ESE's works engine tuner

[TZ350]

Well I be buggered. I knew about the center joint (Hence my 30hp reference) but I always thought they had hollow oval section rods.
Edit and according to this most of them did is yours an early arrow or is it a leader or is the article toss.

Not sure the joint will be a problem, its a good taper, looks strong guess we will find out in time.

Very interesting artical, they were sure onto 2-stroke development in the 60's.

My photos did not do the Ariel rod justice, I don't think its hollow but in cross section it is a slim oval, well finished.



249cc 1960 Ariel Arrow - George Brown Sprint Special

Held the flying Kilometre speed record at 122.45mph. http://www.flickr.com/photos/gordoncalder/4600149198/



The Arrow on the line.

George also Built the Super Nero Vincient Sprinter:- http://www.myvincent.co.uk/people/george_brown.php

[TZ350]

Gee, page 340 allready I will have get all the tec stuff from the last ten pages together again and post it here.

Speedpro has won the race to be the first documented useful Bucket engine at 30rwhp

Muriatic Acid is used for getting alloy smear of cylinder walls.

Muriatic Acid, aquas solution of Hydrochloric acid

From Wiki
Hydrochloric acid is a solution of hydrogen chloride (HCl) in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid. Also called muriatic acid, or historically spirits of salt, hydrochloric acid was produced from vitriol (sulfuric acid) and common salt.

I think this is what is in those green bottles of soldering salts that you can get at hardware stores.

Case reed engines always used to have large volumes,and the RG when a 125 was too big anyway - so reducing the swept volume down to 100cc means we run into even more of an issue.
The latest engines like CR250 have a very small ,wide rectangular "window" from the reed box into the case,so I am trying to replicate something similar. Edit - read here - interesting 2T developments http://www.european-2strokecup.com/

I was just pointing out that the idea of using water, great as it may be in theory, and on a dyno when looking for bottom end, it "works" just fine.
But in a controlled test to see if its was useful, it failed, as the systems effect had to be reduced so much that any gain in bottom end was still offset by a loss in the top end.
As Burgess said, when the effect was useful, it took too long to reheat the pipes.
My thoughts, from the testing I did with a PV and ATAC operated separately ( instead of combined together as many MX engines have now) is that this works real well with no down sides at all, and is easy to implement.

C4 isnt just the end float - its the total radial clearance.
Usually its designed in for where the bearing is pressed onto a shaft ( expanding the inner race) and pressed into a housing ( crushing the outer race).

In our application it also gives the case the ability to move around due to heat expansion and not take up all the end float.

Floating at least one inner race allows the crank to self centre and reduces rolling friction heaps, doing both with a set amount of total end movement is even better.

Just a small point re main bearings.
You should have the crank floating - ie spin the crank in a lathe with the rod taped down and polish the main journals so that the bearing inner race just slides on by hand.
Some engines have one end locked in place by the drive gear, but then I just float the other side.
In fully floating cranks shoot for a min of 0.2mm and a max of 0.3mm side clearance by shimming behind the bearings,or machining the step on the journal back ( or deepen the case pocket.
And always use C3 or C4 fit bearings,fiber high speed cages are best ( expensive) followed by plastic, I would never use a steel cage in a race engine.
You would be amazed how free a floated crank spins.

I now have sets of FXR 150 cam sprocket verniers adjusters for sale. I do an exchange with your sprockets as they need to be drilled and slotted for the verniers.

Each tooth on the sprocket is 10.6 degrees. The verniers split the 10.6 degrees into 10 equal measurements. The disks labelled 0-5, 0 being 0 degrees and 5 being 5.3 degrees. To get from 5.3 to 10.6, you advance the sprocket 1 tooth and put the verniers in back to front.

The verniers can be changed without removing the sprocket from the camshaft. Very easy.

The exchange set is $85

The DR200 I think is a no go. From Memory the FXR150 is a 30mm pin like a Honda.
KTM do a lovely bearing but you can't use that. KTM also do a nice strong rod but can't use that either.
There is a yummy MMC one that weighs only 98 grams as well but you can't use that either.Unless you custom order it then it would be legal?


