Formula 5 question?

[nudemetalz]

Heya,

Yes I do still look at the buckets even though I don't do it anymore...

Got a question...has anyone done a competitive four-stroke F5 bike?
I assume a good base would be an XL-100S (as the limit is 104cc) and ...ahem,..XR-100 parts are fairly easy to find (I would say they're identical internally).

Just,...ummm....curious... ;)

[richban]

Heya,

Yes I do still look at the buckets even though I don't do it anymore...

Got a question...has anyone done a competitive four-stroke F5 bike?
I assume a good base would be an XL-100S (as the limit is 104cc) and ...ahem,..XR-100 parts are fairly easy to find (I would say they're identical internally).

Just,...ummm....curious... ;)

Yeah I have been thinking about that one. CBR125 sleeved down or stroked one or the other. 20mm throttle body. Reving to 15k. That would do the trick.

[SHELRACING]

Yep, I have an XR100 based bucket, and it's for sale.

It's not quite finished and needs work, but most of work is done. I'll post up a pic soon if anyone's interested PM me

BTW : Avalon Biddles bike was an XR 100 I think in an RG frame, and it is/was a great little bike

Steve

[nudemetalz]

How competitive is an XR100 engine next to some of those hot 50's ?
I've heard of 16hp out of the RG's and and XR100 stock is around 9-10hp.

[F5 Dave]

. . . .
I've heard of 16hp out of the RG's . . . :lol::lol::lol::killingme

[nudemetalz]

:lol::lol::lol::killingme


oiii..Dave, I said I only heard.....

We know yours is only 6hp..... :banana: :lol:

[Grumph]

How competitive is an XR100 engine next to some of those hot 50's ?
I've heard of 16hp out of the RG's and and XR100 stock is around 9-10hp.

Fit pedals.....

[Ivan]

Easy to work up the parts all interchange from 100 to 200 and if you use the XL/XR 100 bottom end and cylinder put on a XR200 head you have bigger valves and ports use the XR200 carb even bigger carb build a better exhaust system my mate used to build lots of these motors

[gav]

F5 four stroke is limited to a 20mm carb though ...

F5 4 stroke engines over 53cc are restricted to carburation
equivalent to a single 20mm carburettor.

Might want to check, think a XR100 might run a 22mm carb though?

[husaberg]

Easy to work up the parts all interchange from 100 to 200 and if you use the XL/XR 100 bottom end and cylinder put on a XR200 head you have bigger valves and ports use the XR200 carb even bigger carb build a better exhaust system my mate used to build lots of these motors
Sorry Ivan the Xl100s and the XR100 are a different beast from the normal cb100 xl100 125s and 185 200 etc.


The motor is based on the cb50 XR75 80 model engines.

I think gav may be right I think some were 22 mm carbs and I think some were 20mm Maybe the XL was.

the Xl100S is a points ignition and has (I am lead to believe) a different crank taper from the XR100 though the XR100 which is CDI.
Most of the rest of the engine is similar. The motors are lazy sparkers like a pitbike. They are more of a revver than the old style 100 motors. They do have hop up potential and are lighter than the cb100 Xl100 etc.
the head has a cam carrier bolt on inside the head cover and there is a lot of Cams etc and parts available from the states.

They are a 53mm x 45mm Motor with a 5 speed.
I was always wanted to see if the MB50 6 speed fits (I bet it does) as they in std form share the exact same ratio as a 5 speed MB5 MB100. Which is to large a coincidence.

Stuff that's not legal but bling bling.

http://www.mx-performance.com/id53.html

[nudemetalz]

Fascinating info, Husaberg. Thanks for sharing.

Back in 1985 I used to ride an XL100S (1980 model), with a nice booming Supertrap on it. Used to rev nicely to 11,000rpm (schoolboys have no mercy of course ;) ). Always thought one day I'll get another and see what I can do with it.

[nudemetalz]

Been doing a bit more research lately.

The XL100S engine is 53mm x 45mm (as Husaberg points out)
If you can get an XL75 engine (same as an XR I believe) the bore/stroke is 48mm x 41.4mm. If it can be resleeved to 56.5mm (most 125 4T SOHC Honda's are a 56.5mm piston) you get a capacity of 104cc.

You can get some serious revs without excessive piston speed - ie 14,000rpm still under 20m/s.
Wondering though, even with a hot cam, piston compression etc if the 20mm carb restriction would negate any advantage?

[F5 Dave]

Main bit of cost would be the cam. you won't find a cam profile suited to doing mondo revs for that engine & developing one will be a little trial & error & expensive.

[nudemetalz]

Interesting, thanks Dave.

I guess not having a DOHC head like a CBR150 would make it not quite as easily tunable.

[F5 Dave]

Well just if you are building an engine to do stella more revs than std you need cam timings that will match.


Hey Nudz, why not just find an RG50? I hear they go alright & are light & cheap.

[nudemetalz]

....esp in RS125 frames ay ;)

I looked at Steve's RG/TZR50 on TM and have been considering it.

[Henk]

Hey Nudz, why not just find an RG50? I hear they go alright & are light & cheap.

And like bloody hens teeth it would seem, I've been trying to find one for bloody ages.

[nudemetalz]

They were a dime a dozen back in the 90's.
Back then there were 5 of us that owned one each and we used to do own our race around the Port Hills.
Great fun machine :)

[F5 Dave]

I took my road one to Cold Kiwi from wgtn 6 times.

[F5 Dave]

....esp in RS125 frames ay ;)

I looked at Steve's RG/TZR50 on TM and have been considering it.
oh yeah, can't see it. He's moved out of wgtn now.

Wonder what happened to Chris Sales old one. Chap in Msterton bought it, rode it a couple of times & hasn't been back. That was fast. I could ask Mike.

[jasonu]

They were $1000 each back in the 90's.


Which is what I paid for David Diproses race proven RG50.
I soon found the std ignition was not the way to go and for another $250 DD sold me the RM80 ignition he had removed from the same bike just before he sold it to me. Cheeky buggar!

[F5 Dave]

They were $1600 brand new & I couldn't afford one. When I finally could my road one was $600 & later one which was being ridden to work was $450 & a week later a race bike.

Think I got $500 for my road one when I sold it.

[husaberg]

Been doing a bit more research lately.

The XL100S engine is 53mm x 45mm (as Husaberg points out)
If you can get an XL75 engine (same as an XR I believe) the bore/stroke is 48mm x 41.4mm. If it can be resleeved to 56.5mm (most 125 4T SOHC Honda's are a 56.5mm piston) you get a capacity of 104cc.

You can get some serious revs without excessive piston speed - ie 14,000rpm still under 20m/s.
Wondering though, even with a hot cam, piston compression etc if the 20mm carb restriction would negate any advantage?

A couple of issues here the stuff you are suggesting of course can be done but destroking engines is rarely a good idea as the comp ratio and the resultant combustion shape if it is remedied suffer not to mention the extra costs involved also you will be mixing 3 gudgeon pin sizes there a least.

Cams are available to suit but do cost these engines are used by the NS100 HRC or what aver it is called and used considerably in flat track and other classes inc Super-moto there is even a Honda std supermoto styled model sold in 50 80 and 100cc form. APE I think. The Dream 50 is based on a similar bottom end (the CB50). They rev on the counter in std 100s form to around 12000rpm if not higher. so don't worry about the stroke and the cams being sohc to much.
I will finish the post later.

