ESE's works engine tuner

[TZ350]

losing 3 or more ponies seems a big effect for just 50 cc's.

I think they and a few friends have fallen down the crevasse between the flywheel and crankcase wall.

[Henk]

Losing three ponies might well be worth it if it puts the ones left over in the right place, there is lots of power and the right power, the bikes wining at Mt Welly don't seem to be HP monsters at the moment. Although it has been said that an RS frame acts as a HP multiplier.
I don't want to ride one of those frames due to the effect it will have on my bank balance.

[wobbly]

CCR is hugely affected by 50cc.
Say the vol with the piston at TDC was 350cc total, this gives a CCR of 1.4.
Add 50cc and the vol becomes 400cc, this gives a CCR of 1.333, thats a night and day difference to a very important design element.

[speedpro]

our foreign correspondent mentioned that CCR was important.

[jasonu]

our foreign correspondent mentioned that CCR was important.

I have all of their albums...

[TZ350]

Chambers is taking a serious look at Ned Kellys 22+ rwhp engine to see if there are any spare horsies hiding in there. The carb is a glued up std GP125 24mm carb and those are the engine mounts to fit a Suzuki GP into an RS frame.

[F5 Dave]

I have all of their albums...
How old are you?:shutup:

[bucketracer]

our foreign correspondent mentioned that CCR was important.

Yes, he seemed quite sure there was a correct CCR, but it didn't look like he knew what it was, I think he hoped someone like Thomas would fill in the gaps for him.

[ac3_snow]

I think they and a few friends have fallen down the crevasse between the flywheel and crankcase wall.

So can I ask what the ccr was before and after?
Also the reed block modifications you made to your 50 are potentially going to have a similar effect to CCR, or is this a smaller change and which will hopefully have a negligible effect?

[bucketracer]

So can I ask what the ccr was before and after?
Also the reed block modifications you made to your 50 are potentially going to have a similar effect to CCR, or is this a smaller change and which will hopefully have a negligible effect?

The RG50 case reed inlet is similar to previous ideas tried out when building Buckets4Me's 50 ........

235515

And these are the figures (Based on Blairs Book) I got when I checked out TeeZee's engine for him.


Crankcase Compression Ratios Revisited

Primary or crankcase compression ratio is determined by dividing the full crankcase volume including transfers with the piston at TDC by the crankcase clearance volume with the piston at BDC.

For a 125 the ratio will probably be some where between 1.3:1 and 1.5:1, also according to Blair it is very difficult to get a 50 above 1.4:1 and a 500 below 1.55:1.

Pic-01 the good old Suzuki GP125

Pic-02 I found greasing the piston crown and around the piston in the exhaust port then plugging it with paper towels sealed it up OK with out any leaks.

Pic-03 I used anti freeze and a measuring cylinder to measure the crankcase volume. After pouring the anti freeze in through the inlet port and wriggling the engine to get all the air out I found the full crankcase volume with the piston at TDC to be 470cc.

Pic-04 The engine simulation package Mota requires the crankcase clearance volume below the piston crown when the piston is at bottom dead center (BDC), excluding transfer duct volumes. From the bore and stroke and the transfer duct area of the engine being simulated and it works out the full crankcase volume for itself.

Crankcase compression ratio (Primary Compression Ratio).

Terms
Full crankcase Volume = FV
Crankcase Clearance Volume = CCV
Primary Compression Ratio = PCR
Engine Capacity = CC

Formula
FV/CCV = PCR

As
CCV = FV-CC

Then the formula becomes
FV/(FV-CC)=PCR

Then for the GP125 the primary compression ratio is…….

Primary Compression Ratio = PCR

PCR 470/(470-125)=1.36

The Suzuki GP125 has a crankcase compression ratio or primary compression ratio of 1.36:1

I don't expect we will measure the engine again until it is about to come apart.

Primary Compression Ratio or PCR = Crank Case Ratio or CCR

470/(470-125)=1.36 PCR or CCR

Adding 50cc to the above figures..........

(470+50)/((470+50)-125)=1.32

A difference of 0.04 just did not seem that much

[ac3_snow]

yes it does seem like a huge effect from such a small change, I was also amazed at one of wobbly's previous comments about the effect a o.1mm change in transfer heights has on a KT100 (was about 2hp?!)
When working on what seems to be such a fine knife edge I think you guys have done pretty well to get the results you have.
all part of learning, hopefully you can learn back those three horsies!

[bucketracer]

yes it does seem like a huge effect from such a small change,

TeeZee says, he is wondering if he could have made it worse by something else that he has overlooked, but does not know what that could be.


all part of learning, hopefully you can learn back those three horsies!

Yes Hopefully .........


CCR is hugely affected by 50cc.
Say the vol with the piston at TDC was 350cc total, this gives a CCR of 1.4.
Add 50cc and the vol becomes 400cc, this gives a CCR of 1.333, thats a night and day difference to a very important design element.

I thought that my maths might have been wrong, but using the same formula and putting numbers to Wobblys post I get.

For a 100cc engine.

350/(350-100) = 1.40

and adding 50cc to the crank case volume.

400/(400-100) = 1.33

If a huge difference is 0.07 then TeeZee's 0.04 change could be considered fairly large too.

And so maybe those missing ponies are all in that change of crankcase volume.

I am very impressed by what a big effect such a small number can have ...........

[koba]

I am very impressed by what a big effect such a small number can have ...........

Why do you keep thinking of that as "such a small number"?

I think 50cc is a massive number in that context!

I'm no good at maths but isn't that something like a 12.5% change?

What would a that percentage change in any other aspect of the engine do?

[bucketracer]

Why do you keep thinking of that as "such a small number"? I think 50cc is a massive number in that context!

Just hadn't got my head around it.....

350/(350-100) = 1.40
and adding 50cc to the crank case volume.
400/(400-100) = 1.33
1.40-1.33=0.07
(0.07/1.40)*100 = 5% change for Wobblys example.

TeeZees is about 3%

Yes your right 3-5% of anything would be worth having.

[wobbly]

If you look at CCR in the context of what is accepted as being "normal", then the full range is generally accepted as being a low CCR at 1.3 and a very high CCR at 1.4.
This means a difference of 0.1 from "big" to "small", and the 50cc change in the case, represents 1/2 of the engines swept displacement by the piston in a 100cc bucket..
Aprilias latest engines are in the high 1.2s - and a very fast NZ champ 50 quad I built had 1.42, both on the very outer limits.
Changing from 1.4 to 1.3 would need huge jetting changes, like 4 mains, and this then affects the bsfc, and the pumping efficiency,needing a whole new approach to the transfer designs as well.
It goes on and on.
When you consider what happens when you change say the primary com from 13:1 up to 16:1,then this shows the relativity of the difference created.
But again - even the primary com change has huge effects that are not directly related to the numbers.
16:1 would need Avgas to stop deto obviously and this com would give great jump of the turns but would stop any pipe design from overeving.
Thus a high com engine needs a short pipe, or lots of retard, due to all the heat of combustion being released into the piston and the water - not the exhaust, making it appear longer to the engine. etc etc.
Change one element of a 2T and you are then looking at a whole raft of changes needed to optimise that setup,and it will never "work" if just one other element isnt synergistic with the rest.
And remember a general comment I made a while ago, about crap transfer ducting "liking" higher CCR ratios.

[TZ350]

One or two people have been talking about getting IgniTech Ignitions.

There is a DC-CDI-P2 and DC-CDI-P2 Race, I don't know what the difference between them is but we run the Race version ourselves.

IgniTech CDI Ignition http://www.ignitech.cz/english/aindex.htm

The Sparker DC-CDI-P2 Race can be run “Total Loss” from a battery and/or with a 12v generator ignition and capacitor from a late model Mxer.

The Sparker DC-CDI-P2 Race is for twin 2-strokes like the RGV but one channel can be turned off and the Sparker is good for a single cylinder.

235586

Its best to get one with the plug pre-wired with 2m flying leads, as its a bitch wiring the plug yourself.

Our Igni Ignition is programmed through a computers serial port, I am not sure if there is a USB version, it would pay to check that out as computers/laptops with serial ports are getting hard to find.

Sparker DC-CDI-P2 Race http://www.ignitech.cz/english/aindex.htm

These are available from Wobbly (I think) or directly from IgniTech.

[wobbly]

The Ignitech RACE ECU has the same functionality as the normal P2 except has the extra capability of a second curve,that can be invoked via a handlebar switch or several other trick methods using a pot on the gearchange drum, or a set acceleration rate etc.
Both are programmed via serial port, but can be used with a USB adapter and downloading the specific driver for this.
USB is very prone to RF interference when used with a running bike on the dyno, and causes crashes just when not needed.

Total loss is OK, but I prefer to use a small battery and the charging system, as this then runs at 14.2V all the time, and has power on board to run the ECU for programming without the bike running.

It isnt advisable to use a trigger as shown in the att, as the floating input on the ECU needs a two wire trigger to isolate it from the noisy chassis earth.

I have the P2 and looms in stock - with my own special version of the software, but have some RACE on the way now.

[F5 Dave]

Ooh so you program in your 'wet' curve for if it starts pizzin down. Kinda thought this was tosh but I used my GasGas300 in the weekend in muddy conditions & selected wet mode for the first time. It was brilliant. Course they probably have some development riders to sort the correct curve out to stop it spitting you off without slowing things down too much.

Then of course these days if it rains I question my whole commitment to the cause anyway.:shutup:

[kel]

I have the P2 and looms in stock - with my own special version of the software, but have some RACE on the way now.

How much do these go for?

[TZ350]

235603


It isnt advisable to use a trigger as shown in the att, as the floating input on the ECU needs a two wire trigger to isolate it from the noisy chassis earth.

Thats interesting, NedKelly runs a single wire pickup and when Neds battery gets low <14v and he has to rely on the generator he has all sorts of missfiring problems.

235600

The numbers written on Neds flywheel is the basic setup data for his IgniTech, my engine setup data is different as the position of my pickup and the length of the trigger part on the flywheel is also different to Neds.

I have seen people at race meetings who have not properly marked their flywheels struggling to get their bike going again after disturbing the ignition during a pitside repair.

235601

My own engine uses a two wire pickup from a KX80, I use the flywheel as my motor likes some flywheel inertia and the KX80's flywheel taper fits the GP but I have discarded the HV charging coils.


Total loss is OK, but I prefer to use a small battery and the charging system, as this then runs at 14.2V all the time, and has power on board to run the ECU for programming without the bike running.

235602

This YZ125 flywheel taper is to small for the GP and the four pole stator is a high voltage CDI charger, I think you need an eight pole stator from a late model MX to get a 14.5V generator for charging a battery.

The problem for us is that late model KX and RM125's which have the battery charging coils have a flywheel taper thats to big for the GP.

235604

Neds battery box is under the tail section.

235605

The ignition unit is protected from water and well away from the HV ignition coil.

[wobbly]

The 4 pole stator can be rewound with heavyer wire to give plenty of grunt to run the Ignitech.They only draw about 1.5A @ 14.2V at full noise.
I use an 8 pole stator on the TSS bikes,and this can supply over 10A.
The tapers are all the same ( 1:5 ) on all these engines, so its easy to make a thin wall sleeve to fit a big bore rotor onto any shaft, the key isnt needed except to replicate the original base timing.
You have to be careful re trigger bar length, as I discovered after 2 days waisted on the dyno.
Anything more than about 20mm of bar length, and the voltage drops,before the end of the bar - as it moves under the trigger pole , and you get missfires for no apparent reason.
Short ie less than 4mm is fine.
Contact me via a PM and I will do a cash deal for you guys on a Ignitech.

[TZ350]

From page 181



223789223788223787

10.74 AC Volts from the generator, 13.9 DC Volts from the Pit Bike Rectifier/Regulator.



The 4 pole stator can be rewound with heavyer wire to give plenty of grunt to run the Ignitech.

We tried winding our own charging coil, good for 12V but wound up using a 14.5V battery. You can see in the attachments we used a light bulb to load the generator when taking our voltage readings.

Can you tell me more about the number of turns you used, from memory we had about 420.

[wobbly]

I dont have a record of the turns, but if you were only delivering 10 odd V Ac then that means the wire was too big in Dia.
You need smaller wire and over 20V Ac into the rec/reg driving a battery load.
I dont think you would ever get sufficient VA from a single coil, the 4 pole rewound would work a treat.

[wobbly]

Not the right place I know - but im after a couple of RZ or Banshee cases in good nick.

[TZ350]

You need smaller wire and over 20V Ac into the rec/reg driving a battery load.

Thanks, we weren’t to sure what voltage to aim for as the voltage varied quite a bit as the engine revs increased. We tried to keep things below 20V, as we were concerned about heat dissipation through the regulator.


I don’t think you would ever get sufficient VA from a single coil, the 4 pole rewound would work a treat.

We wound two coils of 210 turns each and wired them in series for 420 turns total. The wire diameter used for the 1.5A was based on transformer winding specs.

We found plenty of info on the net covering the current capacity of wire when used for coils and transformers and it was always larger than that needed for free air.

The wire we used was about 1mm and brought from JayCar.

We will try (actually Bucket and Thomas) to re-wind the four pole for 20V and 3A at 10,000 rpm so we can run the Igni and a small electric water pump.

[Bert]

Thanks, we weren’t to sure what voltage to aim for as the voltage varied quite a bit as the engine revs increased. We tried to keep things below 20V, as we were concerned about heat dissipation through the regulator.

We will try (actually Bucket and Thomas) to re-wind the four pole for 20V and 3A at 10,000 rpm so we can run the Igni and a small electric water pump.

Keen to see your (Bucket/Thomas)'s progress on this; I'm about at the same point with my build (and power requirements; igni & powervalve servos).

Final specs (even instructions) and photos would be great... :innocent:

[wobbly]

The wire used for the AC windings was about 0.7mm from memory, as is the wire in a RS125 stator and the 8 pole one I use.
The VA rating stays about the same for various thicknesses and turns ratios, but you get to a point where you make to much V and the wire cant sustain the A on a continuous basis.
As you only draw 1.5A from the Ignitech and about the same for a pump then you are only pulling around 40W, the reg you are using can dump way more than that.

[TZ350]

The wire used for the AC windings was about 0.7mm from memory, as is the wire in a RS125 stator and the 8 pole one I use.

Yes, we tried various thickness of wire, you can get a whole lot more windings on using 0.7 than you can with 1.0.

