ESE's works engine tuner

[F5 Dave]

Taumarunui 2

275870

Water cooled TF100 CrazyMan 2T ???? rwhp ... 82kg

275873

Kobas MC18 framed MB100 special rwhp??? ... 89kg

275871

FarmerKen's MC18 TF125 rwhp???? but fast ... 85kg

275872

Regans 24 rwhp FXR150 special ... 84kg

275869

Rick52's 21 rwhp RS TF125 special ... 75kg

275868

The Beast 27 rwhp 3LN FZR Suzuki GP125 ... weight ??????

My RG50 while it was still in the Rg frame. . . 59.5kg (was same on those scales up there too).
So how do you feel now?

Actually got slightly heavier in the RS chassis.

[TZ350]

My RG50 while it was still in the Rg frame. . . 59.5kg So how do you feel now?

.......... :facepalm: ... plump

[TZ350]

Jasons new bucket RS125 frame with CBR150 motor 22HP and 78 kg we hope?

RMS Eng has always talked about power and weight, and emphasized the light weight of his bikes.


Its not just about reliable hp and rideability of the bike, there is another essential piece to the jigsaw that TeeZee and more so RMSEng have been talking about.

Yes that's right ... RMS Eng has consistently talked about the importance of making a light bike and I am now totaly convinced he is right.

275907

Rick plus Bike is about 145 kg all up and that works out at 7kg/hp power to weight ratio, Av and her bike are lighter with more hp.

275908

Tim and the Beast (which is much heavier) work out to be much the same as the better 4-Strokes and so there is the answer to why the Beast was not leaping away from them like you would expect from a high 20's hp bike.

I was a bit indifferent before but after watching the bike at Tokoroa and Taumarunui I have become convinced that losing weight is as important as making the hp and power spread that I want.

275909

I have a MC16 frame and could lose a lot of weight by making something new like FarmerKens MC18/TF125 special.

RMS Eng was on to it.

[TZ350]

275910

Following the less is more principle for race winning power and reliability, Chambers is going for the old school approach.

[TZ350]

275911

My super performance CVT bits turned up today, all in plain brown box's with none of the naughty words so everything is totally legal. I have found I can get an even shorter belt so everything will certainly fit in the chassis space available.

For anyone confused about this, the design plan is a solid 6,000 rpm power spread (or CVT equivalent) that equals the FXR's and more power every where for better top speed and punch out of the corners than the best of the 4-Strokes can manage.

Now I am working on three approaches to this.

(1) Improve the 4,000 rpm spread I already have with an ATAC valve and other cunning trickery.

(2) Trombone pipe.

(3) CVT.

So there is three engine development plans on the go at once, and a new 15kg lighter better handling rolling chassis being built for it too.

[jasonu]

RMS Eng has always talked about power and weight, and emphasized the light weight of his bikes.



Yes that's right ... RMS Eng has consistently talked about the importance of making a light bike and I am now totaly convinced he is right.


RMS Eng was on to it.

I thought it was obvious.

[cotswold]

Had to try mine for porkie-ness and by putting it in gear and standing it upright on the bathroom scales :sweatdrop she came to a bit of a podgie 83.6kg.. this includes about 2ltrs fuel. (Old photo of the bike so all the bits that aren't on the photo are on the bike.)

Actually after checking the list it's not too bad, plus I machined many grams out of the new yet to fit go faster cases.

[TZ350]

Had to try mine for porkie-ness and by putting it in gear and standing it upright on the bathroom scales :sweatdrop she came to a bit of a podgie 83.6kg.. this includes about 2ltrs fuel.

Thats 18kg lighter than the Beast ......

[TZ350]

275922 275923

B9 plug after Tokoroa.


The spark plug - why are you running a 9 in a Super Hot air cooled engine that is always going to be running up against the fins thermal ability to reject heat fast enough.
A KT100 making 18 Hp with more finning than you have will tolerate a 9 plug - just.
That is the reason there is no distinct burn line on the porcelain - as ALL of the porcelain is running too hot for an oil zone to form, and give you a reading.
I would be fitting a 10.5 - this is what the 28 Hp, 22,000 rpm 100cc air cooled kart engines HAVE to run or they seize instantly.The end of the earth electrode is blasted clean - that is heat induced deto, or as I said at the beginning, maybe this is causing pre - ignition.

B10 plug after Taumarunui


(2) B10H plug and an extra 4 deg auto retard on top of the TPS retard map did not cure the deto, so probably not an ignition timing or plug thing.

275921 275920

The B10 plug from Taumarunui after some hot laps and a proper plug chop before over rev deto set in. I would be interested in what Wob has to say about it.


(3) Deto in over rev, may mean, not enough blowdown time area for those rpm, Jan, Frits and Wob have talked about that.

(4) I might have to look at some way of automatically dumping pressure out of the expansion chamber when detoing in over rev.


Quite a bit on page 600 too.


Kel sent me this ......

jan thiel on part throttle deto

"I am 100% convinced our engine could have run for 6 hours at max power without seizing.
The problems arise when you close the throttle, or run part throttle!
The piston is mainly cooled by the transfer flow.
And at part throttle there is less transfer flow, causing detonation (auto ignition)
The entering fresh charge is ignited by the remaining, hot, burned gases!
You can see very severe damage to the piston after maybe 10 seconds at 20% throttle.
This still is an unresolved problem! I was thinking about a way to reduce engine power without closing the throttle. But how can you do this? I did not find a solution before I retired.
And nobody else was really interested.
At 100% throttle the engine was undestructible!
By making the transfer ports as wide as possible we had very good piston cooling."

No answer here but at least we are not alone with engines that fail on part throttle

I scraped the full coversation below from here:- http://www.pit-lane.biz/t3173p60-gp1...vermars-part-2

Brian Callahan
Jan or others, how did you control the tuned pipe wall temperature (or EGT directly?) when testing on dyno? This seemed the most difficult thing to mimic when testing either the GP engines at QUB or my R/C boat engines, in the lab. The inertial dyno or computer controlled brake seem to work best because we can match the test engine's acceleration with reality. On steady-state testing, EGT would simply climb 500, 600, 700, 750 °C until way past reality and the piston would seize.

Frits Overmars
This has always been one of Jan's greatest handicaps. He has asked for an inertial test bench over and over, but Aprilias race director Witteveen, or The Great Leader as we call him, never deemed it necessary....

Jan Thiel
When EGT goes up and up there should be some serious problem with the engine.
We never had pistons seize during our steady state tests.
Working on the dyno continuously 5 days a week!
I am 100% convinced our engine could have run for 6 hours at max power without seizing.
The problems arise when you close the throttle, or run part throttle!
The piston is mainly cooled by the transfer flow.
And at part throttle there is less transfer flow, causing detonation (auto ignition)
The entering fresh charge is ignited by the remaining, hot, burned gases!
You can see very severe damage to the piston after maybe 10 seconds at 20% throttle.
This still is an unresolved problem! I was thinking about a way to reduce engine power without closing the throttle. But how can you do this? I did not find a solution before I retired.
And nobody else was really interested.
At 100% throttle the engine was undestructible!
By making the transfer ports as wide as possible we had very good piston cooling.

As Frits has written, I would have liked to have also a dynamic testing possibility, with a flywheel.
In my opinion you should simulate a straight, starting at around 10.000 rpm, and shift through the gears
until you reach top speed. And with the airbox as used on the bike, with a ventilator that simulates the raising
air speed as it would be on track! Maybe it is interesting to know that without a ventilator the engine gave
less power with the airbox fitted.

I was told that such a testing system was too expensive.
And unnecessary as we won anyway!

I can also see a disadvantage of 'dynamic' testing.
Because the duration of the test is so short you can get away with very extreme (too extreme?) settings,
without damage.

GrahamB
Remember that retarding the ignition is used at high rpm to increase exhaust temps and effectively shorten the pipe. So it's likely to increase the heating of the front edge of the piston...

Haufen
Yes I know, but part load egt is usually lower than full load egt. And I think most of us would prefer higher part load egt over part load detonation. Of course, how far one could go and how far one would need to go would have to be tested, and how much would be needed would depend on the engine.

Mic
How about much larger travel on the exhaust power valve.
With a shorter exhaust port duration power is lower. And this is already controlled with the stepmotor over the ECU.

Jan Thiel
This causes detonation (auto ignition)
The problem is that the burned gases do not exit the cilinder!
Retarding ignition also does not make sense.
As you have an AUTO-inition problem!
So the engine does not 'listen' to its ECU anymore!
What you would need is the same fresh gas flow, but with less HP!
Not easy to achieve!
A variable tailpipe might help.

Jan Thiel
Haufen, We also had such a test bench at Aprlia.
The prototype of this test bench was developed by Apicom in collaboration wit Aprilia.
So we had it first, and now anyone can buy it.
It was helpful but not what I wanted.
A so-called step test.
And without the airbox!

Frits Overmars
Like Jan wrote, a shorter exhaust duration will worsen the detonation. What happens is this:
During normal operation, the blowdown time.area of the exhaust ports is sufficient to drop the cylinder pressure below the crankcase pressure before the transfer ports open, even at high rpm.
At part-throttle that cylinder pressure will drop to the same level, but now the crankcase pressure is much lower and exhaust gases will enter the transfer ducts, contaminating and heating the fresh mixture even before it enters the cylinder.
A theoretical solution would be a power valve that enlarges the normal exhaust timing instead of lowering it. But that is impractical as it would ruin the shape of the exhaust duct and it would cause cooling problems in the cylinder's exhaust area.
A variable tailpipe area, like Jan says, can be a more practical approach. I designed a simple solution, shown in the drawing below, but then two-stroke development at Aprilia was terminated because of Dorna's ban on two-strokes

Howard Gifford
Another way to lower HP without sacrificing piston cooling would be to richen the mixture when you want to lower the power. With a signal to a fuel enrichening solenoid you could achieve a power range. It would then be instantaneous and programmable. Not enviornmentally friendly but would work for racing. The mixture ratio difference from high power to low power would need to be just rich enough before a misfire and just lean enough for sustained high power.

The variable tailpipe idea will work but I suspect the pipe temperature would drop off and it would take several seconds to regain full power. But then again rich mixture may have the same problem.
Two strokes are like redheads. Hard to figure out and very temperamental. But when they are happy they are a lot of fun!
HG

Jan Thiel a écrit:
The entering fresh charge is ignited by the remaining, hot, burned gases!
You can see very severe damage to the piston after maybe 10 seconds at 20% throttle.
This still is an unresolved problem! I was thinking about a way to reduce engine power without closing the throttle. But how can you do this? I did not find a solution before I retired.
And nobody else was really interested.

Institute of TwoStrokes
On aftermarket ignitions I use there is a mode I can switch on where a number of indivdual sparks are cut, depending on throttle position. It is now only configured for cutting 1 in every 3 sparks on over run(tps <10% with high rpm). Would that sort of system solve the part throttle detonation? If the number of sparks cut could be varied along with TPS for this to begin and end? If it would be helpful I'm certain the manufacturer would only need a software change to do this.

Jan Thiel
I certainly thought about cutting sparks.
But remember: the problem was AUTO-ignition!

GrahamB a écrit:
Remember that retarding the ignition is used at high rpm to increase exhaust temps and effectively shorten the pipe. So it's likely to increase the heating of the front edge of the piston...

Jan Thiel
Indeed, retarding too much caused detonation!

Institute of TwoStrokes a écrit:
Jan Thiel a écrit: The entering fresh charge is ignited by the remaining, hot, burned gases! You can see very severe damage to the piston after maybe 10 seconds at 20% throttle.
This still is an unresolved problem! I was thinking about a way to reduce engine power without closing the throttle. But how can you do this? On aftermarket ignitions I use there is a mode I can switch on where a number of individual sparks are cut, depending on throttle position. Would that sort of system solve the part throttle detonation?

Frits Overmars
As Jan pointed out, once you have auto-ignition, the engine does not listen to its ECU any more. So you would have to start skipping sparks well before the onset of detonation.
In a foul-stroke your proposed system does work, but a two-stroke would react far from linear. For example, if you skip 1 in 4 sparks, you will loose much more than 25% of engine power because that one missing spark will cause the gasdynamics processes to collapse. The main problem would be to realise a smooth transition from intermittent to full ignition.


Jan Thiel a écrit:
Retarding ignition also does not make sense.
As you have an AUTO-inition problem!
So the engine does not 'listen' to its ECU anymore!
What you would need is the same fresh gas flow, but with less HP!
Not easy to achieve!
A variable tailpipe might help.

Haufen
I think I expressed myself unclearly. What I meant was the following:
Imagine your engine with the throttle opened just above the auto-ignition range. Then you have sufficient transfer flow, but too much power. To lower the power, now retard the ignition. Then you still have sufficient transfer flow, but with less power.

I think Honda used auto-ignition to their advantage on two-strokes. As far as I remember they did it with a (very) variable exhaust power valve.

Frits Overmars a écrit:

Mic a écrit:
How about much larger travel on the exhaust power valve. With a shorter exhaust port duration power is lower. And this is already controlled with the stepmotor over the ECU.

Frits Overmars a écrit:
Like Jan wrote, a shorter exhaust duration will worsen the detonation. What happens is this:
During normal operation, the blowdown time.area of the exhaust ports is sufficient to drop the cylinder pressure below the crankcase pressure before the transfer ports open, even at high rpm.
At part-throttle that cylinder pressure will drop to the same level, but now the crankcase pressure is much lower and exhaust gases will enter the transfer ducts, contaminating and heating the fresh mixture even before it enters the cylinder.
A theoretical solution would be a power valve that enlarges the normal exhaust timing instead of lowering it. But that is impractical as it would ruin the shape of the exhaust duct and it would cause cooling problems in the cylinder's exhaust area.
A variable tailpipe area, like Jan says, can be a more practical approach. I designed a simple solution, shown in the drawing below.

269228

Haufen
I think I have not gotten behind the variable tailpipe idea, yet. What would you like to vary with it and to achieve which effects? At little throttle openings the pressure inside the exhaust pipe is already very close to atmospheric pressure (if not even) on most engines. And if you had say 100mbar inside the pipe at the critical throttle opening, then the engine might have had more power with a bigger tailpipe.

269228

Frits Overmars
'Opening' the end of the reflector will cause a substantial weakening of the reflected pulse and thus less charging of the cylinder. Izze simple, no?

Haufen a écrit:
Variable transfer timing would be nice also, if feasible.

Frits Overmars
That would be my ideal. Lowering all the transfer roofs would shorten the transfer timing and lengthen the blowdown timing, so the cylinder pressure would drop further before the transfers would open. It would cure the hig revs/low power-detonation and it would improve the power band because a too early-returning exhaust pulse would have less opportunity to push the fresh cylinder contents back into the crankcase.
A controllable transfer height would even make a throttle valve unnecessary.
There's only the little problem of how to build it...

Jan Thiel
Haufen, Auto-ignition usually occurs between 10 to 40% throttle at high revs.
In fast, non full throttle corners.

Retarding the ignition was tried to diminish power.
This makes the exhaust very hot.
Then, when you need full power, it is not there because the exhaust temperatures are wrong.
This takes a little time, when the engine is back to full power you are already at the end of the straight!
The same goes for water injection in the exhaust.
It was tried by Rotax about 25 years ago.
There was a LOT more power at low revs, so the rider had to take it easy when opening the throttle.
But the engine revved a little bit less, because the exhaust temperature did not recover at high revs.
And lap times became actually slower.
After a day of testing the system was switched off.
Lap times immediately improved!

A very important thing when accelerating is the power you have after changing gear.
Spark interruption may be not so good for this!
As I did not have the dyno I wanted this gearchange effect could not be tried on the dyno, very regrettably!
Retarding the ignition and weakening the mixture by powerjet can also have a negative effect on this.
The exhaust temperature should be 'Right' for the No. of revs after you change gear.
If the temperature is too high there will be less power!
So it is REALLY complicated!

[cotswold]

Thats 18kg lighter than the Beast ......

Thats quite a lot of pies

[TZ350]

Thats quite a lot of pies

Or dinners at the RSA .... we don't need to diet now :D

[crazy man]

275928here is another pic of the sidecar for the poll

[husaberg]

275928here is another pic of the sidecar for the poll
Fuel tank in frame Cool but where is the gear lever?

Or dinners at the RSA .... we don't need to diet now :D

Like you allude to The bike is only half the equation

Moto3 Class The 125 cc class was replaced in 2012 by the Moto3 class. This class is restricted to single-cylinder 250 cc four-stroke engines with a maximum bore of 81 mm (3.2 inches). The minimum total weight for motorcycle and rider is 148 kg (330 lb).

For some reason i thought there was already a minimum rider weight far before that?
All i know is Dirk Raudies was about 49kg and 5.4" others were probably smaller.
Rich and Budha and Me amonst others are a little more generously proportioned:yes:

[crazy man]

275910

Following the less is more principle for race winning power and reliability, Chambers is going for the old school approach.is that the new wobbly pipe on it ?

[speedpro]

275911

My super performance CVT bits turned up today

One end needs to be flipped over to match up in operation if it's anything like my CVT. With the CVT you won't need to sweat over the powerband, the CVT will take care of it.

[TZ350]

All i know is Dirk Raudies was about 49kg and 5.4" others were probably smaller. Rich and Budha and Me amonst others are a little more generously proportioned:yes:

The difference between Rick52 and his bike and me and the Beast is nearly 60kg, try lifting 60kg and one pretty quickly realises that I am on a hiding to nothing.

[TZ350]

I thought it was obvious.

Nope, well yes, but it took me a while as the HP God had me distracted.

[richban]

The difference between Rick52 and his bike and me and the Beast is nearly 60kg, try lifting 60kg and one pretty quickly realises that I am on a hiding to nothing.

No no no Rob. I have the same weight disadvantage and have come out on top quite a bit. I put it down to momentum. Once that 200kg of man and machine are rolling its like a run away train. Trick is to not use the brakes as much and keep it pinned. Also its harder to get flung off when you are crushing the poor thing under you.

[Yow Ling]

No no no Rob. I have the same weight disadvantage and have come out on top quite a bit. I put it down to momentum. Once that 200kg of man and machine are rolling its like a run away train. Trick is to not use the brakes as much and keep it pinned. Also its harder to get flung off when you are crushing the poor thing under you.

Well said, should be my new mantra, now just need to teach my brain not to be such a scaredy cat

[Buddha#81]

No no no Rob. I have the same weight disadvantage and have come out on top quite a bit. I put it down to momentum. Once that 200kg of man and machine are rolling its like a run away train. Trick is to not use the brakes as much and keep it pinned. Also its harder to get flung off when you are crushing the poor thing under you.

Pah 200kg...........fooken liteweight! That must mean me and pumba have the most planted buckets in the country?

[rgvbaz]

[QUOTE=wobbly;1130461375]

Having a 5000 rpm wide useable powerband from 8500 to 13500 is in fact alot EASYER to build, than having to design for a much higher bmep, to achieve the same power from 6500 to 11500.
QUOTE]



On the usable powerband width.
In terms of change in roadspeed for the 5000 rpm width powerbands , 8.5 - 13.5rpm V's 6.5 - 11.5 rpm, the 6.5 - 11.5 rpm is actually wider if the bike was geared to give the same speed at max rpm of each powerband.
From John Bradleys book:
road speed (mph)= (rpm* radius of wheel (inch))/ (168.1* gear ratio)

Assume wheel radius = 11.8 inch the 13500 rpm upper powerband limit engine I assumed a overall gear ratio of 20:1. To get the same speed( mph) for the engine with 11500 rpm upper powerband limit we need to change the gearing:

11500/13500 = 0.852
0.852*20(8.5 - 13.5 rpm gear ratio) = 17.04:1

At 13500 rpm speed (mph) = (13500*11.8)/(168.1*20) = 47.4 mph

At 11500 rpm speed (mph) = (11500*11.8) / (168.1 * 17.04) = 47.4 mph

At the start of the usable powerbands the speed would be:

At 8500 rpm speed (mph) = (8500*11.8)/(168.1*20) = 29.8 mph
At 6500 rpm speed (mph) = (6500*11.8)/(168.1*17.04) = 26.8 mph

So for 6.5 to 11.5 rpm usable powerband you have a range of (47.4 - 26.8) = 20.6mph for a change in 5000 rpm
For 8.5 to 13.5 rpm usable powerband you have a range of (47.4 - 29.8) = 17.6 mph for a change in 5000 rpm

You can also work out by dividing the end rpm by the start rpm to give you the range of the powerband:

13500/8500 = 1.588
11500/6500 = 1.769 as you can see the lower rpm powerband has a greater range.