[richban]

A couple of issues here the stuff you are suggesting of course can be done but destroking engines is rarely a good idea as the comp ratio and the resultant combustion shape if it is remedied suffer not to mention the extra costs involved also you will be miking 3 gudgeon pin sizes there a least.

Cams are available to suit but do cost these engines are used by the NS100 HRC or what aver it is called and used considerably in flat track and other classes inc Super moto there is even a honda std super moto styled model sold in 50 80 and 100cc form. APE I think. the Dream 50 is based on a similar bottom end the CB50. They rev on the counter in std 100s form to around 12000rpm if not higher. so don't worry about the stroke and the cams being sohc to much.
I will finish the post later



Kevin used that flat track honda grind my old Vespa. And that was a weapon. The question is how big can you go on the valves coz that may be the limiting factor in making an engine to foot it with a fast 2 stroke. If you made 140hp per liter from a 2 valve old piece of crap like that, I would be very surprised. Can't remember what the stroke was but I am sure it was long. So it might have an edge in low end power over a 2 stroke. Best thing to do is just put a skinny fast kid on it and the job is done. I've seen a few of them around lately.

[Rick 52]

Kevin used that flat track honda grind my old Vespa. And that was a weapon. The question is how big can you go on the valves coz that may be the limiting factor in making an engine to foot it with a fast 2 stroke. If you made 140hp per liter from a 2 valve old piece of crap like that, I would be very surprised. Can't remember what the stroke was but I am sure it was long. So it might have an edge in low end power over a 2 stroke. Best thing to do is just put a skinny fast kid on it and the job is done. I've seen a few of them around lately.

Yes if your not quick enough to bring a trophy home yourself..Put a 54kg 13yr old on a XL100s ported and a inner rotor ignition bigger header powered RG 50 framed F5 bike and Bobs your uncle !!or your son in my case..
Very pleased he rode very well and got better through the day ,The bike is easy to ride and is a brilliant first bike to learn on but is never going to be a match for a RG or Derbi powered RS ,When he can ride this to the limit we can put him on a competitive bike and he wont be in Bgrade bedlam for long

[richban]

Yes if your not quick enough to bring a trophy home yourself..Put a 54kg 13yr old on a XL100s ported and a inner rotor ignition bigger header powered RG 50 framed F5 bike and Bobs your uncle !!or your son in my case..
Very pleased he rode very well and got better through the day ,The bike is easy to ride and is a brilliant first bike to learn on but is never going to be a match for a RG or Derbi powered RS ,When he can ride this to the limit we can put him on a competitive bike and he wont be in Bgrade bedlam for long

Let me know if you want a new cam for it. Might be able to get a good deal for an up and coming youngster.

[husaberg]

Kevin used that flat track honda grind my old Vespa. And that was a weapon. The question is how big can you go on the valves coz that may be the limiting factor in making an engine to foot it with a fast 2 stroke. If you made 140hp per liter from a 2 valve old piece of crap like that, I would be very surprised. Can't remember what the stroke was but I am sure it was long. So it might have an edge in low end power over a 2 stroke. Best thing to do is just put a skinny fast kid on it and the job is done. I've seen a few of them around lately.

I guess the tracks he's planing on racing he won't need GP bike power levels. It could make a decent bucket on a tight track. Open track different story.
Given a bit of time on the net at powroll, TB etc he could get a lot of ideas a lot of pistons in the right kind of spec are available for pit bikes etc.
http://www.ooracing.com/store/index.php?act=viewProd&productId=601
http://www.akunar.com/PRO_PISTONS.htm
Have a look at DR atv for piston designs.TKRJ etc

http://webcamshafts.com/mobile/motorcycle/honda/honda_xr_75_(77-79)_sohc_2v.html
http://webcamshafts.com/mobile/motorcycle/honda/honda_xr_100_(81-03)_sohc_2v.html

Well it looks like you can cram in some decent size (by 2 valve Honda standards anyway) valves in one at least. I say Keep the crank stroke std.
bump up the comp sort out the timing both valve and ignition it would be a fun little bike. One of those pit bike inner rotors probably as the guy above fits on easy.

Yes support the local guys with regards to cams too but it can give you ideas with what is done overseas.

[richban]

I guess the tracks he's planing on racing he won't need GP bike power levels. It could make a decent bucket on a tight track. Open track different story.
Given a bit of time on the net at powroll, TB etc he could get a lot of ideas a lot of pistons in the right kind of spec are available for pit bikes etc. Have a look at DR atv for piston designs.TKRJ etc

http://webcamshafts.com/mobile/motorcycle/honda/honda_xr_75_(77-79)_sohc_2v.html

That valve is not as small as I thought it would be. Is that standard inlet 24mm? The valve should not limit power up to about 14 - 15hp. So a well designed cam good compression and you should see improvements.

[husaberg]

That valve is not as small as I thought it would be. Is that standard inlet 24mm? The valve should not limit power up to about 14 - 15hp. So a well designed cam good compression and you should see improvements.

I have seen them opened up and was surprised by the sizes. but they have a flatter combustion chamber compared to the traditional Honda singles.
The real surprise is the size of the CB50 ones they are nearly as big. the xr75 was basically Honda's race motor at the time bigger bore and shorter stroke than the 80 which it predates. According to some the 75 head flows better too. There is a huge amount of info on the net about them and they have there own tuning industry. For a F5 they would be fun I was going to do one at one time but my father gave my old bike away or loaned it to someone whatever when i went to grab it it was gone. They were real revers compared to the std style 100 and 125s etc.

[nudemetalz]

I have also had a CB50 at one time (as well as a CB125T)..and was surprised at how well it went stock. It revved to 12K without much effort, even with the long long long inlet and piddly carb.

Hmmm,...XR75 head on a CB50, huh......damn you, Husaberg for putting all of these ideas in my head ;)

[gav]

Cheap F5 bike here http://www.trademe.co.nz/motors/motorbikes/parts-for-sale/other/auction-421727438.htm

[Buddha#81]

F5 motard anyone? http://www.kiwibiker.co.nz/forums/showthread.php/143864-RMX-50cc-2stroke-anyone-want-it

[gav]

So how does this run in F5 if its a purpose built race bike?
http://www.trademe.co.nz/motors/motorbikes/motorbikes/sports/auction-397931884.htm

[F5 Dave]

Well chassis are open & the engine is a bog std GPR roadbike Derbi. They aren't really that flash bikes either. Good starter though.

[gav]

Purpose built race bike ideal for young teen racer :eek:
Hmmmm .......

[Moooools]

Purpose built race bike ideal for young teen racer :eek:
Hmmmm .......

But it uses a non competition engine. Do some research.

[gav]

But it uses a non competition engine. Do some research.

How does a purpose built race bike use a non competition engine? :laugh:

Oh well, another 50 on the grid I guess ....

[F5 Dave]

well take the engine out & it is legal.

Then notice that the same engine you are holding is a production streetbike engine & put it back in. An awful lot more legal than some of the grey area aftermarket engine bits we have been discussing before.

[Moooools]

How does a purpose built race bike use a non competition engine? :laugh:

Oh well, another 50 on the grid I guess ....

Your logic is that if I put an FXR engine into an rs 125 chassis thus making a purpose built race bike, the FXR engine becomes a competition engine. Which is wrong.