We will try 0.8 next as the coil stack will be smaller and heat dissipation better with the four pole unit.


As you only draw 1.5A from the Ignitech and about the same for a pump then you are only pulling around 40W, the reg you are using can dump way more than that.

Thats good to hear.

At 40W we thought the regulator would get quite hot as its heat sink looks high-ish in the deg-C temp rise / Watts ratio (as a small heat sink, needs to run hotter than a larger one does to dissipate the same amount of thermal energy ) but we are encouraged by what you say and will give it a go.


Final specs (even instructions) and photos would be great...

It might take a week or three but we will post photos and details of wire and windings etc as we go.

There is a change in Voltage with RPM, the resultant Voltage (EMF) becomes higher (stronger) the faster the flux from the magnetic field cuts through the coil windings.

235738

Spin the magnets faster and you get a higher output Voltage.

Because the final AC Voltage of the generator is RPM related, 20Vac at 12K might only be 10Vac at 8K. Anyone making an AC generator to power a DC Voltage rectifier/regulator for their ignition/battery will have to experiment with the number of turns to get something that suits their own engines working RPM.

Generator Voltage readings are only meaningful if you are measuring them at the same time as current is being drawn from the generator, ie Loading the generator by making it do something, like running a light.

The DC voltage rectifier/regulator at the top of the picture is from a Pit Bike.

235741

The light bulb is there to load the generator for accurate voltage readings under actual working conditions.

DC ignition/battery on the left, AC generator on the right, in this pic we need to add some more windings to get the voltage up.

As the AC voltage is increased the regulator will eventually hold the DC voltage some where near 13.5V for charging 12V batteries, I expect it will take several trys to get it right.

Wobbly suggests the AC generator should be over 20V.

[bucketracer]

235788

Instead of a Pit Bike rectifier/regulator and being stuck with 12Volts, by changing the Zenor diode this could be adapted for working with those 14.5Volt electric drill batteries.

[wobbly]

Be careful with the charge voltage to the 14.5V batterys as I believe you need at least 1.2 or 1.5V above the nominal battery rating to get it to charge.
That is why most reg/rect run at 14.2V - for a 12V battery, and you will start getting a yellow error highlight in the Ignitech screen over 15V.

The finned reg/rec in the pic previously is the same one I use and the factory say its rated to shunt to ground the whole output from my 8 pole, that puts out 30 V and 8A fully loaded.

[speedpro]

235788

Instead of a Pit Bike rectifier/regulator and being stuck with 12Volts, by changing the Zenor diode this could be adapted for working with those 14.5Volt electric drill batteries.

The good old 2N3055. What can't be made with them? There should be a 6' high bronze one somewhere in the world, heated to about 200deg, just to make it as lifelike as possible.

[bucketracer]

The finned reg/rec in the pic previously is the same one I use and the factory say its rated to shunt to ground the whole output from my 8 pole, that puts out 30 V and 8A fully loaded.


The Pit Bike rectifier/regulator cost $15 of Trademe, the Red wire is battery positive, Green is Earth, Violet and Pink are Generator AC. A little bit on AC/DC http://www.kpsec.freeuk.com/powersup.htm

235800

A picture of the rectifier/regulator TeeZee's using.........


Be careful with the charge voltage to the 14.5V batterys as I believe you need at least 1.2 or 1.5V above the nominal battery rating to get it to charge.

That is why most reg/rect run at 14.2V - for a 12V battery, and you will start getting a yellow error highlight in the Ignitech screen over 15V.

Then to avoid over voltage on the IgniTech it might be possible to build a 15Vdc Voltage maintenance generator for supporting but not recharging a 14.5V battery drill battery. That way a lot of the running power is supplied by the generator and the battery is there for starting and slow running, but has to be re-charged between race days.

[TZ350]

Interesting posts about voltages etc for the generators, thanks, some good ideas there and I feel pretty confident now about us having another go at NedKellys generator and the four pole one for myself.

235818

These lead-acid-gel batteries seem to work well in the Honda 125T's and other 4-Strokes at Mt Welly, but we had nothing but failures with them.

Often a brand new one would crap out quickly during the day, when at 7Amp Hours it should have lasted all day.

When we got them home they would be completely dead and unable to be re-charged, so had broken down inside somehow. Maybe it was something to do with the 2-Strokers vibration. Don't know for sure, but that is the reason we went to 14,5V battery drill batteries.

Does any one know of a better style of 12V battery to use?

[Yow Ling]

Interesting posts about voltages etc for the generators, thanks, some good ideas there and I feel pretty confident now about us having another go at NedKellys generator and the four pole one for myself.

235818

These lead-acid-gel batteries seem to work well in the Honda 125T's and other 4-Strokes at Mt Welly, but we had nothing but failures with them.

Often a brand new one would crap out quickly during the day, when at 7Amp Hours it should have lasted all day.

When we got them home they would be completely dead and unable to be re-charged, so had broken down inside somehow. Maybe it was something to do with the 2-Strokers vibration. Don't know for sure, but that is the reason we went to 14,5V battery drill batteries.

Does any one know of a better style of 12V battery to use?

I have had a few problems with gel cells too, seem to be affected by vibration, hard to go past a sealed lead acid battery if this is the case. If you could isolate the gel cell from the vibration you would do better.

[Kickaha]

Maybe it was something to do with the 2-Strokers vibration.


I have had a few problems with gel cells too, seem to be affected by vibration

Vibration kills batteries, although if the batter box is either rubber mounted or has enough room to fit something inside it to isolate the battery from vibration it normally fixes the problem

Way back in medieval bucket racing times (pre FXR) we saw a few problems using gel cell when they weren't isolated from vibration

I didn't ever have a problem using a standard lead/acid but there are far better options than those available now

[ac3_snow]

the club bike (slightly different as its a FXR) has the battery mounted on a decent sized chunk of foam and held in place with a rubber strap, I initially thought it was just to stop it rattling around but would kill any vibration rather effectively too.

[ajturbo]

235818




these seam to work ok in my GT125twin...

[Moooools]

Interesting posts about voltages etc for the generators, thanks, some good ideas there and I feel pretty confident now about us having another go at NedKellys generator and the four pole one for myself.

235818

These lead-acid-gel batteries seem to work well in the Honda 125T's and other 4-Strokes at Mt Welly, but we had nothing but failures with them.

Often a brand new one would crap out quickly during the day, when at 7Amp Hours it should have lasted all day.

When we got them home they would be completely dead and unable to be re-charged, so had broken down inside somehow. Maybe it was something to do with the 2-Strokers vibration. Don't know for sure, but that is the reason we went to 14,5V battery drill batteries.

Does any one know of a better style of 12V battery to use?

3 cell Lithium Polymer batteries (11.1 volts discharged. 12.'something' charged.) Cheap as chips from Hobbyking and weigh bugger all. Would have no problem with vibration (made for rc vehicles)
However you would be hard pushed to find one at 7AH, they require a special charger and have a bad habit of exploding if charged wrong.:yes:

Perhaps 3 of these?:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8932
And change when necessary.

And a charger:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8247

Shipping might bite yah...

Just a thought really.
I going to try this out to run my shift light. I found four 1AH versions still in their box on a shelf from a forgotten project.:facepalm:

[TZ350]

Thanks for the tip Moooools ......... But..... :blink:

Lithium cells must be charged very differently than NiCad or NiMH. They require a special charger specifically designed to charge lithium cells. Failure to do this can cause the battery to spew violent flames. There have been many fires directly caused by lithium batteries. PLEASE BE RESPONSIBLE when charging lithium batteries.

http://www.rcgroups.com/forums/showthread.php?t=209187

I might be better sticking with something simpler........ still I like a challange.

[Kickaha]

Lithium cells must be charged very differently than NiCad or NiMH. They require a special charger specifically designed to charge lithium cells. Failure to do this can cause the battery to spew violent flames. There have been many fires directly caused by lithium batteries. PLEASE BE RESPONSIBLE when charging lithium batteries.

Do a search for Shorai Lithium, there is a thread about them on KB, don't need a special charger and don't tend to catch fire

[speedpro]

I always thought Li batteries had circuits built in to balance the voltage of the cells and to monitor battery temp and charge and discharge rates. You most certainly cannot just plug them in to some power supply and walk away.

[TZ350]

Do a search for Shorai Lithium, there is a thread about them on KB, don't need a special charger and don't tend to catch fire

Here we go, the start of the thread ............ thanks


These look really impressive!

Massive weight saving too, as all models are well under 1kg. Only 2 different case sizes though, but they supply special packing material for fitting.

http://www.shoraipower.com/default.aspx

Who's going to be first to import one?:laugh:

[jasonu]

3 cell Lithium Polymer batteries (11.1 volts

Just a thought really.
I going to try this out to run my shift light. I found four 1AH versions still in their box on a shelf from a forgotten project.:facepalm:

You have a shift light on your bucket???

[Moooools]

Thanks for the tip Moooools ......... But..... :blink:

Lithium cells must be charged very differently than NiCad or NiMH. They require a special charger specifically designed to charge lithium cells. Failure to do this can cause the battery to spew violent flames. There have been many fires directly caused by lithium batteries. PLEASE BE RESPONSIBLE when charging lithium batteries.

http://www.rcgroups.com/forums/showthread.php?t=209187

I might be better sticking with something simpler........ still I like a challange.

Meh. So long as you use the correct charger, such as the one I linked, you probably wouldn't have any problems. They aren't particularly perfect for the application on that front though.

I have only had two explode violently.:innocent: (But that was when someone decided to secure them in a box with expanding foam)...

[Moooools]

You have a shift light on your bucket???

Ahhhhhhhhhhh yeeesss. Would you find it less ridiculous if I told you it was an in-helmet shift light?

[jasonu]

Ahhhhhhhhhhh yeeesss. Would you find it less ridiculous if I told you it was an in-helmet shift light?

Probably not.

My shift points were when it ran out of power- goes flat time to change gear.
Good on you for getting it to work though.
Do you think it helps or is it just 'bling'?

[F5 Dave]

Rev it till a rod makes an appearance out of the cases & then shift up.

[Moooools]

Probably not.

My shift points were when it ran out of power- goes flat time to change gear.
Good on you for getting it to work though.
Do you think it helps or is it just 'bling'?

I have yet to test the light on the track, but it is more to stop me over revving it and dropping a valve. Which apparently the CB 125T has a habit of doing at high RPM.

I don't really have an ear for the four stroke, so the shift light will come on at the right RPM to shift and then turn off at the redline.

[Yow Ling]

I have yet to test the light on the track, but it is more to stop me over revving it and dropping a valve. Which apparently the CB 125T has a habit of doing at high RPM.

I don't really have an ear for the four stroke, so the shift light will come on at the right RPM to shift and then turn off at the redline.

A rev limiter would have the job done and dusted before you even realised the shift light had come on, Zeeltronics and ignitechs have them ,

[speedpro]

I have yet to test the light on the track, but it is more to stop me over revving it and dropping a valve. Which apparently the CB 125T has a habit of doing at high RPM.

Don't tell John Connor or Gaz or Manwell or Karl about 125Ts dropping valves. They'll injure themselves laughing. Even with John's "sprint" cam in the engines I don't think it's been a problem. I think a rocker or two may have been broken on the dyno but that's about it. That's with the FZR or GSXR ignitions as well so effectively no rev limit.

[jasonu]

I have yet to test the light on the track, but it is more to stop me over revving it and dropping a valve. Which apparently the CB 125T has a habit of doing at high RPM.

I don't really have an ear for the four stroke, so the shift light will come on at the right RPM to shift and then turn off at the redline.

Ahhhh didn't know it was a coal burner. Now the shift light makes sense.

[Moooools]

Don't tell John Connor or Gaz or Manwell or Karl about 125Ts dropping valves. They'll injure themselves laughing. Even with John's "sprint" cam in the engines I don't think it's been a problem. I think a rocker or two may have been broken on the dyno but that's about it. That's with the FZR or GSXR ignitions as well so effectively no rev limit.

For reals? Craig (down here in welly) told me otherwise, and has been running these engines for a while. Meh, everyone has a different experience I guess.

As for the man who suggested a rev-limiter instead; the shift light could be turned into a rev limiter in about 30 minutes. Just a matter of putting the pickup wires through the NC points on the relay, or the killswitch through the NO points.

But the dual purpose light seems like a nice thing to have.

[F5 Dave]

Take 45 min & create a soft turn off for the injectors to cyl 1 & then cyl 2 a couple of hundred rpm later, followed by an ign cut.

Glad to be of service.:innocent:

[Buckets4Me]

Take 45 min & create a soft turn off for the injectors to cyl 1 & then cyl 2 a couple of hundred rpm later, followed by an ign cut.

Glad to be of service.:innocent:


talk about getting off topic
first it's a shift light
then it's a coal burner
where the hell is the prep for Taupo gone :facepalm:

[speedpro]

That is a worry. 4-stroke talk in the ESE thread. A moderator should have stepped in by now.

[Moooools]

I was going to act like it was a two stroke. But all of these pressuring questions got the better of me, and it just slipped out..:yes:

[koba]

and it just slipped out..:yes:
I hate when that happens...

[F5 Dave]

Sturdier under garments?:blink:

[bucketracer]

.......chamfered the ports before gluing up the transfer porting mistakes, actually over cutting the transfers and then gluing them back up turns out to be a real easy way to get a smooth symmetrical port. I had mistakenly cut the ports so they opened 110deg ATDC when I really wanted 116........

TeeZee has me looking at gluing up the transfer ports on His 30hp cylinder, He wants the timing changed and the port entry area reduced to 1.2 the area of the windows like Wobbly suggested.

These are pics of of the first cylinder where he glued up the transfers to change the timing.

[wobbly]

So you are making the A port roof axial around 25*, the B port should be around 8*, the boost port around 55*.
Then fill the A port duct inner wall to reduce the duct entry area, looking at it , the outer wall would work better if it was filled, but then the case would need doing as well.
This then gives you Aprilia type GP scavenging,next step is dropping the A port to enable really big Ex aux port area.

[Gigglebutton]

I have opposite problem on my RG50. I have got the motor apart and found the transfers are 1.1mm to low. Doh!! So instead of 116* i have 121*. Hopefully fixing these will make my battle with the FXR's easier

[wobbly]

Be careful when lifting the transfers you dont restrict the blowdown STA

[Gigglebutton]

Be careful when lifting the transfers you dont restrict the blowdown STA

Thanks. I'll get TZ to have a look at them before i cut into them

[TZ350]

Fitted the original 27hp cylinder to the engine with the wide clearance crank and richened it up every where.

