ESE's works engine tuner

[TZ350]

late model RGV250 cylinder bored out +1.5mm for the max oversize capacity allowed (130.5cc) for an F4 air cooled cylinder. 130.5cc is 12% more total capacity than allowed for a 100cc water cooled F4 engine. And that is the easiest 12% more power you will ever get.

As power is proportional to the percentage increase in bore diameter for a bored out two stroke cylinder the best you can hope for is an increase in power of 2.7 % for a 57.5 mm bore v's a 56 mm bore. 100 x ( 57.5 - 56.0 ) / 56.0

And that is only true if you enlarge all port widths by the (new bore / old bore) ratio.

Just boring out a cylinder will not alter the angle.areas; it will only decrease the specific angle.areas and it will force you to lower the revs if you wish to keep the original time.areas. In short: the same power with less revs.

But the larger bore will worsen the combustion chamber shape; combustion will be slower and it will heat a larger piston crown area, increasing the deto risk.

Ok not such a great potential power increase ...

....... right!!!! ... now put your hand up, whoever said ... ""there is no substitute for Cu inches"" ...

[TZ350]

Page 890 .....

First question being, where's the best place to buy a decent crucible, clay,sand etc. around here? (ie Auckland/upper North Island).

Cheers,
Will.

Foseco Ltd
David at 09 267 7658
And
Industrial sands Ltd 09 833 7576

Pouring the metal for the YZ360 Crankcases. These could just a s easily be cases for a bucket.......

Yes you can do that with the Ecotrons system too, but I am not sure myself how its done.

Thank you ... I had no idea where to start so it looks like it was pretty much a self inflicted problem and it was the Ecotrons support team that sorted it. After looking at the data I sent them they sent back a calibration file and map that got me started.

The map is very different, and I will try and compare the old and new calibration files to see if there are any "Subtle" differences in the control setup.

Attachment 291791

I like their hardware, it comes with its own wiring loom and is so easy to install.

For anyone wanting to try EFI on a small bike this is the Bees Knees for simplicity. The control algorithms appear to be every bit as professional as any top line EFI system.

And when Ecotrons develops their user software into something more friendly then this will be a very affordable and fun package.

I am looking forward to seeing how the other elements of the project, like the ball valve, boost bottle, chamber pressure valve and exhaust port dam work together with the EFI system.

Getting happier, after looking at my recorded data, Ecotrons support sent me a new cal file based on their idea of what I needed and that was good enough to get me going.

After a little adjustment to the global fuel factor I was able to pull some runs where injector-1 crossed over to injector-2 without all the bucking and banging like before.

The Ecotrons system has a really good data logging application where you can select any of the systems measured or calculated variables and log them.

Attachment 291757

Purple line is the throttle fully open or closed, Green line RPM, Brown intake manifold pressure and Red is load air charge/fuel.

Attachment 291758

RPM and injector on-time.

Large Pink line is rpm, lower Blue line is injector-1 to 7,000 rpm and the small Red hoop lines are Injector-2 up to 12,000 rpm.

The Pink line is rich and looks a little jagged below 7k and between 7 and 12k it looks better but I think a little lean. It will be very helpful when I get the O2 sensor working.

I was starting to get despondent before, but now an affordable Bucket racing fuel injection system is looking possible.

The proof will be in whether I can tune the map and get the Beast running real sharp.

The hardest thing for me was finding a starting point, if it all works out ok on the dyno, I will post my maps and setup data for anyone else wanting to have a go with their 2T.

Now that I have started putting the new air cooled motor together.

Attachment 291646

In the interests of science I have brought a data logger and 4 channel thermocouple interface from europerformance http://www.europerformance.co.nz/ who are a certified distributor for Innovate Motorsports and XT Racing and also carry other performance and race parts.

Attachment 291648

Pocket Data Logger $95 ... http://www.trademe.co.nz/Browse/List...x?id=677818916

Attachment 291647 http://www.europerformance.co.nz/pro...products_id=84

Thermocouple interface $145 ... http://www.trademe.co.nz/Browse/List...x?id=677819590

Attachment 291645

The plane is to use the data logger to help with developing some effective ducting for the new 30+ hp air cooled engine.

Maybe posted before, can't remember so here it is, well worth reading.