Same deal with the metrakit, putting a street engine into a race frame doesn't make it a race engine.

This is pretty damn clear cut!

[F5 Dave]

Now if for example they fitted the GPR engine up with a Metrakit race barrel then that would be a competition motor & illegal.

For some reason they left them std. I suppose that reason was cost & then income as people bought Metrakit parts & fitted them. Cunning really. Still leaves you with an undersized bike on funny wheels. Which is fine for kids, not so for Adults.

[kel]

Now if for example they fitted the GPR engine up with a Metrakit race barrel then that would be a competition motor & illegal.

Why would the metrakit cylinder be illegal? The AM6 was never released as a competition motor (at least I dont think it was) therefore any aftermarket cylinder is legal ;)

[Drew]

So what cc limit is there if one was to turbo a 4 stroke?

[F5 Dave]

Kel, unless we are getting into the 's' conversation then Metrakit release road & competition parts, or is it Kundo (KRD) been a while since I looked. So the race kits are competition parts.

But I think you are getting into the S conversation & I can't find that emocon that gives you a virtual whack with a fish.

Drew. In F5 turbos aren't allowed.

They are in F4.
Read the freeaking rules laziarse.

[jasonu]

So what cc limit is there if one was to turbo a 4 stroke?

Read the rules. They can be found on that fangled internet thingee.....

[nudemetalz]

So has anyone ever made a turbo work on a bucket before, Dave?

[Drew]

One of you homos already knows the rule. What is it, and has it been done? I have no inclination to trawl through MNZ's website trying to find rules.

[Moooools]

100cc forced induction 4 strokes are allowed.

[F5 Dave]

Ahh I forget (this is fun, like having a little brother to torment throwing his teddy between you & your sister. Sadly I was the youngest).

There have been a couple, actually supercharged, er hold on was Diesil's turbo or super charged- whatever.

but the short answer is none that have 1/2 way worked worth a dam that I have ever seen.

[F5 Dave]

ahh crap, spoilsport, we might have got him to cry.

[Moooools]

The impression I have gotten from talking to a few people is that you would need to run about 20-25 PSI of boost to get to a stage where it is worth it, and with 25-30 you would be looking at about 45-50hp. But to get to that level you wouldn't just be able to whack a turbo on and watch it go. You would be wanting to lower compression and put some stronger valves and a new cam in at the very least. And getting the bottom end to take the load wouldn't be easy. It really doesn't sound like a cheap exercise to build one.
It certainly wouldn't be cheap to keep it going.
It would be fun as fuck to ride.

[Moooools]

ahh crap, spoilsport, we might have got him to cry.

My apologies Dave. To make you feel better I will let you beat me in next year's F5 gp.

[jasonu]

The impression I have gotten from talking to a few people is that you would need to run about 20-25 PSI of boost to get to a stage where it is worth it, and with 25-30 you would be looking at about 45-50hp. But to get to that level you wouldn't just be able to whack a turbo on and watch it go. You would be wanting to lower compression and put some stronger valves and a new cam in at the very least. And getting the bottom end to take the load wouldn't be easy. It really doesn't sound like a cheap exercise to build one.
It certainly wouldn't be cheap to keep it going.
It would be fun as fuck to ride.

A good builder would get that done in an afternoon....

[Drew]

The impression I have gotten from talking to a few people is that you would need to run about 20-25 PSI of boost to get to a stage where it is worth it, and with 25-30 you would be looking at about 45-50hp. But to get to that level you wouldn't just be able to whack a turbo on and watch it go. You would be wanting to lower compression and put some stronger valves and a new cam in at the very least. And getting the bottom end to take the load wouldn't be easy. It really doesn't sound like a cheap exercise to build one.
It certainly wouldn't be cheap to keep it going.
It would be fun as fuck to ride.

100cc single isn't capable of driving a turbo or supercharger fast enough to create that sort of boost. It would need to run a turbo and blower. Start with an XL250 bottom end and you've got a bottom end capable of taking 40 horses.

There would be a lot of engineering, but there's no reason it can't be reliable.

[gav]

Your logic is that if I put an FXR engine into an rs 125 chassis thus making a purpose built race bike, the FXR engine becomes a competition engine. Which is wrong.

Same deal with the metrakit, putting a street engine into a race frame doesn't make it a race engine.

This is pretty damn clear cut!

Its not an individual doing the fitting, it's a factory/company. If Suzuki released a FXR150 in an alloy chassis that was set up exclusively for racing, on slicks etc, oh wait and with a bigger (30%) carb fitted, race pipe, also 20% more revs would that be ok would it?
The std GPR50 has a 14mm carb, max power at 10K revs, the Metra has a 19mm carb and 12K revs.
Im sure it starts as a std engine, but if the Forza 155 pit bike was considered unsuitable because its a competition engine/machine I find it hard to believe that this Metrakit bike can be considered legal. If someone bought a Metrakit rolling chassis and then fitted a Derbi 50 fitted thats fine, but thats not what has happened here is it? It's been bought as a purpose built race bike and is sold as such. What next? a TZ250 is ok for F3 because a TZR250 Kocinski rep is based on the same thing? :eek:

[Moooools]

Its not an individual doing the fitting, it's a factory/company. If Suzuki released a FXR150 in an alloy chassis that was set up exclusively for racing, on slicks etc, oh wait and with a bigger (30%) carb fitted, race pipe, also 20% more revs would that be ok would it?
The std GPR50 has a 14mm carb, max power at 10K revs, the Metra has a 19mm carb and 12K revs.
Im sure it starts as a std engine, but if the Forza 155 pit bike was considered unsuitable because its a competition engine/machine I find it hard to believe that this Metrakit bike can be considered legal. If someone bought a Metrakit rolling chassis and then fitted a Derbi 50 fitted thats fine, but thats not what has happened here is it? It's been bought as a purpose built race bike and is sold as such. What next? a TZ250 is ok for F3 because a TZR250 Kocinski rep is based on the same thing? :eek:

Stop being stupid.

If Suzuki brought out that bike it would be legal, and I would buy 10 of them.
Carbs are open. Ignition is open. Pipe is open.
The engine is tock internally in the metrakit.
It doesn't matter for shit who puts the two of them together, that is a road engine, with a race ignition, pipe and carb.


The Forza is an engine build from the ground up as a race engine. So it is obviously in a different category.

[Drew]

Fuckin hell, there's enough rule arguments on these things to keep Biggles happy for years.

Note to self, unsubscribe as soon as someone brings a rule into question...Even if it's me.

[husaberg]

100cc single isn't capable of driving a turbo or supercharger fast enough to create that sort of boost. It would need to run a turbo and blower. Start with an XL250 bottom end and you've got a bottom end capable of taking 40 horses.

There would be a lot of engineering, but there's no reason it can't be reliable.


Yes it is but in the case of a Supercharger the real problem with supercharging a single is the fact the bangs are 720 degrees apart that bit can be got around with a suitable plenum chamber or suitable volume the other problem is the intermittent firing plays havoc with the drive system with is why supercharged singles are not that common. RS engineering in the UK did a Yamaha 660 five valve (Tramonta) if memory serves me right that was one of the few real successes of the concept (70hp) there was a bit of pre and post war stuff as well but the ban on supercharging ended them. I can remember a copper Manx norton the intake pipe was around 6 foot long. Of course a 100cc twin esp with a 360 crank would not have these problems to the same extent. but as Dave mentioned it is no a simple procedure the major hurdle is the expense of the beefed up custom parts required as well as the programmable ignition the inter cooler a the water injection the riding rate pressure regulator if using carbs (possible with a pitot tube and suitable CV carbs and mods) but preferable fuel injection special valves it start to get super expensive.. My one stalled when I could find a suitable forged piston and i figure how much the destroking and the primary drive pinion mods was going to cost.