I wanted to test the wide clearance crank against a setup that I had real confidence in the results from previous tests.
Warmed it up properly and then it nipped on the first pull............ :doh:

I will pull it down Monday night to see what the damage is.

[RMS eng]

I have opposite problem on my RG50. I have got the motor apart and found the transfers are 1.1mm to low. Doh!! So instead of 116* i have 121*. Hopefully fixing these will make my battle with the FXR's easier

this is what i had on my RG50 which is a good start. port timing,trans 132-134* Ex 196-198* inlet 155* 24-26mm carb,STD pipe with new rear cone and RM80-85 ignition,this made a nice smooth 11 hp,good set up for a kart track,but would be 2-3 hp down for a big track.12 years ago this motor in a RG50 with STD forks and running crap 90 yoko tyres did 31.5 s at MT wellington.

[Gigglebutton]

this is what i had on my RG50 which is a good start. port timing,trans 132-134* Ex 196-198* inlet 155* 24-26mm carb,STD pipe with new rear cone and RM80-85 ignition,this made a nice smooth 11 hp,good set up for a kart track,but would be 2-3 hp down for a big track.12 years ago this motor in a RG50 with STD forks and running crap 90 yoko tyres did 31.5 s at MT wellington.

Cheers.. I have spent 3 nights this week and part of Saturday & Sunday , thinking over what to do & working on it. It seems the more i read , talk to people and work on it , the more complex things become. So many theories!!!! So many variables.!!!!!! It's driving me f#*%ing mad.:brick: 50cc's of pure agony and joy. Hopefully it all pays off.

[bucketracer]

Fitted the original 27hp cylinder to the engine with the wide clearance crank and richened it up every where. Warmed it up properly and then it nipped on the first pull............ :doh:

I saw TeeZee hard at work tonight linishing the high spots of his piston. At least this time he didn't have to take 0.004" of to get the piston to fit. When I asked him about it, he said, I guess 0.002" clearance was not enough and it should have been 0.003" like Wiseco said.

It looks like the bike will be back together and ready for another run in a night or two.

[TZ350]

Ok............... it did not nip up this time.

I think 0.002"clearance is not the problem, the problem possibly was/is that KX125 pistons for water cooled motors dont have enough "cam""on them as this piston siezed either side of the gudgen boss, not for/aft on the skirt. So I camed it up with a good linishing around the sides, and left the 0.002" piston/bore clearance the same.

236548

Blue line is the original 27hp motor with the stock 1mm clearance around the crank, the Red line is the same motor with 2mm clearance and the extra 50cc crankcase volume.

It looks like 3.5k rpm usefull power spread and I think it could be better yet with a bit of fiddling with the jets and ignition.

Now that I have something running again, we can also look at Devconning the transfers in the 30hp cly to see what happens.

[gatch]

It looks like 3.5k rpm usefull power spread and I think it could be better yet with a bit of fiddling with the jets and ignition.

Now that I have something running again, we can also look at Devconning the transfers in the 30hp cly to see what happens.

That's a wicked flat torque curve. Awesome.

[kel]

It looks like 3.5k rpm usefull power spread and I think it could be better yet with a bit of fiddling with the jets and ignition.

Firstly thats a seriously fat curve, and anything but peaky.
If memory serves me right this is the cylinder with 200deg exhaust duration and 225deg inlet yet it produces such a fat curve? The cylinder although seemingly wild by todays timings has obviously matched the time areas in all respects yet still runs Bells 1980's suggested durations.
What am I burbling about? Simple, for the torque curve and power output of a thirty + year old air cooled 125 to be that fat then its been engineered to near perfection through utilisation of the teachings of all the readily available texts even though they dont always agree with the modern standards (2mm crank gap and fancy ignition curve aside)

I suggest this motor should be preserved for its engineering prowess and not be let loose on the track, especially not with a certain 125 racer on board!

[RMS eng]

Firstly thats a seriously fat curve, and anything but peaky.
If memory serves me right this is the cylinder with 200deg exhaust duration and 225deg inlet yet it produces such a fat curve? The cylinder although seemingly wild by todays timings has obviously matched the time areas in all respects yet still runs Bells 1980's suggested durations.
What am I burbling about? Simple, for the torque curve and power output of a thirty + year old air cooled 125 to be that fat then its been engineered to near perfection through utilisation of the teachings of all the readily available texts even though they dont always agree with the modern standards (2mm crank gap and fancy ignition curve aside)

I suggest this motor should be preserved for its engineering prowess and not be let loose on the track, especially not with a certain 125 racer on board!

give me a break Kelly,this thing needs to go to the track to see what it can do and if it will last a days racing.dyno sheet looks sweet,should be good for sub 29 at MT welly.mark beat that 125 rider two races ago on his 16HP TS100 and has done a 29.9 lap on that bike.so if ESE put this 27HP motor in a good frame it should be a rocket?

[bucketracer]

mark beat that 125 rider two races ago on his 16HP TS100

Didn't beat her a second time though ........... and sadly paid the price later for over riding trying to keep up, crashing and breaking his collar bone.

[Henk]

if ESE put this 27HP motor in a good frame it should be a rocket?

And for Mt Welly I suspect that is the key.

[kel]

give me a break Kelly,
Nope wont have it.
Read through this enormous thread, ESE havent just opened up a modern two stroke and tried to copy it. They have probably read, absorbed and implemented more info than the rest of the 2 stroke bucket racing fraternity put together, and guess what their learnings and results arent locked away they're dispalyed here for everyone to share. Well done guys!

[RMS eng]

Didn't beat her a second time though ........... and sadly paid the price later for over riding trying to keep up, crashing and breaking his collar bone.

that would be right and what you get for starting mid pack on the grid,Derbi 80s are still the best two strokes at the track at this time.

[bucketracer]

Derbi 80s are still the best two strokes at the track at this time.

236591 TRRS

NedKelly on his ESE bike dusting Dave D's Derbi 80

[RMS eng]

236591 TRRS

NedKelly on his ESE bike dusting Dave D's Derbi 80

daves son on the other derbi was long gone,cheap shot mate as there are only a few bucket riders with as many wins as dave.

[wobbly]

I didnt realise that you guys were running Derbis in buckets, are they left as 80cc or sleeved down to 50cc or bored up to 100cc.
I would love to do the business on one of those to go up to 100cc and blitz everything in sight.
One engine I have done for a European 50cc champ used a Derbi Senda as a basis, but used a new KTM cylinder.
This made 18 RWHp at 13200 with power out to 14500 and a big fat curve.
Great pic of my fat thumb.

[kel]

I would love to do the business on one of those to go up to 100cc and blitz everything in sight.

That pretty much happens already in 80cc format. Ive heard power figures of 20 to 24hp (the 24hp would seem closer to the truth) for these bikes. Wonder if Dave would like to post his motor details here?

[jasonu]

That pretty much happens already in 80cc format. Ive heard power figures of 20 to 24hp (the 24hp would seem closer to the truth) for these bikes. Wonder if Dave would like to post his motor details here?

Don't forget Daves bikes are super light so don't need mega HP to get along. That is something a lot of others need to address too.

[Yow Ling]

Don't forget Daves bikes are super light so don't need mega HP to get along. That is something a lot of others need to address too.

I guess thats why RS125 have flash wheels and skinny everything else, most guys neglect rolling resistance , worn chains, dragging brake pads, totally ignore fat riders, over filled fueltanks etc.

Go look at 50cc gP bikes for some inspiration, cant see me getting down to 45kg though (or my bike)

[ajturbo]

Don't forget Daves bikes are super light so don't need mega HP to get along. That is something a lot of others need to address too.

whats wrong with my 80kg bike???:facepalm::facepalm:

[Gigglebutton]

236591 TRRS

NedKelly on his ESE bike dusting Dave D's Derbi 80

I rode Ned's bike at the last meeting for one race when it had the 22hp motor in it. :yes: The thing is a fat, so easy to ride. No clutching out of corners. This is the same bike Avalon rides. With 27 fat hp and in the hands of one of the top riders. It's potential is huge

[Ned Kelly]

I rode Ned's bike at the last meeting for one race when it had the 22hp motor in it. :yes: The thing is a fat, so easy to ride. No clutching out of corners. This is the same bike Avalon rides. With 27 fat hp and in the hands of one of the top riders. It's potential is huge

Bike is all going back together and has had some proper maintenace. Plastic on all relevant parts all ready for Avalon to ride at Kaitoke. The new engine is being reassemblied this weekend ready for a dyno run early next week. We hope.
Hopefully new porting and chamber well be a good match. We will see. Running out of time yet again.

[bucketracer]

......cheap shot mate.....

Well, on the big track, did Ned dust the Derbi or not.........


daves son on the other derbi was long gone, there are only a few bucket riders with as many wins as dave.

I think at present the front running Derbis at Mt Welly owe a lot of their success to the Diproses ability as top line riders.

But if anyone follows up on Wobblys suggestions then Derbies could become real weapons considering all the after market goodies available for them.

Whatever way you look at it, if you can afford it, a Derbi has got to be a better bet than a 30 year old MB or TF/TS100 or an air cooled GP125 from the 70's.

[jasonu]

whats wrong with my 80kg bike???:facepalm::facepalm:

It is 10kg too heavy.

[F5 Dave]

. . .But if anyone follows up on Wobblys suggestions then Derbies could become real weapons considering all the after market goodies available for them.

Whatever way you look at it, if you can afford it, a Derbi has got to be a better bet than a 30 year old MB or TF/TS100 or an air cooled GP125 from the 70's.
A KTM barrel would clearly be illegal. The aftermarket parts are a grey area in my mind (been argued here a few times), some of these parts it could be argued are for the road use. But clearly anything marketed as race or performance parts is clearly illegal in the rules.

[kel]

A KTM barrel would clearly be illegal. The aftermarket parts are a grey area in my mind (been argued here a few times), some of these parts it could be argued are for the road use. But clearly anything marketed as race or performance parts is clearly illegal in the rules.


CHAPTER 24
24 ROAD RACING - MINIATURE
24-2-4 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Go Kart motors and transmission parts are not permitted.

So this baby is permitted as its an after market part for a road bike?
236641
Its a 50mm bore! Check out those exhaust ports

[bucketracer]

Yep, buy one of those "Performance Kits" , a few $$$ for the other Bits like reeds, carb and manifold, more $$$ for any of the race exhusts available, slap it all on and your a talented top line Bucket race engine builder I recon.

[kel]

Yep, buy one of those "Performance Kits" , a few $$$ for the other Bits like reeds, carb and manifold, more $$$ for any of the race exhusts available, slap it all on and your a talented top line Bucket race engine builder I recon.

Then you'll definitely need one of these

236642

[jasonu]

Yep, buy one of those "Performance Kits" , a few $$$ for the other Bits like reeds, carb and manifold, more $$$ for any of the race exhusts available, slap it all on and your a talented top line Bucket race engine builder I recon.

And most likely you haven't wasted a lot of time and money on failed experimentation and useless parts.

[F5 Dave]

They are marketed as performance parts. Are they competition parts? That is the grey area. I think they are well out of the spirit of the rules, but that is only my feeling. Anyway this has been argued to death several times.

[Henk]

Every time I've seen the debate the spirit of the rules seems to get trumped by the letter of the law.

[Gigglebutton]

And most likely you haven't wasted a lot of time and money on failed experimentation and useless parts.

Yes sir, flash the card, buy the parts, and you still have no fu*#%& idea how it all works, suits some I suppose.

[speedpro]

Works for me.

[Gigglebutton]

And most likely you haven't wasted a lot of time and money on failed experimentation and useless parts.

I get immense enjoyment from getting together with other bucket racers over a few beers to debate all the variables of two stroke tuning and the satisfaction of seeing my efforts on a dyno are worth all the hours spent measuring and filing. Bucket racing is not about what we are prepared to pay for a motor, but more about our collective knowledge, abilities, resources and to develop a class of racing that is both competitive and affordable

[Buckets4Me]

And most likely you haven't wasted a lot of time and money on failed experimentation and useless parts.


just on buying bits that cost the earth

then you get beaten by a girl on an old shitter :facepalm:

[RMS eng]

just on buying bits that cost the earth

then you get beaten by a girl on an old shitter :facepalm:

are you saying that the ESE GP100 in a RS125 GP frame is a old shitter.it don't know but who is leading the points in A grade.

[Gigglebutton]

then you get beaten by a girl on an old shitter :facepalm:[/QUOTE]

Sounds like Scatological Sadomasicism to me. F@#$k Yeah :yes:

[TZ350]

Kel Lent me an old KX125 to look at.

236724 236723

Best as I can tell, squish is 0.85mm

These are the pistons I have been using, (because I have them) but I had never seen the original head before. The squish area in the head is much wider than I expected, it must make the combustion chamber a funny shape.

236725

This is the head shape I use with these pistons. It does not give a lot of squish area, but is a better shape (I hope), It runs with 0.8 squish and 16 deg ignition advance at peak torque.

[TZ350]

236734

Bore 56mm Stroke 50mm

The exhaust port is an unusuall shape with the power valve opening the side ports and a small cutout in the top of the exhaust port window and the piston drops below the port floor at BDC.

[TZ350]

The Transfers

[TZ350]

Main Transfer Angles of the KX125.

236767236766

[TZ350]

Secondry Transfer Angles

[TZ350]

Boost Port Angles

[TZ350]

Exhaust Side Windows

[jasonu]

Bucket racing is not about what we are prepared to pay for a motor, but more about our collective knowledge, abilities, resources and to develop a class of racing that is both competitive and affordable

Is that right???

[bucketracer]

Neds 23rwhp Engine

After three years without a problem, Chambers is giving it a Birthday

236793

Nothing to special, a real simple setup, still using the std carb and roughly polished but other wise unmodified inlet tract, other tech details were posted on page 200.

[richban]

Maybe team ESE could sponsor me on my RGV250. All you would have to do is make it go fast. I really like it but have no idea how to make it go good.

How come there are no 2 strokes at the front of F3?

I've Been watching Motogp classics. Got to love them 500's its got me inspired. Also rode a 50 last night and man it was fun.