Note:
47.4 mph/1.588 = 29.8 mph 47.4 mph/1.769 = 26.8 mph

But as Wobbly says you probably can't get the power you need from a 2T with the lower of the 2 rpm ranges so you are actually stuck with the 8.5 to 13.5 range.

However I think this is where the 4Ts have an advantage as there rpm spread may be the same as the 2Ts but as it is powerband is at lower rpms the effective powerband is wider.

Cheers

Dave

Also it's a good way of working out rpm drops for gearing
Eg, my AM6 has the following gearbox ratios and range between each ratio:

To work out the range between each ratio divide lower gear by next gear up eg:
1st to 2nd = 3/2.06 = 1.45 2nd to 3rd = 2.06/1.53 = 1.35 etc...

AM6
Ratio Range
1st 3
2nd 2.06 1.45
3rd 1.53 1.35
4th 1.23 1.24
5th 1.04 1.18
6th 0.96 1.09

So if you change gear at 13000 rpm the drop is the change rpm divided by the range of the internal ratios
for 1st to 2nd the rpm would drop to 13000/1.45 = 8965 rpm
2nd to 3rd 13000/1.35 = 9630 rpm
3rd to 4th 13000/1.24 = 10484 rpm
4th to 5th 13000/1.18 = 11017 rpm
5th to 6th 13000/1.09 = 11927 rpm
I find it a quick way to assess a power range of a engine curve to the gearbox of the engine.

[TZ350]

Having a 5000 rpm wide useable powerband from 8500 to 13500 is in fact alot EASYER to build, than having to design for a much higher bmep, to achieve the same power from 6500 to 11500.
But as Wobbly says you probably can't get the power you need from a 2T with the lower of the 2 rpm ranges so you are actually stuck with the 8.5 to 13.5 range. However I think this is where the 4Ts have an advantage as there rpm spread may be the same as the 2ts in terms of rpm but at lower rpms so the effective powerband is wider.


I hadn't thought about the effective power spread in terms of road speed, thank you for pointing it out. Looks like I will have to aim for 6-7k rpm now, it doesn't get easier does it.

[husaberg]

Cheers

Dave

Also it's a good way of working out rpm drops for gearing
Eg, my AM6 has the following gearbox ratios and range between each ratio:

To work out the range between each ratio divide lower gear by next gear up eg:
1st to 2nd = 3/2.06 = 1.45 2nd to 3rd = 2.06/1.53 = 1.35 etc...

AM6
Ratio Range
1st 3
2nd 2.06 1.45
3rd 1.53 1.35
4th 1.23 1.24
5th 1.04 1.18
6th 0.96 1.09

So if you change gear at 13000 rpm the drop is the change rpm divided by the range of the internal ratios
for 1st to 2nd the rpm would drop to 13000/1.45 = 8965 rpm
2nd to 3rd 13000/1.35 = 9630 rpm
3rd to 4th 13000/1.24 = 10484 rpm
4th to 5th 13000/1.18 = 11017 rpm
5th to 6th 13000/1.09 = 11927 rpm
I find it a quick way to assess a power range of a engine curve to the gearbox of the engine.

Bert (i think it was you wasn't it Brent) has an most excellent Excel spread sheet program he will post if we ask him nicely..........

[rgvbaz]

I hadn't thought about the effective power spread in terms of road speed, thank you for pointing it out. Looks like I will have to aim for 6-7k rpm now, it doesn't get easier does it.

Sorry, Have just edited above post so it reads a little better. Maybe I should do it before posting:yes:


For our am6 racer at kart tracks here in the UK we have a effective powerband range of 13500/9000 = 1.5

[Bert]

Bert (i think it was you wasn't it Brent) has an most excellent Excel spread sheet program he will post if we ask him nicely..........

Yip.

(placeholder when I find where I put it)..... go down one post, husaburg found it faster than me....

Also:
http://www.gearingcommander.com/
This is useful if you don't know the ratios for your engine. it is a great resource.

[husaberg]

Yip.

(placeholder when I find where I put it)

Also:
http://www.gearingcommander.com/

Thanks brent but i think there may have also been a populated excell spread sheet one.
I will have saved it (somewhere) oh that was easy
Was this from you?

[Frits Overmars]

You can also work out by dividing the end rpm by the start rpm to give you the range of the powerband:
13500/8500 = 1.588
11500/6500 = 1.769
as you can see the lower rpm powerband has a greater range.That's the way to do it: concentrate on the power range. For road racing with a close-ratio sixspeed gearbox you'll need a power range of 1.4.
Anything more is convenient for the rider, but not really useful if he is good at his job. Anything less will lose you valuable time at some tight points of the track, which you won't be able to make up for at the straights.

[Andrei_Kazban]

Goedendag, Frits, mijn naam is Andrew en ik zijn al tuning motoren kart.U Ik heb een zeer interessnaya Research uitlaat. Als u geïnteresseerd bent, ik kan laten zien plny tekst, maar het in het Russi

[Frits Overmars]

Goedendag, Frits, mijn naam is Andrew en ik zijn al tuning motoren kart.U Ik heb een zeer interessnaya Research uitlaat. Als u geïnteresseerd bent, ik kan laten zien plny tekst, maar het in het Russiдобрый день Andrei. Yes, I am interested in your 'research exhaust' and I suppose so will be a lot of Kiwi forum members. So maybe it's better to communicate in English instead of Dutch or Russian :shifty:.

[Andrei_Kazban]

These investigations are not mine, but one famous FSR.On produced a surprising number of glass tubes and used the high-speed camera to take pictures. Although the technology was practiced on a small motor it runs on all cubage.

[Andrei_Kazban]

http://forum.rcdesign.ru/f5/thread241866.html rar-file.wondering if I can help with translation

[teriks]

http://forum.rcdesign.ru/f5/thread241866.html rar-file.wondering if I can help with translation
I had a quick look on that paper, and would love to be able to read it. Seems to be a lot of really interesting stuff there for me. Correct scale of engines for me too :)

[FastFred]

275947



For our am6 racer at kart tracks here in the UK we have a effective powerband range of 13500/9000 = 1.5


That's the way to do it: concentrate on the power range. For road racing with a close-ratio sixspeed gearbox you'll need a power range of 1.4.

Taking the the widest practical of TeeZee's graph ..... 13,000/9,000 = 1.4, for a 5 speed, so a little short, more work required. No doubt TeeZee will get it sorted.

[TZ350]

Taking the the widest practical of TeeZee's graph ..... 13,000/9,000 = 1.4, for a 5 speed, so a little short, more work required. No doubt TeeZee will get it sorted.

Thats interesting as it is the widest 2T graph I have seen posted on here and I would have thought that a 4k power spread would have been enough and I was only being gready trying for more.

Anyway it shows that I have been on the right track, looking to make greater effective width and there is more width needed.

275955 275956

For plumping up the bottom end a bit, FarmerKens ATAC valve looks like a good idea. Instead of the normal Honda ATAC butterfly he has made a slotted drum like the Suzuki RG400/500's have, I will be trying to copy it.

In fact FarmerKens bike had a lot of good ideas I will be trying to copy.

[F5 Dave]

I've got several other gears hidden in the left handlebar lever:laugh:.

[richban]

Thats interesting as it is the widest 2T graph I have seen posted on here and I would have thought that a 4k power spread would have been enough and I was only being gready trying for more.

Anyway it shows that I have been on the right track, looking to make greater effective width and there is more width needed.



I like this way of looking at the power spread.

How dose that graph look with my FXR overlaid Rob. Coz that looks rather good. Put that engine in a sorted chassis and watch out.

I think they are the same a 8500 then yours just takes off nice.

Mine works out at 1.47 with a not so good 6 speed. Would love a close ratio for my bike. Must look into that more.

[bucketracer]

Thats true, Avalons bike that Chambers prepaired for her with Thomas and Bucketracers help annihilated everything when she took it out, its just a pity she is to busy riding in other classes to have been able to bring her F4 Bike to the recent Bucket meetings.


As I understand it (correct me if I'm wrong) the bike that Avalon was riding was 24HP, with a different pipe and suitable blowdown time.

Its pretty much the same in all the important ways as TeeZees current engine. The big difference is Av is a top notch rider and she and her bike weigh much less than any other F4 rider bike combo that I know of, other than possibly Nate D.

[Bert]

Its pretty much the same in all the important ways as TeeZees current engine. The big difference is Av is a top notch rider and she and her bike weigh much less than any other F4 rider bike combo that I know of, other than possibly Nate D.

or possibly Rogan from welly..

[koba]

or possibly Rogan from welly..

Rogan's bike is currently a bit heavier (250 frame, albeit a very small one).

[koba]

I've had a play with my ignition.
I need a better measuring stick and a rev counter to get a proper measurement but the timing light seems OK until at least really high revs, the rate of change that I see by the strobe seems smooth and consistent.

Has anyone purchased a timing dial guage? recommendations? I was considering making a fixture for a dial guage that I can borrow and using that.
I'm gutted to find that the local tool shop have just stopped running a special (huge discount) on some precision measuring equipment.

From my rough measurement it looks like the advance curve spans around 29.5 degrees. That seems like a lot?

I'll post some more once I make it presentable.

Oh also, once I get a better idea of the ignition curve nature I'm going to have a go at simulating an engine based around that. It may be an option for a interim build plan as My engine is very mild at the moment.

[twotempi]

Rob - You can post that Excel gearbox sheet as an Excel file for people to download if you want

[husaberg]

I've had a play with my ignition.
I need a better measuring stick and a rev counter to get a proper measurement but the timing light seems OK until at least really high revs, the rate of change that I see by the strobe seems smooth and consistent.

Has anyone purchased a timing dial guage? recommendations? I was considering making a fixture for a dial guage that I can borrow and using that.
I'm gutted to find that the local tool shop have just stopped running a special (huge discount) on some precision measuring equipment.

From my rough measurement it looks like the advance curve spans around 29.5 degrees. That seems like a lot?

I'll post some more once I make it presentable.

Oh also, once I get a better idea of the ignition curve nature I'm going to have a go at simulating an engine based around that. It may be an option for a interim build plan as My engine is very mild at the moment.

I used to borrow one but after a while i thought well whats the point i want the timing in degrees not mm...
Here is my slant probably not technically correct either........
Go to the Chainsaw shop get a piston stopper (they are made to do up flywheel nuts i think.)
they look like a bolt with a thread to suit the plug hole and have a rounded end. maybe $10
get a timing disk, a nice proper one and make a sturdy marker that for the timing disk numbers.
insert the stopper in the plug hole move around to towards TDC take note of the degrees mark.
Rotate the engine in the opposite direction half way between the two points where it stops (assuming you have a central plug hole and your cylinder is not offsett) will be TDC.
Now put the pointer at true tdc and mark your flywheel in degrees. according for you tests scribe and use different colour nail polish as it stands out nicely and gives a nice visual indication

People used to make stopper and tdc gauges out of hollowed out plugs and steel rods when they wanted to set up the timming in MM

now i can see there will be alternate views on this.

BTW i have used one of these stoppers to tighten a flywheel before in an emergency i am not proud but it worked.
i used to use an old broken gear to lock the primary normally.(stole that idea from Kevin Cameron i think?)

[Bert]

I used to borrow one but after a while i thought well whats the point i want the timing in degrees not mm...
Here is my slant probably not technically correct either........
Go to the Chainsaw shop get a piston stopper (they are made to do up flywheel nuts i think.)
they look like a bolt with a thread to suit the plug hole and have a rounded end. maybe $10
get a timing disk, a nice proper one and make a sturdy marker that for the timing disk numbers.
insert the stopper in the plug hole move around to towards TDC take note of the degrees mark.
Rotate the engine in the opposite direction half way between the two points where it stops (assuming you have a central plug hole and your cylinder is not offsett) will be TDC.
Now put the pointer at true tdc and mark your flywheel in degrees. according for you tests scribe and use different colour nail polish as it stands out nicely and gives a nice visual indication

People used to make stopper and tdc gauges out of hollowed out plugs and steel rods when they wanted to set up the timming in MM

now i can see there will be alternate views on this.

BTW i have used one of these stoppers to tighten a flywheel before in an emergency i am not proud but it worked.
i used to use an old broken gear to lock the primary normally.(stole that idea from Kevin Cameron i think?)

I've got a tdc tool buzziti (spelling?). Then just made up a conversion chart (mm to degrees).
But the spark plug solution works well.

http://www.scooterhelp.com/tips/timing/timing.tools.html

[dinamik2t]

http://forum.rcdesign.ru/f5/thread241866.html rar-file.wondering if I can help with translation

The diagrams and pics in that document look very interesting, but I can't read Russian.. (I have an aunt who can, but I doubt she can help). Perhaps you could say a few works on that research.
Thanks for posting anyhow..

[ief]

Try google translator, I won't say it gets clear as crystal but better then russian.

[cookie1965]

(assuming you have a central plug hole and your cylinder is not offsett) )

I've seen people post that before, and the truth is that as long as the piston stop touches the same point on the piston crown going forward and backward, the middle point between the 2 degree wheel readings is TDC regardless of if the stop touches the highest point of the piston or not.

[F5 Dave]

Rogan's bike is currently a bit heavier (250 frame, albeit a very small one).

I had the chance to borow that bike before they got it. Getting it in the van was enough to convince me to look elsewhere. The 3XV frame is exceddingly stout for a 250. Surprised.
None of which helps the ego as I struggled to chase down that combo a couple of weeks ago.

[TZ350]

How dose that graph look with my FXR overlaid Rob. Coz that looks rather good. Put that engine in a sorted chassis and watch out. I think they are the same a 8500 then yours just takes off nice.

276026

Hi Rich these are the graphs from the back to back test. (Rich Blue Line) in this graph I dont think my extra top end makes up for your better low end drive.

276025

This is my current (old) engine. (Rich Blue Line) this looks quite good from 9 onwards, below that it drops dead. But I am sure with a bit of work it could be extended at the top and bottom.

If my engine could be made to pull from 7,500-8000 rpm I would be a happy chap. Now all I need is to lose 25kg 35 years and build a lighter bike.

276024

The only real difference between the new and old (Blue line) engine is the extra blow down time area of the side ports (Red line). I think that with some sort of valve in the side ports I could join the graphs and then an ATAC valve like FarmerKens for plumping up the bottom end would do the trick.

[TZ350]

276027

Anyway at the moment my interest is the CVT system. The front pulley is upside down because it sits on the table better that way.

At first sight it might seem that the distance between the pulleys has to be very accurate but what does very accurate mean? 10mm 5mm 1mm 0.1mm 0.5mm 0.05mm.

There are some simple ways of getting some sort of idea, like measuring the distance between the shaft centers of a real CVT Scooter and its easy to get a good measurement of the distance between shaft centers with some simple engineering tricks.

After taking a logical look at the way the sheaves clamp the belt I don't think a mm or two here or there between shaft centers will make much difference.

And I think that if one gets it really wrong, the range of effective CVT ratios might be affected but as long as the friction on the belt is high enough when clamped by the moving sheaves the thing will run anyway.

276028

But if one was truly concerned about the relative length between the logical centers of the belt as well as the pulley pre load frictional force on the belt itself, here is a simple solution to adjust the belt tension.

[cotswold]

[QUOTE=TZ350;1130462968]276026


276025


276024

After trying both versions of your engine I would be hard pushed to choose which I would prefer. Before it nipped at Toke the beast was not horrible to ride and with a bit more time on it I think would be the faster of the two, Saying that the Taumarunui version was easy to ride but I was not able to ride it to its potential due to the Det problems and if I had been able to rev it out I may lean towards that one. :scratch:

[TZ350]

With a bit of fiddling I think we may be able to get the best of both.

I am going to take the head off tomorrow to see what damage the det has done, water injection or a pressure dump valve in the chamber for when its in over rev may be the answer.

[wobbly]

Thousands of 2Ts have done thousands of Kms happy running in overev with no issues.
Both of the dyno graphs would indicate that either of the engines as run, are a complete waste of time reving past 12500 anyway.
If the thing is detoing up there, well over the torque peak, then only 2 things can be happening.
There is way too much advance past 12,000, or the air corrector is forcing the A/F ratio way too lean.
This would be the sort of effect you would see if a too big solenoid power jet was being switched off over the top.
Look into and correct these simple issues before even thinking of dicking around with water and and or dump valves that are completely unnecessary.

[bucketracer]

275922 275923

B9 plug after Tokoroa.



B10 plug after Taumarunui

275921 275920

The B10 plug from Taumarunui after some hot laps and a proper plug chop before over rev deto set in. I would be interested in what Wob has to say about it.

Hi Wobbly could you please have a look at TeeZees B10 plug for us.

[TZ350]

276053 276054

Yes, Wob I would be very keen to know if the colour of the B10's fuel ring is more like you would expect.

[husaberg]

Seeing as F4 is way too fast , F5 is dominated by the 50cc zealots from Wellington, if i have any chance of ever winning a title I will need to create my own class F6

49cc single speed pre 1960 that should narrow the field a bit

Heres my entry, after reading in depth about small frontal area , light weight skinny tyres I have arrived at this formula

275248 275249 275250 275251

maybe some of the senior bucket guys like speedpro can shed some of their wisdom as he can probably remember them when they were new


I'm afraid your mass distribution is less than optimal; you might want to have more load on the front wheel.
Ever considered Solex racing ? (yes, it's another crazy Dutch thing. But the French picked up on it as well :weird:).

I found this while looking for something else .Of course I didn't find what i was looking for but what's new.
I have posted Vincenti Paitti stuff before but never put 2 and 2 together.


The other bit is for Grumph we mentioned a while back this guy i certainly never knew he would go to the evil side i guess he is in a way responsible for the Evil FXR150 as Well.
He knew Bugathi as well as co designing the TSCC.
http://docs.google.com/viewer?a=v&q=cache:D5LvEZT9e7YJ:twinspin-ec.com/The Piatti Story_MASTER_Word_02.pdf+patents+for+vincent+piatt i&hl=en&gl=nz&pid=bl&srcid=ADGEESgVOzV8mu0AmIn5ZXdBdPiHpb16eWG0jNGU8qa2 Gb1Kd86ZYlojR3yeSMvOSMMk_CyB1s1lKgOWBi1yZeznOyq2My BOvc5S7XO9hIKF0M7HwNi_FfNUBJBbBaAHfAy2k_3Lk_sg&sig=AHIEtbTx5y12z-YhH3gOMYEJKo7N4HUBhA

http://twinspin-ec.com/Analysis Software.htm

[2T Institute]

Why do you use ES style plugs?

[wobbly]

Is this still running AvGas??
For Av its a bit rich, for Unleaded its a bit lean.
The plug heat range appears good, and the mixture is on the rich side of correct for Av, but here is the kicker - how many times have I said
YOU MUST RUN A RESISTOR PLUG AND CAP.
Would not be surprised at all if the deto noise was caused by an ignition misfire due to RF affecting the ECU.

[TZ350]

Why do you use ES style plugs?

What does ES mean? These were 70 plugs for $50USD of Ebay.


Is this still running AvGas??
For Av its a bit rich, for Unleaded its a bit lean.
The plug heat range appears good, and the mixture is on the rich side of correct for Av, but here is the kicker - how many times have I said
YOU MUST RUN A RESISTOR PLUG AND CAP.
Would not be surprised at all if the deto noise was caused by an ignition misfire due to RF affecting the ECU.

Thanks Wob, yes Av Gas and at Taumarunui I kept going up in jets from 135 best power on the dyno to 162 to try and get rid of the over rev deto.

5K cap, I will get some resistor plugs and try them for over rev deto before I do anything else tuning wise.

[2T Institute]

276053 276054
What does ES mean?




The ones with the big fat J strap and centre electrode. NGK numbering would likely to be B9ES on that plug. It's a wonder you haven't had lead fouling with avgas. Iridium option would be BR9EIX. Swapping to a proper race plug is worth it(R7278-10)

[wobbly]

ES means Extreme Scrimping.