The xl250 is not a goer in my eyes as it would need a new crank (stroke) and the bore is way to big.

I would start with a Aisin amr 300 super charger off a 660 kei class car there is a few about.

the turbo is not really a going for circuit racing or is any centrifugal supercharger as the bottom end is shit and as they are made for a motor 6x the size. The beauty of the roots blower is it can be geared for max boost and will work at all revs not the most efficient blower (screw) is better for the application we would use but available and capable of being downsized if required (not Nes in this Ap just drive a Half speed for around 22psi)


A wee bit of light reading below.

http://www.x386.net/TTR/tech/cgi-bin/charger.cgi
http://victorylibrary.com/supercharger/super-drive4.htm
http://webcache.googleusercontent.com/search?q=cache:ie5FgkvVv7gJ:geometroforum.com/topic/3691319/1/+TURBO+IHI+RHB31+COMPRESSOR+MM&cd=1&hl=en&
ct=clnk&gl=nz&source=www.google.co.nz (http://webcache.googleusercontent.com/search?q=cache:ie5FgkvVv7gJ:geometroforum.com/topic/3691319/1/+TURBO+IHI+RHB31+COMPRESSOR+MM&cd=1&hl=en&ct=clnk&gl=nz&source=www.google.co.nz)
http://www.dune-buggy.com/turbo/fuelsystem.htm
http://autospeed.com/cms/title_Supercharger-Steal-Part-One/A_110294/article.html
http://superchargersunlimited.com/specs.html
http://autospeed.com/cms/A_1931/article.html
http://www.elsberg-tuning.dk/supercharging.html
http://forums.nasioc.com/forums/showthread.php?t=570978
http://www.diygokarts.com/vb/showthread.php?t=9460
http://www.vespalabs.org/User:Internetscooter/Scooters/Dry_Lake_Racer/2011_Upgrades/IHI_RB31_Turbo_Charger
http://www.triumphexperience.com/article/how-to-blow-through-an-su.html
http://autospeed.com/cms/title_The-Complete-Guide-to-Intercooling-Part-2-/A_107760/article.html
http://www.turbomirage.com/water-alcohol-injection-links.html
http://www.nicoclub.com/archives/alcohol-and-water-injection-the-basics.html
http://www.injectacarb.com.au/fuel-pressure-regulator-malpassi-rising-rate-p-91.html?osCsid=7f20a539b789
http:// (http://webcache.googleusercontent.com/search?q=cache:3ERQfYxaKrMJ:www.dragbike.com.au/forum/viewtopic.php%3Ff%3D6%26t%3D23+blow+through+cv+car b&cd=1&hl=en&ct=clnk&gl=nz)www.dragbike.com.au/forum/viewtopic.php%3Ff%3D6%26t%3D23+blow+through+cv+car b& (http://www.dragbike.com.au/forum/viewtopic.php%3Ff%3D6%26t%3D23+blow+through+cv+car b&)
http://www.summitracing.com/parts/MAA-4309/
http://www.turbogemini.com/Turbo Accessories.htm
http://feralinjection.com/cbr.html
http://www.rbracing-rsr.com/waterinjection.html
http://www.ty4stroke.com/viewtopic.php?t=29536
http://victorylibrary.com/supercharger/super-carb6.htm
http://www.thefang.co.uk/news2008.htm
http://www.superchargersonline.com/hp_calculator.asp?submit=1
http://www.caferacer.net/forum/topic.asp?TOPIC_ID=16606&whichpage=2
http://www.chinese-parts-canada.com/turbocharger_fuel_injection.html
http://www.streettuned.com.au/index.php?_a=viewProd&productId=1494
http://www.megasquirt.info/
http://autospeed.com/cms/title_The-Nitrous-Fuel-Controller-Thats-Also-a-Lot-More/A_2546/article.html
http://www.siliconchip.com.au/cms/A_103609/article.html
http://mastercircuits.blogspot.com/2010/05/small-engine-efi-conversion-kit.html
http://forums.evolutionm.net/other-cars/265923-i-can-turbocharge-anything-6.html

[koba]

I rection one could also find the smallest turbo available (I've seen a tiny one on a diesel generator) and turn down the turbine and impeller. One could then make inserts to go in the housing and make it all match up again.

Bah, May work, may not. All just un-academic musings until someone wastes a whole pile of coin on it that would probably be better spent elsewhere.

Watch for some interesting developments if I ever win lotto.

[Moooools]

Turbo would be good if you were prepared to burn some coin on a boost controller and an anti-lag computer.
After that it wouldn't be much worse to ride than those pesky 2 strokes.

[Drew]

Turbo would be good if you were prepared to burn some coin on a boost controller and an anti-lag computer.
After that it wouldn't be much worse to ride than those pesky 2 strokes.

No need for fancy computers, anti lag can be made with an small fuel pump, a diesel injector, and a micro switch on your clutch lever. If ya wanted to get fancy you could put a timer on it so it only pulses a certain amount of time each pull of the clutch, to save having a foot long flame out the pipe when your waiting for the flag.

Boost control is easily controlled with a pneumatic waste gate actuator, and just as easily made to be adjustable.

[jasonu]

Fuckin hell, there's enough rule arguments on these things to keep Biggles happy for years.

Note to self, unsubscribe as soon as someone brings a rule into question...Even if it's me.

That someone sure as hell won't be the MNZ!

[50bucketracer]

The std GPR50 has a 14mm carb, max power at 10K revs, the Metra has a 19mm carb and 12K revs.
Im sure it starts as a std engine, but if the Forza 155 pit bike was considered unsuitable because its a competition engine/machine I find it hard to believe that this Metrakit bike can be considered legal. If someone bought a Metrakit rolling chassis and then fitted a Derbi 50 fitted thats fine, but thats not what has happened here is it? It's been bought as a purpose built race bike and is sold as such. What next? a TZ250 is ok for F3 because a TZR250 Kocinski rep is based on the same thing? :eek:

Sorry for the lag; just catching up with postings on this forum & I see some crossed wires here.

There were 2 versions of the Metrakit 50 when the bike in question was manufactured. One had a race modified motor with different cylinder, big carb etc & made a claimed 19hp. The other had a bog standard Derbi 50 motor with standard cylinder, standard 13mm carb, standard ignition etc & made a real 10hp. They may have changed the spec in 2011, but that was the deal in 2004. The bike for sale is the standard engined version, exactly as you say - a Metrakit race chassis fitted with a standard Derbi 50 engine. Check it out if you want.

Even in that 10hp form with 12" wheels it was fast enough that with a 13 year old rider it lead the 2008 F5 GP ahead of Mark Lattimer, F5 Dave & myself. Just a pity that a brake problem prevented it finishing the race...

[RMS eng]

Sorry for the lag; just catching up with postings on this forum & I see some crossed wires here.