[Yow Ling]

Maybe team ESE could sponsor me on my RGV250. All you would have to do is make it go fast. I really like it but have no idea how to make it go good.

How come there are no 2 strokes at the front of F3?

I've Been watching Motogp classics. Got to love them 500's its got me inspired. Also rode a 50 last night and man it was fun.

Give Wobbly a ring, get one of his 400cc twins, should get you to row 1 in f3

[richban]

Give Wobbly a ring, get one of his 400cc twins, should get you to row 1 in f3

Just going out to buy my lotto ticket.

[RMS eng]

Neds 23rwhp Engine

After three years without a problem, Chambers is giving it a Birthday

236793

Nothing to special, a real simple setup, still using the std carb and roughly polished but other wise unmodified inlet tract, other tech details were posted on page 200.

how many KMs has it done on a piston

[bucketracer]

how many KMs has it done on a piston

The expensive Derbies and some FXR's might need run-time-meters but we don't use them so not to sure about the actual kms.

236811

But Chambers tells me, that as best as he can tell, the piston has been in the engine since April 09 and the bike has done several 2-hours and most Mt Welly race meetings since then and it will be going back as is for another turn.

I think the only things being changed are a dodgy gear that occasionally poped out of engagement and the old main brgs, also the crank will be balanced.

Like the other ESE bikes, it's been reliable and inexpensive to run.

[RMS eng]

Expensive Derbies might need run-time-meters but we don't use them.

236811

Chambers tells me, that as best as he can tell, the piston has been in the engine since April 09 and the bike has done several 2-hours and most Mt Welly race meetings since then and it will be going back as is for another turn.

I think the only things being changed are a dodgy gear that occasionally poped out of engagement and the old main brgs, also the crank will be balanced.

Like the other ESE bikes, it's been reliable and inexpensive to run.

marks Aprilia 50 did 800KM on a piston before it broke,revs to 14000 and a derbi 50 will do a year on a piston ,and the derbis are not that expensive to build,you don't need alot of dyno time to get the most from them,same for marks aprilia 50.also motor wear comes down to how hard you push the bike also.

[bucketracer]

There is only one Derbi and a handful of old RG50's running regularly in F5 now.

Av riding her Honda 100 fitted into a RG50 frame and RG150 front end beat Dave D and his Derbi/RS125 chassis combo the last time she rode in F5, so it can be done.

It would be a good class to get into, not so crowded as B and F4.

[TZ350]

Found this old post to go with those KX125 cylinder pictures I posted earlier.


The Relationship Between Port Shape and Engine Performance for Two-Stroke Engines
Document Number: 1999-01-3333 Date Published: September 1999
Author(s): Hisatoshi Kinoshita and Motoyama - Yamaha Motor Co., Ltd.

Abstract: :eek: Measurement using a three-dimensional anemometric tester was made for the gas flow inside the cylinder of a two-stroke engine while the shape of the transfer port was modified. The relationship between port shape and engine performance was investigated for various factors that characterize the flow in cylinder. In this paper, we focused mainly on two engine running conditions: the maximum output at 11,750 rpm and the output at 10,000 rpm. As a result, we found that the maximum output is most related to the tangential inclination angles of the main transfer port and the inner vent radius of the main transfer duct.

[TZ350]

Maybe team ESE could sponsor me on my RGV250. All you would have to do is make it go fast. I really like it but have no idea how to make it go good.

Start here:- http://www.rgv250.co.uk/forums/index.php?/topic/26089-ignitech-results/

Redmer Bootsma has done a lot of work with his RGV and Ignitech ignitions. He is worth a Google.

Redmer has now moved back to Holand after living in Austraila, and when he was over here working on projects he visited the ESE workshop a few times. Later he sent us a small collection of the info on RGV's that he has posted on forum sites and was the inspirtaion behind us getting Ignitechs, when I can locate the data I will post it for you.

[wobbly]

That KTM cylinder I posted is off a road bike - so is as legal as it gets.
The fact it took 3 days of grinding and dynoing to make it fast,means in fact it would have been cheaper to buy an aftermarket bolt on.
I agree that spending money is needed to go fast,but how you spend that money is sometimes dependant upon the knowledge you have to make the right decisions in the first place.
That old KX cylinder sleeved down to 100cc would make a rocket with a heap of epoxy and grinding - its got all the beginnings of a good engine.
I have that sae paper on ports but the link is broken.

[kel]

Found this old post to go with those KX125 cylinder pictures I posted earlier.

Which illustrates one of several problems faced when trying to coax power out of the KE, there is no inner radius to the transfer ducts, just the the liner. The attached photo shows the minor porting thus far (only about 12hrs work in the cylinder) the plan for today is to add epoxy to the liner to form a 6mm inner radius to the main transfers duct.
What I have realised through this process is that the Suzuki is a better unit for modifying than my Kawasaki - wider and radiused transfer ducts, larger rotary disk, better head etc (Im making excuses in case I dont crack 20hp, that would be embarassing!) although the KE does have a strong 6 speed box.

This is the KE
236848
Im aiming for something like this
236847

[bucketracer]

Another link to useful RGV info http://www.rgv250.co.uk/forums/index.php?/forum/21-rgv-engine-enhancement/

I joined the Forum and found Redmers Profile page and looked up his posts, he spends most of his time in the engine enhancement section, lots of useful stuff there.

Like how to setup the Ignitech for quick shifting and if you have ever wanted one, a link to a professional quality timing light http://www.iequus.com/Product/Detail/FAE5FA18-7D9D-4BFE-95EB-0C48F517AD25

[jasonu]

Which illustrates one of several problems faced when trying to coax power out of the KE, there is no inner radius to the transfer ducts, just the the liner. The attached photo shows the minor porting thus far (only about 12hrs work in the cylinder) the plan for today is to add epoxy to the liner to form a 6mm inner radius to the main transfers duct.
What I have realised through this process is that the Suzuki is a better unit for modifying than my Kawasaki - wider and radiused transfer ducts, larger rotary disk, better head etc (Im making excuses in case I dont crack 20hp, that would be embarassing!) although the KE does have a strong 6 speed box.

This is the KE
236848
Im aiming for something like this
236847

I thought the KE cylinder was a one piece iron casting ie no liner as such.
Why don't you look at grafting a GP125 cylinder to the Kwaka bottom end?

[kel]

[QUOTE=kel;1130039076] the plan for today is to add epoxy to the liner to form a 6mm inner radius to the main transfers duct./QUOTE]

So epoxy and I arent great friends, last time I used the stuff it was a bloody disaster, but this time things have worked out quite well
236861 236862
obviously need a finish up and some more area to be cut into the duct but overall I think this has worked out quite well.
Sorry to high jack the thread TZ but thought you'd like to see the result

[Yow Ling]

What kind of epoxy did you use?
I have tried some Devcon Titanium putty, and also devcon aluminium putty. I found the former cured harder and was a lot easier to grind , but pretty hard to file.
the aluminium stuff stayed kinda soft. Maybe I need to buy fresh stuff

[TZ350]

the plan for today is to add epoxy to the liner to form a 6mm inner radius to the main transfers duct.

236861 236862

obviously need a finish up and some more area to be cut into the duct but overall I think this has worked out quite well.

Thats very interesting, it looks as good as the sample cylinder.

Are you going to make the transfer entry about 1.2 the window area like Wobbly suggests?

We would love to see more of this build as it progresses.

I wish more people would post their work as I hear there are a few hot projects in the pipe line.

[kel]

What kind of epoxy did you use?
Pratley steel putty, $10 for 125g.

[kel]

Are you going to make the transfer entry about 1.2 the window area like Wobbly suggests?

Almost, as ridiculous as it might sound Im trying to follow the ratios that Frits listed for the RSA. He'd probably fall over laughing if he saw the KE.
"There is hardly an optimal ratio of duct area to port window. I generally try to obtain a value of 1,5 but when you look at the B-transfers of an Aprilia (A is the set nearest the exhaust; then come the B-ports, then the C-port opposite the exhaust) you will see that the entry at the cylinder base is almost a rectangle, with a width of 19mm and a 'length' (in riding direction) of 16 mm; that gives 304 mm².
The B-window in the cylinder wall has a width of 25 mm, a height of 13,2 mm and an upward angle of 10°; the effective port area is 325 mm²; it's bigger than the entry area.
That may seem strange, but remember that the entry area is open all the time and the port is not..."

Frits has also written a lot about expansion chamber design problem is the copy I have is in Dutch, would love to hear from someone who can translate to English.

[jasonu]

would love to hear from someone who can translate to English.

Google 'translate'

[kel]

I thought the KE cylinder was a one piece iron casting ie no liner as such.
Why don't you look at grafting a GP125 cylinder to the Kwaka bottom end?

The KH100 was a one piece, that thing was a bitch to port. The KE series were ali cylinders with iron liners.
Yeah thought about whipping one of the many ESE cylinders they have lined up on their benches but figure I've helped myself to enough already, intellectual property that is, besides its time for the return of Kawasaki dominance. :lol:

[ac3_snow]

besides its time for the return of Kawasaki dominance. :lol:

doesn't seem to be happening in many other road race arenas so might as well start in buckets!

[kel]

[QUOTE=TZ350;1130014421 if all that goes well and we are getting good over rev at the top I will try water injection to see if we can extend the lower part of the power spread.[/QUOTE]

Finally dug up the NSR water injection article, thought it was more in depth.

236910 236909

[TZ350]

Ok, I have had a bit of a play.

236917

Red line is the original 27hp engine setup, the blue line is the 2mm clearance (+50cc) crank after a bit of fiddling with the jets and ignition.

So much for peaky 2-Strokes, it looks like a usefull 4k+ power spread, good FXR's run to 5, so we are getting closer to 4-Stroke tractor drivability and I have ideas about how to extend the bottom.

Looks like 2mm clearance might have something going for it, or is it the extra 50cc crankcase volume?

[koba]

I wish more people would post their work as I hear there are a few hot projects in the pipe line.

After getting a bigger carb on mine I've moved away from worrying too much about power as the main bottle-neck turned to ground clearance.
That is hopefully sussed for now, until I improve other areas and it becomes the bottleneck again! Still the handling is slowing me up a bit more than lack of power at Kaitoke. (and Talent issues...)

But then when my bike didn't like the wet (waterproof kill switch is a good idea!) I got to have a go on another MB engined bike that is a lot better developed in the engine and handling and had bloody good fun on it.

It has got the lust for power dangerously high at the moment so I may get all silly and depart from my low(ish) power plans...

[wobbly]

Frits and I have discussed the duct entry ratio before and if you consider that the actual duct entry window starts near the bore radius in the Aprilia, then the ratios are 1.1 and 1.3.
Where the outer duct wall is a long way from the bore ,the same designers added length on the inner wall to reduce the intake window area at the gasket - see RS500

[jasonu]

Ok, I have had a bit of a play.

236917

Red line is the original 27hp engine setup, the blue line is the 2mm clearance (+50cc) crank after a bit of fiddling with the jets and ignition.

So much for peaky 2-Strokes, it looks like a usefull 4k+ power spread, good FXR's run to 5, so we are getting closer to 4-Stroke tractor drivability and I have ideas about how to extend the bottom.

Looks like 2mm clearance might have something going for it, or is it the extra 50cc crankcase volume?

That is the best graph I have seen from you yet.
Now get it to the track to back up and or prove your data!

[TZ350]

Now get it to the track to back up and or prove your data!

How exactly does getting it to the track backup/prove the dyno data, dyno data is dyno data. Better that someone drages a Derbi or Aprilia over and does a back to back on the dyno with my GP and we post the results.

The track is more a measure of riding skill I would have thought, as there is plenty of evidence at Mt Welly of good riders doing well on bikes with inferior engines, Mark for one.

Having said that, it would be interesting to have someone who can ride well, try it out and give us their opinion.

[RMS eng]

How exactly does getting it to the track backup/prove the dyno data, dyno data is dyno data. Better that someone drages a Derbi or Aprilia over and does a back to back on the dyno with my GP and we post the results.

The track is more a measure of riding skill I would have thought, as there is plenty of evidence at Mt Welly of good riders doing well on bikes with inferior engines, Mark for one.

Having said that, it would be interesting to have someone who can ride well, try it out and give us their opinion.

rob i don't think any of the top guys have inferior engines ,they may not make a lot of top end power,but make the right type of power to get around a small kart track fast,Derbi 80s make 20-23hp when dave gets back i will see if he has a dyno sheet i can post,Johns dyno is the one he used.

[TZ350]

.....they may not make a lot of top end power,but make the right type of power to get around a small kart track fast

Totaly agree, do Derbies have a 4.5K rpm power spread?


Derbi 80s make 20-23hp when dave gets back i will see if he has a dyno sheet i can post,Johns dyno is the one he used.

Johns dyno does a good job but only displays hp against road speed and when we were there it was not able to give a print out.

As Jasons comment was "Prove the Dyno Data" if you want that, best someone brings a Derbi over and we run Back to Back comparisons.

This thread was about posting what we and others were doing, and making a few friends.

I hadn't wanted this to be a "" my engine is better than your engine"" thing, and I have nothing against Derbies, it's just not what we have........

But you have made good use of the thread to compaire Derbies in a faverable light at the expense of our efforts with the GP's making it a hijack if your not posting anything interesting at all about your own work.

And if you think the Derbies you put together are that great, lets run em up on the ESE dyno in a back to back test, you can supervise or even do the tests yourself and then we can post the results and people can make up their own minds which they would rather ride.

[Buckets4Me]

That is the best graph I have seen from you yet.
Now get it to the track to back up and or prove your data!


I know I'll use Daves bike and he can ride TZ350's and we will see weather his one can beat TZ's :facepalm:

I bet i can be lapped faster than he can :gob:

[bucketracer]

Now get it to the track to back up and or prove your data!


I know I'll use Daves bike and he can ride TZ350's

Yesss sir that's the answer, Buckets4me rides the RMS Eng prepared Derbi of Dave D's and Dave rides TeeZee's FZR/GP125.

No doubt the Derbies superiority assures Buckets victory.......... :laugh:

[RMS eng]

Yesss sir that's the answer, Buckets4me rides the RMS Eng prepared Derbi of Dave D's and Dave rides TeeZee's FZR/GP125.

The Derbies superiority assures Buckets victory.......... :laugh:

Dave D has done most of the work on his DERBI motors,RMS only did a little machining and fitted the motors in the frame,Dave does all his own set up work.as i have said before the little Derbi motors may not be the best motor out there but are new,light and make enough power to be in the hunt.