Weld a threaded alloy bung onto the head ( you could even machine a couple of fins into it ) to enable use of 3/4 reach race plugs, and use the one I gave you.
Much easier to read both ignition and fuel and is worth an easy Hp or two over shitter plugs.

[2T Institute]

ES means Extreme Scrimping.

Weld a threaded alloy bung onto the head ( you could even machine a couple of fins into it ) to enable use of 3/4 reach race plugs, and use the one I gave you.
Much easier to read both ignition and fuel and is worth an easy Hp or two over shitter plugs.
Extreme Shitters? What you will also notice is the run to the first corner is a bit faster as well.

[TZ350]

OK, As there are six 2T bikes in the team to feed, I needed to make a bargain bulk buy. I now have 60 of Nippon Denso's equivalent to NGK's BR10EIX plugs (or so the seller says) on their way from Ebay, less than $3 USD each after shipping. Plus 10 NGK 5K plug caps $12 USD each after shipping, shipping was a bit of a trap so not such a bargin there.

These bikes had better like those plugs and caps ......

[wobbly]

Yea shipping from Merica is a trap - just remember that a USPS small prepaid Intl box is 16usd, this would easily take 12 caps,or a rotor and stator etc.
Some shippers have tried to charge me 45usd for this - wrong answer.

[TZ350]

I could not find the Nippon Denso W31ES-G listed after a bit of research, but the W31ES-U was listed as a close equivalent to the NGK BR10EIX so I will just have to wait and see what we get. I will keep looking for some NGK B10 resistor plugs that don't cost an arm and leg.

[dinamik2t]

You should search for the R6254K-105 plugs from Kawasaki's KX 80 85 100 125. They are quite cheap for racing spark plugs.

edit:
Wob, would you have any of those exhaust flange step/transition tests on a dyno sheet??

[F5 Dave]

ok changing the topic as I think this has run its course (again).

Ring seal. I've never had much drama from other engines that have passed through my grubby hands. Nickisil is easy & even the iron bores have just been a case of fire in a new ring with a bit of a hone if yer lucky, spend practice, on throttle, off throttle & then first race just got for it. Or a few times through the gears on the dyno.

But using the KT piston in the MB has me scratching my head a bit. I've had a few running problems, some attributable to ign as it turns out, but when I went the next size up from 0.05 to 0.1 the bore had to be honed quite a bit to make it round again. Then it picked up & honed round again. But have ended up with ~3thou & that seems ok. Also it was having patched polished like it had worn the hone away. Maybe the KT piston has to run a little loose for how hot its getting.

So its run about a full meeting (over two meetings) & a couple of dyno sessions. Its going ok, but not fantastically. As I've had these issues with bore polishing I measured the ring seal (yet to build my own tool so got to use a real one). Apparently KTs run about 10% leakage (I suspect do to the large ring gap) on this gauge.

Mine was 36%. Ouch. A little further down from top it was slightly worse.


So plan of attack now is a new ring of another brand (TK? instead of Yam), light hone & run it on Castrol R30 at like 16:1 & see if I can get that leakage better.

Mike doesn't seem to have had the same issues. So why have I?

[Grumph]

ok changing the topic as I think this has run its course (again).

Ring seal. I've never had much drama from other engines that have passed through my grubby hands. Nickisil is easy & even the iron bores have just been a case of fire in a new ring with a bit of a hone if yer lucky, spend practice, on throttle, off throttle & then first race just got for it. Or a few times through the gears on the dyno.

But using the KT piston in the MB has me scratching my head a bit. I've had a few running problems, some attributable to ign as it turns out, but when I went the next size up from 0.05 to 0.1 the bore had to be honed quite a bit to make it round again. Then it picked up & honed round again. But have ended up with ~3thou & that seems ok. Also it was having patched polished like it had worn the hone away. Maybe the KT piston has to run a little loose for how hot its getting.

So its run about a full meeting (over two meetings) & a couple of dyno sessions. Its going ok, but not fantastically. As I've had these issues with bore polishing I measured the ring seal (yet to build my own tool so got to use a real one). Apparently KTs run about 10% leakage (I suspect do to the large ring gap) on this gauge.

Mine was 36%. Ouch. A little further down from top it was slightly worse.


So plan of attack now is a new ring of another brand (TK? instead of Yam), light hone & run it on Castrol R30 at like 16:1 & see if I can get that leakage better.

Mike doesn't seem to have had the same issues. So why have I?

I'm told there are KT pistons and then there are KT pistons.....apparently there are a shitload of brands available but some are rubbish.

I'd hope Wob will have a definitive recommendation for you.

[F5 Dave]

yeah I was using std Yam ones. Strike ones are apparently good but they start in larger oversizes I can't really use.

[tdc211]

[QUOTE=Bert;1130459460]Please tell us a little more. is that a big bore kitted CR85?

Maybe even a port map / listed durations might be interesting for some of us.

Nice work though ~300hp per litre. :2thumbsup



I would like to share it, but this was a very long project. I do not think a Honda CR 85 would be a good choice as it has no power valve. I did mess with port timings/areas all over the place ,1 degree at a time on some timings and more heads/ign timing than I can remember. Compression is really not that high.

[bucketracer]

This plug reading stuff is very interesting I have always wondered how it was done. Cutting open a plug each time looks like a real dedicated way of doing it.


This is what we are looking for, the area above the black line,

276171 276172 NGK B9 Plug


The spark plug - why are you running a 9 in a Super Hot air cooled engine that is always going to be running up against the fins thermal ability to reject heat fast enough.

That is the reason there is no distinct burn line on the porcelain - as ALL of the porcelain is running too hot for an oil zone to form, and give you a reading.

I would be fitting a 10.5 - this is what the 28 Hp, 22,000 rpm 100cc air cooled kart engines HAVE to run or they seize instantly.

The end of the earth electrode is blasted clean - that is heat induced deto, or as I said at the beginning, maybe this is causing pre - ignition.

276170 276169 NGK B10 Plug


For Av its a bit rich, for Unleaded its a bit lean. The plug heat range appears good, and the mixture is on the rich side of correct for Av

I know (because I asked) the B9 and B10 plugs were new and fitted into a hot (up to temperature) 2T engine after practice and plug chopped at the end of one race each so there is not much running time on them.

Is it because the ones below are 4T that there is no (oil ???) stain on the nose of the porcelain like you see on TeeZees plugs.

http://www.wallaceracing.com/plug-reading-lm.html

276173 276174

(http://www.wallaceracing.com/plug-reading-lm.html)

[TZ350]

Bucket, I think they are out of a drag racer and don't get enough time in one run to colour up.

Here is a good bit on detonation from your link. http://www.wallaceracing.com/plug-reading-lm.html
(http://www.wallaceracing.com/plug-reading-lm.html)
"" Preignition/Detonation
Porcelain = the porcelain shows up preignition/detonation, it will not accurately reveal jetting/air/fuel ratios. To look for the first/beginning signs of detonation, search the white porcelain for tiny black specks or shiny specks of aluminum that have fused to the porcelain. When detonation occurs, part of the air/fuel mixture explodes instead of burning, the explosion is heard as a "metallic knock", this audible knock is the result of a sound shock-wave, this shock wave travels back and forth across the clearance volume "disrupting" the cooler boundary layer gases that cover the entire clearance volume area. This disruption allows "more" heat to be transferred into parts, especially, domes/piston tops,...along with the very rapid rise in pressure like a hammer blow, pistons can get torched with melted sides and holes !!! With the early signs of detonation, the shock-wave will also rattle rings causing the tiny amounts of oil that now gets by rings, to be fused to the white porcelain as tiny black specks, also fused as specks are soot that was clinging to clearance volume surfaces in the relatively "still-air" of the boundary layer. One step beyond the black specks, will be tiny specks/balls of aluminum coming off the pistons that will be fused to white porcelin,....the next step to be reached is occasional pieces of the porcelain being broken-off as detonation gets worse, ETC. Soon after that are holes, blown head gaskets, broken connecting rods, ETC.
NOTE: additional signs of beginning detonation are piston rings. By comparing ring's "free-diameter" to "out-of-box" free-diameters of new unused rings will reveals beginnings of detonation before much harm is caused !!! This is a result of the above previous explanation about heat being transferred more readily because the of the relatively insulating/cooler boundary layer being disrupted by the shock-wave. A piston ring is a simple spring, when a spring is over-heated it will loose tension.
Center Electrode = the very tiny sharply defined porcelain - "ditch" that encircles the center electrode, will also show up early signs of preignition/detonation and the wrong heat-range. Look for signs of the ditch beginning to be filled up with melted porcelain, you will need a 5x or 10x magnifying glass. ""

[2T Institute]

I could not find the Nippon Denso W31ES-G listed after a bit of research, but the W31ES-U was listed as a close equivalent to the NGK BR10EIX so I will just have to wait and see what we get. I will keep looking for some NGK B10 resistor plugs that don't cost an arm and leg.

Thats wrong Denso W plugs are ES style plugs, Denso Irridiums are IW-29/31/32 should be available from any Toyota dealer (if you want to get ripped off ) and much cheaper online. Denso race plug is IW01-29/31/32 there are $20 appearing on Amazon last lot we got were $34 landed. BARGAIN.

[2T Institute]

ok changing the topic as I think this has run its course (again).

Ring seal. I've never had much drama from other engines that have passed through my grubby hands. Nickisil is easy & even the iron bores have just been a case of fire in a new ring with a bit of a hone if yer lucky, spend practice, on throttle, off throttle & then first race just got for it. Or a few times through the gears on the dyno.

But using the KT piston in the MB has me scratching my head a bit. I've had a few running problems, some attributable to ign as it turns out, but when I went the next size up from 0.05 to 0.1 the bore had to be honed quite a bit to make it round again. Then it picked up & honed round again. But have ended up with ~3thou & that seems ok. Also it was having patched polished like it had worn the hone away. Maybe the KT piston has to run a little loose for how hot its getting.

So its run about a full meeting (over two meetings) & a couple of dyno sessions. Its going ok, but not fantastically. As I've had these issues with bore polishing I measured the ring seal (yet to build my own tool so got to use a real one). Apparently KTs run about 10% leakage (I suspect do to the large ring gap) on this gauge.

Mine was 36%. Ouch. A little further down from top it was slightly worse.


So plan of attack now is a new ring of another brand (TK? instead of Yam), light hone & run it on Castrol R30 at like 16:1 & see if I can get that leakage better.

Mike doesn't seem to have had the same issues. So why have I?

Are you using a S or a J piston? I ran KSI brand for a few years with no issues. I used to get a kart engine fellow who specialised in the KT motors to do the size and hone.Keeping the bore walls 100% straight is important. I tried to align stars with the hone/piston running a thou and a half clearence slightly rich at a tight twisty track, up to 2 and a half to 3 thou at the fast open track jetted to 1100-1150deg F on the straight. Depened how the meetings were scheduled, but after the third meeting was a hone and a piston again. If I had a 2 short track or 2 long I would get a Strike piston with a 0.01mm step to maintain those clearences. I always ran castor/synthetic at 18:1 in my H100, the only issues I can remember with that engine was with the balance shaft in and high rpm the LH(the big one) would last 1 or 2 meetings and a few people ran the CR hub with no cush drive which caused gearbox problems.

[TZ350]

Thats wrong Denso W plugs are ES style plugs,

Thanks ........ Ohooo well .... it looks like the plugs I have coming are something else to add to the pile of interesting but useless stuff in the shed .... but the good news is I get to go shopping Ebay again ..... :laugh:

[speedpro]

Are you using a S or a J piston? I ran KSI brand for a few years with no issues. I used to get a kart engine fellow who specialised in the KT motors to do the size and hone.Keeping the bore walls 100% straight is important. I tried to align stars with the hone/piston running a thou and a half clearence slightly rich at a tight twisty track, up to 2 and a half to 3 thou at the fast open track jetted to 1100-1150deg F on the straight. Depened how the meetings were scheduled, but after the third meeting was a hone and a piston again. If I had a 2 short track or 2 long I would get a Strike piston with a 0.01mm step to maintain those clearences. I always ran castor/synthetic at 18:1 in my H100, the only issues I can remember with that engine was with the balance shaft in and high rpm the LH(the big one) would last 1 or 2 meetings and a few people ran the CR hub with no cush drive which caused gearbox problems.

I get the kart shop mechanic to hone and size my cylinders as well. He's fanatical. I figure he knows what to do to make KT pistons last. For the same reason I run ELF HTX909 at about the ratio they suggested, plus Wobbly said it was good shit. After the previous piston, a hone to straighten everything up meant the clearance was 1.9 thou with the same size piston. Possibly a smidge loose for a kart track as you said but OK. I'm running genuine Yamaha KT pistons though that might change if I get tempted to run the rings that have a Titanium Nitrate hard coat on the wear face. The ones the kart shop have are for another brand of piston. They reckon no running in is required.

[TZ350]

For anyone interested, this is a list of best times for all bikes from a TRRS. The Bikes/riders are listed in time order fastest to slowest and its instructive to see so many Moto4 Bikes (F4 Buckets) up amoungst much bigger bikes.

276223

The fastest Bike/Rider combo in Form.4 I can see is F5Dave on a KV100, then Richard Deller and Rick52.

[F5 Dave]

Much as I'd like to own up to that I think that year the timing was pants & a sw anomaly got a first incomplete lap or something.

[F5 Dave]

Are you using a S or a J piston? I ran KSI brand for a few years with no issues. I used to get a kart engine fellow who specialised in the KT motors to do the size and hone.Keeping the bore walls 100% straight is important. I tried to align stars with the hone/piston running a thou and a half clearence slightly rich at a tight twisty track, up to 2 and a half to 3 thou at the fast open track jetted to 1100-1150deg F on the straight. Depened how the meetings were scheduled, but after the third meeting was a hone and a piston again. If I had a 2 short track or 2 long I would get a Strike piston with a 0.01mm step to maintain those clearences. I always ran castor/synthetic at 18:1 in my H100, the only issues I can remember with that engine was with the balance shaft in and high rpm the LH(the big one) would last 1 or 2 meetings and a few people ran the CR hub with no cush drive which caused gearbox problems.

Thanks, the S (the J is about 6" tall). The polished bits were surprising.

[husaberg]

Much as I'd like to own up to that I think that year the timing was pants & a sw anomaly got a first incomplete lap or something.

So is the (Presumably) Koba time of the RG150 accurate at 1:19.........

[F5 Dave]

Just ahead of Vicki on the 749, yeah that would have pissed her off.:rolleyes: but not too likely, - handy rider that he is not withstanding.

The other alternative is that we are both Oarsome.

[husaberg]

http://www.youtube.com/watch?feature=player_embedded&v=SgrGhJ5u5oM

[Moooools]

http://www.youtube.com/watch?feature=player_embedded&v=SgrGhJ5u5oM

That is very cool.
Depemnding on whether or not i can get sponsorship I am planning to investment(lost wax) cast a couple of throttle bodies this year for FSAE. However the plan is to get the wax rapid prototyped . Which means pretty well no limitations on geometry and fantastic surface finish. Not perfectly dimensionally stable but a very cool process.
It could be interesting for making your own barrels. With a bigger block of wax it would be a bit more dimensionally stable. You could do a barrel where the only finishing work was to machine the top and bottom surfaces and bore it out and nikasil it. Making the CAD file would probably be the hardest bit. I hate to think what it would cost though.

[koba]

So is the (Presumably) Koba time of the RG150 accurate at 1:19.........


Just ahead of Vicki on the 749, yeah that would have pissed her off.:rolleyes: but not too likely, - handy rider that he is not withstanding.

The other alternative is that we are both Oarsome.

2 things going on there, is that one even when we ran short track and other classes long?
We did run the sort track but can't remember what they did.
1:19 does sound too fast for a 749 on the fast track though...
Yeah that other thing was the timing was up the shit; Paddy, Jason Cameron and I were all quite close that year but the timing has us miles apart.

Oh there is a 3rd thing, I'm just that awesome that my SS150 time puts me something like 6th in F3 and not last in F2; I Think not!

Edit: I do remember giggling about all that at the time, I gave Vicky shit then; maybe it's time for a reminder...

[koba]

Another question,

What type of muffler is best?

I've been building a pipe, including a muffler that doesn't weigh 3kg.
I've made an aluminium body and some end caps but the hot glue gun ran out of gas before I could finish the thing.

I was having trouble deciding what guts to put in it.
I'm sure the top one in the pic will be plenty quiet enough but I'm tempted by the weigh savings of the middle picture type.
Maybe I could also build something like the lower pic?

I'd bee keen to hear other thoughts.

[Grumph]

Another question,

What type of muffler is best?

I've been building a pipe, including a muffler that doesn't weigh 3kg.
I've made an aluminium body and some end caps but the hot glue gun ran out of gas before I could finish the thing.

I was having trouble deciding what guts to put in it.
I'm sure the top one in the pic will be plenty quiet enough but I'm tempted by the weigh savings of the middle picture type.
Maybe I could also build something like the lower pic?

I'd bee keen to hear other thoughts.

Just stick to what works...the top one.

High frequency vibration and normal loss of packing material will soon enough give you one of the others and you'll find out quickly how bad they are.....

[TZ350]

Recently I have been trying to find the posts that talk about pipes and collate and edit them. There is heaps of it and pages 620 630 640 650 660 670 and 680 have un edited collections of raw material. If your interested in expansion chambers they are worth a look.

Pages 610 600 590 580 570 ..... 100 etc all have links lists to other stuff, then there is the Thread-Tools View-Thread-Images option that also helps to find the interesting pictures and posts.

http://www.underdogsracing.com/fospipe.html (http://www.underdogsracing.com/fospipe.html)

509

Before you get all out of control, consider a couple of factoids.
Turning the cylinder around has alot of advantages in pipe shape as well as allowing easy forward movement of the whole engine - remember the RSW is better than the RSA for that reason alone..

Secondly, I have shown conclusively several times to disbelieving audiences that using a PV can double the power of a highly tuned 2T at the bottom of the useable range.
So - imagine the single exhaust GP125 with double the power at say 6000, then draw a straight line up to its 31 Hp peak at 12500.

A ATAC system can achieve a similar result, the trombone is capable as well, this system has been used in hydro racing forever ( remember Konig and the Kiwi ).
So getting a 4T killer setup is staring everyone in the face, you - meaning Rob et al, just need to commit to one approach and develop it.


More questions for the wise ones,
How good does the seal around the butterfly need to be : should there be clearance to allow for expansion of the flap ??
How critical is it to have the butterfly open into the ex, stream? ( mine is going to be about 5mm from the inside wall of the header when open and close to 10 when closed )


I am not wise but if you have a look on Ebay Cr125 about 1986 there are plenty. Remember it opens Parallel to the flow as well not into it.

P513

The throttle plate or whatever you design must seal well.
I did a sliding flat plate with a hole in it design like they use in fuel injection throttle plates, that worked well on Champ winning jetski, as this got the plate real close
to the header and there was very little flow disruption when closed.
A small leak into the cavity will kill power real quick with an ATAC system.


Using the det sensor with lights makes it dead easy to shape the curve to suit the engine, you dont need a brake at all.
You can dyno load cycle the engine as fast as you like, and for the short period it may deto, in a small band of rpm - the lights go off like a Xmas tree.
Takes a bit of fiddling with sensitivity to get in the ballpark and read actual deto - not normal noise, as the det frequency is
determined by the bore diameter.
Just make sure the M8 bolt thru the Bosch sensor is tightly fixed to the head or case, with no washers to crush etc.
Data logging the sensor output against rpm is the trick way to go, but simply watching the revcounter and the lights to see where deto is happening during a pull, is easy.
Works just like the deto warning when running EngMod - see the warning and fix the excess advance before a rod comes thru your screen, your choice.