Anyway I digress here is a nice 37mm big end long rod SR125 in the first list
http://www.mxcomposites.com/con_rod.php
http://www.connectingrod.com.tw/ktm.htm
http://www.pro-x.com/downloads/Technical.pdf
more rods here for the inquisitive types
http://www.kevinbreedonracing.co.uk/...ts_conrods.asp
http://www.connectingrod.com.tw/honda.htm
http://www.samarin.nl/webshop/index....ewCat&catId=32
http://www.tkrj.co.jp/
http://findebookee.com/c/connecting-rod the one is capt

Here are some one of them I was going to use for the original stroker xr200.

A clear reason?

Direct from MNZ website

24 ROAD RACING - MINIATURE

24.1 The Miniature Road Racing class or `Bucket Racing’ as it is also known, shall be
deemed to include solo motorcycles and sidecars.

24.2 Motorcycles Technical:

24.2.1 Solo motorcycles shall have two engine capacity classes:
F4 2 stroke 55-100cc
2 stroke 55-125cc air cooled
4 stroke 55-150cc
F5 2 stroke 0-50cc
4 stroke 0-100cc air cooled

24.2.2 Sidecars shall have one engine capacity class:
2 stroke 55-100cc
2 stroke 55-125cc air cooled
4 stroke 55-150cc

24.2.3 The maximum capacity for rebored engines shall be:
F4 2 stroke 55-100cc - 104cc
2 stroke 55-125cc air cooled - 130.5cc
4 stroke 55-150cc – 158.09cc
F5 2 stroke 0-50cc - 53cc
4 stroke 0-100cc - 104cc

24.2.4 Engines must be derived from non-competition motorcycles. Motocross, Road Racing,
Enduro and Go Kart motors and transmission parts are not permitted. There shall be
no restriction on the make, type or design of carburettor, ignition, exhaust, piston,
cam, valve springs or cooling system except for class eligibility. All engines must be
normally aspirated except F4 4 stroke engines of less than 100cc capacity, which may
be turbo or supercharged.
F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single
24mm carburettor, F5 4 stroke engines over 53cc are restricted to carburation
equivalent to a single 20mm carburettor.

Link http://www.mnz.co.nz/download/2010_M..._Miniature.pdf
Or http://www.mnz.co.nz/competitionrules.aspx

Definitive I Think.

This Bucket Engine list was put together by Malcolm McNabbs.

The following bikes are possible buckets.
Some need more modification than others to make them competitive but all are possible starter bikes.

F5 2 stroke
Aprilia RS50
Suzuki RG50
Suzuki RMX50
Suzuki A50
Suzuki AC50
Suzuki AP50
Suzuki TR50 Street Magic
Yamaha RD50
Yamaha RZ50
Yamaha TZR50
Honda MB50
Honda MBX50
Honda MT50
Honda NS50
Derbi 50
Gas Gas 50SM

F5 4 Stroke
Honda CB100
Honda CT90
Honda XL100

F4 2 stroke
Suzuki DS80 perhaps (legality questionable)
Suzuki T90
Suzuki RV90
Suzuki A100
Suzuki AX100
Suzuki GP100
Suzuki GP125
Suzuki TC100
Suzuki TF100
Suzuki TS100
Suzuki TF125
Suzuki TS125
Suzuki T125 stinger
Suzuki GT125 (would need carburation mods to be legal)
Suzuki RGV150 (sleeved to 125cc)

Honda MB100
Honda H100
MT125 perhaps (legality questionable)
Honda NSR80

Yamaha DT100
Yamaha LS2 100
Yamaha YB100
Yamaha RS100 & 125 Yamaha
Yamaha RD125 twin
Yamaha AS3 125
Yamaha RX125
Yamaha DT125

Kawasaki AR80
Kawasaki K100
Kawasaki KV100
Kawasaki G4TR100
Kawasaki KH100
Kawasaki KH125
Kawasaki KV125

Derbi 80

F4 4 Stroke
Honda CG110
Honda CB125 (single)
Honda CB125T (Twin)
Honda CBR150
Honda TL125 (Trials version of CB125)
Honda GL145
Honda XL 125?
Honda CG125
Honda SL125
Honda CBR125
Honda CBR150

Suzuki GN125
Suzuki GS125
Suzuki DR125
Suzuki FXR150

Yamaha YZFR15
Yamaha YZFR125?

