ESE's works engine tuner

[TZ350]

For those who just have to search for something special.

Dimensions and part numbers, find what you want then look up the part number to see what its off.

Piston Dimensions

http://stores.ebay.co.uk/Janets-Bike...ts-page-1.html

http://stores.ebay.co.uk/Janets-Bike...ts-page-2.html

http://stores.ebay.co.uk/Janets-Bike...ts-page-3.html

ConRod Dimensions

http://stores.ebay.co.uk/Janets-Bike...imensions.html

http://stores.ebay.co.uk/Janets-Bike...ensions-2.html

Rear Sprocket Dimensions

http://stores.ebay.co.uk/Janets-Bike...imensions.html

Front Sprocket Dimensions

http://stores.ebay.co.uk/Janets-Bike...ns-Type-2.html

[TZ350]

Compairing The Plenum with some of the more applicable Dyno Charts that have been posted here.




The first thing I noticed was that if you use the DIN way of representing HP you get a higher figure than using SAE.

Not having customers to impress we prefer the more conservative SAE method ourselves but as other charts are in DIN we will have to display ours that way too so as to compare apples with apples.

And its worth while following the quotes back to their original posts, as there is a lot of interesting stuff there.

If anyone tries to tell me that the transfers are too small (from the pictures), then they are right, they are only 10% bigger than the pics to give the results in the graph.....makes you think about transfer port area .....

I can't claim responsibility for this engine, but (so far) the highest power I have seen from this capacity with a 24mm Carb is this series of runs.

The red line was a different exhaust

This one is the Plenum (blue line) compaired with a conventional side carb (red line) and both running with Buckets first ever chamber designed by himself, maybe not spectacular but not a bad effort either.

Attached is a pretty old dyno chart. Ignore the red line that was a dodgy experiment. The line going to 13,500 was the old MB100 sidecar. That engine only had the original 2-petal reed block and a 28mm Keihin. The other line is my old piston port only TS100. 200deg timing on both intake and exhaust. I have no idea why it made such good power. Both peaked at 19.9rwhp.

[motorbyclist]

ok, searching this thread looks a bit daunting so I'll have to ask:

why is the intake plenum placed downstream of the carby, as opposed to upstream of the carby? (ie, why have it wet rather than dry?)

what advantage does this arrangement give and how?

(I'm somewhat qualified so please don't dumb it down)

[TZ350]

why is the intake plenum placed downstream of the carby, as opposed to upstream of the carby? (ie, why have it wet rather than dry?)

what advantage does this arrangement give and how?

This class of racing (F4) limits 125 2-strokes to a 24mm carb and air cooling.

The hoped for advantage, was that the motor sucking air/fuel from the plenum through an internal inlet tract larger than 24mm would allow it to make more power than it could by sucking directly through the restrictive 24mm carb.

To make power the carb needs to be bigger, or at least the inlet tract needs to be bigger and pass more air.

The idea is the motor only sucks from the plenum when the inlet valve is open and thats for only 50% of the time more or less, but the restricive 24mm carb at WOT gets to fill the plenum for a 100% of the time.

Using the plenum in theory allowes the 24mm carb to flow much more air than it would have if it was attached to the motor in the conventional way.

It works but still needs some development, the problem is oil/fuel dropout within the plenum, the plenum has potential but currently we are making more power from this motor in other ways and will take another look at the plenum later, and probably do something along the lines that Yow Ling has sugested to me.

The picture is of the Plenum (blue line) and conventional setup (red line) both with Buckets own first ever pipe design.

[bucketracer]

.

An interesting take on needle/jet http://www.youtube.com/watch?v=h0Rj_yvDo8Q

An idea so obvious, why it has'nt been done before..........

[F5 Dave]

Ahh fer heavens sake I tried to watch it & it was taking him 15 min to take the lid off the carb.

What was it, the drilled parallel hollow needle? They've been trying to pump that since the 90s. Never took off, obviously not the be all & end all.

[TZ350]

What was it, the drilled parallel hollow needle? They've been trying to pump that since the 90s. Never took off, obviously not the be all & end all.

New to us..............

[motorbyclist]

This class of racing (F4) limits 125 2-strokes to a 24mm carb and air cooling.

The hoped for advantage, was that the motor sucking air/fuel from the plenum through an internal inlet tract larger than 24mm would allow it to make more power than it could by sucking directly through the restrictive 24mm carb.

To make power the carb needs to be bigger, or at least the inlet tract needs to be bigger and pass more air.

The idea is the motor only sucks from the plenum when the inlet valve is open and thats for only 50% of the time more or less, but the restricive 24mm carb at WOT gets to fill the plenum for a 100% of the time.

Using the plenum in theory allowes the 24mm carb to flow much more air than it would have if it was attached to the motor in the conventional way.

It works but still needs some development, the problem is oil/fuel dropout within the plenum, the plenum has potential but currently we are making more power from this motor in other ways and will take another look at the plenum later, and probably do something along the lines that Yow Ling has sugested to me.