[TZ350]

Page 260

Recent Interesting technical comments gathered together here so they are easier to find, other link lists can be found on the decade pages starting with Page 80.

There are over 1,200 images on this thread, to find the interesting ones use “Thread Tools”, then “View Images” near the top of this page. You can view the images 70 at a time from the beginning. It’s a quick way to find some of the interesting posts too.

A handy (and cheep $16 USD) Porting Calculator from:- http://www.porting-programs.com/ is based on Blairs and Jennings work. And gives blowdown areas required for a selected power output.

Kel gave me this link to a very interesting book. www.prme.nl/download/engine-1.pdf (http://www.prme.nl/download/engine-1.pdf)

A good reference to sharpening or re-shaping drills:-
http://users.bart.nl/users/summer/16mmngm/Articles_htms/ColinBinnie/DrillSharpening.htm


If you have any issues with the Mallory coming loose ( hope you dont) you can Tig weld them in place.
In the stroker Banshee/RZ/LC cranks I build, they are 0.08mm press fitted, then Tig tacked each side.


Just one thing to add here re the screamer 100 engines we are looking at building. To make the sort of power we are looking for, we have to use around 200* of Exhaust timing. This works with a TL of around 800mm to give power up to the 14000 mark. But this timing and pipe length is a resonance mismatch. For it to work, and rev that high, we HAVE to use a solenoid powerjet, to get heat into the pipe ( along with pulling out timing to near TDC ). This combination will not run above the power peak on a normal carb. To get power and revs with a "normal" carb requires a timing of around 83* ATDC and a tuned length of around 830, but this seriously limits the blowdown STA and thus the power that can be achieved. And I use a 182MC right angle head ,available from C C Speciality in the States, for porting the transfers - but I hate it with a passion.


The only reason that the clutch slips in the taller gears is because its a crap clutch pack and needs more plates or more spring to take the applied torque.


….. high rpm coughs between gear changes? sometimes they appear on bikes with tame, well, not radical inlet durations (piston port & rotary).


See this all the time in kart racing - reeds as well, usually its the needle/tube combo going lean as you pass thru 3/4 throttle, when backing off for the change.
Get an Ignitech on there and do full throttle shifts - easy.


Also happens when an engine is reved too far past peak power before a gear change. The airflow drops in the overev, the carb goes lean and it will backfire as the change is made ( even using a speedshifter). RS125 engines in karts do it with steep baffles, as soon as you rev them too hard.


Jan Thiel
When rpm raises still more there is no more transfer flow and the engine stops completely. So transfer flow depends completely from what is 'allowed' by the exhaust (blowdown) flow!


The dyno load ( gear ratio) should be selected to simulate the end use.
ie do you want the thru the gears performance as seen at Mt Welly or pulling 6th gear for several seconds at Taupo, where you have a huge wind drag factor to push against. Around a sprint track you can use way more timing and not see deto due to the short "power on" period. But either way the heat soak in the pipe and case should be similar to what would be seen on the track.

Re the rotary valve timing.The problem here is that every engine is different, with the case vol interacting with the timing and the carb length/size.
Basically when you exceed 140/88 you get finicky jetting and questionable power increases at the expense of drive down low.

Only way to define what is best is to leave the closing at say 88 and go from 135 up to 145 in 2* increments. Stop or go back if no useable power is seen.
Then see if top end is lost by going back to 86/84 on the closing.


The RSA does not have any taper at all at the top of the duct divider ( septum), the end of the divider just has a small radius on each side. This is to reduce the area ratio between the duct entry and the port exit.


If you look at the old Rotax pic it has a duct entry to port ratio of about 1.4. The base gasket dimensions are virtually identical to the late model cases. The RSA/RSW has a ratio close to 1.2, so its still tapered down to the port exit but no where near as much. If you look at the Delivery Ratio of a full on 2T engine, virtually all the volume that ends up in the cylinder, is actually sitting in the transfer ducts, NOT the case. The smaller this volume is, the quicker it can be accelerated through the duct into the cylinder.


Jan Thiel
…. flowing the transfers makes little sense! The important thing is more their direction and how they influence upon each other. At high rpm there is some reverse flow, the transfer ducts becoming black, and even the crankcase and carburettor bellmouth because of the entering burned gasses. This happens because with raising rpm. the pre-exhaust flow (blowdown) becomes insufficient. When rpm raises still more there is no more transfer flow and the engine stops completely. So transfer flow depends completely from what is 'allowed' by the exhaust flow!


Wobbly sent me an email (and permission to post it) re the shape of the RSA rotary valve disk.

Hi Rob Here is a pic I just got from Frits, I asked about the RV timing as I am building up a Sim of the RSA/RSW. He said that the opening wasn’t critical between 140 and 145, the closing between 85 and 88 depending upon the rider and track. He said they tried opening timings all the way to 155*, but 142 to 145 was the norm. The angle on the closing side is purely to help with wear on the case. Cheers Wob


My opinion of closing angle (the important number) is that the later RSA has a much narrower port width than the RSW, and thus these timings give a much increased STA, as the disc is covering the port for less time, with the same actual timings.

Thus maybe that engine can deliver better performance within an envelope of non "radical" port timing numbers. In the old Rotax tandem twin, going from 85* ( stock) to 88* is like night and day in overev performance, but carburation becomes finicky and alot of bottom end power is lost.


The rotary valve timing.The problem here is that every engine is different, with the case vol interacting with the timing and the carb length/size.
Basically when you exceed 140/88 you get finicky jetting and questionable power increases at the expense of drive down low.

Only way to define what is best is to leave the closing at say 88 and go from 135 up to 145 in 2* increments. Stop or go back if no useable power is seen. Then see if top end is lost by going back to 86/84 on the closing. Graphing power Vs rpm takes the load out of the equation,


Riley Will
The 125cc engine made 48 hp (sae) at the rear wheel. I believe I can make more with the reed valve engine by focusing development on the reedcage and inlet. However, it has been my experience that the mid range power of the disk valve engine is always superior. I have found over rev power of the reed valve engine to sometimes be easier to achieve. In the past I would also produce more peak hp with the reed valve engine but the mid range maybe 7% less than the disk valve. I have also made tests on a 125cc disk valve engine with fuel injection. This made 10% more power everywhere than carburated!!!


Yes, dead right the STA numbers havnt changed at all since the theoretical work was published out of Queens in Belfast by Blair etal. Aprilia completely changed the whole layout from previous 3 port geometry. Instead of the main port being right at the 72% limit, they reduced this to 68% and dropped the main transfers below the rest.This enabled the large secondary Ex ports to be added, plus gave room to pull all the transfers around and create more area with less timing.

What this lead the way with,is being shown all the time now in the sims I run, that the Ex STA means jack shit, Blow Down STA is Everything.


Its not scavenging that’s directly the issue, its lack of blowdown time, that effects scavenging efficiency and delivery ratio. Means the cylinder is full of exhaust residuals, as much of the mixture waiting in the ducts is reverse flowed back into the case.


Jan Thiel
At high rpm there is some reverse flow, the transfer ducts becoming black, and even the crankcase and carburettor bellmouth because of the entering burned gasses. This happens because with raising rpm. the pre-exhaust flow (blowdown) becomes insufficient. When rpm raises still more there is no more transfer flow and the engine stops completely. So transfer flow depends completely from what is 'allowed' by the exhaust flow!

[TZ350]

Electric Power Jet Carb.


The FPE superkart engine that won the NZ road title at Manfield a few weeks ago makes 92 RWHp on the Dynojet 168 I use.
Still not quite as good as the RS250 setup we did that won at Laguna Superkart Worlds a couple of years ago.

The powerjet carb is controlled by the Ignitech with a combination of throttle position and rpm in a "truth table".
In general the solenoid is activated with 12V ( no fuel flowing) below 4000 rpm and 75% throttle on the TPS.
Above 75% and around 12400 rpm it is activated again to lean off the fuel curve over the top of the pipe.
Looks like you will be able to reverse the fuel exit, blocking off the hole on the throttle bore side, and take off fuel from the outside bung, thru a needle jet and into the top of the venturi next to the slide.


And something that I scraped from the net.........

""The solenoid control on TZ type powerjets really just shuts off fuel flow to the powerjets right at the top of the rev range to lean the mixture off to increase the over-rev once you are past peak power.

I don't have the solenoids plugged in currently though as I find they work well enough for my current needs with the powerjets simply responding to venturi vacuum pressure in pretty much the same way as the oem 3MA powerjets work.""

And here is a picture of the carbs and what I can make out, a dyno graph without, and with the power jet solenoids shutting off (red line) and extending the over rev.

So it looks like you can use an electric power jet like a standard one and when the carburation is sorted, try switching it of by activating the solenoid at or just after peak power and see what happens with the over rev.


You have to be very carefull with the switch point and the run time on the dyno.
The switch point is dead critical to 100rpm,so i always set it too high initially and make sure that the dyno is loading the acceleration rate to be as close to that on track as you can.
This gives the pipe time to heat up and affect the power over the top, as it would in reality.
On a RS250 dropping the switch point from 12800 ( std) to 12400 gives easily another 800 rpm of virtually no power drop past peak.
On the track,if the rider can feel the switch point ( it feels like hooking another gear)the jet is too big,when its right it should be seamless and just keep reving out.
Leaded fuel is the opposite to unleaded, in that as leaded likes to run lean - you can only use a small powerjet and thus only switch off a small amount.
A leaded engine works best with around 35 to 38 PJ, the unleaded fuel can switch a 60, in Keihin numbering, as the crap fuel makes best power at peak when quite rich..

Mallory Metal Plugs


If you have any issues with the Mallory coming loose ( hope you dont) you can Tig weld them in place.
In the stroker Banshee/RZ/LC cranks I build, they are 0.08mm press fitted, then Tig tacked each side.

[TZ350]

236972

This is where we started, can't say we haven't taken the traditional bucket racing route.

[wobbly]

Bastards, taking a perfectly exellent road bike and making it into a bucket - shouldnt be allowed.

[F5 Dave]

3 years on from now that bike on Trademe, once the H2s, T500s & Z1s have dried up, will probably be worth some serious coin & Team ESE members will be hunted like dogs in the same manner that builders of Vincent Chops were previously.

[jasonu]

How exactly does getting it to the track backup/prove the dyno data, dyno data is dyno data. Better that someone drages a Derbi or Aprilia over and does a back to back on the dyno with my GP and we post the results.

The track is more a measure of riding skill I would have thought, as there is plenty of evidence at Mt Welly of good riders doing well on bikes with inferior engines, Mark for one.

Having said that, it would be interesting to have someone who can ride well, try it out and give us their opinion.

Yes mate. What I was getting at was to get it on the track to see how it performs, carburates, revs etc. Your latest curve is really similar to mine up to 10k when mine has more or less peaked at 22.5hp and yours keeps going for 5 more HP. My bike is very tractable for a 2 stroke so if everything is as your dyno results look I think you will have a rocket.

By the way I wasn't having a go or anything like that, just really interested in seeing how these dyno results translate to track performance which (I think) is what it is all about.

[F5 Dave]

and to say go out & spank those coal burners!:woohoo:

[Henk]

and to say go out & spank those coal burners!:woohoo:

Diesels are the future :chase:

[F5 Dave]

So is a dusty waterless irradiated wasteland, but I try not to dwell on it too long.

[TZ350]

.....really interested in seeing how these dyno results translate to track performance......

Hopefully this weekend .........

[TZ350]

Ok, got it throttling a bit better.

237012

A comparison with one of the better FXR's at Mt Welly (red line).

Only a little bit more, and we have an easy to ride bike like an FXR. And I have few ideas how that and more can be achieved ........

237013

Speedpro is still King of the Hill at 29.4 (red line).

[Buckets4Me]

3 years on from now that bike on Trademe, once the H2s, T500s & Z1s have dried up, will probably be worth some serious coin & Team ESE members will be hunted like dogs in the same manner that builders of Vincent Chops were previously.


so we dont tell them that that is the 5 th bike to get the chop :facepalm:

I set fire to one with a plasma gun once :woohoo: (much faster than a hacksaw)

[wobbly]

If Diesels are the future then why have Evinrude , using E Tec got the lightest, most powerfull, most fuel efficient, least polluting outboard on the planet.
Yes its a 2 stroke and the only reason every 2 wheeled device used for transport isnt a 2 stroke right now, is that the technology used for effective direct injection is patented and stupidly expensive.
This will change very soon and the big, heavy, slow, expensive to maintain ,polluting sacks of shit called 4 strokes, will be down the dunny along with Hondas corporate masturbation antics - exactly where both belong.

[bucketracer]

Only a little bit more..........

Looks like TeeZee is close to developing a stroker with more power and a broader power band than the dominant 4-Strokes, that should change things a bit.

[Henk]

If Diesels are the future then why have Evinrude , using E Tec got the lightest, most powerfull, most fuel efficient, least polluting outboard on the planet.
Yes its a 2 stroke and the only reason every 2 wheeled device used for transport isnt a 2 stroke right now, is that the technology used for effective direct injection is patented and stupidly expensive.
This will change very soon and the big, heavy, slow, expensive to maintain ,polluting sacks of shit called 4 strokes, will be down the dunny along with Hondas corporate masturbation antics - exactly where both belong.

I was fishing.

[koba]

I was fishing.

I think you got a bite...

I know you know that your shitty Diesel is a pile of crap!

[Henk]

The bike we have that I enjoy the most is Max, and I try and stay off that because I value my licence.

Oh and my shitty diesel is staying home this weekend because it started blowing smoke at Toke, to paraphrase Gavin V " If you fuck the head throw the engine away" bloody overcomplicated piece of junk.

[richban]

Looks like TeeZee is close to developing a stroker with more power and a broader power band than the dominant 4-Strokes, that should change things a bit.

Well just to keep the 4 strokes in the party I should have the new engine in after this weekend. More dev than the last attempt and at the edge of what is possible from an air cooled FXR. Its first breath of life was very impressive can't wait to ride it.

[TZ350]

......really interested in seeing how these dyno results translate to track performance which (I think) is what it is all about.....

Yes the track is the test, but things have fallen through for the weekend. My interest is probably more in building them than riding them so to give it a fair test I will see if Kel or Gigglebutton will take it for a test run in the A group at the next Mt Welly meet.