Donor Chassis The following bikes are not eligible to be used but can be used for donors of frames and running gear.
Honda RS125 (GP Bike)
Yamaha TZ125 (GP Bike, Havn't seen one)
Aprilia RS250 Aluminium Beam Frame
Suzuki RGV250 Aluminium Beam Frame
Suzuki RG250 Aluminium Perimeter Frame
Honda NSR250 Aluminium Beam Frame
Honda NS250 Aluminium Perimeter Frame?
Yamaha TZR250 Aluminium Beam Frame
Kawasaki KR1 ? Aluminium Beam Frame
Aprilia RS125 Aluminium Beam Frame
Cagiva Mito Aluminium Beam Frame
Suzuki RGV150 Steel Perimeter frame
Suzuki RG150 (Quite heavy at 14.5kg standard frame and 5.5kg swingarm) Steel Beam Frame
Suzuki GSXR250 Steel or Aluminium Beam Frame Depending on year
Honda CBR250 ?
Yamaha FZR250 Steel or Aluminium Beam Frame Depending on year
Yamaha FZ250?
Kawasaki ZXR250 Aluminium Beam Frame

Donor Engines These engines are available for sale new without a bike. A good addition to a donor chassis.
Loncin CBD 150 (Modified Clone of Honda GL 145)
Loncin CBD 125 (Honda laydown stepthough clone)
Loncin CBD 110 (Honda laydown stepthough clone)
Loncin AX 100

[Dutchee]

Finally, when comparing the power developed by a two-stroke engine with that of a four-stroke of equal cylinder capacity, it must be appreciated that the actual working or swept volume of the two-stroke cylinder is only that which is contained above the top edge of the exhaust port.
Given a volumetric efficiency of 100% the cylinder of a four-stroke engine of 200 cc will contain 200 cubic cylinder of combustible mixture at the beginning of the compression stroke, but the compression of the mixture in a two-stroke cylinder cannot commence until the rising piston has closed the exhaust port.
This initial movement will occupy at least 25% of the stroke, so that even with 100% volumetric efficiency a 200 cc two-stroke engine must derive its power from only 150 cubic centimetres of mixture.
This fact is perhaps more readily appreciated when it is realised that in moving from the upper edge of the exhaust port to bottom dead centre and back again, the piston is performing the same function as the complicated valve gear of a four-stroke engine.
In order, therfore, to make a fair comparison, the performance of a 325 cc two-stroke for instance, must be set against that of a four-stroke engine which is the total volume of the cylinder, and the swept volume which is the volume of the cylinder above the exhaust port.
It is fortunate that organisers of motor-cycle competitions do not take this discrepancy of cylinder capacities into account for if this handicap were removed then two-stroke and four-stroke machines could compete on an equal footing.
~ The Two Stroke Engine - its Design and Tuning (K.G. Draper)

[TZ350]

Very interesting and Yes I would think it fair to measure 2-stroke CC's that way ........

....... but the compression of the mixture in a two-stroke cylinder cannot commence until the rising piston has closed the exhaust port.....

It appears "compression cannot commence, before exhaust port is closed" untill you think about the role of the expansion chamber.



When you think about the plugging effect of the return pressure wave from the expansion chamber stopping fresh charge from spilling out of the cylinder as the piston starts on its way back up to close the exhaust port and maybe even stuffing some back in, in the last moments of closing.

You can see how compression of the fresh charge can happen earler than the exahust port closing point, effectivly making it a bigger engine when its "on the pipe". Some call it the supercharging effect..... whether it results in more than 100% volumetric efficency of the total swept volume I don't know, but it certainly gives more than a 100% of the swept area above the exhaust port.

There it is, the whole mistery of racing 2-strokes reveled in the last two posts, everything else is just detail, thanks Dutchee.

[husaberg]

There it is, the whole mistery of racing 2-strokes reveled in the last two posts, everything else is just detail, thanks Dutchee.

I guess the fact that it fires twice as often and contains far fewer moving parts is a bit of an advantage to sometimes too.
The two stroke is a superior engine otherwise why would they keep changing the rules to try and make the four stroke more competitive Dave reckons Honda did it. I blame The Green party myself.
so oh well you wont be needing this then

shucks for old times sake and as i enjoy reading them anyway.

The last of the aprillia story to 95

To read them properly they have to be zoomed as well.

The book above the Dutchee quotes is the book i was talking to Koba about a couple of pages back.

I think the capacity of the ac 125 2 smokes and the 100cc LC 2 smokes vs the 155 ish 4 smokes is about ideal. Although the kt piston in a 100cc without the destroking would be perfect if you throw in open bearings as well.