Detonation Management – The Key to 2stroke Power and Reliability
a technical paper by Harry and Gerhard Klemm of Klemm Vintage Racing Engines

http://www.klemmvintage.com/deto2.htm

Attachment 291641

Attachment 291586

Fuel Injected Suzuki 750

Attachment 291587

A very interesting collection of links to all sorts:- http://teamheronsuzuki.blogspot.nl/2...tam-rg500.html

Can your scope give you an FFT of the pickup? (http://en.wikipedia.org/wiki/Fast_Fourier_transform)

That way you can see a single peak at the current RPM and if it moves the single peak will move up or down the X axis, but if it is randomly missing revolutions you will get several peaks.



Hmmmm. Depending on how much crank inertia you have that can prove problematic. If your tune is spot on then it can run very happily. But if it isn't any sudden accelerations and decelerations can't be accounted for, which can put your spark and injection timing way on the piss, which just makes it all worse.

Single pulse trigger, not a multi tooth with gap type trigger wheel.

Attachment 291499

I am using the stator plate and pickup (no charging coil) and the flywheel from a KX80



Good thought, I will put the scope on it tommorow,

What type of trigger wheel are you using?

It isn't just running so damn rough that it is kicking the RPM signal around is it? I have seen it before.

Thankyou for the ecouragement, I have had a look at them and it will be where I go next if I have to.



Ecotrons confirm that adding another injector plug wired in parallel on a channel for two injectors is OK, but as its turned out, I have only been using 1 injector on each channel so the extra plug has been a handy measuring point for the scope.

The main problem is that I have seen on the scope screen the ECU dropping pulses just after the cross over point to the bigger second injector. This does not happen when the ECU is driven by the signal generator.

And if I set the system up to run only one injector it will run well past the troublesome cross over point for two injectors so I think the map and pickup are not the problem.

i found it interwrestling.

Rob with the Mirco squirt there is a software program that can self trim the mixtures does the econotrons have a silimilar setup?
http://www.megamanual.com/megatune.htm#autotune
The big potential advantage i can see with an electronic fuel injection set up is you could set it up to be "fuel cooled" to lessen power fade rather than any hp gains......

i had a gander at this the other day re the injector size..
http://www.rbracing-rsr.com/calcinjpulse.html
http://www.rbracing-rsr.com/fuelinjectors.htm
http://www.rbracing-rsr.com/efiharley.htm

So if I have this right there is closed loop feedback that tries to determine if the engine is doing something it is not supposed to be and corrects it, and you don't have control over that feedback? Or have you just not found the window that controls it yet? I take it you mean a hysteresis setting such as 'when acceleration gets over X remove Y much fuel until it is below Z acceleration'?

The more I have seen of the Ecotrons software the more it looks to be way over complicated. The fact that you have to input your injector size alone seems like a hugely redundant feature. Just so you have an idea here is the process we run on the Link:

We have a master fuel control that has a the pulse width control and a master fuel multiplier.

There is a setup sheet that deals with the base timings and setup of pickups and firing order.

A table that is RPM vs TPS for fuelling and ignition timing.

A table for start enrichment.

And that is everything to get the engine to run.
If you can I would highly recommend turning every damn fun feature of the Ecotrons off until you have just the fuel, ignition, and a start correction running. Get rid of any closed loop feedback to eliminate sensor issues. By this stage you should be down to 2 variables that control every point, rather than 10 and then some more that you don't know. Try to do all of your changes just on your fuel and ignition tables, avoiding making changes to the master fuel enrichment and the injector settings. Even if there are still some spots that run rough don't worry about it until you can get the thing to rev to whatever you want it to rev to. Then put in a rev limiter. Then put in acceleration and overrun enrichment. Then do the rest of the closed loop control as you see it needs it. Usability first, then complexity.

If all fails then use the link.

Thank you for the offer, I think if I had of borrowed Flettners Link and with your help I would have been up and running long ago.

but I am keen to get the Ecotrons working properly if I can, then we can afford to fuel inject some of our other bikes too.

I have been able to run the Ecotrons on a single bigger injector to 12,000 rpm which suggests its not lean map settings and I have tried other tricks like under reporting the size of the second injector so the system will run rich after cross over. With the settings rich on one injector the engine will continue to run (badly) but not hunt violently like it still does on two however rich I make the second one.

The problem seems to be that the Ecotrons EFI system with 2T split injection runs and crosses over to injector 2 OK all the way to 13,000+ rpm when its driven by a signal generator.

But when its running live with the motor it becomes unstable after the cross over point at about 8,000 rpm.

The only difference I can see between the signal generator and real running is that with live running the motor forms a feed back loop.

