ESE's works engine tuner

[TZ350]

This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.

I would love to see much more posted of your work. ...

[seymour14]

I just lurk on this forum, but I am here.

This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.

Had a good read on your two stroke forum. Really excellent work, lovely machining. Shame about the cancellation of speed week, patience is a virtue!

Here's a picture of the race bike we have just finished with a three piece CNC barrel and CNC air cooled head, it pulls outrageous hp and torque figures for its bucket racing restrictions. Will post up more pictures tomorrow.

[husaberg]

Do you typically lean the mixture with boost bottles?
I have a CR 125 that needs help on the low end.

http://www.eric-gorr.com/images/docu...TuningTips.pdf

[bjorn.clauw.1]

I just lurk on this forum, but I am here.

This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.

Hello Makr, read your thread on 2strokeworld and am amazed by the amount of work and detail you have put into this project. The powercurve is impressive to say the least. I believe a lot of people would like to know more about your project.

[Frits Overmars]

frits you might be happy to know I made a mistake and after some thought I revised these cylinders so water can go fully around the exh port.
sometimes you have to look at something a few times before you see a better way .

I'd say you improved the aesthetics as well as the cooling .

Is there a way to utilize flowbench data in the simulation?

In theory we could collect flowbench data per crank degree of port opening for each port and then use these data to create angle.flow tables instead of angle.area tables for the sim to work with. But getting the proper flowbench data is far from simple.
Let's take a look at the blowdown phase. The cylinder pressure at the start of the blowdown phase can be as high as 12 bar, creating sonic outflow. A flowbench may be able to generate a pressure differential of say 200 mbar; it's no comparison.
The second factor is inertia. The mass of gas in an exhaust duct is accelerated to Mach 1 within a couple of crank degrees. A regular flow bench generates a nice constant flow - no acceleration at all.
True, we could build a pulsating flowbench. But we would also have to operate it with a gas at 12 bar and 1800°C...
Luckily such devices exist. They run on petrol; we call them engines .

I just lurk on this forum, but I am here .
This is my build. Not much has ever been posted on it, but if you are interested I am would be happy to share. It made within a HP of what wobbly figured it would.

Hey Mark, welcome. Good to have you with us.

Do you typically lean the mixture with boost bottles? I have a CR 125 that needs help on the low end.

A boost bottle causes a somewhat more constant flow through the carb, with weaker suction pulses, so less fuel gets added to the air. In short: yes, it weakens the mixture. I think I wrote a bit more on boost bottles here in the past but I can't find it right now.
One more important aspect to watch: unless you mount the boost bottle with the connecting hose at the lowest point, fuel tends to collect in the bottle, upsetting the mixture strength at certain revs.

[41juergen]

I played a bit more with the ExDuct and "stinger" design as Wob recommended. That's the Mach numbers which gave the best power. Are these data close to what is reasonable?
BTW: Yes, I collect all comments from you guys having much more know how than I have to learn more about these tricky machines... Thank's a lot!

[1948rod]

hi would a water cooled first section of the ex. header be a help to cool returning ex gases after transfer closing. a fabricated header with inlet from around ex. port like wobbly post with outlet on top of header. a seperate inlet and outlet using the water out of top of head before it returns to the rad. could be used. this would be easy to do on 100cc kart engines and also incorporate the nozzle if required. love your forum.

[Frits Overmars]

hi would a water cooled first section of the ex. header be a help to cool returning ex gases after transfer closing. a fabricated header with inlet from around ex. port like wobbly post with outlet on top of header. a seperate inlet and outlet using the water out of top of head before it returns to the rad. could be used. this would be easy to do on 100cc kart engines and also incorporate the nozzle if required. love your forum.

The idea is sound, 1948rod (my year of birth). But in a well-designed engine the washed-through fresh mixture doesn't make it all the way into the header; it stays in the exhaust duct of the cylinder. Water cooling the first section of the header would withdraw energy from the spent gases at the expense of pulse strength.
Maybe your scheme could work in those 100 cc kart engines because I seem to remember that those had extremely short exhaust ducts.

[peewee]

frits did you say the volume of water in the cooling system should be small and move fast ? is it like a small pot of water on the stove could absorb the heat a lot faster than a large pot of water ?

[Frits Overmars]

frits did you say the volume of water in the cooling system should be small and move fast ? is it like a small pot of water on the stove could absorb the heat a lot faster than a large pot of water ?

A small pot of water will absorb heat slower than a large pot. Moreover the water in that small pot will heat up quicker, so the temperature difference between water and stove drops, slowing heat transfer down even more.