In this case we are dealing with an aircooled scenario - remember two things here, Avgas loves com to make power, and the pipe loves retard to get heat for revon power.
Whenever you have high com or lots of advance a larger % of the heat of combustion is directed out from the chamber into the finning, via mainly the ring contact with
the bore, reduce either or both and more heat ends up in the pipe, making it appear shorter due to the increased wave speed..
Thus when you are thermally limited by the finnings capability to reject heat, you must reduce the heat input by limiting the com.
This then means more heat is available in the pipe, so more power can then be made by upping the advance - just another balancing act.
Its a Catch 22 when there is high dynamic com - ie, when the engine is on the pipe,there is danger lurking, but below that point - the cylinder filling is so piss poor the only way to get good
throttle response off slow corners is to pile in plenty of advance - its safe as houses as there is very little effective com.
This engine has no powervalve so the cylinder filling efficiency comes on slowly, so you roll of the advance slowly, then pull it out quicker as the system starts to work well.
With a powervalve its the opposite - as soon as the valve starts to lift the efficiency increases dramatically, so the advance needs to be pulled out much quicker and sooner.
Any well set up race engine will love 28* below the pipe when running Avgas.

In one of the World Champ skis I did we had 35* of mid advance, as the only time it was in that band was at full throttle from a standing start.
It would jump real hard using that advance to generate cylinder pressure - but troll around on part throttle at that rpm and it would kill the engine by loosening the barrel nuts with rampant deto.


You must take into consideration the fuel being used, and how the factory engineers approached the problem.
Unleaded ( FIM that needs gloves and a respirator ) will go to 15:1 but must be run VERY rich to achieve best power with that level of com.
Leaded was run up at 19:1 in GP engines and at the end of the day the result was that the advance curves changed very little.
The big advance was in using the powerjet solenoids.
The unleaded scenario uses BIG powerjets ( 60 + ) to turn off the rich mixture past peak power.
The leaded setup was very lean at peak power, so only needed small ( 35 ) powerjets to keep the pipe temp up, over the top of the pipe.
Later of course that bastard Thiel came along and did the clever thing of PWM controlling the powerjet, thus even closer continuously matching the A/F ratio to the pipe
temp needed for max power.
Makes me sick just thinking about how clever he was, and how advanced the results became.
We are all just wankers floundering around in the mire of a mediocratic 2T wasteland - buckets.

P547

Re coating pistons with ceramic - the cool boundary layer in the squish helps suppress deto of the trapped end gases.
The ceramic surface is HOT, the alloy underneath is COOL.
Coating the piston or head in the squish CAUSES deto.
HPC have done dozens of pistons and heads for me with a spray mask, to keep the coating in the middle only.
Even doing a clear ceramic for classes where coatings are illegal - woops didnt say that.

And I got the Britten Ex ports coated to help stop the thing boiling on the grid - worked a treat and made more power as well.
Except the first time it was done the valve seats all fell out from the baking process.

P547

found this it is from Rob Tuluie from what i understand used to be head of R&D at Renualt F1 and was a Rocket scientist so i guess he is reasonably clever or has good PR. Edit he did this all before turning 39 .
he also designed the frames above.

its about Detonation i haven't actually read it yet.
http://www.motorcycle.com/how-to/wrenching-with-robchemical-soup-the-mystery-of-detonation-3420.html
http://www.motorcycle.com/how-to/wrenching-with-robchemical-soup-the-mystery-of-detonation-3420.html

fuel
http://www.motorcycle.com/how-to/wrenching-with-robchemical-soup-the-meaning-of-gas-3417.html




So, I might have read more into it than there was, anyway, this is the post I was thinking about.

Originally Posted by Frits Owermars @ Pitlane
In theory enclosed cranks are good. Jan Thiel did some experiments at Aprilia with a kart engine that had its reed valve at the front: the incoming mixture had to move against the direction of crank rotation. And although the crankcase stretched over the crank webs, reversing the direction of rotation brought another HP. So the crankshaft does have an influence.
But in practice, if you reduce the distances between crankshaft and crankcase walls to less than 1 mm, the viscous friction of the mixture between the surfaces really costs power at high rpm. And if you make the clearances so tight that lubricating oil can no longer reach the big-end and crankshaft bearings, it will also cost engines
Another negative aspect: any volume with a narrow 'entrance' between the crankshaft and crankcase surfaces acts as an hydraulic damper on the Helmholtz-resonance in the crankcase.
Aprilia has avoided this by making the space between the crank webs as wide as the big-end bearing. As a result the crankcase volume of the 125 cc RSA engine at TDC is about 650 cc, so the exhaust pipe really has some volume to breathe from.
So much for the fairy tale of high crankcase compression

There might be more on this subject over there, will look around a bit more, if I find more I'll add it to this post.

P552

I havnt constructed a stock RZ EngMod file but from the numbers given I can say outright the design wont work well at all.
The RZ has 50mm in the duct, and assuming no spigot on the cylinder ie the pipe fits flush on the cylinder face, then the header length is 36% - way too long.
Then the diffuser end is 58% and way too short.
The header angle at 2.35* is way too shallow, and the rear cone setup with 19* then 15.8* is back to front, and is a disaster on the dyno - been there ,tried that - no free lunch.
The stinger is way too big for anything but a full race setup,and the body at 116 dia is simply too fat, and will drag on the ground no matter how well the pipe is tucked under the bike.


Sorry,yes i forgot the 50mm in the cylinder with the diffuser end calc, its 678/1083 = 62%, a very old fashioned number..
For a street setup the longer header and longer diffuser expand the powerband width, but as it has a powervalve this changes everything,due
to the very low blowdown area when the valve is down.
Normal range for header = 30 to 33%, and for the diffuser = 64 to 68%, so I would be shooting for the longer on both for a stock add on pipe.
The longer diffuser gives better max case depression around BDC,later in the cycle, thus boosting mid scavenging efficiency.
Very long - 36% headers only work on piston port engines - like say TZ350,as this then allows a steeper initial diffuser angle, boosting power in the limited band the piston port can operate within.
There is no case for a header angle under 3* incl and dual angle rear cones are best with shallow then steep angles.
The main effect here is to increase the belly volume, thus smearing the wave amplitude over a lower, wider band.
Its always a combination of compromises, but helps you if the basic geometry suits the application,and the physical limitations presented.


.... turned your equations to an online calculator a few months back. It's here: http://www.underdogsracing.com/fospipe.html


The large cone angles come with high piston speeds and short exhaust timings. I can only guess at the exhaust timing you used, but aiming for max. power above 10,000 rpm in a twofifty is definitely provocative. I don't think the time.areas will be up to it. But like I wrote: try it and you'll find out.

Cone angles in themselves have little meaning, especially when reflector cones are dealt with. Short pipes tend to have steep cones and there is nothing wrong with that. The longer a pipe, the more the reflected wave is developing a steep front on its way back to the cylinder and the greater the risk of it developing into a shock wave that is very inefficient in shoving back washed-through fresh mixture.

One last word of advice: I would not build the second pipe in the above drawing. You succeeded in making it look like an Aprilia pipe, but those many cones just require too much cutting and welding. My overall rule of thumb: keep it simple.


Keep it simple, Ief. That ratio should be exhaust volume divided by cylinder volume. 30 is a good value, but it's not critical (and you probably won't be able to achieve it on an RD350; not if you want to keep some cornering clearance).


I could babble on forever about pipe specifics but here are a few pointers.
Rear cone ( single ) max out at around 28*,the multi angle setup used by Aprilia can be equalled simply by a single cone set at around this angle.
In a 250 it is counter-productive shooting for the same swept/pipe vol ratio as a 125, you need to be aware that there is a finite amount of energy in the wave
running down the pipe, and huge diffuser angles dumping into a huge mid section will loose more of this energy than will create a bigger depression around BDC,or a bigger
plugging pulse heading toward EC from a very steep rear cone..
I have found the best compromise is at around 135 dia.
The very over square engine will theoretically rev harder, but you will by default a have a very heavy piston, plus needing big timings to create the STA necessary for power over 10,000
means any perceived advantage is lost in reality.


Many combinations will "work " just as well as a myriad of others, when you are offsetting the negative effect of one element by overriding it with the positive effect of another.
That isnt clever, its just using knowledge to mitigate the necessary down side of some one else's arbitrary decision, that was wrong.
Simply put the best way forward, is to limit the down sides,and implement as many truly clever elements as you can, to synergistically work together.
For example , the proven need for huge case vol in a full house race rotary valve engine, isnt even close to being a positive element in a stocker reed valve engine with
seriously crap transfer ducts.
Quite the opposite will produce better power in that scenario.
The smaller case vol gets the flow going sooner and more effeciently when the duct geometry is compromised , but then of course peak power
cant be the object of the end game, with that upsetting mechanical limitation.
Its been proven a hundred times in Jetsjkis etc that have won world titles with ease, due to combining the best effects to limit the inherent issues preventing a better result.


Diffuser positioning is a very hard variable to pin down,but experience has shown that moving the steep part of the flare closer to the header
helps to pump up the power higher in the rev range.
Up to a point though.
Early versions of Aprilia pipes had the steep cone connected directly to the header.
But later ( more powerful ) versions had a short additional section that pushed the steep cone further out, but increased its angle.
This gave a deeper depression closer to BDC, even though it started later.
The other idea that works well also for many designs is the use of a shallow,short,end diffuser.
This increases the main diffuser angle again, and also increases the belly volume.

You have to be careful though with this clever stuff when dealing with crap transfer ducts.
Very effective and well timed diffuser action, can easily create so much depression around BDC, that the compromised transfers cant keep control
over the scavenging stream integrity.
Alot of the fresh charge disappears out the pipe, without clearing out the remnant exhaust residuals.
Fat pipes dont work on things like RDs - even if you could fit them in.


Old, cast Rotax cases,make better power than CNC billet replica ones as the rough cast surface sheds heat more effectively.
Even where both are watercooled.
On the dyno the CNC cases heat fade very quickly.

Very very little transfer flow is created due to case com, except in your lawnmower,its all to do with the diffuser depression around BDC.

And there is a Catch 22 happening with the piston.
Transfer flow needs to attach to the crown to cool it, but this heat transfer affects the volumetric efficiency badly.
Cant have one without the other, but the piston simply isnt able to shed heat fast enough, just thru the ring and skirt alone to the cylinder wall.

In a 125 engine at 50 Hp, raising the head exit temp from 50 to 60* looses a couple of Hp instantly.

The deto sensors are connected one wire to earth, the other to the guage.
A good direct connection to the guage and chassis earth is essential.
In the units I have tested with two wires I havnt seen any connection of the sensor body to either of the wires and polarity doesnt seem to matter - except where there is a shield
strap.P556


Flowing the wrong way between Transfer Open and BDC is not the result of a too-early returning exhaust pulse, but of insufficient blowdown time.area.

What I meant was the instant just before Transfer Closure. The stuffing pulse from the exhaust should not arrive at the cylinder just yet, but at rpms under the powerband it will, raising the pressure in the cylinder while the transfers are still open. So the fresh charge gets pushed back into the crankcase, leaving little of it in the cylinder. And on top of that, just after the transfers close, that stuffing pulse reverses sign and direction, and sucks what little charge is left in the cylinder, out...

Loss of heat should be avoided all right, but if you want power, it is more important to avoid detonation. The part of the exhaust duct where washed-through fresh charge temporarily resides, should be kept cool to avoid heating up that charge. And it is much simpler watercooling an exhaust duct that is part of the cylinder, than cooling a duct that is part of the pipe.

[speedpro]

Another question,

What type of muffler is best?

Top one. Not even worth thinking about others.

I make mine from .8mm MS sheet for body of can, rolled perforated sheet for inside tube, and prefer machined alloy for end caps but have made them from .8mm MS sheet. Use standard muffler packing stuff from bike shop and pack it in. End weight is not much.

[wobbly]

Use SilentSport packing - lasts forever and will not blow out.

[G Jones]

Use SilentSport packing - lasts forever and will not blow out.First post here - I've been lurking for a while now :) - anyone tried Acousta-fil ? - I've been using it myself for a couple of years for our TZ350...
Supplied in "Mat" Form - I use 300mm wide - ideal for packing our silencers...
http://www.maplesigns.co.uk/partslist/images/photos/acoustafilafter.jpg

[F5 Dave]

S'funny I've just gone & bought some Daytona packing as I've had best luck with it. I still have a bunch of silent sport but it doesn't seem to work as well when I've used it, You(Wob) had mentioned you'd done a lot of muffler testing for Kart track. Did you use this material?

Any thoughts on the ring seal issue on previous page/page before?

[koba]

Just stick to what works...the top one.

High frequency vibration and normal loss of packing material will soon enough give you one of the others and you'll find out quickly how bad they are.....


Top one. Not even worth thinking about others.

I make mine from .8mm MS sheet for body of can, rolled perforated sheet for inside tube, and prefer machined alloy for end caps but have made them from .8mm MS sheet. Use standard muffler packing stuff from bike shop and pack it in. End weight is not much.


Use SilentSport packing - lasts forever and will not blow out.

Thanks for the advice.

Top one it is.

I may even get my hands on some perforated sheet to roll into a pipe, sure beats an hour in front of the drill press!

[husaberg]

Top one. Not even worth thinking about others.

I make mine from .8mm MS sheet for body of can, rolled perforated sheet for inside tube, and prefer machined alloy for end caps but have made them from .8mm MS sheet. Use standard muffler packing stuff from bike shop and pack it in. End weight is not much.

Isn't alloy meant to be quieter? supposed better absorbion less ringing with a thicker material and less resonance. I always use Aluminum tubing from Mico's made for irrigation tubing cheap as chips..........tigg'ed some sheet alloy once what a mongrel hours of filing and sanding/polishing.

My sons first CRF50 had a end cap made out of a centerbearing housing of a starter motor (M80?)looked beautiful esp with a bronze accent (re bush)in the middle.

[koba]

With the last pipe I put on the bike (Rg400, Lower Left; I think) It was a bit of an odd fit so, considering it was a far from scientific build I took the stinger from the center of the pipe, in the parallel wall section.
I'd seen this before on the KV100 that Dave had on loan, I think from Jimmy Steadman.

Anyway, I have no idea if it hindered performance or not but one thing I can say is the pipe was very quiet.
At one event the muffler can came loose and parted company with the bike, it got louder but was still quieter than most bikes on the track!
I've part made a new pipe and I tested it with no stinger (Just the end of the baffle cone...)
3 Neighbours poking heads out the window within 2 seconds of it running was a bit of a clue that it was on the loud side.

This got me thinking about the muffler and taking it from the centre again.
I know I can make it come from the end and still be quiet enough, with a good muffler, but there are other issues with that, making it is harder. It's likely to attach to the subframe which I will be changing shortly (part built new one) and it puts more weight (only a bit) further back which is in the wrong direction on this bike.
This is all a bit 'compromisey' but that's something I'm learning to live with when making bikes from available parts.

For shits and giggles I tried comparing the noise from the rear to the noise from the side.
I made a hole in the side of the pipe and temporarily blanked off the end of the baffle cone.
A Quick run on the street gave me a quick (subjective) idea of the difference in noise between the two (see pictures for results).

I'll likely never know what/if there is a power difference between the normal way and what I've done but the way I've made it means I may actually be able to test it at some point. It will be interesting if I do.

The noise issue is really not a great deal but I'm getting obsessive about band-aiding the poor weigh distribution of the bike so this really appeals.

I've also attached a pic of this part way through construction, please excuse the bird-poo.

[Yow Ling]

Nothing to do with buckets , everything to do with racing and innovating

Way better use of your time than OCC


http://www.youtube.com/watch?v=GFCBOwD-BwI

[wobbly]

Once you have ground off the Gannet shit try shoving the stinger up inside the end of the baffle, up to the parallel section is best, 1/2 way along is not.

[Yow Ling]

With the last pipe I put on the bike (Rg400, Lower Left; I think) It was a bit of an odd fit so, considering it was a far from scientific build I took the stinger from the center of the pipe, in the parallel wall section.
I'd seen this before on the KV100 that Dave had on loan, I think from Jimmy Steadman.

Anyway, I have no idea if it hindered performance or not but one thing I can say is the pipe was very quiet.
At one event the muffler can came loose and parted company with the bike, it got louder but was still quieter than most bikes on the track!
I've part made a new pipe and I tested it with no stinger (Just the end of the baffle cone...)
3 Neighbours poking heads out the window within 2 seconds of it running was a bit of a clue that it was on the loud side.

This got me thinking about the muffler and taking it from the centre again.
I know I can make it come from the end and still be quiet enough, with a good muffler, but there are other issues with that, making it is harder. It's likely to attach to the subframe which I will be changing shortly (part built new one) and it puts more weight (only a bit) further back which is in the wrong direction on this bike.
This is all a bit 'compromisey' but that's something I'm learning to live with when making bikes from available parts.

For shits and giggles I tried comparing the noise from the rear to the noise from the side.
I made a hole in the side of the pipe and temporarily blanked off the end of the baffle cone.
A Quick run on the street gave me a quick (subjective) idea of the difference in noise between the two (see pictures).

I'll likely never know what/if there is a power difference between the normal way and what I've done but the way I've made it means I may actually be able to test it at some point. It will be interesting if I do.

The noise issue is really not a great deal but I'm getting obsessive about band-aiding the poor weigh distribution of the bike so this really appeals.

I've also attached a pic of this part way through construction, please excuse the bird-poo.

Awesome pictures, is the braille on your filing system wearing down a bit?

[koba]

Once you have ground off the Gannet shit try shoving the stinger up inside the end of the baffle, up to the parallel section is best, 1/2 way along is not.

You are telling me to shove it?!

Cool, I'll give that a go.

It really is quite ugly on the outside, but it's what's on the inside that counts, yeah?
Grinding on the inside was meticulous, it's pity the design is less than perfect after all the effort. Still I know that when I started and just want to get something, anything, better than what I've got now.
Construction bill is up to around 45 hours so far, but I expected that due to the learning curve involved.
Money side is whatever it costs me to fill the now empty CO2 bottle and about 15 bludging-shit-off-mates credits.

One thing I notice was how much 'having your hand in' counts, I've been able to weld well in the past but it took me half the welding on the pipe 'till I got the hang of it back enough to be able to get it so it had nice penetration with a tiny bead on the inside that needed little/no grinding.

I'm looking at getting an old TIG sorted; got to be better than the 'Gannet Gun'.

[koba]

Awesome pictures, is the braille on your filing system wearing down a bit?

Filing system?

What is that?

[Kickaha]

everything to do with racing and innovating

Pretty cool, one of the guys off the UK sidecar forum I use is in Team Page so I've been following it

[speedpro]

Once you have ground off the Gannet shit try shoving the stinger up inside the end of the baffle, up to the parallel section is best, 1/2 way along is not.

What he said, as usual. I had a bucket years ago and length of pipe was a problem. I slid the stinger up inside to the end of the centre section and the start of the baffle cone. I put three thin supports in to stop it snapping off. The bike ran fine, it cut the noise down, and it fitted. I have not however done any dyno testing with this type of setup.

[F5 Dave]

So what if you did a side entry with a venturi nozzle?

[cookie1965]

Once you have ground off the Gannet shit try shoving the stinger up inside the end of the baffle, up to the parallel section is best, 1/2 way along is not.

Interesting, when I built my last set of pipes I stuck the stingers back down the cone because I'd read that it would cut down the noise and we run at a track with very restrictive noise rules (88dB). I finished up another set of pipes yesterday, welding in the stingers the same way, not really paying a lot of attention to how far in they went but more to how far they stuck out to keep the silencers from extending past the rear tire. My last pipes were quiet enough and made decent power (enough to run with the leaders anyways). When you say "1/2 way along is not" are you suggesting they'd make more power if they went in that far or that they'd be quieter?

[F5 Dave]

the ye olde experiments of Jennings suggested the stingers should be fully in or fully out, but half in & half out caused loss of performance. i can't explain why, but follows the mantra of test everything.

Wob is talking about the exit mid section as pictured as the 1/2 way along. Peter Steadman ran his like this on the KV I borrowed. I wondered if a venturi nozzle here might amend any stinger issue. Wonder if anyone has tried it?

[wobbly]

Yes, when the stinger entry is about 1/2 way along the rear cone ( when shoving it in from the exit end ) power is lost.
I have tested the full in stingers and found no loss in power - and to my surprise no change in temp or internal pressure.
Depending upon how the rear cone is terminated, then having the stinger exit from the mid section may be better or worse - dunno, but it wont be any quieter, as you
are drawing off from the same low pressure wave intensity area..

[2T Institute]

I'm looking at getting an old TIG sorted; got to be better than the 'Gannet Gun'.