[ac3_snow]

When you think about the plugging effect of the return pressure wave from the expansion chamber stopping fresh charge spilling out of the cylinder as the piston starts to close the exhaust port and maybe even stuffing some back in, in the last moments of closing.

Got my engine running again tonight! And something I found quite interesting was testing the compression. 160 psi with no pipe, then added the expansion chamber and 165 psi! so the pipe definitely has the effect of pushing more air back into the cylinder (yea, captain obvious!).

Also have to add that the engine seems to rev alot quicker/snappier with the crank 'floating' (although this may be all in my head) should be even better when I finally get around to putting decent bearings in. - did find one bearing had previously 'spun' wearing out the crankcase housing, so hopefully a bit of locktite is enough to fix this

I have a cooler plug for tomorrow (B9ES) bigger jet (was 130 main now 160) and will retard the timing a little so with any luck I can keep my piston whole.

[husaberg]

Got my engine running again tonight! And something I found quite interesting was testing the compression. 160 psi with no pipe, then added the expansion chamber and 165 psi! so the pipe definitely has the effect of pushing more air back into the cylinder (yea, captain obvious!).

Also have to add that the engine seems to rev alot quicker/snappier with the crank 'floating' (although this may be all in my head) should be even better when I finally get around to putting decent bearings in. - did find one bearing had previously 'spun' wearing out the crankcase housing, so hopefully a bit of locktite is enough to fix this

I have a cooler plug for tomorrow (B9ES) bigger jet (was 130 main now 160) and will retard the timing a little so with any luck I can keep my piston whole.

Great to hear Snow
Wob mentioned above a 10 a couple of pages ago
Plus you never metioned the fuel Avgas?
Along this line

But dont give me any grief when the thing melts using an 8 plug when any engine making any power at all, should have a 10 iridium as a baseline.

[ac3_snow]

Wob mentioned above a 10
Plus you never metioned the fuel Avgas?

Yup race gas, and I had ordered the 9's before I read Wobbly's post unfortunately and didn't have time to get any 10's, my scientific plan is to.....

ummm.....


keep my fingers crossed.

[husaberg]

Yup race gas, and I had ordered the 9's before I read Wobbly's post unfortunately and didn't have time to get any 10's, my scientific plan is to.....
ummm.....
keep my fingers crossed.

Sorry not trying to put the wind up you, Just making sure you caught it.
9 is far better than 6 so you should be alright. You could always ask around at riders briefing?
I used to get away with NGK B9 EGV and it seemed to offer an improvement for me anyway over a std plug 9 plug HS?. Iridium plugs weren't around then. Well i never seen them.

I was reading an old article the other Day and it mentioned the TM 250 cdi offers static timing ie no advance or retard it was meant to be the hot ticket on a Suzuki TM125 race bike. Back in the Day.

[wobbly]

I think the analysis of the 2T working cycle when compared to the 4T in the example is a bit simplistic and missleading.
A full house 4T like say the Britten V1000 has a VE around 125% and an Ex duration of over 300*.
The 4T uses the exhaust tuning to create a depression during TDC overlap, giving the intake stream a chance to purge residuals out of the chamber.
In a 2T the Ex creates a depression around BDC, giving a Delivery Ratio of 1.25 ( same number effectively as the 4T ) and this purges residuals in the same way as the 4T.
BUT, the 2T uses the open Ex port in concert with the pipe design, to reverse the outflow,shoving clean, overscavenged clean Air/Fuel back into the cylinder, using a duration number closer to 200*.
The real kicker for the 2T is the huge efficiency gained by firing every revolution, doubling the Ex frequency, and thus the energy that can be used to good effect.

[speedpro]

I run a B8 or B9 on the kart track. It doesn't hurt with either. Big tracks I've always used a B9. On a kart track I don't think you are on the throttle enough to worry. If it blows up it's because the tuning is seriously screwed up.