There were 2 versions of the Metrakit 50 when the bike in question was manufactured. One had a race modified motor with different cylinder, big carb etc & made a claimed 19hp. The other had a bog standard Derbi 50 motor with standard cylinder, standard 13mm carb, standard ignition etc & made a real 10hp. They may have changed the spec in 2011, but that was the deal in 2004. The bike for sale is the standard engined version, exactly as you say - a Metrakit race chassis fitted with a standard Derbi 50 engine. Check it out if you want.

Even in that 10hp form with 12" wheels it was fast enough that with a 13 year old rider it lead the 2008 F5 GP ahead of Mark Lattimer, F5 Dave & myself. Just a pity that a brake problem prevented it finishing the race...

just a side note,Marks GP winning Aprilia 50 may be for sale if any one is after a fast 50 race bike.

[Henk]

Could be keen. Let me know as and when. Seem to be building up an F5 collection at the moment

[Dutchee]

Could be keen. Let me know as and when. Seem to be building up an F5 collection at the moment
No dear, I have my F5 bike, you have my reject parts to sort out into a "running" F5 bike. See the difference. I'm not cursing my mechanic, I'm having fun.

[husaberg]

No need for fancy computers, anti lag can be made with an small fuel pump, a diesel injector, and a micro switch on your clutch lever. If ya wanted to get fancy you could put a timer on it so it only pulses a certain amount of time each pull of the clutch, to save having a foot long flame out the pipe when your waiting for the flag.

Boost control is easily controlled with a pneumatic waste gate actuator, and just as easily made to be adjustable.

The lag is not really the problem I am referring too although it will be a real issue with a supercharger designed for at beat an engine 6x the size.
Any kind of anti lag will not get around this simple problem size. Whilst it may be possible to get it to spool up, it will still have an incredibly peaky power curve.
Where as a supercharged engine with a Rootes style blower will be user friendly and have no issues to deal with lubrication either.

[Drew]

The lag is not really the problem I am referring too although it will be a real issue with a supercharger designed for at beat an engine 6x the size.
Any kind of anti lag will not get around this simple problem size. Whilst it may be possible to get it to spool up, it will still have an incredibly peaky power curve.
Where as a supercharged engine with a Rootes style blower will be user friendly and have no issues to deal with lubrication either.


Anti lag goes on a turbo, a supercharger doesn't need it because it is always spinning. It is true that a turbo is peaky in it's power delivery, which is why I say to run both. Supercharger to get things moving, turbo to create power up high.

Lubrication isn't really fuck all to worry about, it's dead simple most of the time.

It's all time consuming to build and engineer though, so I've got a better idea. N.O.S! It's cheap, it's fuckin easy, and it's readily available.

[Gigglebutton]

Use the Nos before the turbo spools up = no lag

[grantnz]

I rection one could also find the smallest turbo available (I've seen a tiny one on a diesel generator) and turn down the turbine and impeller. One could then make inserts to go in the housing and make it all match up again.

Bah, May work, may not. All just un-academic musings until someone wastes a whole pile of coin on it that would probably be better spent elsewhere.

Watch for some interesting developments if I ever win lotto.javascript:

http://www.ebay.com/itm/110695313833?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Heres one for you...

[husaberg]

Sorry if this sounds like a sermon It is not meant to. I enjoy your give it a go spirit. Or as it may be, give it a go after spirits.

This is not about scoring points it is just about getting some basics established.



Anti lag goes on a turbo,

Anti lag is not is not solving the problem. While it may help a little. The problem is the turbo designed for an engine 6-9 times the size. With more cylinders.
Anti lag is to do that lessen lag of a slightly oversize or trimed turbo not a hugely 6-9 times oversized turbo. you may get away with 3-4 times 6-9 is asking a bit much.

For instance this turbo

250855 (http://www.nitrous.info/motorcycle-nitrous-injection-system.htm)

http://www.ebay.com/itm/110695313833?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
posted above is designed for a 660 cc 3 cylinder and i believe it was also used on a cx500 turbo possibly. It has been used on a lot of bikes but is not likely to be effective on a 100cc engine without significant mods.


It is true that a turbo is peaky in it's power delivery

A correct size and trimmed turbo will have a nice flat power curve. With the waste gate controlling over boost.
A rootes blower achieves a fixed rate of delivery say 300cc (Aisin AMR300) it will provide 300cc per revolution, IE a fixed rate of boost regardless of speed.IE 1.5 atmospheres above base for a 100cc engine if driven at half engine speed. About 22psi with is possible with legal fuel plus water injection high quality engine internals and effective intercooling more boost is possible with a more efficient blower or turbo.
Not all superchargers are Rootes style. the are also vane, screw and some common ones are centrifugal like a turbo.http://victorylibrary.com/supercharger/super-choices3.htm
but their design is not 2x the boost a twice the revs. like people seem to think they have a real curve biased to the top end
ie In general, centrifugal superchargers or turbo's produce boost in direct proportion to their displacement per revolution, and the square of their rotational speed

Yes a waste gate can control this.
On a adequately sized application not a problem. but it will do nothing on this application. As the turbo is over sized rather than undersized.


which is why I say to run both. Supercharger to get things moving, turbo to create power up high..

A superturbo

250853250854

would be a great idea but they are still to large and complex and heavy. An overriding electromagnetic clutch also used on the MR2 would make it easy.
This set up was available on the Nissan march mircocar in the early 80s. But and its a big But.
It used the same size turbo and supercharged that is being talked about here but on a engine 9x the size.



Lubrication isn't really fuck all to worry about, it's dead simple most of the time.
Unless of course you have low pressure lube system like pretty much all the bikes that are bucket size or legal. the turbo needs decent pressure and cool clean oil.

As well the engine if it was to produce 40-45hp will need a 40-45 hp cooling system. It will need to be water cooled if it was to survive on petrol and more than just short bursts.



so I've got a better idea. N.O.S! It's cheap, it's fuckin easy, and it's readily available.

NO2 is great and easy it is also illegal i thought it would be sweet but lost a chocolate fish with Jason on it. The party poopers at the MNZ already ruled it illegal.

http://www.mnz.co.nz/newsDetail.aspx?SectionID=29&ArticleID=28927

It is fun and cheap though. A real giggle as it were..

http://www.nitrous.info/motorcycle-nitrous-injection-system.htm

(http://www.nitrous.info/motorcycle-nitrous-injection-system.htm)http://www.nitrous.info/nitrous-faq.ht (http://www.nitrous.info/nitrous-faq.htm)m


(http://www.nitrous.info/motorcycle-nitrous-injection-system.htm)

[Drew]

I'm a bit gutted that NO2 isn't allowed. It's no different to turbo or supercharging in essence.

You are obviously well versed in turbo technology dude, but I think you are also over thinking it. I know a bit about chucking a turbo on a motor it doesn't belong on, I've done it once or twice. And lots of people who have taken it further.

There are tiny turbo's out there, and it is quite possible to make them smaller to accommodate the smaller engine displacement.

The engineering is extensive for sure, and the limiting factor in my opinion.