Put the MIG torch down
Step away from the welder
keep your hands where I can see them


Reminds me of the first pipe I made except yours fitted better:laugh:

[wobbly]

The venturi nozzle is there to do one thing - the stinger is a resonant length tube and strong pressure gradients leap up and down it off atma.
When a strong negative sign wave launches down the stinger it can, and does, destroy some of the positive pressure wave that ultimately stuffs the cylinder
with the A/F sitting in the Ex duct, as the piston approaches Ex closure.
Adding a tapering cone after the true pressure bleed venturi helps to prevent this bad wave affliction from affecting the "in pipe "action.
Was invented by Helmut Fath - my hero - for the Honda factory team that ran Freddy in 250/500 the same year, it had one stinger 450 long, and one 150 long.
The new nozzle invention, took away the length effect of these disparate stingers, making tuning each much easier - and closer .
Thus using a nozzle in the belly is not going to have enough effect on this low intensity zone to make much difference.
BUT, being a 2 stroke it will probably work superbly, just to piss me off.

[husaberg]

The venturi nozzle is there to do one thing - the stinger is a resonant length tube and strong pressure gradients leap up and down it off atma.
When a strong negative sign wave launches down the stinger it can, and does, destroy some of the positive pressure wave that ultimately stuffs the cylinder
with the A/F sitting in the Ex duct, as the piston approaches Ex closure.
Adding a tapering cone after the true pressure bleed venturi helps to prevent this bad wave affliction from affecting the "in pipe "action.
Was invented by Helmut Fath - my hero - for the Honda factory team that ran Freddy in 250/500 the same year, it had one stinger 450 long, and one 150 long.
The new nozzle invention, took away the length effect of these disparate stingers, making tuning each much easier - and closer .
Thus using a nozzle in the belly is not going to have enough effect on this low intensity zone to make much difference.
BUT, being a 2 stroke it will probably work superbly, just to piss me off.

While we are on Pipes Wob
the brackets for the chamber i always ran were a folded section on the belly (contoured and welded either side of the belly section) as a mount secured with springs as per MX bike with a flush stub at the front. With the (tight fitting) slip on stinger again secured with springs at the rear with more very small folded brackets. What is the best way to make the brackets on the pipe and stinger to avoid cracking?
This is the closest i can find to a decent picture of it including the irrigation tubing silencer.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=276374&d=1358234601
Nothing to do with the post but seen it and loved it.
Stealth cafe racer (i guess 350LC motor?)
<img src="http://3.bp.blogspot.com/_VDCGGBYmNCk/TQupqqQfZ-I/AAAAAAAARg8/--1px3G4pF8/s1600/rd400.jpg" width="500px"/>

[koba]

I've built my first pipe so I can insert a venturi, restrictor or blanking plate in either the end or the side of the pipe.
I hadn't really considered the pulse effects much, I was more focused on tuning the pressure retained in the pipe.
I think I may have a bit of a play with back vs side and see if it makes any difference.
Annoyingly my testing is going to have to be somewhat subjective.

It will be ages away but I'll post my impressions when I've tried it. (not really results due to subjective nature of testing)

EDIT: I may have to increase the diameter that this sits in I meant it to be 23mm but the pipe I found was smaller. Maybe should have gone bigger again to give me maximum options for size of the verturi.

[koba]

Nothing to do with the post but seen it and loved it.
Stealth cafe racer (i guess 350LC motor?)

I don't really see the stealth in that?

[bucketracer]

276380276381276382

Hi TeeZee I know you have been looking at cutting the side of your pistons next to the transfer ports.

These are Mercury outboard racing pistons, so it looks like the idea is a good one and it can be done OK.

[Frits Overmars]

I may have to increase the diameter that this sits in I meant it to be 23mm but the pipe I found was smaller. Sounds like "I didn't mean to start smoking, but I found a packet of sigarettes" , Kuba :msn-wink:.

[cookie1965]

Yes, when the stinger entry is about 1/2 way along the rear cone ( when shoving it in from the exit end ) power is lost.
I have tested the full in stingers and found no loss in power - and to my surprise no change in temp or internal pressure.
Depending upon how the rear cone is terminated, then having the stinger exit from the mid section may be better or worse - dunno, but it wont be any quieter, as you
are drawing off from the same low pressure wave intensity area..

Thanks Wobbly, I measured mine last night and the stinger is about 70% of the way along to the junction with the parallel section. My last pipes would have been more like 60% of the way. Something to play with on the dyno I guess, to find out how much difference it makes.

http://i48.photobucket.com/albums/f224/cookie1965/newpipes_zps047e0b27.jpg

[wobbly]

This rear mount will not crack - even in stainless.
Forgive the poo.

[richban]

Hi Guys

Hey I was wanting to start working with an EGT setup and have it fitted and running all the time. Question. I don't want to create any kind of reversion in the header. How far into the pipe will I have to have the probe protruding? Another thought was when I make my stainless header could I strap the probe to the outside of the pipe and lag over it. Or even just tig it on. What ever I do I will be starting with a dyno session to record temps at the correct AFR. What do you reckon? I would prefer to not have anything in the header at all but I am at the stage that I really need to tune with EGT.

Ta.

[Haufen]

Hi Guys

Hey I was wanting to start working with an EGT setup and have it fitted and running all the time. Question. I don't want to create any kind of reversion in the header. How far into the pipe will I have to have the probe protruding? Another thought was when I make my stainless header could I strap the probe to the outside of the pipe and lag over it. Or even just tig it on. What ever I do I will be starting with a dyno session to record temps at the correct AFR. What do you reckon? I would prefer to not have anything in the header at all but I am at the stage that I really need to tune with EGT.

Ta.

Mine's in the middle of the header, did not cost any hp at all. For fast and accurate readings that's the place the probe needs to be, I suppose.

[F5 Dave]

My limited experience with EGT probe was on my 50 which you will appreciate has a very small header. Just before a GP I got a nut welded on & fitted the probe at about 6" from piston & poking in to the centre of the header.

On the dyno & the temp kept rising with every gear change. power was suppressed several hp. Eek No time left, blocked off the hole, power returned as per normal, phew. Put on a shelf & pack up to leave.

I think the probe tube was overheating the returning charge. I should have tried it pulled back flush & just the thin bit of the probe in the stream. Its on the 'I'll get around to it' track.

[F5 Dave]

I looked at my KT ring last night. It too shows some polished areas & dull areas. Clearly not sealing well.

[Frits Overmars]

On the dyno & the temp kept rising with every gear change.That's a classic sign that the probe is too slow for the application: too much thermal mass and too much isolation. If you really want to see the EGT go up and down with the engine power, you will need an open junction probe. Not as long-lasting as a shielded one, but much more informative.

[F5 Dave]

Yes but it was also getting waaay hot & power was suppressed so it wasn't in the ideal position I would think. it was quite a thin end (exposed tip) probe (last 8mm).

[richban]

My limited experience with EGT probe was on my 50 which you will appreciate has a very small header. Just before a GP I got a nut welded on & fitted the probe at about 6" from piston & poking in to the centre of the header.

On the dyno & the temp kept rising with every gear change. power was suppressed several hp. Eek No time left, blocked off the hole, power returned as per normal, phew. Put on a shelf & pack up to leave.

I think the probe tube was overheating the returning charge. I should have tried it pulled back flush & just the thin bit of the probe in the stream. Its on the 'I'll get around to it' track.

Good to know. Yeah well being a dirty 4 stroke the first 200mm of the header has an ID of only 25mm. So not much room to play with really. Will just have to try it and see what happens.

[F5 Dave]

I looked at my KT ring last night. It too shows some polished areas & dull areas. Clearly not sealing well.

Well I've got another hone of the cyl & it looks good & round & gapped a 0.2 ring so its a nice fit so it all has a chance of sealing now.

But the question is running bean oil (Castrol R) as I am going to try to get a good ring seal;

I hear anecdotal stories of it not blending with Av & possibly 98 (contains Ethanol now). I can't use Acetone to blend anymore I don't think. Is this right re Av? I might have to run 95 & make sure comm isn't that high.

[wobbly]

AvGas will separate out, and in some cases wont mix at all with many oils that contain castor.
Acetone fixes this, havnt seen any issues with pump gas.
In karts no mixing agents are allowed - but MNZ still allows this I believe.

[Grumph]

AvGas will separate out, and in some cases wont mix at all with many oils that contain castor.
Acetone fixes this, havnt seen any issues with pump gas.
In karts no mixing agents are allowed - but MNZ still allows this I believe.

Correct - but be aware that the Ethanol blends are not legal in buckets "alcohol based fuel or fuel additives are prohibited"
Not a prob in the SI as we don't yet get E10 but you Norfeners should be aware.

[NOID]

this should read


Correct - but be aware that the Ethanol blends are legal in buckets "alcohol based drinks are required".

:laugh::laugh::laugh::laugh::laugh::laugh::laugh:: laugh:

[F5 Dave]

Great. Thanks Wob, Thanks Greg &, erm, thanks I think Noid:confused:.

[kel]

Correct - but be aware that the Ethanol blends are not legal in buckets "alcohol based fuel or fuel additives are prohibited"
Not a prob in the SI as we don't yet get E10 but you Norfeners should be aware.

Classic, the local fuel stations pump fuel is no longer legal for buckets. Think I may have to raise a protest against every 4 stroke that beats me :lol:

[richban]

Classic, the local fuel stations pump fuel is no longer legal for buckets. Think I may have to raise a protest against every 4 stroke that beats me :lol:

C16 is legal though, init? Kidding kidding. First you will have to get back on a bike if you want to get beaten by the 4 strokes. I like that your attitude.

[Grumph]

Classic, the local fuel stations pump fuel is no longer legal for buckets. Think I may have to raise a protest against every 4 stroke that beats me :lol:

Well good luck with that....You lot should be aware of Choppa's thread in the racing section Fuel samples are away being tested now.
The "main" classes have to meet fuel specs in the rulebook and funnily enough don't actually have the line I quoted...24-2-5.

The remedy if you think you need one is to put up a remit specifying that any fuel commercially available for road use is acceptable for miniature road racing....sidesteps the fuel specifications and keeps the rule current.

There is AFAIK no advantage running E10 - the calorific value is I think a bit lower than straight gas and the anti knock pretty much the same. E85 on the other hand, I can't wait till it's readily available and legal....

[husaberg]

Correct - but be aware that the Ethanol blends are not legal in buckets "alcohol based fuel or fuel additives are prohibited"
Not a prob in the SI as we don't yet get E10 but you Norfeners should be aware.


Great. Thanks Wob, Thanks Greg &, erm, thanks I think Noid:confused:.


Classic, the local fuel stations pump fuel is no longer legal for buckets. Think I may have to raise a protest against every 4 stroke that beats me :lol:

Greg is just being ironic
The pump gas must conform to FIM unleaded which is a bit of a F-up on the MNZ's behalf as it should have been unleaded Super
as per the rest. But regardless the FIM fuel spec allows for a aromatic content plus Buckets are "self policing"

The alcohol based fuel or additives means just that alcohol based.
E10 is still "based" on Petrol. it is a pump gas so the additives do not refer to how it comes from the pump but what is done to it after..........imo.
Intersting if Gull E10
80% is Gasolene
10% is ethanol
3% is Benzene
4% tolulene
Whats the rest?????????????

I am sure some will can remember the fuss over Aaron slight and Meklau(i think it was ) loosing points for running illegal fuel in about 93-94 in WSB
The authorities only tested 2 bikes, they both failed the fuel inspection.
Honda protested and had the points reinstated because ELF admitted everyone was running the same fuel ELF had supplied (by mistake),
Ducati (even though they had all run the same fuel as well) protested and the points were again taken of Slight and co and it was a shit fight all the season. Back and forth.The laywers got rich as per usual.
I think in the end Slight lost the points and a fair chance at the championship.

[Grumph]

Greg is not being ironic...greg is being literal.

Convince me that Ethanol in E10 is not (a) Alcohol....and (b) an additive to the base petrol...

Given that this is NZ and we only pay lip service to the FIM there's no requirement for us to try and match the FIM unleaded fuel composition - and a lot of very good reasons why our fuel regs should be based on what is actually on sale here...

A couple of years back the word was that E85 was going to replace avgas at least at the pumps at Ruapuna. I was told that most of the car formulae were going to run on it and that avgas as a race fuel would be phased out in NZ....hasn't happened due I believe to shortage of supply but it still could as the decision was based on what seem sound principles.

[husaberg]

Greg is not being ironic...greg is being literal.

Convince me that Ethanol in E10 is not (a) Alcohol....and (b) an additive to the base petrol...

Given that this is NZ and we only pay lip service to the FIM there's no requirement for us to try and match the FIM unleaded fuel composition - and a lot of very good reasons why our fuel regs should be based on what is actually on sale here...

A couple of years back the word was that E85 was going to replace avgas at least at the pumps at Ruapuna. I was told that most of the car formulae were going to run on it and that avgas as a race fuel would be phased out in NZ....hasn't happened due I believe to shortage of supply but it still could as the decision was based on what seem sound principles.

http://www.gull.co.nz/fuel-products/
http://www.gull.co.nz/assets/Uploads/Gull-Force-10.pdf
its not an additive, because that is how it is sold from the pump.
i agree with the relevance in regards to F4 and F5 but the fuel regs missed them. big surprise which is also ironic.
http://www.mnz.co.nz/regulations/rules/general-rules
F4 and F5 must conform to 10.17.1 which is the AVgas or FIM unleaded.
As Ethanol is not listed ad being a component of the FIM unleaded Fuel even though the rest of the ingredients are fine.

So Greg you Are right the FIM fuel Fuel that covers F4 and F5 plus the other classes not listed under 10-17.2 and 10.17.3 .................

[Ocean1]

Given that this is NZ and we only pay lip service to the FIM there's no requirement for us to try and match the FIM unleaded fuel composition - and a lot of very good reasons why our fuel regs should be based on what is actually on sale here...

I blame Helen Clarke. Was her that drove the compulsary biofuels content goals for our domestic supply. Trouble is she didn't change the rules to allow biofuels to be profitably made here, so the mandatory biofuel content for NZ is mostly imported from Au. :facepalm: Who import the raw materials from NZ. :brick:

[F5 Dave]

....The remedy if you think you need one is to put up a remit specifying that any fuel commercially available for road use is acceptable for miniature road racing..... and Av gas, as many are using it. No additives allowed. . .except 2 stroke oil:rolleyes:.

[wobbly]

The way I read the rules, would in fact allow VP - C12 to be used in Post Classic and Superlight for example as all its specs are within the limits of "AvGas ".
If you wanted the last ounce of performance and were happy to pay 4 times the rate at the local airport.

[jasonu]

The remedy if you think you need one is to put up a remit specifying that any fuel commercially available for road use is acceptable for miniature road racing....sidesteps the fuel specifications and keeps the rule current.

....

Or just say fuck 'em and run the pump gas of your choice.

That is (the inverse) what I did in the good ol' 90's when they started selling petrol imported from (I think) Singapore. Some may remember it caused 4 out of 5 Cortinas to catch fire because it ate old fuel lines. For one reason or another my bike ran like shit on it so I started using not Bucket legal Av gas instead. The bike didn't seam to run any better than before the petrol change and I let everyone know what I was doing.
Don't forget, Buckets is self policeing so if someone had an issue with you using the 'illegal' pump gas you should be able to settle it over a brew or two.:niceone:

[F5 Dave]

My 50 ran great on the old 96 leaded, but dreadful on the new gas as described. Changed to Av & restored most of the power, but it wasn't as good as what I was using before at least for my engine. I tried pissing around with 1/2doz different head shapes & volumes, tuning for each but had no real improvement. Av is stable though & best of a bad lot.

[Grumph]

Or just say fuck 'em and run the pump gas of your choice.

That is (the inverse) what I did in the good ol' 90's when they started selling petrol imported from (I think) Singapore. Some may remember it caused 4 out of 5 Cortinas to catch fire because it ate old fuel lines. For one reason or another my bike ran like shit on it so I started using not Bucket legal Av gas instead. The bike didn't seam to run any better than before the petrol change and I let everyone know what I was doing.
Don't forget, Buckets is self policeing so if someone had an issue with you using the 'illegal' pump gas you should be able to settle it over a brew or two.:niceone:

Fair enough - and i don't disagree....But i'd point out that the bucket GP is usually held at a National round or the equivalent so there is likely to be fuel testing given that it's become a pressing question...Also, if it's an MNZ permited meeting, fuel testing can be done at random....Just pointing out the obvious....

[jasonu]

Fair enough - and i don't disagree....But i'd point out that the bucket GP is usually held at a National round or the equivalent so there is likely to be fuel testing given that it's become a pressing question...Also, if it's an MNZ permited meeting, fuel testing can be done at random....Just pointing out the obvious....

Yeah fair enough. Better safe than sorry maybe.

[TZ350]

Wobbly put me onto this TPS, I think its from a Aprilia RS250

258168 258169

Posted because someone asked about them.

276488

This is a car TPS from a fuel injection throttle body. It has a spring return and looks like it could easily be fitted with a bracket for a throttle cable.

276489 the Aprilia TPS is in the top middle of the picture.

The unit I currently use with the Ignitec is from an Aprilia and I think 5k Ohm but the cable box is very bulky.

If I was putting together another TPS system I would look at ones from cars but you have to be careful as they vary in their resistance, I have seen 5k to 25k units so when you go to Pick a Part take a multi meter with you. There will be three pins, and for an Ignitec you want 5k between two pins, they are usually the outside pins with the central pin as the variable resistance.

276487

This is one of the ND W31ES-G plugs, unfortunately not the resistor type, but if I ever find a use for them I have plenty. I was thinking of trying to cut the earth electrode into different shapes on the tip and try out the Taper Tip, V Notch and Cut Back to the center of the central electrode ideas that you see on some other plugs.

[TZ350]

... weld a threaded alloy bung onto the head ( you could even machine a couple of fins into it ) to enable use of 3/4 reach race plugs ...

276496

Thanks for the idea Wob.

[wobbly]

The Ignitech doesnt give a shit what TPS resistance is used.
It supplies 5V and the variable pot wiper reads the value of the resistance from 0 to 5000 mV on the servo screen..
The middle of a 5K pot will give 2500 mV, just as a 25K pot will.

[Bert]

Sitting around tonight having beers and we were wandering what the final result to the poll?

Griffiths boy said they had 3l of fuel on board the sidecar....

[TZ350]

The middle of a 5K pot will give 2500 mV, just as a 25K pot will.

Almost true in theory ... but its not as simple as a series resistance voltage divider problem.

276533

Because you have overlooked the question of how much current is needed to support the variable voltage seen at the TPS's wiper, and the current passing through a 25k pot is 5 times less than through a 5k one.

To realy know, we would need more information about the current drawn by the Ignitecs input, as it can't be nothing, (Gods law) physics says it must be something and the higher the TPS's resistance is, any current drawn by the Ignitec's input however small will have a greater distorting effect on the voltage picture at the wiper of a 25k TPS than a 5k one.

Checkout Series Parallel Circuit theory.

The TPS is two resistances in series R1 and R2 and the Ignitecs input is a resistance R3 in parallel with R2, so its a series/parallel problem and the voltage measured at point 2 with a 25k pot in the middle of its stroke will not be the same as a 5k one, in fact it could be much less.

276532

I remember having trouble, maybe it was me maybe it was the pot maybe the Ignitec does not like 25k and flashed up an error message.

I could not find any guidelines from Ignitec and was having to figure it out for myself.

In the end I found that the 5k TPS worked OK on my setup and I can recommend it.

Next time I get a chance I will try the 25k one again and pay more attention to why it did not seem to work for me.

[TZ350]

Sitting around tonight having beers and we were wandering what the final result to the poll? Griffiths boy said they had 3l of fuel on board the sidecar....

276530

Taking the average of both sides, it was evenly split, 50% thought the Beast was heavier than the sidecar which is a pretty big vote of confidence in the Griffiths brothers engineering. I only feel slightly miffed.

276586

[Henk]

276530

Taking the average of both sides, it was evenly split, 50% thought the Beast was heavier than the sidecar which was a pretty big vote of confidence in the Griffiths brothers engineering. I only feel slightly miffed.

