youtube.com/watch?v=dACKfxJ8qr4

The other method i've used is shaping, good for cutting gears where you have a limited amount of space, just like the top two gears on the cluster in the pic. the cutter rotates slowly in time with the gear to form the teeth, its another set the machine up according to the charts fiddle a bit more then magic happens and you have the gear.
Shaping and then hobbing:
http://www.youtube.com/watch?v=XZgsV...eature=related

[Moooools]

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.

I'm too young to know what thickness 16 gauge steel is. However the internet says about 1.5mm. (mmmm metric)
That works. For some reason I had a picture of thick plate in my head, don't quite know why.

As for composites experience, I am no real expert, but I do work alongside some guys ( who build a carbon monocoque chassis for a car each year (I work on power train; motorcycle engine however). I get to duck in and out of their lair and quite a bit of useful info gets dispersed. Also watching a guy make a composite plenum this year has highlighted how much is sucks. Even for a normally aspirated engine. His first attempt (last year) would pulse heaps while running.

For any Facebook users interested: https://www.facebook.com/photo.php?f...type=3&theater

Oh and like that page. Good for our sponsors and getting one over other universities.

[Sketchy_Racer]

DON"T use a welded alloy plenum....been there cracked that repeatedly. Did ours in 2mm alloy initially but it wouldn't stand the pulsations and cracked. The replacement in 16G mild steel was a quickie but held up well. Had we continued we were looking at moulding one in carbon fiber as everyone we spoke to said it had no natural resonant frequency and they swore it wouldn't split....
Being a single yours will pulse worse than our 180deg twin...
I'd think even if you use large dia tube as the plenum body it will still crack the ends and seams.

Sorry, it ain't easy....

I had wondered about the pulses fatiguing the alluminum, I guess it has been proven right here. I will have to make it out of stainless steel though, It's got to look the part

Yes gears do have an optimum pitch circle diameter, which allows the gear to run most efficiently. however the specified standard diameter can't always be used when setting up multiple gears fixed on one shaft as per the pic of the gear cluster i made below. The Diameters can be fudged to a certain extent, but it changes the shape of the tooth and as you'd expect larger diameter makes the tooth wall flatter as it rises to the point.

Thanks for that champ, it's cool learning new shit!

I'm too young to know what thickness 16 gauge steel is. However the internet says about 1.5mm. (mmmm metric)
That works. For some reason I had a picture of thick plate in my head, don't quite know why.

As for composites experience, I am no real expert, but I do work alongside some guys ( who build a carbon monocoque chassis for a car each year (I work on power train; motorcycle engine however). I get to duck in and out of their lair and quite a bit of useful info gets dispersed. Also watching a guy make a composite plenum this year has highlighted how much is sucks. Even for a normally aspirated engine. His first attempt (last year) would pulse heaps while running.

For any Facebook users interested: https://www.facebook.com/photo.php?f...type=3&theater

Oh and like that page. Good for our sponsors and getting one over other universities.

Dude, that project looks awesome mate, I would have loved to do something like that. The design of the V twin is so cool. What is the intake air restriction for the 500cc motors?

[Sketchy_Racer]

Okay so made quite a bit of progress today.

Got the body finished off and also ordered the fuel injection and ignition kit. I though bugger it, it's worth a shot and having youtubed it and seen bike running with it they all seem to run great and its had great reviews (can you see the self reassuring about my $600 spend....)

It comes with a O2 sensor which is awesome as I can do the inital engine setup via that without having the spend hours at the dyno.

Link here for those who may have missed it earlier

http://www.ecotrons.com/Small_Engine...o_PNP_kit.html

I was planning on going with an ignitech but it seems the layout of this software is the same so hopefully it is as good.

Anyway, again here are some pictures.

Cheers,

-Sketchy

[fi5hy]

Your a very sick little boy Glen. I like it

[Moooools]

Dude, that project looks awesome mate, I would have loved to do something like that. The design of the V twin is so cool. What is the intake air restriction for the 500cc motors?

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.