[speedpro]

One of the things you can do to increase the rate of spool-up is to plumb in a volume between the manifold and the wastegate actuator with a small bleed controller. This causes delay in actuating the waste gate as the volume takes time to fill through the bleed so the pressure at the actuator stays low for longer and the wastegate stays closed for longer allowing maximum gas flow "through" the turbo. This also has the added advantage if the motor is already making power but off boost that you will get a momentary over-boost when you open the throttle. I played with this on a Nissan Gazelle with an RB20DET and it worked real good. With the bleed controller I machined up I could easily control the momentary overboost and max boost as well. The Gazelle only ran 5lbs stock but was quite happy with 11lbs on the dyno and the gas analyzer.

With even the smallest turbo though I don't think it's going to be an issue as getting any boost will be a problem on a bucket engine.

As stated also if the turbo suits the engine the power curve will be huge and flat if all is well, and by winding in the waste gate for more peak boost it will also have an effect on spool-up and off-peak boost available as wastegates creep open bleeding off gas before peak boost value is reached which slows spool-up. I ran 19psi in my big bike at Taupo once and it pulled noticeably more boost at various revs lower down when the throttle was opened.

[nudemetalz]

It's amazing what has come out of this thread after my original O/P of 100cc four-strokes ;)

[Drew]

It's amazing what has come out of this thread after my original O/P of 100cc four-strokes ;)

I raised the turbo question to find out if it could be done to a 100cc bike. Kinda got out of control.

[husaberg]

It's amazing what has come out of this thread after my original O/P of 100cc four-strokes http://www.kiwibiker.co.nz/forums/images/smilies/wink.gif

The same old arguments. Sorry





One of the things you can do to increase the rate of spool-up is to plumb in a volume between the manifold and the wastegate actuator with a small bleed controller. This causes delay in actuating the waste gate as the volume takes time to fill through the bleed so the pressure at the actuator stays low for longer and the wastegate stays closed for longer allowing maximum gas flow "through" the turbo. This also has the added advantage if the motor is already making power but off boost that you will get a momentary over-boost when you open the throttle. I played with this on a Nissan Gazelle with an RB20DET and it worked real good. With the bleed controller I machined up I could easily control the momentary overboost and max boost as well. The Gazelle only ran 5lbs stock but was quite happy with 11lbs on the dyno and the gas analyzer.

With even the smallest turbo though I don't think it's going to be an issue as getting any boost will be a problem on a bucket engine.

As stated also if the turbo suits the engine the power curve will be huge and flat if all is well, and by winding in the waste gate for more peak boost it will also have an effect on spool-up and off-peak boost available as wastegates creep open bleeding off gas before peak boost value is reached which slows spool-up. I ran 19psi in my big bike at Taupo once and it pulled noticeably more boost at various revs lower down when the throttle was opened.

Yes thats what i was trying to explain to Drew was that the turbo has to be sized to the engine and it is asking a bit much for a turbo designed for instance for a 7 liter diesel to work great on a 1300cc escort for instance. Anti lag or not.

With the bit you brought up waste gate creep is now commonly controlled with a electronic boost controller with a blow off valve to control transient throttle conditions as most performance engine now do. You can make one your self quite easily if you are keen on the soldering and so on.They were commonly based on debounce circuits from memory.
The bleed into a chamber kind of intrigues me?
Or are you just talking of a plain air bleed to fool the factory set limit? oh i see you mean this.http://autospeed.com/cms/A_107770/article.html i had never seen it before.


On the previous page i posted some useful links that explains a lot in common terms.
The victory library and the Autospeed pages are well worth a look for anyone contemplating forced induction.

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]--> http://victorylibrary.com/supercharger/super-carb6.htm
http://autospeed.com/cms/A_1931/article.html
<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]--> (http://autospeed.com/cms/A_1931/article.html)http://autospeed.com/cms/A_110294/article.html
http://autospeed.com/cms/A_110213/article.html
http://autospeed.com/cms/A_108651/article.html






(http://autospeed.com/cms/A_1931/article.html)

[husaberg]

I'm a bit gutted that NO2 isn't allowed. .

Your telling me probably not as gutted as I was. Although I felt a lot better after I ate the Chocolate fish I had brought for Jason to settle the bet.
The thing the MNZ cretins never picked up on was it is not a fuel. It is an oxidiser.:brick:


.there are tiny turbo's out there, and it is quite possible to make them smaller to accommodate the smaller engine displacement.
The engineering is extensive for sure, and the limiting factor in my opinion .
For sure but probably not worth it when supercharging is so much easier.
I still stick by the original bit about the best results either way would be with a twin. (more weight)
The last project I gave a rough costing to was over $5000. It could be done cheaper of course if all the right parts come up at the right time.

The ancillary parts are the real killer for money and for space.

[Bert]

Your telling me probably not as gutted as I was although after I ate the Chocolate fish I had brought for Jason to settle the bet. I felt a lot better.
The thing the MNZ cretins never picked up on was it is not a fuel it is an oxidiser.
.


what about increasing the dissolved oxygen levels in the fuel???
http://www.patents.com/us-6273072.html

we use a similar technique for the calibration of environmental sensors
(can't really get 100% saturation but you can get to about 90% at 15 degrees; which is about a 30% increase in dissolved oxygen).

no idea what the levels are in fuel nor what improvement to combustion it would even make???

I did read somewhere that the biggest improvement to fuel is to keep it as cold as you can (on ice in the shade); in essence will stop the losses of both small chain hydrocarbons and dissolved oxygen levels. thus the above kind of makes sense...

[husaberg]

what about increasing the dissolved oxygen levels in the fuel???
http://www.patents.com/us-6273072.html

we use a similar technique for the calibration of environmental sensors
(can't really get 100% saturation but you can get to about 90% at 15 degrees; which is about a 30% increase in dissolved oxygen).

no idea what the levels are in fuel nor what improvement to combustion it would even make???

I did read somewhere that the biggest improvement to fuel is to keep it as cold as you can (on ice in the shade); in essence will stop the losses of both small chain hydrocarbons and dissolved oxygen levels. thus the above kind of makes sense...

Some of the race fuels have this but again its illegal to modify the fuel in a bucket.



If you wanted to go the whole hog in a Forced aspirated the 80's F1 fuel Jungle juice was 84 percent Toluene (available from almost any fuel distributer)the rest was N heptane.

No doubt it is in unleaded fuel now in NZ.

They also used to add water to the fuel as well after briefly using water injection. Not as easy as it sounds, do not try this a home.http://autospeed.com/cms/A_110213/article.html

In a modded car it can be used, Either on demand with either a micro switch or preferable a pressure switch triggered by the boost level that it is required at.

I have an article about it from one of my fav Tech editors I will post later.

[TZ350]

Oxiginating pump gas http://www.patents.com/us-6273072.html

"A combustion engine fuel system apparatus saturates and diffuses a gas, such a air, into a liquid fuel."

Thats an interesting idea, diffusing air (oxigen) into the fuel on its way to the carb in much the same way as Co2 is diffused into softdrinks, now there is a thought.

(pls don't try this with raw oxygen unless spontanious combustion is your thing, those warnings about grease and oil on oxygen gauges arn't there just for fun)


but again its illegal to modify the fuel in a bucket.

Which rule covers it?

[husaberg]

Oxiginating pump gas http://www.patents.com/us-6273072.html

"A combustion engine fuel system apparatus saturates and diffuses a gas, such a air, into a liquid fuel."

Thats an interesting idea, diffusing air (oxigen) into the fuel on its way to the carb in much the same way as Co2 is diffused into softdrinks, now there is a thought.