Our sidecar was 10kg heavier than the Griffiths chair, swingers about the same, riders we made our 10kg back with interest :)

[Sketchy_Racer]

Hey guys,

I noticed earlier you have knock sensors hooked up to you bikes, I was wondering if they are also suitable for 4T engines and where I may source one?

Cheers,

-Glen

[husaberg]

Its a bit of a pick and mix so I highlighted the dollar amounts so you can see where the prices come from.


$63.50 NZD for a counter from RS components

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/180904010253?pt=Race_Car_Parts&hash=item2a1eb8220d&vxp=mtr

Knock Gauge $49.99 plus option 1 switch to ground for the IgniTec ignition retard add $20 plus option 3 pulsed 0v to 5V for the counter so add another $20

$90 USD for the Knock Gauge part off Ebay.

Less than $200 NZD should cover it.
263051263052

Good luck with the Deto sensing TZ. I like the little warning instrument!
My sensor has a PN 0-261-231-001, what's yours?
According to this http://www.phormula.co.uk/KnockCalculator.aspx , deto freq for 56mm bore should be 10.2kHz.
According to Bosch datasheets for PN -047 (http://www.bosch-motorsport.de/en-US/literature/en-US/Knock_Sensor_KS-R_Datasheet_51_en_2779074187.pdf) & -120 (http://www.bosch-motorsport.de/pdf/sensors/knock/KS-P.pdf), sensors are able to catch frequencies from 1 to 20 kHz.
I assume all Bosch sensors can sense knock within this range (?)

edit: As for the pick-up voltage, I think it won't be more than +-10V. I had a voltage test yesterday with a data acquisition device in real time! I spinned the crank by hand and recorder the voltage waveform from the pick-up in the PC. As RPM increase, amplitude (and freq of course) of the pulses increase - by hand-spinning it didn't exceed 3~3.5 VAC. Sure it was a lot of fun to watch! :D

Its funny you say that. I have presactly the same Subi deto doofer & knockgauge. I connected it yesterday & went to the dyno. Rang up like a tree. I ended up ignoring it & feeding in smaller jets & advanced timing increased the power so I can't believe it was setup right.

My sensor is on the side of the cylinder. I wonder it it is just getting too much vibration? Not that it vibrates that bad. . . I turned the dial to try calibrate it & didn't get much change. maybe it is in a sensitive plane to operate the piezo.

I have just been putting on my knock gauge on the bucket and when I run her in the drive with the sensitivity set half way, reving the bucket up the gauge went off like a christmas tree and I am wondering what others have there gauges set to?
The gauge is from http://www.knockgauge.eu and the sensor is off a subaru car. It's mounted on a 100cc LC two stroke on a head stud straight onto the head with nothing inbetween if that is any help.


263028

Ok mine turned up today.

263027

And a couple of two wire sensors I picked up cheap from the local garage.


Forget the homemade bullshit, get one of these with the extra wire to ground.
When it sees deto it can ground an Ignitech input and retard the timing automatically.
You get flashing lights and engine protection all in one shot, and cheap as chips - made in Czech so it likes being connected to an Ignitech - same lingo..
Works perfectly - when you get it trimmed correctly it will tell you where to manually pull out timing, then it just operates as a failsafe.

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/110818862446?pt=Race_Car_Parts&hash=item19cd51a56e&vxp=mtr#ht_1582wt_1297

[crazy man]

Our sidecar was 10kg heavier than the Griffiths chair, swingers about the same, riders we made our 10kg back with interest :)so your saying l'm a fatty:gob:

[Henk]

so your saying l'm a fatty:gob:

In a word, yes. Don't you weigh more than your rig?

[Bert]

so your saying l'm a fatty:gob:


In a word, yes. Don't you weigh more than your rig?

That might be tooo close call :psst::bleh::bleh::bleh:
it could be the next poll (though it could be a close call between a few members of team GPR) :drinkup:

[Henk]

That might be tooo close call :psst::bleh::bleh::bleh:
it could be the next poll (though it could be a close call between a few members of team GPR) :drinkup:

Bert, I'll give you a clue, there is 2 kg in it, you decide which way.

[TZ350]

so your saying l'm a fatty:gob:In a word, yes. Don't you weigh more than your rig?

I weigh as much as the Beast, do I get a chocolate fish?? .... :laugh:

[TZ350]

... it could be the next poll ...

If you are going to run a new poll, I suggest you don't do it on your own thread as polls are real hard to get rid off, I needed the Mod's help to clean up the ESE thread after the Sidecar/Beast poll.

Next time a poll sounds like a good idea I am going to start a new thread just for it and when its run its course, I will let it float off into the distance and post the results here.

[TZ350]

Forget the homemade bullshit, get one of these with the extra wire to ground.

When it sees deto it can ground an Ignitech input and retard the timing automatically.
You get flashing lights and engine protection all in one shot, and cheap as chips - made in Czech so it likes being connected to an Ignitech - same lingo..

Works perfectly - when you get it trimmed correctly it will tell you where to manually pull out timing, then it just operates as a failsafe.

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/110818862446?pt=Race_Car_Parts&hash=item19cd51a56e&vxp=mtr#ht_1582wt_1297


263051263052



263028

Ok mine turned up today.

263027

And a couple of two wire sensors I picked up cheap from the local garage.

Knock Gauge.... $49.99 USD plus $20 for option 1 "As switch to ground;"


I found some steel head bolts and faced one off, then drilled and tapped it. And made a standoff that was carefully faced off as the knock sensor likes to be securely mounted on a very flat surface. The black goop (silicon glue) on the blue wire is there as a strain relief and hopefully it will stop the vibration breaking the wire where it is attached to the copper head fin.




269009

703TR002N-512D RS part number 183-5952 $63.50 ... 5-12V and less than 10mA so easily self powered and at 500Hz fast enough to count all deto events as seen by the Knock Gauge or similar, as 200Hz in a 2-Stroke equals 12,000 rpm.

269008


Knock Gauge and Det Counter ..... $49.99 USD plus $20 plus $20 for option 1 "As switch to ground;" and option 3 "As 0v + 5v output;" frequency output for the Det counter to count.




270747

I have just received another Knock Gauge, this one has two extra outputs. http://www.knockgauge.eu/content/blogcategory/22/41/

YouTube links showing the Knock Gauge in action.

The two green lights, the orange warning light then you see the red det light. http://youtu.be/aZkZR-JBr_E and http://youtu.be/vFoZyw_sHmA

Like last time, one that goes to ground for signaling the IgniTec to retard and a new one that pulses from 0V to +5V each time the Knock Gauge sees a detonation event.

The Curtis event counter can then count the detonations. Now I have the makings of a det sensor, ignition retarder and det counter.

I have yet to try the Knock Gauge come Det Counter, but it looks promising.

[husaberg]

Seen these today.
http://images.trademe.co.nz/photoserver/41/168711441_full.jpg

antaper Sticks & sanding Belts
This Auction is for one Sandtaper stick with one belt and an additional 5 replacement sanding belts Total $ 23
On completion of Auction choose which grit you want from
120 240 320 400 and 600
What many are doing is just buying one stick and a range of 5x5 papers
But they end up coming back for the set as they work so well
Fast, easy, economical way to reach detailed, hard-to-reach areas. Plastic stick, tapered at the end, holds a replaceable 1/4" wide sanding belt. The aluminum oxide belt is held in place by a patented spring- loaded mechanism that allows the belt to be rotated 360. Rotating the belt exposes a new sanding surface and allows the entire belt to be used.
I find these a valuable asset enabling me to get into those hard to sand areas on my carving or texture on my woodturning
Replacement Belts pack of 5 in either 120 240 320 400 or 600 grits $14
Additional Santaper sticks $8 any color (http://www.trademe.co.nz/crafts/woodcraft/auction-553354009.htm)

[Sketchy_Racer]

Thanks for the info guys, sorry I was too lazy to search for it, busy making superchargers an all :laugh:

Once I get the supercharger performing I will invest in one of these as I'm sure you can imagine boost will encourage det.

Actually, a question for who may be in the know - Fuel, would AV gas be better fuel to run in an forced induction motor? Detonation is going to be the killer of my little chinese motor so I would have thought that Av gas will help this?

Cheers,

Sketchy

[F5 Dave]

I must imagine Av would be the safest when lots of boost is required. You can have a guernsey at my knock gauge. I have to get it reattached when the bike is watercooled, perhaps you can try it out till then.

[bucketracer]

Totally Legal Good Part.

276629

TeeZee no need to make one, here is a rear pulley sheave with curved slots like you were talking about.

276630

NCY describes some of their parts as "Race".

But there are none of the naughty race words on the manufacturers web page for this sheave, or the sheave itself that would make it an illegal race part.

In spite of what the re sellers might love to call it, it looks like it was manufactured by NCY to be just a better part for a gy6 street bike/scooter.

276628

http://www.ncy-motor.com.tw/product3_view.php?lang=en&car=115&car2=&car3=&search=&page=1&pid=449

A Totally Legal Good Part.

[Frits Overmars]

TeeZee no need to make one, here is a rear pulley sheave with curved slots like you were talking about.

276630Now if you could find a sheave with axial slots, that would be someting....

[ac3_snow]

Hey TZ,

What do you reckon the beast is capable of in a straight line? Maybe F5 Dave would stand a chance on his 50.

http://www.flyingmile.co.nz/
Held on Goudies road between Taupo and Rotorua.
It does mention invite only, but then goes on to list the cost of entering, so don't know what your actually chances would be of entering.

I believe the current record stands at;




50cc
17/3/84
P.D. Sales (Im guessing that is Pete sales)
80.212 MPH
Suzuki
Waihopai Vally, Blenheim.


125cc
16/9/95
RH Bleach
119.06 MPH
Honda
Christchurch

[TZ350]

Was the Honda a fully faired RS125?

[Grumph]

Was the Honda a fully faired RS125?

Yes - and wire wheels too...

The morning was foggy and Russ was riding quietly up the road guided by the verges until he could see the group standing by the traps....then he'd nail it....

if it had been clear weather the record set then would be a lot quicker as that was a pretty good RS.
i believe there has been a slightly quicker record set since. Don't think it's in the book as it may have been one way.
From the look of the info on line the organisers are not doing NZ records as they must be two way and the venue plus clocks certified....

The rider who impressed me at those record attempts was Jane Parrett (now Reynolds) who comfortably exceeded the NZ 250 record - 140mph plus - but lost it in the measuring as the TZ owner didn't know the exact stroke and the measurer got it wrong....

[SS90]

Yes - and wire wheels too...

Tif it had been clear weather the record set then would be a lot quicker as that was a pretty good RS.
i believe there has been a slightly quicker record set since. Don't think it's in the book as ...

Im pretty sure it still stands, On more than one occasion Russel said he hoped the record would be broken by a small increment to encourage others to hold the honour )opposed to "smashing"'it and becoming a play ground of financial "elites"

[Kickaha]

Fiddler went to the flying mile or whatever it was near Invergiggle it was with the intention of breaking it, then it rained and got windy and was called off :facepalm: l

[SS90]

Fiddler went to the flying mile or whatever it was near Invergiggle it was with the intention of breaking it, then it rained and got windy and was called off :facepalm: l

I totally forgot about that, like the Jane Parrot story, speed trials attempts the world over are littered with bad luck stories.

[TZ350]

276683

Anyway at the moment my interest is the CVT system. The front pulley is upside down because it sits on the table better that way.


HI all, I am looking for some GY6 125/150 4T CVT parts. I need the shafts that the front and rear CVT sheaves run on.

A would like to buy a ruined GY6 125/150 crank and good rear gearbox input shaft, as I just need the two shafts themselves.

Alternativly I would look at a GY6 125/150 bottom end or complete wrecked engine to get the parts I need.

276684

I have no idea what this is but its those two shafts for a GY6 125/150 that I am after.

Please PM me if you can help.

[koba]

Yes - and wire wheels too...

The morning was foggy and Russ was riding quietly up the road guided by the verges until he could see the group standing by the traps....then he'd nail it....

if it had been clear weather the record set then would be a lot quicker as that was a pretty good RS.
i believe there has been a slightly quicker record set since. Don't think it's in the book as it may have been one way.
From the look of the info on line the organisers are not doing NZ records as they must be two way and the venue plus clocks certified....

The rider who impressed me at those record attempts was Jane Parrett (now Reynolds) who comfortably exceeded the NZ 250 record - 140mph plus - but lost it in the measuring as the TZ owner didn't know the exact stroke and the measurer got it wrong....


Fiddler went to the flying mile or whatever it was near Invergiggle it was with the intention of breaking it, then it rained and got windy and was called off :facepalm: l


Ivan Juggins currently holds the 125cc record, he set it on Murphy's line, just out of Featherston, a few years ago.
It took MNZ ages to officially publish it.
He set it on an average post 95 RS125.

It was on their old website but I can't find it on the new one.
Ages ago (before that record attempt) I e-mailed them and got all the info, after nagging them for it.

The event at Murphy's line was the only one I know of that's met all the criteria for official records to be set.
The road met the requirements for elevation but was too bumpy for the faster bikes, Malcolm Breadmore was seen with his Nitrous Oxide fed Hyabusa a quite far off the ground and doing 300 and something Kph.

[husaberg]

Imagine for a minute how dangerous this could potentially be in the wrong hands.


I must admit i had never seen this before.
ADJUSTABLE MAIN JET FOR KEIHIN CARBURETOR

http://www.4hd.net/images/products_full/q80a2ef0db46.jpg

Eliminates (http://www.4hd.net/product_information.php?product_id=836) incorrect multiple jet changes when replacing exhaust pipes or air cleaners on all Keihin-equipped models (except CV type) from 1976 thru 1989. Full adjustability permits precise tuning for maximum performance with every combination of engine, pipes and air cleaner. This kit frees you from the limitation of the few fixed jet sizes available and the labor of drilling jets. Use new gaskets and seals when installing. The installation tool marks the float bowl for a proper fit.

Question for the Aprilia types.
I was looking at the RSA and RSW power valves.( below)
<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=276704&d=1358678743" width="590px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=276705&d=1358678743" width="540px"/>


Is the second blade just for the inner bade to slide in and out of and how does it move in and out i can't make it out from the parts fiche.
I always thought it was a eccentric or cam operated (Directly on the blade) So is 19 and 12 the levers to that operate the blade?

In comparison the road bike (Rotax powered RS125) seems much simpler (Below)
<img src="http://images.motorize.de/garagesale/apriliars-1318686349-11780.jpg" width="430px"/><img src="http://images.motorize.de/garagesale/apriliars-1268315165-671.jpg" width="410px"/><img src="http://v2.club2t.org/club2tpub/Bibl/art_powervalves/rave_valve.jpg" width="280px"/>

Was the method of operation to save space? Or two make the control easier on the twin? Or the obvious reason i have likely missed? (like quicker operation)

<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=276717&d=1358681199" width="380px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=276718&d=1358681603" width="360px"/>

[Frits Overmars]

The Rotax cylinder only has a single blade. The Aprilias have a two-stage powervalve system: first only the lower blade opens; then it takes the upper blade with it.
The drawing above left is from the RSA manual; the drawing above right is from the RSW manual. In typical Italian fashion the numbering of the parts differs between the two drawings.

RSW (right): When the shaft 7 turns, the lower blade 14 is lifted by the arm 2. When the lower blade hits the upper blade 13, both blades are lifted further together.

RSA (left): When the shaft 14 turns, the lower blade (not numbered) is lifted by the arm 15. When the lower blade hits the upper blade (also not numbered), both blades are lifted further together.

All other parts are to do with spring-loading the blades, converting the cable movement into turning of the shaft and fixing the cables to the cylinder.
In the 250 cc twins the shafts are coupled by push-pull rods which in turn are cable-operated. The 125 cc singles ared directly cable-operated. The picture shows the RSA's cables.

[wobbly]

The idea behind the two stage blade is that with a single PV, as it is retracted it pulls away from the piston.
At 1/2 sroke it is virtually useless due to excessive leakage.
With the two stage as the lower blade retracts, the upper blade is still close to the piston.
At 1/2 stroke the lower blade is sitting flush with the uppers bottom edge.
They then both retract up flush with the roof.
This gives a sealed blade when down at say 100* atdc, and it is still sealed against the piston at 1/2 stroke, say 90* atdc.
This is why the Aprilia PV still works effectively, such that the blades are not fully up at the 80* atdc point till around 12,000rpm.
Exactly the same system in the RZ400, and that PV isnt fully up till 10500, in an engine that peaks at 11500.
The Honda dropping gate or the Yamaha rotary spool valve overcome this by keeping the seal face close to the piston throughout the entire stroke.

[F5 Dave]

Hey TZ,

What do you reckon the beast is capable of in a straight line? Maybe F5 Dave would stand a chance on his 50.

I considered doing Murphys, until I realised that my bike is F5 legal, but speed classes will need to be std bore, ie just under 50cc.

[TZ350]

Hey TZ, What do you reckon the beast is capable of in a straight line?

Thanks for the heads up, it would be a fun thing to do.

I think the Beast as it is could clock 85-95 mph. I know 30hp bikes should go faster but the Beast has a lot of frontal area and I expect a high coefficient of drag to boot.

276797

Maybe if the Beasts engine was in a fully fared RS chassis like NedKellys RS/GP125 Bucket it could crack the Ton. But I can't see a 30hp engine in a RS chassis ever setting a higher speed record than a Honda RS125 race engine can, now if they had an F4 class.....

276795

The 30hp Beast plus rider is 60kg heaver than Rick and his RS/TF combo.

276798

Rick and his low 20's light weight bike have a similar power to weight ratio as the 30hp Beast.

There have been a few suggestions that loosing a couple of hp from the Beast would make it a more competitive bike, but I don't think the idea was well thought through.

Having seen both 30hp (Tokoroa) and 27hp (Taumranui) versions in action and listening to Tim's comments. No matter how smooth the Beasts new reduced power engine might be. I don't think the Beast will ever be able to cut it, with its new and unfavorable power to weight ratio, when pitted against the better handling RS125/TF and 4T's.

It become pretty obvious that the 27 and 30 hp options were both rideable in different ways and that reducing the Beasts power did not make it any faster ...... going fast seems to be more about the power to weight ratio.

Trimming the 30hp Beasts weight for a more competitive power to weight ratio looks like a much more rewarding way to go.

[wobbly]

Now you are onto it TeeZee.
Having 30 RWHp ( say 35 crank ) is only 10 Bar BMEP.
This is NOT pushing any 2T envelope at all, and once you get it sorted it will run sweet and stay that way, all day every day.
At this level it is easily possible to shape the powerband to suit any track configuration you want, ignore the tossers telling you it is "too much " power that is causing problems.

[F5 Dave]

Thanks for the heads up, it would be a fun thing to do.

I think the Beast as it is could clock 85-95 mph. I know 30hp bikes should go faster but the Beast has a lot of frontal area and I expect a high coefficient of drag to boot.
. . .
The unrestricted 125s in UK would just tickle 100mph & were doing about 25/26 at the rear. But they aren't big bikes.

[cotswold]

Now you are onto it TeeZee.
Having 30 RWHp ( say 35 crank ) is only 10 Bar BMEP.
This is NOT pushing any 2T envelope at all, and once you get it sorted it will run sweet and stay that way, all day every day.
At this level it is easily possible to shape the powerband to suit any track configuration you want, ignore the tossers telling you it is "too much " power that is causing problems.

I'm with you Wobbly, the beast is a work in progress and that 30hp motor was not hard to ride at Toke and sure it's had some issues but they are being addressed and once Tee Zee has worked through the problem they seem to stay fixed, ie no repeats once identified, thats called development, We would all be riding Bantams without it.
That motor in a lighter more nimble chassis will be a right up there.....

[ief]

Small engmod Q.

What would be an appropriate TUmax for say a fast road bike? (if that makes a difference, guess it does)

[fixer]

Interesting times ... have had my new baby (2002 Aprilia RS50) on the ESE dyno a couple of times now, with some interesting results.

Saturday Jan 12
With standard pipe - a subdued 5hp (though I raced it like that at Tokoroa and it was still fun!)
With ex-David-Diprose Conti pipe (for Derbi 50) - a much healthier 7.7hp. Pipe wouldn't fit so was held on with springs and masking tape. There was an earlier post about this.