And some how after the cross over point to the larger injector 2 the EFI control becomes unstable and that re enforced instability leads to violent hunting until the average engine rpm drops back below the cross over point and the motor recovers.

The Ecotrons EFI system was originally developed for GY6 CVT scooter engines and in the Ecotrons advanced calibration menu there are any number of hysteresis settings maybe something here is responding to what it thinks is runaway (but normal 2T) acceleration and tries to hard to damp things down.

Anyway that is where my current thinking is.

If you do end up switching to the link I am more than happy to do the loom for you if you pay for materials. And also help you set it up.



Are you sure you aren't seeing interference from unshielded injector leads? I can't quite gather if you hooked the signal gen up and ran it up to 12500 with all the injectors in. But even if you did a potentially weaker signal from the crank pickup may be having a bad time in amongst some noise.

What sort of crank pickup are you using? Reluctor? And a single tooth timing wheel or multi tooth with one missing? Could you switch to a Honeywell GT101DC hall effect? They are mad bulky but produce an awesome clean signal and are very hardy. They are the general standard for motorsport and only set you back about $60 from Motorsport Electronics.

Is your pickup sensor lead shielded? Probs do that if it isn't. Interference is a bitch. As are a lot of things with FI but as soon as you have it right you will love it.

As for the batteries don't even worry as long as the charging system produces enough power to keep up. I think we pull 9A on the racecar to run the engine, a DAQ system and an electric water pump and radiator fan. We have a meaty charging system (160W) which keeps us well in the green. I wouldn't even dream of running total loss on FI.
Actually the standard WR450F is FI and is set up to have the battery removed! It just has a capacitor that charges enough from a kickstart to prime the fuel pump and get the thing to go. Incredibly impressive.

I have a battery charger connected to the battery all the time I am working with the EFI system on the dyno. When I get it going properly I will have to junk the old total loss system and upgrade the bikes electrics to include a decent charging system.

i know when it comes to fuel injection a real good battery is needed , my mate glen that race's f3 has a 1000 dollar battery and is only good for 1 race . thats why i have left the charging system on my aprilia

Attachment 291468

Connected up a signal generator and oscilloscope to the Beast and had a look at how the EFI injector pulses behaved at a simulated 2,000 to 12,500+ rpm. And then with the motor running.

Five things I learned about my EFI setup today.

1, I don't have to worry about how fast the injectors open/close, and probably all good (modern) injectors are plenty fast enough with a latency < 1.75ms and good for > 16,000+ 2T rpm.

2, That with a simulated engine rpm signal from 2,000 rpm to 12,500+ rpm the oscilloscope showed perfect injector traces and cross over with no problems.

3, That when the bike was run on the dyno the oscilloscope clearly showed the EFI system swapping to the second injector and it running for a bit then as the rpm tried to climb the ECU started dropping pulses and the engine running became increasingly unstable until it was violently surging from injector 1 to injector 2 and then back again.

4, At the swap over point the second injector starts working but the injector driving signal becomes unstable. This only happens when the rpm is changing dynamical and not when the rpm is being changed relatively slowly by hand.

5, It makes me even more sure that its nothing to do with the injectors or whether the Alpha-N map is lean or not, the 2nd injector is coming on. So I think its in the software setup there is a box that should be ticked or un-ticked or some variable with a wrong value. For some reason the system is stable when bench tested with a simulator but with exactly the same settings, unstable under dynamic running conditions.



Attachment 291465

The oscilloscope trace is taken from the active or -ve side of resistors pushed into the injector plugs. The second injector is actually two injectors in parallel. As there will be a spare second injector plug when I run the motor up it will be easy to get a signal from the second injector for the oscilloscope so I can see what happens at cross over from the smaller slow running injector 1 to the bigger power and rpm injector 2.

Attachment 291464

Simulated 12,500+ rpm with the signal generator.

Attachment 291467

Both injectors at a PWM of 3.1ms

Attachment 291463

Perfect matching traces at 12,500+rpm.

I am measuring on the active (-ve) side of a resistor inserted in the injector plugs. Now it has to be remembered, this is only a trace of the ECU's signal to the injector and it tells us nothing about the shape of the curve of the fuel flowing from the injector during each pulse.

How the EFI system works, is that the ECU supply's 12V to the injector and when it wants it to fire, the ECU closes a switch and grounds the -ve side of the injector to 0V so current flows through the injector coil. This voltage swing to earth or oV is what I am tracing and is the flat line you can see at the bottom. The flat line is 3.1ms long.