(pls don't try this with raw oxygen unless spontanious combustion is your thing, those warnings about grease and oil on oxygen gauges arn't there just for fun)



Which rule covers it?

It would be the fuel one? why?
http://www.mnz.co.nz/competitionrules.aspx
Appendix E oxygenates.

you can just give the Choc Fish direct to Jason U. I think he is also willing to accept Peanut slabs.

[Grumph]

When is open fuel not open ? When it's limited to Methanol....

Back in the day, Tolulene was very useful in bikes here in Nz because it simplified the fuel delivery system...

Ford found when they went to Indy with the pushrod V8's that an 80/20 meth/tol blend gave 20% better economy than straight meth...one pitstop less at Indy. When both straight meth and the blend were optimised straight meth won out by 2% on HP but as I said the blend was 20% better on economy.
How does this help us ? For one thing you can run it through taps sized for petrol...and use a carb set for a rich petrol mixture rather than modified for meth. The blend keeps better than straight meth too - less willing to pick up water.

The blend was a great base for adding nitro too - keep the same tol % but reduce the meth content, replacing with nitro. The tol seemed to assist in lighting the mixture.

Ah, the memories...and the smells....

[speedpro]

In a modded car it can be used, Either on demand with either a micro switch or preferable a pressure switch triggered by the boost level that it is required at.



What I did for my on-boost fuel enhancement was cast a cylinder and piston. The piston has a spring on one side and boost pressure on the other. The spring has a threaded adjuster to vary the preload and therefore the boost pressure at which the piston lifts off it's seat. Screwed into the piston is a 6mm shaft which extends through a seal into a fuel metering cavity. At the end of the shaft is a tapered needle which projects through a jet. With no boost the needle seats on the jet with an o-ring completely sealing off the fuel flow. Boost pressure at which it activates is adjusted with the spring preload, Initial fuel flow is set by the needle base diameter and the jet size, and the fuel delivery progression is controlled by the needle taper being lifted through the jet as boost is increased. One "problem" I had was getting a good seal where the shaft went through the seal. In the end I figured it was better without a good seal because even with a short small diameter delivery tube from the valve to the carb there was a brief delay every time it opened before the extra fuel got to the carb inlet. With a poor seal a little inlet manifold pressure leaked past the seal and blew the fuel down down the delivery tube.

I also reconfigured one to control the pressure in the fuel tank. Manifold pressure is used to pressurize the tank. At startup the tank is pressurized manually but once running relies on manifold pressure to keep the pressure up. The problem I had was that pressure would drop and not enough fuel would flow to the carb to create much boost for long. I needed a device that would flow a lot of air to pressurize the tank but which also limited the pressure to a set value.

I still have a few I haven't machined yet.

[husaberg]

When is open fuel not open ? When it's limited to Methanol....

Back in the day, Tolulene was very useful in bikes here in Nz because it simplified the fuel delivery system...

Ford found when they went to Indy with the pushrod V8's that an 80/20 meth/tol blend gave 20% better economy than straight meth...one pitstop less at Indy. When both straight meth and the blend were optimised straight meth won out by 2% on HP but as I said the blend was 20% better on economy.
How does this help us ? For one thing you can run it through taps sized for petrol...and use a carb set for a rich petrol mixture rather than modified for meth. The blend keeps better than straight meth too - less willing to pick up water.

The blend was a great base for adding nitro too - keep the same tol % but reduce the meth content, replacing with nitro. The tol seemed to assist in lighting the mixture.

Ah, the memories...and the smells....

Yes the old rules used to allow a wee bit of Acetone as well to assist in the mixing of oil in the two strokes great stuff back in the leaded days.

[speedpro]

When is open fuel not open ? When it's limited to Methanol....

Back in the day, Tolulene was very useful in bikes here in Nz because it simplified the fuel delivery system...

Ford found when they went to Indy with the pushrod V8's that an 80/20 meth/tol blend gave 20% better economy than straight meth...one pitstop less at Indy. When both straight meth and the blend were optimised straight meth won out by 2% on HP but as I said the blend was 20% better on economy.
How does this help us ? For one thing you can run it through taps sized for petrol...and use a carb set for a rich petrol mixture rather than modified for meth. The blend keeps better than straight meth too - less willing to pick up water.

The blend was a great base for adding nitro too - keep the same tol % but reduce the meth content, replacing with nitro. The tol seemed to assist in lighting the mixture.

Ah, the memories...and the smells....

I've still got a tin of Toluol in the shed. I quickly learnt which type of plastic jug to use when mixing. I was running 75% Methanol, 25% 100 octane, a litre of Toluol for every 20L of mix, and enough Acetone to blend - about 400mL per 20L. You needed all the doors and windows open as well when mixing - some serious fumes from that stuff.

The unleaded shit we buy for fuel now has a high percentage of Toluol/Toluene which is the reason why there was a few car fires after the switch from leaded to unleaded - the fuel lines were dissolved, only if they were using crap plastic line from the local hardware store.

[husaberg]

What I did for my on-boost fuel enhancement was cast a cylinder and piston. The piston has a spring on one side and boost pressure on the other. The spring has a threaded adjuster to vary the preload and therefore the boost pressure at which the piston lifts off it's seat. Screwed into the piston is a 6mm shaft which extends through a seal into a fuel metering cavity. At the end of the shaft is a tapered needle which projects through a jet. With no boost the needle seats on the jet with an o-ring completely sealing off the fuel flow. Boost pressure at which it activates is adjusted with the spring preload, Initial fuel flow is set by the needle base diameter and the jet size, and the fuel delivery progression is controlled by the needle taper being lifted through the jet as boost is increased. One "problem" I had was getting a good seal where the shaft went through the seal. In the end I figured it was better without a good seal because even with a short small diameter delivery tube from the valve to the carb there was a brief delay every time it opened before the extra fuel got to the carb inlet. With a poor seal a little inlet manifold pressure leaked past the seal and blew the fuel down down the delivery tube.

I also reconfigured one to control the pressure in the fuel tank. Manifold pressure is used to pressurize the tank. At startup the tank is pressurized manually but once running relies on manifold pressure to keep the pressure up. The problem I had was that pressure would drop and not enough fuel would flow to the carb to create much boost for long. I needed a device that would flow a lot of air to pressurize the tank but which also limited the pressure to a set value.

I still have a few I haven't machined yet.

Thanks Mike.
I just assumed you meant a bleed i had not long finished editing my reply to your origional after i clicked on to it on rereading it. If you go back a page there is a pic of it on the Autospeed. site I can spend hours there.http://autospeed.com/cms/A_107770/article.html

[Grumph]

If you have a sealed tank you shouldn't need a vast quantity of pressure air. I've seen a roadrace sidecar which had a small accumulator which was pumped up prior to use and pressurised the tank to 5 psi via a regulator. Good for a days racing at least.
Frame spars can and have been used for the same purpose.

[speedpro]

I could leave it sitting in the garage and it would hold pressure fine. However in use the pressure dropped quickly on the first lap and basically you had to give it a bit of boost to keep the tank pressure up initially which could be a bit spooky on cold tyres etc.

[jasonu]

The unleaded shit we buy for fuel now has a high percentage of Toluol/Toluene which is the reason why there was a few car fires after the switch from leaded to unleaded - the fuel lines were dissolved, only if they were using crap plastic line from the local hardware store.