Monday Jan 21
With pipe properly mounted and an adaptor turned up to match the exhaust port in the barrel (25mm) to the pipe header (32mm) - a bit more hp (8.1hp I think) but the powerband was narrower and moved up the RPM range. Initially this adaptor had a sharp step in it from the smaller diameter up to the larger diameter.

This is where it got interesting. A suggestion was made to smooth out the step in the adaptor and try it again. Instinctively, this seemed likely to produce a positive result. In fact it wasn't. The result was worse in every respect. There was less peak power and the powerband was narrower!

I have a new-found respect for those who dabble in 2-stroke exhaust pipe design. Nothing, I suspect, is obvious.

Tim

[wobbly]

You can increase the com or the timing or the squish velocity till the program SCREAMS - "DETONATION " this happens close to a TuMax of 1000.

[kel]

Tim
re the exhaust port outlet - I posted this some time back. Pictures and quote courtesy of pit-lane.biz [GP125] All that you wanted to know on Aprilia RSA 125 ...


TZ mentioned how the Honda RS pipe inlet is larger than the GP exhaust port outlet, while this is common place on 4 strokes for the purpose of AR I wasnt aware it was used on 2 strokes but on reviewing RSA photos I came across this
276952276953
Jan Thiel "One wants the pressure wave coming back into the cilinder but NOT the burned gases that are hot and can cause detonation!"
Makes sense.

[husaberg]

Tim
re the exhaust port outlet - I posted this some time back. Pictures and quote courtesy of pit-lane.biz [GP125] All that you wanted to know on Aprilia RSA 125 ...

and i followed with Mr Honda's version
The removal of this step removes HP
From Memory Mr Bangs foul stroke also has one built in.


Jan Thiel "One wants the pressure wave coming back into the cilinder but NOT the burned gases that are hot and can cause detonation!"
Makes sense.

[richban]

and i followed with Mr Honda's version
The removal of this step removes HP
From Memory Mr Bangs foul stroke also has one built in



Ah yes it does. Funny last night I just made the step bigger on the bottom and a little less at the top. Mad into building pipes at the moment. Should have lots of stuff to try on the next big dyno session.

[koba]

Ah yes it does. Funny last night I just made the step bigger on the bottom and a little less at the top. Mad into building pipes at the moment. Should have lots of stuff to try on the next big dyno session.

It's great to see you are gearing up some pipes for a big session...

[richban]

It's great to see you are gearing up some pipes for a big session...

I am pretending to know not, what you mean.:doobey:

[kel]

Ah yes it does. Funny last night I just made the step bigger on the bottom and a little less at the top. Mad into building pipes at the moment. Should have lots of stuff to try on the next big dyno session.

Isnt that the wrong way round, or are you just trying to mislead the followers

[koba]

I'm still playing with MOTA, I'm finally learning to meaningfully read the wave data and pressure traces.
MOTA seems really limited in this compared to Engmod but that's expected. It's still got enough in there for me to learn a good amount from.

I'm starting to feel confident that I'm reading the data well and making informed conclusions.

The next step for me is probably starting again on the engine with all new measurements and shooting for a clear goal.
Currently I've been trying lots of things with the goal of learning by playing, I've kept good notes which helps but It's still really easy to get lost in the hundreds of files and many different directions of experimentation.

This new effort will take quite some time as I have a lot of measuring to do and I like to keep the bike operational for each round.

[koba]

Isnt that the wrong way round, or are you just trying to mislead the followers

If he means it top relative to bottom perhaps but that reads more like before relative to after to me...

Shit that doesn't make much sense.


I know there will be more authoritive, modern sources but if that is from Bell's 4 stroke book I seem to recall him mentioning it's a worthy area to experiment in.
Not that I would admit to wasting time reading books on poppet droppers.

[richban]

I know there will be more authoritive, modern sources but if that is from Bell's 4 stroke book I seem to recall him mentioning it's a worthy area to experiment in.
Not that I would admit to wasting time reading books on poppet droppers.

Its all experiments. Yeah I have re read Bells book recently and now just working through options that could improve things. Will find out what works and what doesn't. Funny though coz the transition now does look quite like the RSA header port match. Or should I say mismatch. Anyway its fun playing.

[koba]

Its all experiments. Yeah I have re read Bells book recently and now just working through options that could improve things. Will find out what works and what doesn't. Funny though coz the transition now does look quite like the RSA header port match. Or should I say mismatch. Anyway its fun playing.

Yes, yes it is!

[2T Institute]

I have a new-found respect for those who dabble in 2-stroke exhaust pipe design. Nothing, I suspect, is obvious.

Tim

Not quite right it always obvious just you only realise it after the fact, two strokes are like women and kids they never do what you want them to do.:lol:

[Frits Overmars]

Interesting times ... have had my new baby (2002 Aprilia RS50) on the ESE dyno a couple of times now, with some interesting results.
Saturday Jan 12 With standard pipe - a subdued 5hp (though I raced it like that at Tokoroa and it was still fun!)
With ex-David-Diprose Conti pipe (for Derbi 50) - a much healthier 7.7hp. Pipe wouldn't fit so was held on with springs and masking tape. There was an earlier post about this.
Monday Jan 21 With pipe properly mounted and an adaptor turned up to match the exhaust port in the barrel (25mm) to the pipe header (32mm) - a bit more hp (8.1hp I think) but the powerband was narrower and moved up the RPM range. Initially this adaptor had a sharp step in it from the smaller diameter up to the larger diameter.
This is where it got interesting. A suggestion was made to smooth out the step in the adaptor and try it again. Instinctively, this seemed likely to produce a positive result. In fact it wasn't. The result was worse in every respect. There was less peak power and the powerband was narrower! I have a new-found respect for those who dabble in 2-stroke exhaust pipe design. Nothing, I suspect, is obvious.
re the exhaust port outlet - I posted this some time back. Pictures and quote courtesy of pit-lane.biz [GP125] All that you wanted to know on Aprilia RSA 125 ...Tim, right now you may be more interested in ' All that you wanted to know about the Aprilia RS50'. Here are some numbers to play around with. Exhaust pipes don't come any simpler than this, but don't let that fool you; this pipe was good for eight championships. Just don't show it to the Poms; year after year they keep trying to beat those Dutch 50 cc bikes :D.
About the step in the exhaust duct: if there is a step and you remove it, you lose power. I think the main reason is that in removing the step you increase the duct volume. The Malossi cylinder I experimented with has no step at all, but as you can see in the pipe drawing, the exhaust duct is quite narrow. That works.

[Neal]

About the step on the flange - why does it work for the honda when a exhaust port match to round transition flange used ? Claims of 1.5hp on the RS125 .

[wobbly]

Frits is right as usual re the duct step.
I have done a huge amount of work testing the duct exit geometry, short answer is that smaller duct exit area is better, cutouts for promoting the Aux flow is better again, and remove the steps and you loose power.
But a CNC oval to round transition works best.
In a RS125 aftermarket cylinder design I beta tested ,it started with a 41 by 36 oval with steps.
I then reduced the size to 41 by 32 with a press in insert.
This made better power - then I added a CNC oval to round transition ( like all HRC A kit pipes have ) and the result was between 1.5 and 2.5 Hp increase everywhere.

Re the 4T steps.
This is a different scenario all together.
Steps in a 4T are trying to kill reversion, and due to the fact that flow velocity is compromised on the short turn radius, the reversion flow will be greater on the port floor.
Many race engines have no step at the top, and a big step at the bottom.
Many with a flat floor to increase port velocity and also create the big 1/2 moon floor step, at the flange face.

[Ocean1]

and i followed with Mr Honda's version
The removal of this step removes HP
From Memory Mr Bangs foul stroke also has one built in

Used to be a fairly common VW feature, the header tubes belled out at the joint to the manifold flange. Wasn't worth much, but apparently it did work IF the rest of the system was correct.

[TZ350]

More on the TPS thing.

This is an email I sent to Ignitec.

Hi
We have several bikes with Ignitec Sparker DC-CDI-P2 tunable two channel ignitions.
We want to use the TPS function.
We found that a 5K Ohm TPS unit worked OK but a 25K one gave us trouble.
Is a 25K resistance wrong?
What resistance TPS do you recommend?
Thanks

This is their reply.

Hello,
Standard automotive TPS has resistance about 5 kOhm.
25 kOhm is strange. Is it regular automotive TPS ?
276981
We recommended to use automotive TPS.
Jiri Krejzl
IGNITECH

It Looks like a (nominal) 5k Ohm TPS is the unit of choice for the Ignitec.

[bucketracer]

Im not forgetting the rider at all there Rick, just continuing the idea that less is more as far as power goes. I really was certain that the bike Avalon was riding had 24HP, but it goes to show that the race wins for ESE have all come on the shoulders of the lower side of the maximum power, Am I correct in saying the fast 4T engines have around 24 HP at around 11,000 RPM?

Compairing hp with hp may not be the apples with apples comparison you imagine.


Rick and his low 20's light weight bike have a similar power to weight ratio as the 30hp Beast.

There have been a few suggestions that loosing a couple of hp from the Beast would make it a more competitive bike, but I don't think the idea was well thought through.

It become pretty obvious that the 27 and 30 hp options were both rideable in different ways and that reducing the Beasts power did not make it any faster ...... going fast seems to be more about the power to weight ratio.

Trimming the 30hp Beasts weight for a more competitive power to weight ratio looks like a much more rewarding way to go, than loosing a few hp.

TeeZee points out that a truer performance comparison would be the power to weight ratio of engine and bike with rider aboard.

Av and her bike probably have a better power to weight ratio than possibly any other bike and Ricks is pretty good too.

A lot of the fast 24 hp 4T's in lightweight chassis have a better power to weight than the 27hp Beast and a wider spread as well.

Talking about hp alone does not tell the whole story, its taken TeeZee to point it out.

[NOID]

pritty sure it was said ages ago, if you eat too meny pies etc you need to cut weight/add power to your bike. cut down weight and youll be amazed at the performance. cutdown on the pies also. WEIGHT LOSS is the best way to go faster cheaper (sometimes) aswell

[fixer]

Thanks for constructive comments on exhaust step. thanks also to Frits for the numbers. I have printed them out and they are now under lock and key guarded by deaf-mute Ninja warriors.

Another couple of sessions on the ESE dyno have yielded more interesting (and positive) results. First step was to finalise the jetting and then fiddle with the length of the adaptor between the barrel and the pipe. The length of the adaptor seemed a likely area to investigate since a roughly fitting but longer adaptor produced significantly better power than a good fitting but shorter adaptor.

These steps were taken yesterday.

Please forgive me if there are issues with the photos. I've never attached any before.

Photo 1 shows the long adaptor which is long (about 35mm) but fits only very roughly (it came with the pipe).
Photo 2 shows the short adaptor we made up which fits perfectly but is short (about 15mm).
Photo 3 shows the short adaptor with a hose clip added to extend its effective length to about 23-25mm.
Photo 4 compares the performance of the long adaptor (blue) and the short adaptor (red). The short adaptor makes very slightly more peak power but gets there later and drops off more.
Photo 5 compares the performance of the short adaptor (red) and the same adaptor with the hose clip added to increase its length. With the hose clip added, the peak power is the same but it comes in earlier and drops off less.
Photo 6 compares the performance of all three options. Merely adding the hose clip gets us from the peakier performance of the short adaptor almost back to the fatter and earlier power curve of the original long adaptor.

Woo hoo! Next step ... 2 hose clips! Alas, 2 won't fit, so a longer adaptor has to be made.

[bucketracer]

pritty sure it was said ages ago, if you eat too meny pies etc you need to cut weight/add power to your bike. cut down weight and youll be amazed at the performance. cutdown on the pies also. WEIGHT LOSS is the best way to go faster cheaper (sometimes) aswell

Actually I think your right, maybe I should have said "took TeeZee to remind us of it", looks like SS90 got a bit off track with his less hp is more idea.

[bucketracer]

Woo hoo! Next step ... 2 hose clips! Alas, 2 won't fit, so a longer adaptor has to be made.

Interesting pictures and graphs, looking forward to hearing how tuning by hose clips works out.

[husaberg]

Interesting pictures and graphs, looking forward to hearing how tuning by hose clips works out.

I seem to remember Wob used one to balance a stator.........

Useless or maybe interesting factoid/Question
What works bike ran a aluminum alloy RR77 crankpin with a hardened sleeve. that was reliable for 9500 hard racing miles with a future multiple world champion on it when he fitted one to his production racer model?

There could be two chocky fish's in this one for the correct answer

[Moooools]

More on the TPS thing.

This is an email I sent to Ignitec.

Hi
We have several bikes with Ignitec Sparker DC-CDI-P2 tunable two channel ignitions.
We want to use the TPS function.
We found that a 5K Ohm TPS unit worked OK but a 25K one gave us trouble.
Is a 25K resistance wrong?
What resistance TPS do you recommend?
Thanks

This is their reply.

Hello,
Standard automotive TPS has resistance about 5 kOhm.
25 kOhm is strange. Is it regular automotive TPS ?
276981
We recommended to use automotive TPS.
Jiri Krejzl
IGNITECH

It Looks like a (nominal) 5k Ohm TPS is the unit of choice for the Ignitec.

Automotive TPS units tend to break down pretty frequently when subjected to vibration and heat. Might be worth getting a proper motor sport one. I just did an inventory of all our sensors and there were 12 broken TPS sensors in the box, collected over 6 years. We use a different model now but I can't remember what it is off of the top of my head.

[fixer]

Just before we gave up for the night yesterday, we thought we'd try out my fancy new NGK BR9EIX iridium spark plug ($29 from Scootling in Auckland). The BR9ES that was in the bike was of completely unknown vintage and might have been there since the bike was new (in 2002). The results suggest that I can save myself a few bob on spark plugs in future.

But notice I'm still smiling. This dyno business is fun!

Tim

[fixer]

Another day and a longer adaptor has been made up. About 5mm longer even than the original adaptor. Results very pleasing.

Photo 1 shows new long adaptor (or nozzle if you prefer) fitted.
Photo 2 shows the 3 adaptors we've used. From top to bottom:
- new long adaptor
- new short adaptor (with hose clip)
- old long adaptor (that came with the bike and doesn't fit into the barrel).
Photo 3 shows a comparison of the power curves of the new long adaptor (blue), the new short adaptor (green) and the new short adaptor with the hose clip fitted (red)
It would seem that size IS important. The new long adaptor makes the best peak power and at the lowest RPM. We have a winner!
Photo 4 shows the same comparison with the addition of the curve from the original pipe.

It may be rampant optimism talking, but I think the bike is going to be a lot more fun to ride at the track this weekend. The others may pass me but I don't think they'll have a bigger smile. Except maybe Cully - he'll definitely be smiling when he passes me! :-)

Tim

[Henk]

Used to run standard BR8ES plugs in the dirt bikes, three of those replaced regularly seemed to give better performance than a expensive plug changed less often. Wob will probably tell me I'm wrong but I'll stick with that approach for now.

[rgvbaz]

[QUOTE=Frits Overmars;1130484219] Just don't show it to the Poms; year after year they keep trying to beat those Dutch 50 cc bikes :D.
QUOTE]

To late Frits :cool:

[fixer]

One last post from today's dyno session.

We did a few runs though all the gears, first using the clutch (photo 1) then without the clutch (photo 2). The comparison is in photo 3. The spikes when using the clutch in the lower gears seemed to suggest that the bike was making over 9hp. The conclusion we have reached is that clutch slippage when letting out the clutch allows the engine revs to rise and when the clutch grips, the extra inertia of the rotating engine parts is transferred to the dyno drum and gives it a little bit of extra shove.

9hp looks quite exciting on the chart, but in reality while the clutch is slipping I guess I'm not moving forward as fast, so what I gain when the clutch grips, has already been lost. Oh well.

[2T Institute]

Seems that Euro tuners were onto the pipe step years before Japan Inc 'discovered' it. From a 79 390

[F5 Dave]

Just before we gave up for the night yesterday, we thought we'd try out my fancy new NGK BR9EIX iridium spark plug ($29 from Scootling in Auckland). The BR9ES that was in the bike was of completely unknown vintage and might have been there since the bike was new (in 2002). The results suggest that I can save myself a few bob on spark plugs in future.

But notice I'm still smiling. This dyno business is fun!

Tim
I think you will find the results are conclusive only for that engine in that state of tune. Raise the com any further & you may find the std plugs no longer cut it. Good to see another 50 out there, but time to crank in some decent power & turn a few revs.

[kel]

Good to see another 50 out there, but time to crank in some decent power & turn a few revs.

Agreed. Great to see the enthusiasm Tim but you're never going to get any real performance with the standard setup. Bolt up parts costing less than a thousand dollars will double the power output, considered modifications and testing from that point will deliver nearer 20hp! A few dollars and an expression of talent and the two Daves 50cc reigne may well be over

[ief]

Still don't find the step story complete, it's not only the outlet is smaller then the first dia of the pipe but also the other way around. If one finds the proper outlet dia/ duct volume, why still make the pipe bigger? (thus having a step or as mallosi did a venturi if i get it right?)

Mmmmmmm, moral of the story would be they where on to something but not quit there yet?

[Frits Overmars]

Still don't find the step story complete, it's not only the outlet is smaller then the first dia of the pipe but also the other way around. If one finds the proper outlet dia/ duct volume, why still make the pipe bigger? (thus having a step or as mallosi did a venturi if i get it right?)Malossi did not do that venturi; I did. The Malossi-text in the pipe drawing means 'for Malossi'; not 'by Malossi'.

...moral of the story would be they where on to something but not quit there yet?You reckon, if I'm not explaining all of it, I don't know about it, Ief? :D

[ief]

Malossi did not do that venturi; I did. The Malossi-text in the pipe drawing means 'for Malossi'; not 'by Malossi'.
You reckon, if I'm not explaining all of it, I don't know about it, Ief? :D

My bad on the first part, missing some subtle (or obvious) nuance here I think, I really don't get what you're saying in the second part, guess I should stick to dutch :baby:

[F5 Dave]

Agreed. Great to see the enthusiasm Tim but you're never going to get any real performance with the standard setup. Bolt up parts costing less than a thousand dollars will double the power output, considered modifications and testing from that point will deliver nearer 20hp! A few dollars and an expression of talent and the two Daves 50cc reigne may well be over

My whole bike cost less than that. Bloody chequebook racers:lol:

[jasonu]

My whole bike cost less than that. Bloody chequebook racers:lol:

Does it make 20hp???

[kel]

Bloody chequebook racers:lol:

I havent seen a cheque book in years. Maybe we should call you "Old School Dave",
Quick look on line and the Malossi MHR replica top end kit (not the MHR team) is available for 275 euro's. Bit of a tickle, larger carb and reed block, Frits Overmars pipe ... :shit:

[Yow Ling]

I havent seen a cheque book in years. Maybe we should call you "Old School Dave",
Quick look on line and the Malossi MHR replica top end kit (not the MHR team) is available for 275 euro's. Bit of a tickle, larger carb and reed block, Frits Overmars pipe ... :shit:

Credit Card Racers?

[TZ350]

277040

This is an old graph but it shows how a pipe that peaked at 10,500rpm can be made to extend the power curve by progressively shortening it.


277041

... a comparison of the power curves of the new long adapter (blue), the new short adapter (green) and the new short adapter with the hose clip fitted (red)
Tim

Frits told us about the trombone, I have simulated it for my 125 and Tim has shown that for his 50, shortening the header dynamically by only 20mm could be beneficial.

Tim, it will be interesting to see where you can get to by developing the porting on the standard cylinder.

[F5 Dave]

Does it make 20hp???

funnily enough no.

[F5 Dave]

I havent seen a cheque book in years. Maybe we should call you "Old School Dave",
Quick look on line and the Malossi MHR replica top end kit (not the MHR team) is available for 275 euro's. Bit of a tickle, larger carb and reed block, Frits Overmars pipe ... :shit:

"The MHR Replica 50cc Racing cylinder is the little brother of the 80 MHR variant. The Strongest what Malossi has to offer in the 50's displacement class. 6 transfer and three outlet ports make for enormous gas cylinder change procedures and make this an absolute weapon in the 50cc range"

I still think buying a complete aftermarket cylinder is a grey area. meh. Its not in the. . .damn, almost tricked me into saying it.:msn-wink:

[crazy man]

Does it make 20hp???daves one was always 80cc

[F5 Dave]

So how big was VBs? 125?