[kel]

Yes the track is the test, but things have fallen through for the weekend. My interest is probably more in building them than riding them so to give it a fair test I will see if Kel or Gigglebutton will take it for a test run in the A group at the next Mt Welly meet.

That sounds like me :woohoo:
note to self, its a test run no pressure to go sub 30 - UNLESS I WANT TOO!
note 2 to self, you may have just lost the ride

[diesel pig]

If Diesels are the future then why have Evinrude , using E Tec got the lightest, most powerfull, most fuel efficient, least polluting outboard on the planet.
Yes its a 2 stroke and the only reason every 2 wheeled device used for transport isnt a 2 stroke right now, is that the technology used for effective direct injection is patented and stupidly expensive.
This will change very soon and the big, heavy, slow, expensive to maintain ,polluting sacks of shit called 4 strokes, will be down the dunny along with Hondas corporate masturbation antics - exactly where both belong.

Fucking A Wobbly! I recommend checking out the the Evinrude site, it has video's on it showing how much less polluting an Evinrude E Tec is, and they don't muck around saying conpared to brand 'X' They actually show you the Yamaha and Johnson 4 strokes they are doing the conparsions to.

[TZ350]

That sounds like me :woohoo:
note to self, its a test run no pressure to go sub 30 - UNLESS I WANT TOO!
note 2 to self, you may have just lost the ride

Ok Kel is the test pilot........... great stuff, now I am looking forward to the next Mt Welly.

[Gigglebutton]

Yes the track is the test, but things have fallen through for the weekend. My interest is probably more in building them than riding them so to give it a fair test I will see if Kel or Gigglebutton will take it for a test run in the A group at the next Mt Welly meet.

F%$#K Yes!!!! :yes:
I,m not as fast as Kel but I,m keen as. Saturday practice maybe? Then Ned or Avalon could ride it in anger on Sunday

[richban]

Yes the track is the test, but things have fallen through for the weekend. My interest is probably more in building them than riding them so to give it a fair test I will see if Kel or Gigglebutton will take it for a test run in the A group at the next Mt Welly meet.

Send it to wellington with someone. I will give it a bash around Kaitoki head to head with my bike. Promise to use all the power she has.

[TZ350]

Send it to wellington with someone. I will give it a bash around Kaitoki head to head with my bike. Promise to use all the power she has.

That was on my mind, but it needs a bit of dialling in first, that will be Gigglebuttons job come next practice day, then hopefully Kel gets to go head to head with the fast boys race day.

[wobbly]

He He, watch out or I will tell No Mates you guys think you are fast - and he will turn up with the 5 year old 29 Hp RG100/RS125, just to put you all in the fence.

[F5 Dave]

. .. sacks of shit called 4 strokes, will be down the dunny along with Hondas corporate masturbation antics - exactly where both belong.
That's a bit harsh, what have Honda ever done to you? You meet the nicest . . .etc etc. . :sick:

[richban]

He He, watch out or I will tell No Mates you guys think you are fast - and he will turn up with the 5 year old 29 Hp RG100/RS125, just to put you all in the fence.

Oh fuck yeh, bring it on. I'd like to see that. 205kg of me and FXR don't get put in the fence that easy. We will be waiting all weekend. Have a track all organized.

[kel]

205kg of me and FXR .
So if the FXR is 135kg that makes you 70kg. Is there a fly weight class in buckets?

[kel]

He He, watch out or I will tell No Mates you guys think you are fast - and he will turn up with the 5 year old 29 Hp RG100/RS125, just to put you all in the fence.

Ive heard a rumour that there just might be an apperance at the next round.

[richban]

So if the FXR is 135kg that makes you 70kg. Is there a fly weight class in buckets?

No that would make me 6'2 and 96kg and you can work out the rest.

[speedpro]

Oh fuck yeh, bring it on. I'd like to see that. "205kg of me "and FXR don't get put in the fence that easy. We will be waiting all weekend. Have a track all organized.

Richban @ 205Kg
FXR @ 95Kg
Total @ 300Kg, is how I read it. He goes all right for a fat bastard, eh?

I saw someone who didn't know any better putting the lean on Warwick Snow once. Only once!

[richban]

Richban @ 205Kg
FXR @ 95Kg
Total @ 300Kg, is how I read it. He goes all right for a fat bastard, eh?

I saw someone who didn't know any better putting the lean on Warwick Snow once. Only once!

Thanks Mate. No comeback for the one.:facepalm:

[TZ350]

Well Thomas has come up with the goods again.

Making more power than the 4-Strokes with a peaky 2-Stroker is relatively easy but having a wider effective power spread than the FXR's is something else and has been a goal of mine for a while.

As I see it, having a powerful easy to ride bike with a very wide power spread is the key to beating the FXR150's with a Stroker. As part of the plan I have been looking for a practical variable inlet and Thomas came up with a good idea.

237059

And it could be the answer to lifting the lower rpm power of the GP (blue line) and thereby having a wider power spread than the FXR's (red line).

237056

The way the engine is now, the rotary valve closes the inlet tract 85 deg ATDC. The idea is that its not necessary to have a continuously variable closing point, in practical terms, a stepped closing from 55 to 85 deg ATDC that is opened automatically by something sensing the rpm would work just as well.

237054

With a divider down the middle of the inlet track right up to the rotary valve and a gate that closes one half of the inlet tract the closing point of the rotary valve with the gate closed would effectivly be much earlier, 55 deg ATDC. With the earlier closing and the inlet tract being effectively much smaller this should extend and lift the lower power spread.

237055

By opening the gate you get the full inlet tract and later closing point of 85 deg ATDC for high rpm power.

237057

With a high velocity fuel atomizer region in the carburetor (like we use), the rotary valve and inlet tract divider does not have to extend very far into the carburetor.

237067

I think this variable inlet idea could work equally well with reed valves if the reed block has a divider fitted inside like some modern ones have.

[wobbly]

Have a look at this idea.The Lectron carbs have a venturi behind the slide, so you get high velocity at half throttle, but actually in bench tests they flow more air than the same size PWK when wide open.
Add a 1/2 throttle plate and the flow wont be as disrupted , as it would be with a plane "gate" when inserted.

[TZ350]

Have a look at this idea.The Lectron carbs have a venture behind the slide......

The lectron venture looks a bit like my 24/28 idea.

I would be very interested in where the size of the Lectron carburetor is calculated (measured), is it at the slide or inside the venture? might settle a few arguments about the legality of my 24/28 carb.

[TZ350]

Add a 1/2 throttle plate and the flow wont be as disrupted , as it would be with a plane "gate" when inserted.

Thanks for the post, looks to be a better (and easier) way of doing it, it encourages me to give the idea a go,

I think the FXR's should be afraid, very afraid, this could be the first 2-stroke Bucket with more power and a wider easy to ride power spread than the popular FXR 4-Strokers.

Watch this space, if we can get this to work, home built 2-Strokers could soon be making a comeback .........

[ac3_snow]

Home built Strokers could be making a comeback .........

Well along that tune, with uni holidays at the moment I have had a time to make some progress on my bucket.
so its a TF125, first attachment is the port map for its current state.
This gives me timings of :
Exhaust opens 81 ATDC so 200 duration
Main transfer opens 117 ATDC so 126 duration
and the Piston inlet ports open 74 BTDC with 158 duration.
I'm fairly confident I have the right exhaust width for the necessary blowdown time area.

However after talking to giggles and reading speedpros comments I think I may have got a little carried away on the inlet ports. Might see how it goes and can always put a little devcon in if needed.


Don't get carried away with the piston port intake as the pistons will start cracking and if you don't catch it in time you'll do some serious damage.

Transfer openings/ window seem to have about a 1.5 ratio by my very rough measurments so have not widened them at all will just match them nicely to the cases.
The main transfers have a 126 duration but the secondary trasnfers open about 2 degrees earlier, should I raise them both slightly to increase the main duration closer to 130??

I also plan on copying giggles and Tezees RG50s and cut down the crank case reed and epoxy it in flat to the bottom of the barrel. Then do a little grinding to help the air/fuel find its way into the transfers


The head has far to big of a squish area at the moment and needs almost 2mm taken off to bring it down to 0.9mm.
I have heard speedpro mention previously that a centered sparkplug will perform better than one offset. I don't know if I want to attempt this might be beyond my capabilities and tools.

Its all going into a cbr250 frame.
6 months ago I new less than nothing about 2 strokes, have managed to bluff my way this far can't wait to have it all together and see if it actually goes or not!

[speedpro]

Love the toothpick.
Don't raise the transfers, blowdown is most important on a motor with a single ex port and you don't want to reduce it.
My old TS100 had 200deg duration of intake timing and I devconned over the reed valve to make a nice smooth intake port. The theory was that with the intake timing tuned for 10-11K there was no need for the reed to extend the working revs. I'm not sure why it turned out to be such a nice engine, see the graph green line labelled KR100.

[TZ350]

Its all going into a cbr250 frame.
6 months ago I new less than nothing about 2 strokes, have managed to bluff my way this far can't wait to have it all together and see if it actually goes or not!

It all looks good ........ actually, it looks very good.

[kel]

Good to see the student loan being spent on something useful, I bought a CR125 with mine (many years ago of course)

[ac3_snow]

The theory was that with the intake timing tuned for 10-11K there was no need for the reed to extend the working revs. I'm not sure why it turned out to be such a nice engine, see the graph green line labelled KR100.

I was under the impression that the reeds worked at lower revs and helped to increase the lowdown power? (I realise this also depends on the thickness off reed used)

finding an ignition is my next duty, I looked at the KX80 as you suggested tezee but they all seemed semi pricey, for this reason I grabbed a cheap RM80. Turned out to be an expensive mistake as the taper is different :facepalm:
So back to looking at KX80s again and if anyone wants a rm80 ignition let me know, $70ono!

[TZ350]

Interesting bit of reading......... http://www.saltmine.org.uk/dale/dale-faq.htm

And a down loadable PDF of Dale Alexanders work with RD's http://www.saltmine.org.uk/pdfs/dale-faq+p.pdf

And a bit about jets thats worth a look http://home.arcor.de/martin.kieltsch/jet_size_problem_english.pdf

[TZ350]

A place that dynos products and publishes the results.
http://www.oocities.org/gtthunder.geo/testbed.html

Some interesting Dyno Graphs.

237090

Like this "O" ring chain power loss comparison, not much in it apparently.

237088 237089

And these MX80 dyno runs, not much point in running MX80's in Buckets as we already make better power.

237087

Even with all the fruit the 80cc MX'rs arn't that great.

237086

The Team ESE GP125 of mine compairs pretty well to this 99 Suzuki RM125 MX'r, and thats water cooled with power valves.

[bucketracer]

Pick up some bits and bobs for your Derbi here and get 22hp (DIN at the crank):- http://www.rrd-preparation.com/kit-80cc-malossi-mhr-team-d.50mm-aluminium-pour-moteur-derbi-euro-1-2/product_info.php/products_id/869/language/en?osCsid=atsaod576ffon4krhae3k47ap2

And you won't need to do a lot of hard work or spend much on dyno time as its all been done for you.

Famous kit MALOSSI MHR TEAM used for various cup MALOSSI GP 80 and trophies

237102 237105

Technical summary:

Real cubic capacity 78,6cc in race origin 40mm (rod 90mm on the origin) compression Report/ratio advised 1:15,4
Spacing advised segment ends: 0,15mm
Play piston/minimum cylinder: 0,051 has 0,059mm
Volume of room advised: 5,4cm3
Squish advised 0,55mm
Announced power MALOSSI MHR: 22cv has 12000 turns/minutes
Couples announced MALOSSI MHR: 13kgm with 11750 turns/minutes
Diagrams 189° for the exhaust and 129° for the admission
Selling price advised MALOSSI MHR: 424,98 euros

237106

There is an interesting port map in the picture, it shows the main Ex port at 62% of bore dia.

They say you will need the race crankshaft to go with the cylinder kit:- http://www.rrd-preparation.com/crankshaft-connecting-rod-assembly-polini-evolution-race-39mm-silks-of-d.17mm-for-mecaboite-driving-minarelli-am6/product_info.php/products_id/1214

237103 237104

Summary:
Rod cuts origin 85mm
Full masses for a maximum of precompression
Dynamic balancing 15.500 turns/reality minutes carried out for a maximum of inertia without vibrationsReinforced to the maximum Needle cage Ø 12X15X15mm (size reinforced origin)
Silks: Ø17mm cuts origin
Keying for lighting: site of origin
Race: 39mm (origin)
Ø16mm crank pin

Derbis are obviously modern motors, real gems and beautifully made.

But its instructive to note that those who were most vocal about TeeZee’s 24/28 carb, although maybe legal were adamant it was definitely against the spirt of Buckets, and they are by in large the same people who are OK with these Race/ Performance Enhancing parts developed for European Bikes.


Wonder if Dave would like to post his motor details here?
One thing is for sure though, by applying some personal effort to the traditional Bucket engines one can still develop something that makes more and better power, it just takes a little skill.

[jasonu]

Pick up some bits and bobs for your Derbi here and get 22hp (DIN at the crank):- http://www.rrd-preparation.com/kit-80cc-malossi-mhr-team-d.50mm-aluminium-pour-moteur-derbi-euro-1-2/product_info.php/products_id/869/language/en?osCsid=atsaod576ffon4krhae3k47ap2

And you won't need to do a lot of hard work or spend much on dyno time as its all been done for you.

Famous kit MALOSSI MHR TEAM used for various cup MALOSSI GP 80 and trophies

237102 237105

Technical summary:

Real cubic capacity 78,6cc in race origin 40mm (rod 90mm on the origin) compression Report/ratio advised 1:15,4
Spacing advised segment ends: 0,15mm
Play piston/minimum cylinder: 0,051 has 0,059mm
Volume of room advised: 5,4cm3
Squish advised 0,55mm
Announced power MALOSSI MHR: 22cv has 12000 turns/minutes
Couples announced MALOSSI MHR: 13kgm with 11750 turns/minutes
Diagrams 189° for the exhaust and 129° for the admission
Selling price advised MALOSSI MHR: 424,98 euros

237106

There is an interesting port map in the picture, it shows the main Ex port at 62% of bore dia.