In the mid 90's they started importing petrol from (I think) some Asian country and that is when, as Mike said, there were car fires caused by fuel lines dissolving. IIRC it was mostly old shitters like cortinas. My bucket ran like shit on the new fuel so I resorted to illegal Avgas. I didn't make any secret about it and nobody objected. The bike didn't run any better on av than it did on the old leaded stuff but it did run properly.

[speedpro]

Thanks Mike.
I just assumed you meant a bleed i had not long finished editing my reply to your origional after i clicked on to it on rereading it. If you go back a page there is a pic of it on the Autospeed. site I can spend hours there.http://autospeed.com/cms/A_107770/article.html

That was something else. The bleed device was a restrictor with a variable bleed off to atmosphere. The more bleed the higher boost was needed to actuate the waste gate. The restrictor slowed down filling the volume which "delayed" the actuation of the waste gate which resulted in a momentary overboost which most engines can handle. We're only talking +3 to 5psi for say 2 or 3 seconds.

[husaberg]

That was something else. The bleed device was a restrictor with a variable bleed off to atmosphere. The more bleed the higher boost was needed to actuate the waste gate. The restrictor slowed down filling the volume which "delayed" the actuation of the waste gate which resulted in a momentary overboost which most engines can handle. We're only talking +3 to 5psi for say 2 or 3 seconds.

I was meaning this one


One of the things you can do to increase the rate of spool-up is to plumb in a volume between the manifold and the wastegate actuator with a small bleed controller. This causes delay in actuating the waste gate as the volume takes time to fill through the bleed so the pressure at the actuator stays low for longer and the wastegate stays closed for longer allowing maximum gas flow "through" the turbo. This also has the added advantage if the motor is already making power but off boost that you will get a momentary over-boost when you open the throttle. I played with this on a Nissan Gazelle with an RB20DET and it worked real good. With the bleed controller I machined up I could easily control the momentary overboost and max boost as well. The Gazelle only ran 5lbs stock but was quite happy with 11lbs on the dyno and the gas analyzer.

With even the smallest turbo though I don't think it's going to be an issue as getting any boost will be a problem on a bucket engine.

As stated also if the turbo suits the engine the power curve will be huge and flat if all is well, and by winding in the waste gate for more peak boost it will also have an effect on spool-up and off-peak boost available as wastegates creep open bleeding off gas before peak boost value is reached which slows spool-up. I ran 19psi in my big bike at Taupo once and it pulled noticeably more boost at various revs lower down when the throttle was opened.

[TZ350]

It would be the fuel one? why?
http://www.mnz.co.nz/competitionrules.aspx
Appendix E oxygenates.

250914

The bucket rules must be talking about Alcohol fuel additives only as they also refer to 10.17.1 which says that FIM equivalent is OK for solo road racing ....

250915

And FIM allows for 2.7% oxygenates by mass.

The way I read it, you can dissolve enough air into the fuel to get 2.7% by mass of oxygen into unleaded and be legal.

[jasonu]

250914


The way I read it, you can dissolve enough air into the fuel to get 2.7% by mass of oxygen into unleaded and be legal.

But who would officially and properly police it? (in a self policeing class)

[husaberg]

250914

The bucket rules must be talking about Alcohol fuel additives only as they also refer to 10.17.1 which says that FIM equivalent is OK for solo road racing ....

250915

And FIM allows for 2.7% oxygenates by mass.

The way I read it, you can dissolve enough air into the fuel to get 2.7% by mass of oxygen into unleaded and be legal.

That's the way i read it. but, they will already be close to that if not that already. ie from vibration and the stuff already in it. So you may be out of luck.


If not it can be our secret.

[TZ350]

But who would officially and properly police it? (in a self policeing class)

250916 ... bugger

It will be easy to see who has over cooked it ....

[husaberg]

But who would officially and properly police it? (in a self policeing class)

Good point I hear Yamaha R1's might well be legal now. I might be in with a chance with one of them. Until someone else gets one.

Police is a good anology as they seem to be mainly used as a revenue gathering tool now. sounds familiar.:rolleyes: Although they do (The police rather than the MNZ)seem to at least police the rules.

[jasonu]

250916

You will be able to tell those that have over done it, they will be the ...

...ones suddenly doing all the winning.

[Bert]

A can of worms I see.... maybe I shouldn't have started this conversation.:facepalm:

That will teach me for waking up early on a Saturday with out a hangover and posting something stupid..

[husaberg]

A can of worms I see.... maybe I shouldn't have started this conversation.:facepalm:


Heya,

Yes I do still look at the buckets even though I don't do it anymore...

Got a question...has anyone done a competitive four-stroke F5 bike?
I assume a good base would be an XL-100S (as the limit is 104cc) and ...ahem,..XR-100 parts are fairly easy to find (I would say they're identical internally).

Just,...ummm....curious... http://www.kiwibiker.co.nz/forums/images/smilies/wink.gif

It's amazing what has come out of this thread after my original O/P of 100cc four-strokes http://www.kiwibiker.co.nz/forums/images/smilies/wink.gif

F5 anyone i hear thats what this thread was about. Any one got a xl100s crf100 xr100 xr75 could make a good fun f5:wacko:

[Henk]

F5 anyone i hear thats what this thread was about. Any one got a xl100s crf100 xr100 xr75 could make a good fun f5:wacko:

Strangely enough in the past year there have been four bikes built up here running small Honda four strokes and one that I know of that will hopefully be finished in the next couple of months. Some are definite works in progress and some go quite well. F5 is a blast and in Auckland seems to be the way to get completely new riders started without having to deal with big fields and some quite fast guys on fast bikes. They aren't competitive with the quick two strokes but there are starting to be enough of them that the mid field battles are becoming interesting.

[husaberg]

Strangely enough in the past year there have been four bikes built up here running small Honda four strokes and one that I know of that will hopefully be finished in the next couple of months. Some are definite works in progress and some go quite well. F5 is a blast and in Auckland seems to be the way to get completely new riders started without having to deal with big fields and some quite fast guys on fast bikes. They aren't competitive with the quick two strokes but there are starting to be enough of them that the mid field battles are becoming interesting.


Are they the XR100 style motor or the small bore ie cb100 125 style motor?

[Henk]

Some of both. The xr style seems the better bet, smaller lighter, parts easily available, but only a five speed.

[husaberg]

Some of both. The xr style seems the better bet, smaller lighter, parts easily available, but only a five speed.

Did you miss the same gear ratios as the mb100 bit.
same output sprocket to.
Coincidence i think not.

I should check out the part numbers really.

Later

Well they seem to be a mix of both.
The bearings do differ but that shouldn't be a major problem.
definitely warrants further investigation me thinks.

to be continued..................

[Buckets4Me]

Did you miss the same gear ratios as the mb100 bit.
same output sprocket to.
Coincidence i think not.

I should check out the part numbers really.

Later

Well they seem to be a mix of both.
The bearings do differ but that shouldn't be a major problem.
definitely warrants further investigation me thinks.

to be continued..................

I have a much easier solution but not going to spill the beans till my 100 turboed monster is going :bleh::eek:

[husaberg]

I have a much easier solution but not going to spill the beans till my 100 turboed monster is going :bleh::eek:

pics or it never happened

[Buckets4Me]

pics or it never happened

bugger now i need to download photoshop (well all the big engines used one program or another)