The curved upper line is the ECU opening the switch again and the -ve side of the injector rising back up to 12V. The vertical drop is the -ve side being switched to 0V again to turn the injector on once more. The multiple trace lines are not my shaky hand but at 3ms the trace gets re drawn very quickly and the camera catches several images.

Attachment 291466

The spiky line is the trace from a real injector. The high voltage spike is from the inductance of the injectors coil wanting to keep the current flowing when the ECU opens the switch to turn the injector off.

When the motor was running I could clearly see the trace swap over to the second injector, the second injector would pick up and start to run and the rpm would start to increase just before the ECU began dropping pulses and the motor rpm started swinging ever more wildly between injector 1 and 2.

I did not have enough hands to get pictures or video of this, but it was good to see, as it confirms the problem is not in the EFI units hardware or injectors.

Thanks, the offer is much appreciated.



Attachment 291457

Slightly different process, compressed air is also used, possibly a peak and hold injector to, for fast opening. But like you say, it makes you think, why can't port injection be done with only one injector too. I will have a go.

Attachment 291458

just going of a book i read in around 2000 with a kart engine with direct injection just had 1 injector on the head , seen it had no gearbox it would have to run good in its hole rev range, but maybe direct injection works diffient ...dont know

Attachment 291448

Thanks, but I am a glutton for punishment and want to try and conquer this thing.

Your welcome to borrow my Link ECU, it's not in use at the moment.
Actually I've also got an Ignijet ECU as well, although I don't know anything about it yet, you could try it if you like.

Something is wrong, it just should not be this hard to get sorted.

Dosen't work, too indirect to the cylinder. You will get inconsistant fuel mixtures up to the cylinder, remember the fuel is being deposited as small pockets in the main air streem. How do you know that small pocket will end up in the cylinder accurately every cycle. There is a pumping crank case in the way ( not 100% pumping efficent at below 1/3 throttle ), some fuel stays behind, some fuel goes through to the cylinder. This is where most twostroke EFI setups are comming unstuck.
In fact thats what happens, combustion chamber "sees" rich / lean every few cycles.
Stick to your guns Rob, I'm just not too sure I trust that ECU.

It's that "jolly" ECU ! Abandon it and use a Link. I've got a spare one here for you to use. You will just need a new wiring loom.

Found this handy little site:- http://users.erols.com/srweiss/tableifc.htm

Attachment 291421

Fuel injector Data

Attachment 291422

From the table, at 80% duty cycle my IWP023 injector can support 23 crank hp and the IWP043 48hp.

More Numbers:-

13,000rpm
= 217 rps or rp1000ms
217 x 1.5ms latency = 325ms
80% duty cycle = 800ms
800ms-325ms=475ms
475ms/217rpms
= 2.18ms of fully open injection time per revolution
and
If the maximum opening + closing speed of an injector is 1.5ms, then 1.5ms = 666 Hz or 40,000 rpm. So my injectors should be able to easily open and close fast enough for 13,000rpm.

This is the best I have found so far about latency times:- http://www.eng-tips.com/viewthread.cfm?qid=333911

Attachment 291420

""Assuming reasonable spring loads for most production injectors. Most port injectors have opening times in the 1-1.5ms range and closing times in the .4-.7ms range.""

The thing I would really like to know is, is how fast the the Chinese after market Pico IWP023 and IWP043 fuel injectors can be opened and closed.

Some quick 2T numbers.

13,000 rpm
= 216 rps revolutions per second.
= 75,000 degrees per second.
= 75 degrees per milli second.
= 4.8 milli seconds per revolution.
= 3ms, If it takes the injector 1.5 ms to fully open and 0.3ms to close, then 360 degrees and 3ms is all the time you have for conventional fuel injection @ 13k.

For direct fuel injection after the exhaust port is closed its much less, approximately 80 degrees or 1ms.

Interestingly if blowdown is 36 degrees, then at 13,000 rpm a decent mass of gas leaves the cylinder in approximately 0.5ms.

This project is hampered by my inexperience with EFI, I have no idea of what can be realistically expected from an injector. So I don't really know if my switching problem is a hardware or software/setup issue.

Not what I wanted but interesting, Scraped from the net:- http://www.eng-tips.com/viewthread.cfm?qid=333911

Fuel injector latency and offset

Short story in a nutshell: -

The 'Effective Injection Pulsewidth' is the time that the injector is held open, during which fuel flows at the static flow rate at that condition [F=(dp over injector tip, rated flowrate of injector)]

As the injector driver goes 'on' there is a finite time for the flow to ramp from zero to full, likewise when the driver goes 'off' there is a finite time for the flow to ramp down to next to nothing.