[husaberg]

http://www.mxsracing.com/img/mxs-gp-racing-promo.jpg[IMG]<img src="http://www.bayareatwostroke.com/forum/attachment.php?attachmentid=3297&stc=1&d=1355473613" width="360px"/><img src="http://www.bayareatwostroke.com/forum/attachment.php?attachmentid=3298&stc=1&d=1355473754" width="360px"/><img src="http://www.bayareatwostroke.com/forum/attachment.php?attachmentid=3299&stc=1&d=1355473754" width="360px"/><img src="http://www.bayareatwostroke.com/forum/attachment.php?attachmentid=3295&stc=1&d=1355472086" width="540px"/><img src="http://www.bayareatwostroke.com/forum/attachment.php?attachmentid=3294&stc=1&d=1355472086" width="540px"/>

The MXS GP90 is a 50mm bore that is matched up to a 46mm crank. Still a bit of an over square (which both Frits and Jan repeatedly state is bad for a stroker), but its closer to a square engine then most of the big bore kits available for the various Bats bikes. One has to wonder though--if they had made it a 46mm bore how much better it would actually perform.

MXS claims to have performed over 3,000 dyno runs developing this top end, and with the proper equipment that 32 HP can be produced with on a Derbi EBE050 engine--that would really test the little transmission. There's a lot of innovation brought market with this top end. It will be available in February 2013 and versions made for the EBE, D50B0, AM6, and probably a couple of other 50cc engines. You do need to get their crank for it (some of the engines sport a 45mm stroked crank), and you'll need a big pipe and a huge carb.



Originally Posted by poorly translated by Google
MAXISCOOT and MXS Racing (competition MAXISCOOT Department) are proud to present to you the fruit of many years of development: the pack cylinder crankshaft pot MXS 46mm Derbi GP90 race Euro2! You are of course offered at a great price!

With an original design patented, pot pack cylinder crankshaft 46mm stroke Derbi GP90 MXS Euro2 has a displacement of 90cc (50mm diameter / 46mm stroke).

Its exclusive mounting system developed by MXS RACING design allows transfers intake and exhaust duct completely new to this type of high engine "mécaboite 50cc!"

Indeed, on the cylinder studs are not replaced a patented hollow screw heads now only its base. Aluminum caps followed in times and places of traditional studs. These plugs will fit the shapes transfers intake and exhaust design thus allowing completely "free" those parts of the cylinder.

Another exclusive MXS: the stud bolt has a slot allowing it to remain fixed on the valve cover, this preventing it from rotating when removing your candle preserving your o-ring.

Designed specifically for drivers of high competition, this pack cylinder crankshaft pot MXS 46mm Derbi GP90 race Euro2 achieves very high performance!

With the right parts and associations through its many innovations, high engine develops an output of about 28 to 30 horses without any modifications. The exclusive design of its transfers also provides a "couple" absolutely phenomenal (18Nm) and at low speeds!

This pack cylinder crankshaft pot MXS 46mm Derbi GP90 race Euro2 is extremely efficient at startup, acceleration and speed. Its reliability is also a "high-end" through careful design and use of high quality materials (made in Europe). Its cooling capabilities have receive a lot of attention from MXS who designed the mold of the cylinder so that the coolant flows perfectly around the exhaust pipe (the hottest point of the cylinder).

It is essential to use this pack with fuel with an octane rating of 100 to assure him power and reliability! You will also associate a carburetor at least 30mm (38mm is ideal), a clutch of competition "upscale" with a maximum of discs, competition gearbox (Bidalot) and a digital ignition rotor internal (Stage6 R / T or Bidalot).

Warning: you will countersink slightly in front of your crankcase for the passage of the rod as well as the bottom of the piston (map included).

It is possible to get more power with the cylinder using the stud bolt "competition" sold separately (only the essence of competition!), Bringing the power up kit from 30 to 32 hp .

*

Power of about 28 to 30 horses (without any changes)
Exclusive Design transfers for a "couple" absolutely phenomenal at low speeds (18Nm)
Made in Europe
Stud bolt guided by pin
Water circulation system optimized
*

The package included the following:

The crankshaft MXS Derbi GP90 Euro2 EBITDA (stroke 46mm)
The pot MXS Derbi GP90 Euro2
The cylinder head MXS Derbi GP90 Euro2
A set of crankshaft bearings with oil seals



Michael Burgard
http://www.bayareatwostroke.com/forum/showthread.php?t=3666
i will fastly introduce my self
my name is Michael iam from germany and i do develope 2stroke parts for Maxiscoot.......
its intresting to see that you compare the MXS cylinder with the RSA ones........
perhaps there are some similarities but its not at all similar..........
i now verry good the architecture of the RSA cylinders......and Frits is a frend of me..... i only took a little bit inspiration of the RSA cylinder this you can see verry good at the exhaust......but transfers and exhaust design is the result of 2 years developement.........

so if you got any questions about this cylinder......ask me


regards Michael


That's cheque book "racing"

[F5 Dave]

Bit of Devcon & I could fill in the writing & fashion "Street legal" into the barrel. Right, where's that stolen C.crd? Look at those aux ports. Nice.

[crazy man]

So how big was VBs? 125?think he realied on 9 dollar a letre fuel . but engine wise was fine

[speedpro]

50mm bore + MB100 crank @ 49.5mm = 97cc, and more or less square.

Now where was that article on the disc valve Honda?

Hand me my cheque book, boy.

[husaberg]

Bit of Devcon & I could fill in the writing & fashion "Street legal" into the barrel. Right, where's that stolen C.crd? Look at those aux ports. Nice.

Nah use the bezona stuff TZ has:laugh:


50mm bore + MB100 crank @ 49.5mm = 97cc, and more or less square.

Now where was that article on the disc valve Honda?

Hand me my cheque book, boy.

[twotempi]

What works bike ran a aluminum alloy RR77 crankpin with a hardened sleeve. that was reliable for 9500 hard racing miles with a future multiple world champion on it when he fitted one to his production racer model?


John Surtees with a Triumph Cub ?? Or a Vincent Comet Black Shadow ??

[husaberg]

What works bike ran a aluminum alloy RR77 crankpin with a hardened sleeve. that was reliable for 9500 hard racing miles with a future multiple world champion on it when he fitted one to his production racer model?


John Surtees with a Triumph Cub ?? Or a Vincent Comet Black Shadow ??


John Surtees Vincent grey flash (or half a Black Lightning) but yeah i get the joke, but you miss the chocky fish
Burns and Wright lightning spec shadow had 2x ex works Grey Flash front heads....

Seen this today nice product placement
http://1.bp.blogspot.com/_LhXKxeMf2Ws/S43aAZIsQkI/AAAAAAAABBM/YcHNNxmJRDo/s1600/wkshop.jpghttp://3.bp.blogspot.com/_LhXKxeMf2Ws/S43Pz72QqVI/AAAAAAAABBE/jQ4rnvzMPxc/s1600/IMG_0115.JPG
Thats a fair bit of Space was it any more compact than the Swissauto 4

[TZ350]

pretty sure it was said ages ago, if you eat too many pies etc you need to add power to your bike. cut down weight and you’ll be amazed at the performance. Cutdown on the pies, WEIGHT LOSS is the best way to go faster
Actually I think your right, maybe I should have said "took TeeZee to remind us of it"

NOID is right and it was Thomas who recently reminded me to look at the actual power to weight ratio of the faster bikes, and at 30hp and 210kg with rider and gear the Beast is not that flash. Avs is much better and I think the Beast is easily equalled or bettered by Rick, (FarmaKen maybe) and some of the light 4T's.

So we have the hp, now we need to make a lighter bike.

277055

This is FarmaKens bike, MC18 frame and TF125 engine. Its much lighter than the Beast, he let me have a good look and take some photos (and an extra big thanks because he is ok with me posting them too).

277058

Nice little out of the way place for the ignition.

277054


Dinky little lightweight seat sub frame and R6 shock.

277056

3.5 x 17 front wheel from a big Suzuki.

277057

Neat little adapters for the disk and sprocket and light weight caliper.

[TZ350]

More of FarmaKens Bike

277061

Front brake to die for.

277062

Light home made footrest brackets and levers.

277059

FarmaKens chamber with the ATAC valve mechanisim. Basically a slot in a spindle like the Suzuki RG400/500's

277060

The other side of the ATAC valve, the ATAC chamber itself is not fitted in this picture.

I have a MC16 frame and have been collecting wheels forkes brakes etc so I can make something similar, and have even been cutting back on the pies too ....:msn-wink:

[Frits Overmars]

http://www.mxsracing.com/img/mxs-gp-racing-promo.jpg[IMG]Here is the picture that says more than a thousand words: the drawing from Michaels patent application.

[husaberg]

Here is the picture that says more than a thousand words: the drawing from Michaels patent application.


Thanks Frits i guess it would have made much more sense in its original language.......
But i guess you know how much i love pictures by now:laugh:
.
....indeed, on the cylinder studs are not replaced a patented hollow screw heads now only its base. Aluminum caps followed in times and places of traditional studs. These plugs will fit the shapes transfers intake and exhaust design thus allowing completely "free" those parts of the cylinder.......
It is possible to get more power with the cylinder using the stud bolt "competition" sold separately (only the essence of competition!), Bringing the power up kit from 30 to 32 hp .

http://tomahawktuning.files.wordpress.com/2012/11/3130520220_2_18_bu5gu2ce.jpg
my gut says its pure competition part.... is this the case?
Even if i ignore the name.

[Yow Ling]

Thanks Frits i guess it would have made much more sense in its original language.......
But i guess you know how much i love pictures by now:laugh:
.

my gut says its pure competition part.... is this the case?
Even if i ignore the name.

If you have to buy the "competition" studs seperatly then that would suggest this is a non comptition part and at 379 euro is cheaper than a replate in nz

[Haufen]

Here is the picture that says more than a thousand words: the drawing from Michaels patent application.

Do you happen to know when Michael patented his idea? I have seen such a modification on another cylinder on the internet some time ago (2 years or so). Just thought Michael might want to know that.

[F5 Dave]

Here is the picture that says more than a thousand words: the drawing from Michaels patent application.

The swine. I've seen something similar in a dream a few years ago. Haven't had time to implement & well. . . his is well more advanced than my trying to get around a compromise of a 1979 engine. But I'll sue!

[kel]

If you have to buy the "competition" studs seperatly then that would suggest this is a non comptition part

Well said, clearly a non competition part. I wonder how long it will be before some bolts one of these up to a KE125 bottom end :msn-wink:

[Haufen]

The swine. I've seen something similar in a dream a few years ago. Haven't had time to implement & well. . . his is well more advanced than my trying to get around a compromise of a 1979 engine. But I'll sue!

Not sure if I understand you correctly. What I meant to say was, that, if the other picture had been published before the patent application, that patent might be useless or less useful as it costs money every year and chances in court might have been diminished.

277093

[F5 Dave]

I was kidding of course, but it shows that there are no original ideas, just innovative implementations by motivated people. My motivation can be a bit simian.

Ohh look, Bananas!

[TZ350]

I have often wondered why no one has really gone into expansion chambers in a big way on this thread.....
They have you just weren’t looking. In fact your first rants were about how Thomases cousin stole the worlds best pipe design from your mate the pipe genius and that was why all Asians could not be trusted ever again
Recently I have been trying to find the posts that talk about pipes and collate and edit them. There is heaps of it and pages 620 630 640 650 660 670 and 680 have un edited collections of raw material. If your interested in expansion chambers they are worth a look.


Pages 610 600 590 580 570 ..... 100 etc all have links lists to other stuff, then there is the Thread-Tools View-Thread-Images option that also helps to find the interesting pictures and posts.

http://www.underdogsracing.com/fospipe.html (http://www.underdogsracing.com/fospipe.html)


The Basic Team ESE Suzuki GP125 1980's Engine.

277787

Transfers open 114 ATDC for 132 Duration A port angled 12 deg up (Std), B port 5 deg up.
Exhaust opens 80 ATDC for 200 Duration and 72% port width.
Inlet opens 145 BTDC closes 80 ATDC 32mm equivalent dia port window, 24mm taper bored carb, 135mm inlet tract from RV to bellmouth.
Old Honda RS125 exhaust.

We got most of the improved performance from widening the rear transfers as much a possible and opening the exhaust port to 72%

277788

The only real difference is the 30hp engine has an exhaust port opening 78.5 ATDC for 203 duration and 75% wide.

277789

Comparison of 27 and 30 rwhp engines.


Page 500 .....

No need to have a peaky engine. Here are Two Very useful Tools. EngMod2T a 2-Stroke simulation package and a handy (and cheep) Porting Calculator from:- http://www.porting-programs.com/ which is based on Blairs work.

Rich's 4-Stroke

Post has links to basic info for 27hp engine


Because a few people have asked about the GP engine, to save wading through 270 pages, these links go to the more relevent posts about the 27hp engine. Different link collections can be found on the decade pages 80-90-100.....260 etc.

277787

27rwhp 1978 Suzuki GP125

Post has links to basic info for 30hp engine


EngMod2T

277788

For something different Page 400 is going to be the basic info for building a 30+hp Suzuki GP125 taken from the EngMod2T simulation files.

Crank HP. Simulated Dyno Graph from EngMod2T using an early RS125 pipe.

EngMod2T's main screen for developing the model.

Basic engine dimensions.

Exhaust port dimensions.

Transfer port and duct dimensions.

Transfer port cylinder entry design and angles.


There are over 3,500 images on this thread. To find the interesting ones use Thread Tools near the top of this page and View Images, then sort them from the Beginning and 70 to a page. Click on the Image to view it and the little N/A sign to go to the Post about it.

On each decade page, 490, 480, 470, 460 etc there is a collection of links or a collection of the more interesting technical posts from the last ten pages.

A bit of an index .....

Page 490 The Trombone, Ex port resonance and Transfer port stagger.
Page 480 A vid of the Trombone, transfer timing and hot gases entering the transfers because of insufficient blow-down for the rpm.
Page 470 Blow-down STA ... Specific Time Area.
Page 460 No list but the page talks about Boost Bottles.
Page 450 Links to the basic info for building a 30+ hp Bucket.
Page 440 No list, page talks about power and air correction jets.
Page 430 Carb inlet lengths and crankcase volumes.
Page 420 Transfer ports and the importance of the up swept angles, the Leaning Tower of Pisa principle explained.
Page 410 Rolling road dynos, main and power jet ratio.
Page 400 Links to the basic info for building a 30hp Suzuki GP125 Bucket engine.
Page 390 Links to Frits collection of Aprilia stuff.
Page 380 Transfer duct shape and STA's.
Page 370 No list but the page talks about Jan Thiel and racing 50's.
Page 360 Frits chamber calculations formula.
Page 350 PJ switching, Wob and crank shaft balance.
Page 340 Muriatic Acid, main brg float, Husburgs con rod dimensions.
Page 330 No list, page talks about expansion chambers, race gas.
Page 320 High temp silicon, Yama Bond, crankcase sealing, air solenoids Vid clips of Mamola.
Page 310 Copper for cooling, sprockets for cooling, steering head brgs.
Page 300 How to determine STA numbers.
Page 290 B/E dimensions, delivery ratio, Honda Ex Step, stinger nozzel
Page 280 Aprilia RSA port layout explained, pumper carb, links to gluing up the GP cases.
Page 270 Link list on how to make a decent high 20's hp Suzuki GP125 Bucket engine.
Page 260 Over rev cough and what it means, Mallory metal for crank balancing.
Page 250 27hp from a 1978 Suzuki GP125
Page 240 Aprilia RSA cylinder stuff.
Page 230 Porting Calculator and a lot of other useful tech links.
Page 220 RG50 part numbers, 2-stroke carb atomisers explained
Page 210 Page is mostly about the results from the TRRS
Page 200 Simple 18 hp Suzuki GP Bucket engine using a RG250 pipe.

Etc ...

For the 4T boys ... the Polyquad Head


interesting article:
http://motortecmagazine.net/article.asp?AID=1&AP=1

[Farmaken]

[QUOTE=TZ350;1130485469]NOID is right and it was Thomas who recently reminded me to look at the actual power to weight ratio of the faster bikes, and at 30hp and 210kg with rider and gear the Beast is not that flash. Avs is much better and I think the Beast is easily equalled or bettered by Rick, (FarmaKen maybe) and some of the light 4T's.

So we have the hp, now we need to make a lighter bike.


My bike on the scales at Taumaranui was 85 kg with fuel

Me on the scales with riding gear is 87 kg

Grand total of 172 kg - still miles off Rick and his RS/Tf

I have no idea of Hp for my bike, but am hoping the new triple Ex ports will give me a couple more and cure the hesitation when getting back on the gas after a tight corner - I am pretty sure closed throttle under brakes after being wide open on straights has been leaving the crankcase full of contminated fuel charge( due to insufficent Ex blow down) and causing a big wait and see effect when opening the throttle again.

[F5 Dave]

Depress the lever on the left handlebar 1/2 way. Open throttle part way. Wait for it. Wait for it. NOW - let go of lever & turn throttle as fast as you dare.

[Farmaken]

That is the exact system I have been using up till now - replaced dead clutch on the Saturday at taumaranui . Every thing comes at a price :msn-wink:

[FastFred]

I really was certain that the bike Avalon was riding had 24HP, but it goes to show that the race wins for ESE have all come on the shoulders of lower power.

Lower power won't make a heavier bike faster ....

The ESE wins have come on the shoulders of a really good ""power to weight ratio""......

[husaberg]

Lower power won't make a heavier bike faster....

The ESE wins have come on the shoulders of a really good ""power to weight ratio""......

There is still a missing piece of the puzzle steering geometry and weight distribution.
That NSR frame (i think TZ has two) has to be altered/chopped to achieve it.

PS i won't be buying a MXS cylinder i intend to do something else a little more homegrown..........

[FastFred]

That NSR frame (i think TZ has two) has to be altered/chopped to achieve it.

I see TeeZee has been looking at that frame you got him, its light but I think he is looking at how to get even more weight out of it.

Whats this homegrown thing your talking about, new frame, wheels???.

[husaberg]

I see TeeZee has been looking at that frame you got him, its light but I think he is looking at how to get even more weight out of it.

Whats this homegrown thing your talking about, new frame, wheels???.

That's next week.........

[Yow Ling]

That's next week.........

Hey Husa SS90 must have your login

[husaberg]

Hey Husa SS90 must have your login

He can't have as i don't have any prewar 50cc 2 stroke turbo scooter pics:msn-wink:

[Frits Overmars]

my gut says its pure competition part....Can you define 'competition part'? I guess anyone can put it on his street bike and go shopping... But yes, it is primarily meant to win races. So what is decisive? The text on the box?


Do you happen to know when Michael patented his idea? I have seen such a modification on another cylinder on the internet some time ago (2 years or so).I don't remember exactly, Haufen. It may have been a couple of years ago.


...I am hoping the new triple Ex ports will give me a couple more and cure the hesitation when getting back on the gas after a tight corner - I am pretty sure closed throttle under brakes after being wide open on straights has been leaving the crankcase full of contminated fuel charge( due to insufficent Ex blow down) and causing a big wait and see effect when opening the throttle again.The 'wait and see' effect can have a couple of other causes. Resonances in the inlet tract when the throttle is closed, can push the fuel in the needle tube down. Then afer re-opening the throttle the engine runs 'dry' for a moment.
And in reed valve engines the opening of the reed in the power band largely depends on exhaust pulsation. Once you close the throttle, combustion stops and there is no more exhaust pulsation. Re-opening the throttle initially has no effect because the exhaust pulsation depends on combustion, and there is no combustion if the reed stays closed. So you open the throttle a little more... and a little more... and then at some point there will be enough fresh mixture in the cylinder to get it firing again. But now the throttle is wide open.... Maybe you can manage that on a bucket but I have seen more than one 500 cc GP-rider flying high in such a situation. Ouch...

[wax]

Hey guys, tz i have been away for a bot how are you going with that cvt setup. Happy to help you where I can. Do you still want to get hold of some cases