ESE's works engine tuner

[Frits Overmars]

I just came across this link in the kiwibiker bucket foundry. It impressed me enough to decide posting it here as well.
http://www.brewracingframes.com/safe...sgene-gas.html

[husaberg]

I just came across this link in the kiwibiker bucket foundry. It impressed me enough to decide posting it here as well.
http://www.brewracingframes.com/safe...sgene-gas.html

Frits it looks like its is the chlorinated solvents that are the cause, it seems most brake cleaners now no longer contain them.

Keep Solvents Away From Flames and Heat Do not use or store chlorinated solvents near open flames or excessive heat (such as ovens, furnaces, space heaters, welding operations and pilot lights). When solvent vapors are exposed to extreme heat, they can decompose, yielding highly corrosive or toxic products such as hydrogen chloride, carbon dioxide, carbon monoxide and chlorine, which can create greater hazards than the solvent itself, including metal corrosion in the workplace and toxicity to employees. Under certain conditions such as welding, very low levels of phosgene may form.http://www.dow.com/webapps/lit/litor...1.pdf&pdf=true

[Frits Overmars]

Frits it looks like its is the chlorinated solvents that are the cause, it seems most brake cleaners now no longer contain them.

I don't intend to find out....

[husaberg]

I don't intend to find out....

Smells like fresh cut grass apparently. That fresh cut gas smell. I don't intend to be trying to create any either.

[41juergen]

About carbon reeds:
Wob I believe you mentioned for using carbon reeds (together with the rev and stopper plates) "take the thinnest you can get".... The thinnest I found is a set of 0.42mm carbon reeds, is that what you had in mind or do you use more thinner material (for a 125 ccm reving to approx. 12.500 rpm)....
cheers
Juergen

[Lef16]

Hey Wob,as you say the rule of 75% at the exhaust port exit works well with tripple exhaust ports,with oval shape and an oval to round adapter to the header(which starts at full 100% of exhaust port window eff dia).
Does it apply to round exhaust port exit?And then what?A round to round adapter which starts at 75% eff diameter and ends with 100% in the header? And what about its length?
Also,did you try it to single exhaust port,like a lot of production 2 strokes?I dont think that this 75% apply there..
Thank you..
Cheers!

[Tim Ey]

@Juergen, have a look here:
http://www.lambretta-teile.de/Membra...ini%20membranp
there are also 0,3 and 0,35mm plates.

@Lef16:
I remember reading about 90% of the Area with a single exhaust port.

I have a question on that topic as well:

This is a picture, stolen from an IAME Homolgation Paper.
Is the reduction allready made in the cylinder, right as the auxiliary exhaustports joins the main?

An other question:
If I got a single exhaust port with 100%, go linear to 90% at the flange, how shall I design the 25mm long adaptor to go back to 100%? Tangential coming from the flange with the upper angle kept straight?

[41juergen]

@Tim: thank's a lot, I saw them by accident but I'm wondering what the minimum thinkness might be before they might fail under high revs...

[FastFred]

Last lap pass ....



On my Knees.....

[Muciek]

Question about port angles.
For street use would it be good to use 25*A 10*B (non PV so A 1st then B and C) axial angles or some others would give wider powerband?
Also would it work converting old Yamaha porting (wide A port , small B , A flat , B angled up B ports limited by mounting holed ) into more modern eg A 25* B 10* ?
Here's a picture.

[wobbly]

I tested a huge number of reed combinations for the SKUSA Stock Honda 125 project I have just completed.
This also revs to 12500 so the result would be similar, but of course depends upon the intake geometry.
I ended up with a 0.35mm top carbon petal with straight cuts between ports.
The bottom petal was 0.295mm and had a 1/2 round reduction in width each side at the clamp point to make it softer.
The backups were 0.35 fibreglass as were the rev plates.
Backups seem to work better with the glass material,as its softer and also has a different natural resonant frequency than the carbon main petal.
I also added a rev plate under the stopper plate as this cannot be cut or modified.
I tried a 0.285 top with a 0.276 bottom ie softer again, but in this case it did pump up the mid by 1.5 Hp, but lost all the very valuable over power
at 12500 I was looking for.
Using backups with a rev plate means there is no issue with soft petals failing due to rev induced flutter.

Re the area guides for 3 port or T port.
In a 125 size the best oval shape was 41 wide by 32 high for the T port, the Aprilia shape works best for a 3 port with 75% area at the spigot face.
Both then need the 100% area at the header start.
For a single port the 90% area works fine with the header the same size, going back out to 100% does not make more power.

Re the old Yamha port setup.The B ports can be widened alot despite the stud holes as these drillings are smaller where the port goes around the corner.
But with no PV the A port at around 25* and stock width, with the B port lower at 10* as wide as you can get it ( watch the ring pins ) will always work alot better
but usually needs welding of the B port roof to get enough material for this angle.
Of course the A port can simply be epoxied up to for the 25* angle.
The boost port is easily re-angled to 55*.
Old model RS125 cylinders had 28* and 15* but I dont know if this really made more mid power or not.

Re the IAME duct.
You can see that the designer has added material to the floor to reduce the area where the Aux ducts are widest, then reduced the ski jump height as it approaches the exit.
This is WRONG.
The Aux ducts should be extended right up to the exit face, making two 1/2 moon shapes on each side, then slowly tapering to nothing inside the spigot as it approaches the header.
This promotes the blowdown flow running down these additional ducts right into the header.
To keep the area down at the exit face the floor should be lifted ( filled in ) to maintain the correct area ratio.

[peewee]

like wobbly said check the location of your ring pegs. you may or may not need to relocate them depending where theyre at. i just had some relocated and its a easy process for a experienced machinist if you can find one. then again maybe you have the tools to do it yourself.

to add to what wobbly said about reversing the flat A and steep B. once you flaten out the B, you may need some epoxy on the inner wall radius closest to the bore. reason is because often times that inner radius was cast at a steep angle to coincide with the steep outer wall

[peewee]

I just came across this link in the kiwibiker bucket foundry. It impressed me enough to decide posting it here as well.
http://www.brewracingframes.com/safe...sgene-gas.html

typically its recomended to use acetone for the preweld cleaning of alloy. i have a can in the garage but never bothered to check the ingredients. ill assume it wont make phosegene as im still alive but maybe i should take a look

[nick gill]

Well, maybe Namura (first time I've heard of it) did do you a favour. The skirt length is not determined by the stroke but by the distance from TDC to exhaust port bottom. If you raise that bottom (TZ350 posted lots of how-to pictures) you can use your pistons and you may also be in for a pleasant surprise, power-wise.

I'd love to Frits, but this particular cylinder is cast iron, or should I say 'pig iron'

[Frits Overmars]

If you raise that bottom (TZ350 posted lots of how-to pictures) you can use your pistons and you may also be in for a pleasant surprise, power-wise.

I'd love to Frits, but this particular cylinder is cast iron

So?