This total time is the latency, confusingly only the initial ramp is referred to as 'the latency' as this is the time between on & full flow with the the ramp down being described as 'lag'.

Long story .....

In the world of programmable ECU's, injector latency, sometimes referred to as offset, is the term that is used that correlates to opening time of the injector. (To an injector design engineer, Opening time is different than offset, as Dave points out. In the SAE spec he references, it defines both, and how to calculate them. In my experience, the ECU manufacturers use this term interchangeably. Latency is really "opening time" = the time elapsed from the start of the logic pulse, to the start of fuel delivery from the injector. In a port injector, this is a function of many design parameters and calibration spring load in the injector used. It's also directly affected by the voltage supplied to the injector by the driver and the operating delta pressure across the injector. Peak and Hold driven injectors are less affected by the battery voltage, compared with saturated drive injectors, but they are still affected.

For example, when I calibrated my 3.8L Porsche club racer with a MOTEC controller, I needed the effective opening time at the dynamic calibration point for a range of battery voltages from 6-16V. I got opening times measured at 1V increments, and used that for programming the look-up table in the ECU.

Dave is correct about closing times being very important in having good linearity. Closing time is not as important to the controller, however, as it primarily impacts the effective duration of injection. (i.e. fuel keeps being delivered after the logic pulse ends) I say it's "not as important" because most ECU's now have so much control authority than they can adjust (lengthen or shorten) the pulse width being commanded of the injector by a large amount, and the effective duration of injection is sort of lost in the noise, as long as it's not excessive. Modern ECU drivers for high impedance injectors employ a zener diode to shunt the flyback current, which allows the magnetic field to collapse very quickly after the drive pulse ends. Assuming reasonable spring loads for most production injectors, most port injectors have closing times in the .4-.7ms range. The important part is that it needs to be CONSISTENT, in which case the ECU's capabilities mask it, making it SEEM unimportant. Opening time, or latency, is more important to the ECU from a timing perspective, to get the fuel shot delivered at the appropriate time. Since most port injectors have opening times in the 1-1.5ms range, this is more critical to overall timing.

Fuel injector latency and offset

This is a value calculated by measuring static and dynamic flow rates or you can also do a linear regression through a series of dynamic flow points such as 3, 4, 5, 6 & 7 ms at 10 ms pulse repetition period (100 Hz). Check out SAE spec J1832 for the standard definition.

If you plot flow on the vertical axis and pulsewidth on the horizontal axis the x-intercept is the offset or dead time in milliseconds. This is a function roughly of both the opening time and the closing time but it's more complicated than that because the flow/lift curve and pintle bounce also contribute. Closing time is very important in getting good linearity to small duration of injection.

my experience in automotive fuel systems has shown that many aftermarket manufacturers don't utilize the standards and don't always use correct terminology. In the case of aftermarket ECU manufacturers, they act like they have never looked at an SAE specification for an injector and create all sorts of differing terms for things that are already well defined. I've run into this before in the case of latency, vs. the correct term, "Injector Opening Time". I've also seen offset misused, which has a very specific mathematical definition per SAE. It is sometimes misapplied when the aftermarket manufacturer really means "Injector Opening Time"

Total dwell seat to seat is defined by SAE as "Effective Duration of Injection". That is equal to (in simple terms) (the duration of the logic pulse applied)-(opening time)+(closing time) typically referred to in ms. So, for a port injector with a 1.25ms opening time, and a 0.50ms closing time, the effective duration of injection for a 3.00 ms injection pulse is 2.25ms. Dwell at full flow isn't really much different. Good port fuel injectors are designed so that the transit times from fully closed to fully open for the armature/ball, or armature/pintle, or just armature in the case of a plate style injector are very fast relative to the logic pulses. These are typically on the order of 50 microseconds or less; the best designs are a lot less.

Sensible, and works for a 4T but the problem I face with my 2T is that an injector small enough for starting and clean running at low rpm is to small when the engine gets on the pipe so you have to have two different sized injectors and swap between them for high and low speed running.

I think my real problem is in finding injectors dynamic enough to handle what would be 28,000 rpm in 4T terms.

It might be that I will have to run two injectors in parallel firing on alternate cycles.

second thing run a extra butterfly and servo operate it .. run it as a overide

just go simple, 1 injector at the body good fuel mixing, well thats what i would do

Attachment 291415Attachment 291416Attachment 291417

Tried some original Ecotrons fuel injectors yesterday. Its all a bit tight so I had to make a new setup for them and cut the plastic away from around the top feed so that the plug and fuel barb could be rotated in different directions.