They say you will need the race crankshaft to go with the cylinder kit:- http://www.rrd-preparation.com/crankshaft-connecting-rod-assembly-polini-evolution-race-39mm-silks-of-d.17mm-for-mecaboite-driving-minarelli-am6/product_info.php/products_id/1214

237103 237104

Summary:
Rod cuts origin 85mm
Full masses for a maximum of precompression
Dynamic balancing 15.500 turns/reality minutes carried out for a maximum of inertia without vibrationsReinforced to the maximum Needle cage Ø 12X15X15mm (size reinforced origin)
Silks: Ø17mm cuts origin
Keying for lighting: site of origin
Race: 39mm (origin)
Ø16mm crank pin

WTF its all legal for Buckets because you can fit lights to it........ apparently.

Keying for lighting: site of origin


In my opinion, there are several ways to approach Bucketting.
Say someone went out and spent a good sized chunk of cash on something modern with a nice frame, suspension, wheels and motor and then tweak it with not a lot more cash but a lot of thinking and some DIY where ever possible.
Then compare that with someone else who might buy a $150 old commuter then spend countless hours and $100 there and $200 there over say 3 years to get where the afore mentioned person is. (an RS frame and wheels will cost $750+)
If you add the $'s drip fed a bit at a time in the 2nd senario you will almost certainly see there will be buggar all difference between the two approaches to the sport. If anything the 1st person probably has spent less in the long run and quite possibly still has the better bike.
Whatever floats your boat.

[bucketracer]

In my opinion, there are several ways to approach Bucketting. Whatever floats your boat.

Actually I agree, but I had intended my post to be seen as, more about the hypocrisy of trying to stall TeeZee's carb idea by claiming it was against the spirit/intent of Buckets while promoting/using parts that most would think were not in the spirit or intent themselves.

[jasonu]

Actually I agree, but I had intended my post to be seen as, more about the hypocrisy of trying to stall TeeZee's carb idea by claiming it was against the spirit/intent of Buckets while promoting/using parts that most would think were not in the spirit or intent themselves.

My slant on the carb wrangle was that the carb size should be measured at the same place the manufacturer who produced the carb measured it at. It still is.
TZ himself has stated the carb restriction is not limiting the HP he has found. Just look at his most recent results posted here, a fat 27hp with a 24mm carb. If that bike rides as good as the graph looks it will be killer.

[bucketracer]

24mm carb for a 125 two stroke needs to be measured 24mm over the area where the slide runs, when Jason ,M green and myself made up these rule we did our home work,


My slant on the carb wrangle was that the carb size should be measured at the same place the manufacturer who produced the carb measured it at. It still is.

That all sounds good, not what the rules say, but keep carb development within the original spirit and intent of Buckets can't argue with that.

I think there were also other noble ideas like, preventing the Air-force boys bringing after market performance parts back from overseas, the spirit and intent was that it had to be original/modified or home made parts from engines recognized as "non competition".

The spirit and intent of Buckets when the rules were setup, was also, to not use store brought hot up bits, do I understand that correctly? am I wrong?

So are these factory made performance/race parts from Europe within the original spirit and intent of Buckets.

I don't think so, what’s your take on it?

[jasonu]

That all sounds good, keep carb development within the original spirit and intent of Buckets can't argue with that.
If you dig up my replys to this a few months ago you will see that I talked about 'clarifying or re wording' the rule stating exactly where the measurement should be taken. I kinda think this subject is a dead horse now as TZ who was (for want of a better word) challengeing the rule with his carb innovations has stated the 24mm rule is not the limiting factor on the pursuit of HP and has proved this with his latest power gains.

I think there were also other noble ideas like, preventing the Air-force boys bringing after market performance parts back from overseas, the original spirit and intent was that it had to be original/modified or home made parts.
That is before I got involved so I don't really know. Ask Mike Green or Kevin Gray, they were right in the thick of it.

The spirit and intent of Buckets when the rules were setup, was to not use store brought hot up bits, do I understand that correctly? am I wrong or have things changed?
Were there store bought hot up bits available in those days? I think not so the original bucketteers probably didn't consider this point. (in my opinion)



So are these factory made performance/race parts from Europe within the original spirit and intent of Buckets.

I don't think so, what’s your take on it?

Not totally sure. If the parts in question meet the 'non comp' rule then wouldn't they be legal??? I doubt the original bucketteers thought it would get to this.

[wobbly]

The Derbi Mallosi MHR "kit" is made specifically for scooter racing, not as a replacement for a road bike setup, its illegal as it can get.
Where as in all other sports I have been involved with the carb size is nominated as whatever is the min cross sectional area, its position in the inlet tract is undefined.
Now,if someone wanted to use a 38mm powerjet carb, and sleeve it down some where within its body to 24mm then so what.
The European 50cc race rules have two sizes allowed, 22mm for "as made" carbs and
20mm for sleeved down items with venturis or whatever.

[Rick 52]

RS frame and wheels for $750 ......double that and if you can find any then spare wheels $400 discs and so on ...

[jasonu]

RS frame and wheels for $750 ......double that and if you can find any then spare wheels $400 discs and so on ...

I found a 95 (honda) RS 125 frame with subframe for $500, shock for $200, forks for $350, swingarm for $200,all from NZ. Linkages $25, Aprillia rs125 triple clamps for $50 UKebay. Front disk (actually got 2 and the bolts)ex GSXR1000 $10 USA craigslist. Already have wheels. Will have to make a lot of stuff like adaptors for forks, caliper and disk, front wheel spacers and axel, will make bolts where possible, will buy hard to make swinmgarm and engine mount bolts probably $50 each. Still on the lookout for a seat, radiator and tank.
Some will say that is a lot of $'s. My thinking is to build something as modern as possible that will hopefully stay competitive for a long time.

[TZ350]

I found a 95 (honda) RS 125 frame with subframe ...... My thinking is to build something as modern as possible that will hopefully stay competitive for a long time.

I would have to say the RS is the best bet, but something for those of us who find a RS physically to small for comfort.

1991 3Ln FZR250 roller $600 http://www.trademe.co.nz/Browse/Listing.aspx?id=370679045

With the original alloy wheels mine comes in at 93kg with a splash of fuel and Chambers FZR with wire wheels is 81, and I think NedKellys Honda RS was 72. (all weighed on the Mt Welly Kart track scales)

[Buckets4Me]

RS frame and wheels for $750 ......double that and if you can find any then spare wheels $400 discs and so on ...


rs with spares for $750 just look and jump when they come up :)

it was a better option that upgrading the suspention and brakes on my bike anyway :shit:

and Neds was $2000 with an rs125 engine and brand new tyres ($600)
(sell the engine and off you go)

[ac3_snow]

can any one say what a 'race ready' FXR weighs in at? think I have heard about 110kgs...

[Buckets4Me]

can any one say what a 'race ready' FXR weighs in at? think I have heard about 110kgs...

sounds close enough around the 100+

[richban]

sounds close enough around the 100+

Weighed mine yesterday and it is 102 with about 2 liters of gas.

[Gigglebutton]

He He, watch out or I will tell No Mates you guys think you are fast - and he will turn up with the 5 year old 29 Hp RG100/RS125, just to put you all in the fence.

I have spoken to him already. Looks like he will come down for practice and put us into the weeds

[Gigglebutton]

I was under the impression that the reeds worked at lower revs and helped to increase the lowdown power? (I realise this also depends on the thickness off reed used)

finding an ignition is my next duty, I looked at the KX80 as you suggested tezee but they all seemed semi pricey, for this reason I grabbed a cheap RM80. Turned out to be an expensive mistake as the taper is different :facepalm:
So back to looking at KX80s again and if anyone wants a rm80 ignition let me know, $70ono!

I can re-cut the taper if you want

[RMS eng]

I can re-cut the taper if you want

marks TS100 has 1995 RM80 set up, taper was fine,and we ran 1980-85 RM80 and 125 rotaors on our RG50s and TS100 motors,fitted good.

[jasonu]

I would have to say the RS is the best bet, but something for those of us who find a RS physically to small for comfort.

1991 3Ln FZR250 roller $600 http://www.trademe.co.nz/Browse/Listing.aspx?id=370679045

With the original alloy wheels mine comes in at 93kg with a splash of fuel and Chambers FZR with wire wheels is 81, and I think NedKellys Honda RS was 72. (all weighed on the Mt Welly Kart track scales)

I am hopeing for 68 -70kg. My TZR weighed 76 with water and oil. We know the RS frame is 7kg less than the TZR frame. The RS swing arm is a bit heavier. This bike will have RS wheels so there will be a good saving there. If I take a good dump before getting on it that is another kg maybe more. Diet and exercise, fuck that!

[kel]

Question for Wobbly
Is there an optimum relationship between the transfer port axial angles specifically the boost. The industry standard would seem to be around 25deg main, 10deg aux and 50 to 60deg for the boost. Does the boost angle increase with the aux or is it an inverse relationship? and does a greater boost angle lift midrange power output? should the boost tangential flow taper in towards the exhaust as per the majority of recent motors Ive seen and what is the reason for this?
Ive epoxied up the boost and thought some profeesional input to the final angles might be in order.
Cheers

[rabidnz]

The mhr kits are usually pretty clearly stated as race only on most of the sites ive seen!

[wobbly]

Shit, it would need a PhD thesis to even begin to answer that question.
The problem is are we talking refining toward an optimum setup, or just trying to get shit designs to work better.
The RSA leads the way with the "refining" approach and its very evident that the inner radius size and angle is the key to keeping all the flow attached and heading in the right direction.
It has A port angles of 28 roof,16.5 floor.B port is 6.8 roof and 7.4 floor,Boost is 53.3 roof and 37 floor.
A 2008 CR250, very undersquare and with a flat top piston has 25/10/55 roof.
There is only 2 ways to optimise any system like a 2T port layout.Do what Aprilia did, employ a genius and have 150 people try shit he tells them to do.
Or, like Yamaha did around 2000 when they won the 250GP title,and use an Anemometric flow visualiser, even better a Laser Doppler one CNC driven.
We dont have those luxurys but all we can do is try to emulate what we know the trick shit stuff has for geometry,big inner rads and plenty of roof upward axial.
But if we understand why the axials are why they are that way, then maybe a light will come on above your head.
Here goes - the flat roof B ports collide in front of the boost, this clears out alot of residuals that normally are left behind, and as these opposing flows slow down - they are pulled upward by the boost port ( its flow has already attached to the rear wall).
The A port flows over the top of the B port flow, and they all join together in the rear 1/2 of the cylinder as a slowly rising column - the famous "loop".
The idea is to create as much coherent flow entering the column as possible,and at the same time clear out as much exhaust residuals as we can,ahead of that column with no mixing.
Thus if the Delivery Ratio is high, and we keep the streams entering the cylinder "coherent" then the Scavenging Efficiency will be high.Then if the pipe works properly the Trapping Efficiency will be high and lots of power is released.
If it all works together, then a 30+ Hp bucket is easy.

I dont quite understand " the boost tangential flow taper in towards the exhaust", please draw it or explain to my limited intellect in another way.

[kel]

Sorry using Yamaha's terminology and probably should have said boost tapering to the centre of the bore. See attached RGV/RS250 port map
237274

The KE mains are at 20deg aux at 5 and boost at 55deg. I was thinking that possibly the angle relationship between aux and boost maybe inverse to help drag flow up the rear wall to the combustion chamber i.e. would the low aux angle benefit from increasing the boost from 55 to say 60deg.
I like those CR angles, they seem to agree with the majority of text Ive been able to find on the subject, but it would mean adding even more epoxy to the ports.

Another question if I may, whats the advantage of the loops to the rear of the aux transfers ports which turn the flow back towards the centre of the bore (as shown on the attached portmap), vs the angled across the boost port to the rear wall approach? Figure its to further enhance removal of exhaust gas, but (limited understanding disclaimer) wouldnt this cause seperation from the rear wall?

[wobbly]

That port map is derived from the Suzuki where the engine came from and is not very modern.
Aprilia GP has the B ports walls both dead square across the bore, with the rear wall hooks meeting at bore centre.
The boost port has parrallel side walls with taper only in the front/back direction.
Increasing the boost angle will reduce its effective flow area, and yes it will attach earlyer to the rear wall, but will be much less effective,in grabbing the B port flow and pulling it up the back.
Personally I would epoxy the A port roof, to give 25*, and fill the front wall of the B port to make it square to the bore, having a flat top septum as per the GP cylinder.

Its all a matter of trying to emulate a well we can what is SOTA and wins GPs.

[cotswold]

I just opened a flikr account so should be ok this time.

http://www.flickr.com/photos/timcoopey/?saved=1

[Henk]

Looking good. I dread to think how you will go on a fast bike.

[cotswold]

Looking good. I dread to think how you will go on a fast bike.

Be nice to find out

[kel]

Ok Kel is the test pilot...........

Right, ESE have agreed to my terms and conditions so looks like we are all go for next month, thankfully they have short memories, my last encounter with the ESE bike went a little like this :innocent:
237296

[ac3_snow]

I can re-cut the taper if you want
Is there anything you guys can't do?

marks TS100 has 1995 RM80 set up, taper was fine,and we ran 1980-85 RM80 and 125 rotaors on our RG50s and TS100 motors,fitted good.
Yeap I had a look at it again today and the taper is correct but the rm80 crank seems to have been shorter so the rm80 rotor on my Tf crank sits out further.
I figure I could make a plate to mount the stator on to bring it out 10mm to meet the rotor. The weight of the rotor still sits in the same position on the crank so I don't see it causing any problems?:scratch:

[F5 Dave]

Hard to see in pics, but a zillion have been made with a plate converter. Or you could get someone to cut the taper bigger. Don't need much to move it quite a bit. You don't 'need' the woodruff key, it's just there for aiding assembly, if the taper wasn't gripping it will break. But I like to re add it as it makes assembly a breeze.

[TZ350]

237407 237408

A couple of ignitions that have had spacer plates made for them.

[ac3_snow]

hopefully the answer to this one isn't quite so obvious. I realise I will need to spend the time with a timing light to get the spark at the right point, as Tomas did way back when.

.
The steps were.

1: Set the piston position at the correct firing point using a DTI in the plughole.

2: Clean and re-mark the flywheel so the actual firing point can be checked with a Timing light.

3: Make adjustments and go back to 1: Repeat untill you get it right.

There is about 15 degrees of retard built into the CDI and Tomas set the advance at 35 degrees BTDC at idle so the ignition retarded to the correct setting of 20 degrees BTDC at 8,000 rpm which is the point that the GP comes onto the pipe.