[TZ350]

Finally, when comparing the power developed by a two-stroke engine with that of a four-stroke of equal cylinder capacity, it must be appreciated that the actual working or swept volume of the two-stroke cylinder is only that which is contained above the top edge of the exhaust port.
Given a volumetric efficiency of 100% the cylinder of a four-stroke engine of 200 cc will contain 200 cubic cylinder of combustible mixture at the beginning of the compression stroke, but the compression of the mixture in a two-stroke cylinder cannot commence until the rising piston has closed the exhaust port.
This initial movement will occupy at least 25% of the stroke, so that even with 100% volumetric efficiency a 200 cc two-stroke engine must derive its power from only 150 cubic centimetres of mixture.
This fact is perhaps more readily appreciated when it is realised that in moving from the upper edge of the exhaust port to bottom dead centre and back again, the piston is performing the same function as the complicated valve gear of a four-stroke engine.
In order, therfore, to make a fair comparison, the performance of a 325 cc two-stroke for instance, must be set against that of a four-stroke engine which is the total volume of the cylinder, and the swept volume which is the volume of the cylinder above the exhaust port.
It is fortunate that organisers of motor-cycle competitions do not take this discrepancy of cylinder capacities into account for if this handicap were removed then two-stroke and four-stroke machines could compete on an equal footing.
~ The Two Stroke Engine - its Design and Tuning (K.G. Draper)

Very interesting and Yes I would think it fair to measure 2-stroke CC's that way ........

....... but the compression of the mixture in a two-stroke cylinder cannot commence until the rising piston has closed the exhaust port.....

It appears "compression cannot commence, before exhaust port is closed" untill you think about the role of the expansion chamber.



When you think about the plugging effect of the return pressure wave from the expansion chamber stopping fresh charge from spilling out of the cylinder as the piston starts on its way back up to close the exhaust port and maybe even stuffing some back in, in the last moments of closing.

You can see how compression of the fresh charge can happen earler than the exahust port closing point, effectivly making it a bigger engine when its "on the pipe". Some call it the supercharging effect..... whether it results in more than 100% volumetric efficency of the total swept volume I don't know, but it certainly gives more than a 100% of the swept area above the exhaust port.

There it is, the whole mistery of racing 2-strokes reveled in the last two posts, everything else is just detail, thanks Dutchee.

I think the analysis of the 2T working cycle when compared to the 4T in the example is a bit simplistic and missleading.
A full house 4T like say the Britten V1000 has a VE around 125% and an Ex duration of over 300*.
The 4T uses the exhaust tuning to create a depression during TDC overlap, giving the intake stream a chance to purge residuals out of the chamber.
In a 2T the Ex creates a depression around BDC, giving a Delivery Ratio of 1.25 ( same number effectively as the 4T ) and this purges residuals in the same way as the 4T.
BUT, the 2T uses the open Ex port in concert with the pipe design, to reverse the outflow,shoving clean, overscavenged clean Air/Fuel back into the cylinder, using a duration number closer to 200*.
The real kicker for the 2T is the huge efficiency gained by firing every revolution, doubling the Ex frequency, and thus the energy that can be used to good effect.

Thanks for expanding on that ........

[marsheng]

When you burn a fixed amount fuel and air you get an fixed amount of energy. So working backwards, the maximum BEMP of a 4 stroke is about 240 psi, 2 strokes are around 400 psi. If the volumetric efficiency of the 4 stroke is 100% then by that ratio, the VE of the 2 stroke is about 85% remembering that it has 2 strokes per cycle. (PS This ignores the extra friction of the 4 stroke engine. )

[wobbly]

It may be semantics but why "change" the calculation of bmep for a 2T by doubling
it because it fires every revolution.
The bmep of a full house 2T is around 200 psi, as this is a calculated relationship between measured torque and displacement.
The calculation is a measure of the ability to produce power PER CYCLE, divided by the number of power cycles.
Thus a 4T has a higher bmep capability, but is hamstrung by the halved number of available cycles.
This is an inherent advantage of a 2T, you cant just factor it away in the calculation.
And the VE numbers are simply a measure of the amount of air ingested per cycle divided by the displacement, and are essentially the same for full noise designs.

Its a bit like the people that go on about the measurement of power on a dyno.
The guys with huge Harley engines say that the power should be "corrected" for the big heavy pieces of shit when compared to a small screamer 125cc GP bike.
The reality is that the big , heavy pieces of shit are exactly that, and what is measured at the rear wheel, is the actual power delivered in the real world.The fact that they have huge flywheels that absorb "power" to spin up, is an inherent
part of the design, and in my opinion cant be ignored by applying some fudge factor that makes them feel better, about the Hp/cc figures.

[speedpro]

38.45?

We'll see