The picture is of the Plenum (blue line) and conventional setup (red line) both with Buckets own first ever pipe design.

right, so why not put the plenum on the dry side, like a conventional airbox/intake tube? How is pushing the air any different than pulling it? If the carb was that close to the intake that the air was not at a near constant velocity then why not just space it out appropriately and use an airbox/plenum to force air to the reeds where it won't fill with fuel?

I'm well aware of the bucket rules and how the plenum works, but I'd like to know the reasoning behind your design decision. Trying to smooth the air flow with an accumulator and assumedly with resonance for a boost just seems like a good way to slow engine response and cause issues with flooding.

got any drawings/pictures of what it looks like (don't worry I won't be stealing your ideas)

[TZ350]

got any drawings/pictures of what it looks like (don't worry I won't be stealing your ideas)

A drawing...........

http://www.kiwibiker.co.nz/forums/at...5&d=1281168712

And a picture............

http://www.kiwibiker.co.nz/forums/at...4&d=1281168712



And the dyno graph, plenum blue line, conventional carb red line, no other changes, back to back tests.

There is over a 1,000 pictures on this thread, and there are a few of the plenum. If you use "Thread Tools" near the top of the page then "View Thread Images" you can find all sorts of interesting pictures and related posts that people have put here, looking through the pictures to find related posts is easier than trawling the thread for info........

[motorbyclist]

And the dyno graph, plenum blue line, conventional carb red line, no other changes, back to back tests.

There is over a 1,000 pictures on this thread, and there are a few of the plenum. If you use "Thread Tools" near the top of the page then "View Thread Images" you can find all sorts of interesting pictures and related posts that people have put here, looking through the pictures to find related posts is easier than trawling the thread for info........

cheers for that - I never knew that feature existed!

I don't doubt it makes power, I just reckon putting it on the dry side would be easier. Of course now I see how you've done it perhaps an external plenum would be more difficult to build...

I do like the simple way in which you've done it - and what's with the head? extra cooling?

[TZ350]

- and what's with the head? extra cooling?

An air-cooled head typicaly runs between 125 to an upper limit of around 350 degrees C. Water cooled performance 2-stroke engines typically run around 50-80 degrees C. The higher temperature of the combustion chamber limits the amount of power that can be made and sustained in an air cooled engine.



Combustion Chamber C2 runs hotter than C1 because of the longer thermal path to the fin. To keep the combustion chamber cool the thermal path needs to be as short as possible.



I think its this necessity to keep the thermal path to the radiating surface (fin) as short as possible that we see the splayed head design like this high powerd kart engine where the roots of all of the fins are as close as possible to the combustion chamber shell. Unlike the Suzuki GP head which has a much longer thermal path to the outer fin tips.



The copper forms the squish band and with coppers better thermal properties it conducts heat away from the squish band area better than aluminium would have and I think the squish should run cooler with the copper there.



Copper transfers heat twice as fast as aluminium, in the picture below you can see the head has a large flat area machined on it. And the copper is used to transfer heat from the combustion chamber area towards the outer fins, in that way the chamber runs cooler as the outer fins get to dissipate more of the waste heat load.



And if you are playing with all of this copper it makes sense to me to extend it out into an extra fin. By in large my engine runs cooler than other air-cooled 2-strokes I have been able to measure. But best of all, it seems much less prone to fading during a race.

[motorbyclist]

wow that's a pretty novel way to cool the motor and resist detonation all in the same package.... bloody brilliant! are the copper fins measurably hotter than the aluminium ones?

[motorbyclist]

The higher temperature of the combustion chamber limits the amount of power that can be made.

isn't it moreso the fact that we can't extract waste heat fast enough, thus limiting power by the material properties of the motor (ie melting of aluminium)? IIRC hotter engines are more efficient right up until the motor siezes and/or melts or the fuel auto-ignites (which makes your copper squish band a very good idea)

ie, given stronger cooling, we can handle the extra heat from higher power output

[SS90]

IIRC hotter engines are more efficient right up until the motor siezes and/or melts or the fuel auto-ignites (which makes your copper squish band a very good idea)

ie, given stronger cooling, we can handle the extra heat from higher power output

Am I reading that right?

"Hotter engines are more efficient right up to when they seize"?

I wouldn't subscribe to that at all.

[TZ350]

.......hotter engines are more efficient.......

Depends on what kind of efficiency you are talking about, maximum work extracted from minimum fuel used (like, lean burn) or maximum power achieved from an engine and air consumed (as in, rich best power).


Taken from “Physics in an Automotive Engine” a big read but worth the effort and even interesting and amusing in places........

By increasing the temperature of the thermostat, in other words, reducing the effectiveness of the cooling system and making the engine run hotter, a SLIGHT improvement in fuel economy is achieved. However, the hotter engine tends to heat incoming air up which REDUCES the air density and therefore reduces the power produced by the engine. Now you know WHY the engine seems to have more power if you replace the modern 195°F thermostat with a 165°F one, but the engine creates more pollution due to poorer burning and it also has worse gas mileage.


The full text can be read here.... http://mb-soft.com/public2/engine.html


In searching the net for the good stuff, I am more impressed by items like this one where the author uses maths to explain his point of view and provides credible references that can be followed up..........