Unfortunately nothing improved, the engine still behaves badly at the swap over point around 8,000 rpm. 8,000rpm is of course 16,000 4T rpm. On the test bench and oscilloscope everything looks to be working OK so I am not sure if its a software problem or the injectors just can't keep up.

For Xmas I was given a complete set of top feed Alpha Sud fuel rails, regulators and 14mm injectors. This one has the injectors retained in the fuel rail by a clip so I can easily make a test rig and plug in my Pico IWP injectors.

I will now be able to study and measure the fuel delivery behavior of the injectors under real conditions and see whats happening at the point where the EFI system swaps from injector 1 to injector 2.

I am off to find SAE standard J1832 to see what it has to say about evaluating low pressure automotive fuel injectors.

including Burts Velo, coincidentally "The worlds fastest Velocette"

There is the Southward car musem and its collection of motorcycles. http://www.southwardcarmuseum.co.nz/gallery.html





Another one of those fantastic stores:-

This Hardware Store in Invercargil is a real gem, its a real hardware store with a fantastic collection of bikes and Burt Munro Indian memorabilia.

E Hayes ltd http://www.ehayes.co.nz/Hayes-Motorw...ection-__I.214

Chapter 24 Miniature RR (Buckets)

F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single 24mm carburetor.

Appendix D Championship Classes, Solo motorcycles shall have :-


F4
2 stroke 55 -100cc.
2 stroke 55 - 125cc air cooled.
4 stroke 55 -150cc.


So you have to look in at least two places to read the rules covering 125cc F4 2T's. And liquid cooled is not mentioned, only the term "air cooled" is used, and does air cooled mean you can't use a drop of oil to thermally connect a heat source to its cooling element?

This interests me as I intend using a lot of copper wire and copper dust wetted with oil for themal contact, to transport heat from its source to the heat sinks.

The best quote and story of them all has to be from here.

http://www.superbikeplanet.com/dontpaymeenuff.htm

There is the Southward car musem and its collection of motorcycles. http://www.southwardcarmuseum.co.nz/gallery.html

Attachment 283657

A real air cooled 2-Stroke, Geff Perrys TR500R and Trophies

Attachment 283653

And Ron Grants water cooled TR750R

Work had me in Greymouth. While I was there I meet Robin Gray and he showed me around his Hose and Hydralic stor which is also an Aladins cave of interesting bikes and things. With lots of interesting old bits and bobs like miners helmets, lamps, hand made model trains and steam engines and an old BSA in the window.

Attachment 264346

Another one of those fantastic stores:-

This Hardware Store in Invercargil is a real gem, its a real hardware store with a fantastic collection of bikes and Burt Munro Indian memorabilia.

E Hayes ltd http://www.ehayes.co.nz/Hayes-Motorw...ection-__I.214

Found this handy little site:- http://users.erols.com/srweiss/tableifc.htm

Attachment 291421

Fuel injector Data

Attachment 291422

From the table, at 80% duty cycle my IWP023 injector can support 23 crank hp and the IWP043 48hp.

[TZ350]

I have some shagged old style ones you could have for a beer.

Thanks ......

[Yow Ling]

What is the plating like in the cylinder you have ? Were you going to have it replated after you bore it or sleeve it?
One is easy and expensive the other is hard but cheap.
Te aircooled RG150 I have here is sleeved down from 150, if you try to sleeve the VJ22 you will probably need to bore +5mm just to be left with a 1.75mm thick sleeve, which could cause a problem with the bridge overheating.
If your existing plating is ok , I would go with that and 124cc

[TZ350]

What is the plating like in the cylinder you have ? If your existing plating is ok , I would go with that and 124cc

The plating is usable and I was going to try it as is to test the concept of air cooling a water cooled cylinder. If it all works and I want to re plate I was going to go to the maximum oversize allowed.

[husaberg]

And that is only true if you enlarge all port widths by the (new bore / old bore) ratio.
Just boring out a cylinder will not alter the angle.areas; it will only decrease the specific angle.areas and it will force you to lower the revs if you wish to keep the original time.areas. In short: the same power with less revs. But the larger bore will worsen the combustion chamber shape; combustion will be slower and it will heat a larger piston crown area, increasing the deto risk.
Right!