Tomas had to go through the process of making adjustments, setting the piston position and remarking the flywheel several times to get it right but it runs like a charm now.

.

But the RM flywheel does not have any markings which indicate at which point on the flywheel it would fire. Have spent all morning and all I have been able to find out is that it may spark when the keway is at the midpoint on the stator as pictured(doesn't sound too scientific to me). Does anyone know if this is in the right ball park, I don't see anyway to find the spark point with out either a timing mark on the flywheel(as Tomas found with the gp/tf, the keway can be different anyway) or a running engine?
237415
If it does fire at that point then it is close to TDC there and would give me a good starting point for when I get a timing light onto it. If not them I'm a little lost..

[jasonu]

Is there anything you guys can't do?

Yeap I had a look at it again today and the taper is correct but the rm80 crank seems to have been shorter so the rm80 rotor on my Tf crank sits out further.
Correct
I figure I could make a plate to mount the stator on to bring it out 10mm to meet the rotor. The weight of the rotor still sits in the same position on the crank so I don't see it causing any problems?:scratch:
That is correct also.



10characters

[jasonu]

You don't 'need' the woodruff key, it's just there for aiding assembly, if the taper wasn't gripping it will break. But I like to re add it as it makes assembly a breeze.

Really Dave, are you serious about not needing the key???
If you don't use it to clock the flywheel to the crank in the exact same place everytime your timeing will be different (ie fucked up.)

[TZ350]

With a timing light and the help of a friend its pretty easy to get a RM ignition setup.

237417

Mark the stator with a felt tip. Have your friend spin the motor over, now you should be able to pickup a spot on the rotor that matches the stator when the timing light flashes.

Mark the spot on the rotor that you saw with the timing light, like in the picture, these two points should line up when the timing light flashes, now you have a reference point for setting the ignition timing.

Turn the crank until the piston is 20deg BTDC (1.6mm or whatever timing you want). Now hold the crank steady and turn the stator plate so your marks line up again and presto, your ready for a trial run or the dyno.

But remember, this only gets you going, you still have to dial in the ignition timing exactly, and a dyno is probably the best place for that.

[F5 Dave]

Really Dave, are you serious about not needing the key???
If you don't use it to clock the flywheel to the crank in the exact same place everytime your timeing will be different (ie fucked up.)
Hey plenty of people don't use a key. Just you have to find out where you are at & rescribe new marks & faff about. That's why I always go to the hassle of regrooving a keyway. Sometimes in a different position that suits where the pulsar coil fits into the cases best on that engine with a bit of wriggle room if it is asymetrical.

I was just pointing out that it is the taper that provides the strength of the joint, not the key as is commonly thought & that you can run without it if you must.

[jasonu]

Hey plenty of people don't use a key. Just you have to find out where you are at & rescribe new marks & faff about. That's why I always go to the hassle of regrooving a keyway. Sometimes in a different position that suits where the pulsar coil fits into the cases best on that engine with a bit of wriggle room if it is asymetrical.

I was just pointing out that it is the taper that provides the strength of the joint, not the key as is commonly thought & that you can run without it if you must.

A dodgey practise frought with perils I say.

[gatch]

Hey plenty of people don't use a key. Just you have to find out where you are at & rescribe new marks & faff about. That's why I always go to the hassle of regrooving a keyway. Sometimes in a different position that suits where the pulsar coil fits into the cases best on that engine with a bit of wriggle room if it is asymetrical.

I was just pointing out that it is the taper that provides the strength of the joint, not the key as is commonly thought & that you can run without it if you must.

+1

Woodruff keys are not absolutely necessary, but makes timing anything 10x easier. Ignitions, machinery parts, whatever.. You can do without if you have to but use em if you got em.

[ac3_snow]

Alright thanks for the advice everyone. I never really thought about it just assumed that the engine needed to be running for a timing light to work. So borrowed a broken timing light:facepalm: which isn't so broken any more. Then spent the rest of the night making a rather boogie spacer plate, solid as tho. Working tomorrow so with the girlfriends alowance I might be able to dail in the ignition sunday.

Turn the crank until the piston is 20deg BTDC (1.6mm or whatever timing you want)
Your wisdom has been pretty spot on so far so I won't start doubting you now!

[bucketracer]

Some things that might be helpful.

BTDC means turning the crank clockwise when looking from this side.

These RM ignitions have quite a heavy retard initially so when setting them up you need to spin the engine fairly fast to find the initial steady firing point.

Then from 2,000rpm to 8,000 they retard about 7-9 deg. So you need about 26 deg initial advance at 2,000 rpm.

237714 237713

If you compare the angle between the ignition stator and cylinder base of the RG50 (R/H Pic) you will see you have to turn your stator slightly clockwise but otherwise your pretty much on the money.

[F5 Dave]

arrgh! again

Apostrophe 'e'

'you are'

is shortened to

'you're '

not 'your'

:shutup: How many times????


I remember seeing a RG50 pilot setting his timing a ways back. He'd loosen the mounting plate screws, start the bike, hold it wide open & push the plate back & forward until it sounded like it was revving highest. Made me shudder.

[ac3_snow]

Your wisdom has...
You are wisdom has...??

you will see you have to turn your stator slightly clockwise
you will see you have to turn you are stator slightly clockwise....??



arrgh! again

Apostrophe 'e'

'you are'

is shortened to

'you're '

not 'your'

:shutup: How many times????


arrrrghhh matey correct but not in this scenario I believe... these are what you're referring to? correct me if I'm wrong.

[F5 Dave]

. . .(R/H Pic) you will see you have to turn your stator slightly clockwise but otherwise your pretty much on the money.


. .
arrrrghhh matey correct but not in this scenario I believe... these are what you're referring to? correct me if I'm wrong.
Correction forthcoming;

no, . Graphically demonstrated in above sentence. Once correctly used, once incorrectly.

[ac3_snow]

right you are. I'l go back and learn how to read I think.

[Henk]

Bloody grandma nazis

[F5 Dave]

I googled Grandma nazi & sadly didn't come up with the picture I had in my head.

bit odd though.:blink:

[F5 Dave]

ok late enough for a musical interlude (it's been about 100 pages since the last)

(don't worry I considered Dead Kennedys Nazi Punks, but decided against it 'cause its a shit song).

http://www.youtube.com/watch?v=xwhBRJStz7w


and for something completely different; one of the strongest female vocalists performances this side of Wendy o Williams

http://www.youtube.com/watch?v=BXk5w91chgI

Just don't make the mistake of buying a Sevendust CD.

[cotswold]

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

Try this and it's fairly topical

[cotswold]

[QUOTE=TZ350;1130018790]On page 200 there is a simpler 23 rwhp setup using a RG250 chamber modified to RM125 specs.

And on this page, the basic details for 27rwhp from a 1978 Suzuki GP125 Engine and RS125 Expansion Chamber.

235170

Not at all peaky, 3.500 rpm power spread.

Cylinder Deck Height (Squish) 0.8mm.
Exhaust 25.8mm from top of cylinder, and opens 80deg ATDC for 200deg Duration.
Transfers 40.8mm from top of cylinder, and open 116deg ATDC for 128deg Duration.
Inlet port opens 145 BTDC closes 80 ATDC and is 45deg wide and inlet port opened to 30mm equivelent dia with 24mm carb.
Std 1990 Honda RS125 Pipe. The pipe is 40mm and the exhaust port is 36mm, we leave it as is and don't match the Ex port to the pipe.

235176

Opening the rear transfers and flatening the port roof to 5 deg. Main std at 12 deg. Boost std at 55 deg, but all opening together.

235175

Primary transfer pretty much std., secondrys and boost as wide as possible, Exhaust 72% of bore diameter.

235172

A view of the transfers, the copper is to take heat from the exhaust port area and distribute it to the extra copper under cylinder finning we use.

235174

Dimensions of a Honda RS125 Pipe.

235171

Suzuki GP125 engine and RS pipe in a Yamaha FZR 3LN 250 rolling chassis.

Hi Guys, would you be willing and able to give me a port map for this configuration.
Thanks

[F5 Dave]

That's topical in a 2 stroke tuning thread?


(Not that I'm saying Skunk Anaisie is).

[kel]

Hi Guys, would you be willing and able to give me a port map for this configuration. Thanks

Are you serious?
Buy portcalc and map analyser then you can quickly draw it yourself then compare any changes you may have in mind. Otherwise you could sketch it or draw in AutoCAD as all the measurements are there.
Monday morning :crazy:

[ac3_snow]

Page 240

Links and Interesting Quotes from the last 10 pages, other link lists can found on the decade pages starting with Page 80.

A handy (and cheap $16 USD) Porting Calculator from:- http://www.porting-programs.com/ is based on Blairs and Jennings work.



Money well spent



port map for this configuration.


The pics are pretty good, however would be interesting to see, in the name of science and all...:innocent:

[TZ350]

Cylinder Deck Height (Squish) 0.8mm.
Exhaust 25.8mm from top of cylinder, and opens 80deg ATDC for 200deg Duration.
Transfers 40.8mm from top of cylinder, and open 116deg ATDC for 128deg Duration.
Inlet port opens 145 BTDC closes 80 ATDC and is 45deg wide and inlet port opened to 30mm equivelent dia with 24mm carb.
Std 1990 Honda RS125 Pipe. The pipe is 40mm and the exhaust port is 36mm, we leave it as is and don't match the Ex port to the pipe.
Opening the rear transfers and flatening the port roof to 5 deg. Main std at 12 deg. Boost std at 55 deg, but all opening together.
Primary transfer pretty much std., secondrys and boost as wide as possible, Exhaust 72% of bore diameter.

Hi Guys, would you be willing and able to give me a port map for this configuration.
Thanks

The cylinder is on my bike now.

237848 237849

The essential details are in the text and these are the axial angles as best as I remember them.

The main transfers are left pretty much as they were, its only the secondry transfers, boost port and exhaust that have been radicaly changed.

[TZ350]

Gluing the 27hp Engine Cases.

237852 237851 237850

These are the places that need gluing before porting the inlet and transfers.http://www.kiwibiker.co.nz/forums/images/misc/pencil.png

[cotswold]

Are you serious?
Buy portcalc and map analyser then you can quickly draw it yourself then compare any changes you may have in mind. Otherwise you could sketch it or draw in AutoCAD as all the measurements are there.
Monday morning :crazy:

Mmm yes pretty serious, I am the first to put my hand up to admit that my mechanical ability is, on a sliding scale, near the bottom, but I am able to trace around something. If I bought the portcalc I would not have a clue how to use it.
My Rotax race bike was tuned by Queens university and Mike Hatherall tuned my Honda, why because they were very good at it, this is why I am asking ESE for their help, they are very good at it. Thanks for the idea though

[cotswold]

These are the places that need glueing before porting the inlet and transfers.[/QUOTE]

Thanks for that, I am sure I will be able to muddle through as I have a friend who loves the tuning side of things. I sent him your thread and he got quite excited, he was the one who asked if a port map was available, I will have to get him a degree wheel, I spotted a template on line.

[TZ350]

237863 237859

Not all new pistons are good pistons. This die cast Prox piston lasted less than a 1/2 hour on the dyno before it started cracking up.

I think we will stick with forged pistons from Wiseco, the last one was in for more than three seasons.

[TZ350]

Thanks for that, I am sure I will be able to muddle through as I have a friend who loves the tuning side of things.

Its very interesting watching someone else making one of these. I will post a few pictures on the basic steps/tricks we did, like the gluing if that helps.

[cotswold]

Its very interesting watching someone else making one of these. I will post a few pictures on the basic steps/tricks we did, like the glueing if that helps.

Every scrap you send me will be accepted with gratitude

[TZ350]

27 hp Inlet Port

Inlet port opens 145deg BTDC closes 80deg ATDC, the port is 45deg wide and was opened out to a 30mm equivelent dia and feed by a modified 24mm carb.

237884 237883

To get the inlet port as large as possible a small sleeve was glued onto a spigot machined on the rotary valve covers inlet, the clutch cover was machined out so the sleeve could poke through it.

237885

The area of the port window was maximised and the rotary valve cut for slow closing. This may or maynot be a good idea and it might help reduce mechanical wear at the port closing point more than help performance, we don't realy know, we copied it from an early Benelli racer.

237878 237882

The inlet side crank wheel was champhered for a better inlet flow.

237887

Modified OKO 24mm flatslide with a rubber wind shield fitted to the bell mouth and a filter setup as a header tank with a tap (unseen in photo) between the filter and carb. And another (main) tap is in the black hose between filter and tank. The clear hose on the top of the filter is a breather and has been added so the filter fills properly.

[Gigglebutton]

56 hours of measuring, grinding, filing and machining

Rear sets made and fitted

Altered port time area and angles to "Wobbly Spec"

Altered reed block with new reeds to "Speedpro Spec"
Inlet port bogged and filed to match new reed block "Speedpro Spec"

Cases ground to "TZ350 spec"
Head welded and re machined to "TZ350 specs"
Barrel skirt cut away to "TZ350 Spec"

Barrel bored and honed

The bike started first time. Feels way fatter. A bit of a cough at high revs. I will put it on the Dyno tomorrow and let Rob play with it and see what we have achieved

Cheers Guys :yes:. A few pies, beers and loads of theory hopefully will show results

[Gigglebutton]

237930237929

After a bit of a thrash on the dyno....... Red is the old curve, Blue new.
Well worth the hours worked on it. Next step a better ignition. Thanks guys

[ac3_snow]

Thats wicked! next stop a grade..

[wobbly]

What pipe is on that dyno run, looks as though it would make alot more power yet as something is making it sign off early???
Ignitions will be here any day.

[gamma500]

few interesting videos:

GP125 cylinder casting by Gnani

http://www.youtube.com/watch?v=I-2rJtnkYq4

http://www.youtube.com/watch?v=Lj4h9666d9s&feature=related

http://www.youtube.com/watch?v=A50p3cg90s4&feature=related

:corn:

[kel]

What pipe is on that dyno run, looks as though it would make alot more power yet as something is making it sign off early???
Ignitions will be here any day.

looks like a big suck pipe with a shallow taper reverse cone?

[F5 Dave]

um, are you sure that isn't a std GP125 run you have transposed there by mistake?

peak power at 10,000 & above 10hp for 3,500rpm? Sheesh!