As power is proportional to the percentage increase in bore diameter for a bored out two stroke cylinder the best you can hope for is an increase in power of 2.7 % for a 57.5 mm bore v's a 56 mm bore. 100 x ( 57.5 - 56.0 ) / 56.0

Seems like an expensive modification for such a small potential power increase!

What about go the other direction and sleeve down the cylinder to the maximum allowable capacity for a "100 cc" watercooled engine? This would also move your bore/stroke ratio in the right direction.

not only that but the carb needs to be bigger etc.

Ok not such a great potential power increase ...

....... right ... now put your hand up, whoever said ""there is no substitute for Cu inches"" !!!! ...

but as people have said the result would be similar with a 100cc LC, but you should be able to achieve a wider spread of power with the extra cc's i am talking 125 vs 100cc. That could be quite an advantage when most of your races are short duration on a kart track.
ESP since there are many 125cc 2 strokes with a PV other than Pete Jones's one Yow has.

That aside it would be cheaper for you to stroke to get to the max engine size for overbores etc it as i guess it has a silly pin size anyway... does it?

[richban]

Thanks ......

Know worries I will try find them.

Check the Xmas holiday project.

[Ocean1]

....... right!!!! ... now put your hand up, whoever said ... ""there is no substitute for Cu inches"" ...

Smokey Yunick?

[TZ350]

Smokey Yunick?

Yep ... good old smokey.

Top 50 quotes .... from http://www.ridelust.com/the-50-great...s-of-all-time/

1. To finish first, you must first finish. – Juan Manuel Fangio 2. Nobody remembers the guy who finished second but the guy who finished second. – Bobby Unser

3. The winner ain’t the one with the fastest car, it’s the one who refuses to lose. – Dale Earnhardt



4. You win some, you lose some, you wreck some. – Dale Ernhardt Sr.

5. Aerodynamics are for people who can’t build engines. – Enzo Ferrari

6. The client is not always right. – Enzo Ferrari



7. If you think the last 4 words of the national anthem are gentlemen, start your engines, you might be a redneck. – Jeff Foxworthy.

8. Need to tie some kerosene rags around his ankles so the ants don’t eat his candy #$@ - Dale Earnhardt speaking of Mark Martin.

9. The lead car is absolutely unique, except for the one behind it which is identical. – F1 commentator Murray Walker.



10. Turbochargers are for people who cant build engines. – Keith Duckworth

11. Here Kitty Kitty Kitty! - Tony Stewart

12. We broke something, I think it was traction… – Carl Edwards after getting spun out by Dale Jr. at Michigan


13. Auto racing, bull fighting, and mountain climbing are the only real sports… all the others are games. – Ernest Hemingway
14. Calling upon my years of experience, I froze at the controls. – Stirling Moss
15. Faster, faster, faster, until the thrill of speed overcomes the fear of death… – Hunter Thompson


16. I don’t know driving in another way which isn’t risky. Each one has to improve himself. Each driver has its limit. My limit is a little bit further than other’s. - Ayrton Senna

17. It is amazing how may drivers, even at the Formula One Level, think that the brakes are for slowing the car down. – Mario Andretti

18. Once you’ve raced, you never forget it…and you never get over it. - Richard Childress



19. Race cars are neither beautiful nor ugly. They become beautiful when they win. – Enzo Ferrari

20. There’s no secret. You just press the accelerator to the floor and steer left. – Bill Vukovich

21. To achieve anything in this game you must be prepare to dabble in the boundary of disaster. - Sterling Moss



22. To achieve anything in this game you must be prepare to dabble in the boundary of disaster. – Sterling Moss

23. What’s behind you doesn’t matter. – Enzo Ferrari

24. When you win a race your on top that day, so take it for what its worth, have a good time and party, cause the next day when you get out of bed, the meter goes back to zero again. - Bobby Allison



25. No, no, he didn’t slam you, he didn’t bump you, he didn’t nudge you… he *rubbed* you. And rubbin, son, is racin’. – Harry Hogge, Days of Thunder

26. If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

27. If you’re in control, you’re not going fast enough. – Parnelli Jones



28. Mr. Bentley – He builds fast trucks. – Ettore Bugatti

29. Why worry about death, it’ll come sooner or later. - Jim Dunn

30. Speed has never killed anyone, suddenly becoming stationary… that’s what gets you. – Jeremy Clarkson



31. Auto racing began 5 minutes after the second car was built. - Henry Ford

32. As far as cheating goes, they’ll never stop it. The only way it can be done successfully, only one person can know about it. – Smokey Yunick

33. It’s like flying jet fighters in a gymnasium - Dick Trickle was asked what racing at Windchester Speedway was like.


34. You can’t fix stupid - Larry Morgan, NHRA Pro Stock driver

35. You can tell that you’re in trouble when you feel the air on the back of your neck instead of in your face. - Buddy Baker

36. I got hit in the head pretty hard. My clock ran backwards for two years. - Buddy Baker



37. He ran out of talent about halfway through the corner. – Buddy Baker

38. After the third flip, I lost control………… - Don Roberts after crashing in the Jade Grenade at New England Dragway in 1975.

39. We worked 80 hour weeks for 30 years to keep from having to get a real job. – Tom Lemon’s comment on the rigors of being a drag racing.



40. It’s basically the same, just darker. - Alan Kulwicki, on racing Saturday nights as opposed to Sunday afternoons.

41. Auto racing is boring except when a car is going at least 172 miles per hour upside down. - Dave Barry

42. If someone said to me that you can have three wishes, my first would have been to get into racing, my second to be in Formula 1, my third to drive for Ferrari. – Gilles Villeneuve



43. There are seven winners of the Monaco Grand Prix on the starting line today, and four of them are Michael Schumacher. – Murray Walker

44. When I raced a car last it was at a time when sex was safe and racing was dangerous. Now, it’s the other way round. - Hans Stuck

45. I love this kind of racing, (but) these guys sure change their personalities in race mode. They’re like Doberman Pinschers with a hand grenade in their mouths. – Road racer Boris Said speaking of NEXTEL Cup drivers.



46. The crashes people remember, but drivers remember the near misses. – Mario Andretti

47. When I started racing my father told me, ‘Cristiano, nobody has three balls but some people have two very good ones. - Cristiano Da Matta

48. Moonshiners put more time, energy, thought, and love into their cars than any racer ever will. Lose on the track, and you go home. Lose with a load of whiskey, and you go to jail. – Junior Johnson, NASCAR legend, and one time whiskey runner.


49. There have been other tracks that separated the men from the boys. This is the track that will separate the brave from the weak after the boys are gone. – Driver Jimmy Thompson speaking about Daytona International Speedway.

50. Winning is everything. The only ones who remember you when you come second are your wife and your dog. – Damon Hill

[TZ350]

The best quote and story of them all has to be from here.

http://www.superbikeplanet.com/dontpaymeenuff.htm

[teriks]

I think the rule says liquid.........
I have mentioned Paraffin wax before as it is common solid at room temp and during phase change it can buffer huge amounts of heat.
Rob have a gander at this.
http://en.wikipedia.org/wiki/Phase-change_material

Silver is not that dear is it..... Norton used it on the Works 500's and i think so did AJS with the Porcupine.
http://www.engineeringtoolbox.com/th...ity-d_429.html

Ah..eeeh..well...ehrr.. call it gas cooled then, since the was majority of the heat transport would be vapor moving from a hot surface to a cooler surface. ;-)

Next option, fill with cerrotru or similar low melt temp metal alloy, together with the copper wire thing.
The thermal conductivity of those metals are quite poor, but it might give a better thermal coupling to the cylinder surface than thermal paste + oil.

Or, it could be used as the phase change material in husabergs post. You might even end up with some convection, but then there's the liquid thing again.

[husaberg]

Kevin Schwantz' "Wait 'til you see God-then brake!"

[TZ350]

Chapter 24 Miniature RR (Buckets)

F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single 24mm carburetor.

Appendix D Championship Classes, Solo motorcycles shall have :-


F4
2 stroke 55 -100cc.
2 stroke 55 - 125cc air cooled.
4 stroke 55 -150cc.


So you have to look in at least two places to read the rules covering 125cc F4 2T's. And liquid cooled is not mentioned, only the term "air cooled" is used, and does air cooled mean you can't use a drop of oil to thermally connect a heat source to its cooling element?

This interests me as I intend using a lot of copper wire and copper dust wetted with oil for themal contact, to transport heat from its source to the heat sinks.

[Grumph]

We had the same philosophical discussion years ago in Speedway. They insisted on air cooled motors for TQ's but given most were using big oil coolers anyway, when someone tried an air/oil GSXR 750 no one could complain.

Ironic really as most were internally cooled by the lavish use of Methanol.....

[husaberg]

Bravo Bob....... but conversely as it is over 104cc it will therefor have to be air cooled..... funny enough i remember Suzuki making a big deal in the early 80's over the GSXR's cooling system.