I didn't say the volume should be small. I said that a large volume of slow-moving, almost stationary water is not effective. Water passages should be narrow so that most of the water is in contact with the walls instead of flowing down the middle without touching the hot metal surfaces. Narrow passages will also keep the flow velocity up, which helps heat transfer from those surfaces to the water.

[Makr]

I would love to see much more posted of your work. ...

Had a good read on your two stroke forum. Really excellent work, lovely machining. Shame about the cancellation of speed week, patience is a virtue!

Here's a picture of the race bike we have just finished with a three piece CNC barrel and CNC air cooled head, it pulls outrageous hp and torque figures for its bucket racing restrictions. Will post up more pictures tomorrow.

Thank you. Yes, it is a shame. My family's first year out there was '74, so most of my life has been landspeed racing. The state of things makes my heart hurt.

Cool bike.

Hello Makr, read your thread on 2strokeworld and am amazed by the amount of work and detail you have put into this project. The powercurve is impressive to say the least. I believe a lot of people would like to know more about your project.

Thanks. I give a huge amount of credit for the power it makes to wobbly. That guy is a genius, and feel honored he helps me.

Hey Mark, welcome. Good to have you with us.

Thanks Frits.


Not really sure where to start. Wob and Frits have seen most of it, and it seems the TSW thread has been viewed.

I run a Yamaha RD400 on the salt flats with a RZ case and transmission. The rest is mine. I have to keep the stock case to keep in the class I am running.





So from my 2014 engine to 2015 I went back to iron liners, made the transfers much bigger, went to larger reed, and carbs. I also ran coolant under the crankcase, which I hope was worth something because it was a pain in the ass to do. Partially because I am a fair-at-best welder.



I connected the webbed pockets as a maze and then capped the pockets.

[seymour14]

Hope you don't mind TZ, will pop some of the old work on your site for posterity, it seems to get some great viewing internationally and is a pool for all time...

Here is that CNC billet build, will show some of the end stuff first so that it can be followed easier. Essentially it was a two piece barrel, head, and sleeve, all CNC'ed.

Good to know I am not the only sadist on this planet, it's a lot of hard work to knock up that first one...

Air cooled 125cc Two stroke, based on a KR150 bottom end for bucket racing.

First photo is very early on, barrel is barely machined, the lower part in the photo gets spigotted inside the barrel and forms the "swept" intake, sleeve is second photo, head barrel and exhaust stub in the last.

[peewee]

A small pot of water will absorb heat slower than a large pot. Moreover the water in that small pot will heat up quicker, so the temperature difference between water and stove drops, slowing heat transfer down even more.

I didn't say the volume should be small. I said that a large volume of slow-moving, almost stationary water is not effective. Water passages should be narrow so that most of the water is in contact with the walls instead of flowing down the middle without touching the hot metal surfaces. Narrow passages will also keep the flow velocity up, which helps heat transfer from those surfaces to the water.

I think I get it. with less temperature difference there will be less heat transfer to the water ? ive got to either buy a radiator or have one made (either larger or smaller than whats currently available, based on what ever advice you could give me). this is a methanol drag racing bike remember. to reduce weight ive seen some guys use just a very small rectangle aluminum tank, so water can still be pumped through the cylinders and head but there is no fins or tubes on the tank, basically just a rectangle alloy box. other guys use a radiator but its very small, to reduce weight I suppose.

i guess those methods would work for one run and shut the engine off but i need a system that offers good cooling for continuos multiple runs. from what ive seen, the water temp is lower with methanol but eventually it starts to creep up near that of what you would expect from a average 2t gas engine. do you have any rule of thumb for radiator size ?

[peewee]

those look like mikunis ? im looking for some carbs around 40mm that will still function halfway normal while slanted forward at a fairly steep angle. i was thinking of lectrons unless theres something better thats readily available . do you have any advice on this ?

[41juergen]

Thank you. Yes, it is a shame. My family's first year out there was '74, so most of my life has been landspeed racing. The state of things makes my heart hurt.

Cool bike.



Thanks. I give a huge amount of credit for the power it makes to wobbly. That guy is a genius, and feel honored he helps me.



Thanks Frits.


Not really sure where to start. Wob and Frits have seen most of it, and it seems the TSW thread has been viewed.

I run a Yamaha RD400 on the salt flats with a RZ case and transmission. The rest is mine. I have to keep the stock case to keep in the class I am running.





So from my 2014 engine to 2015 I went back to iron liners, made the transfers much bigger, went to larger reed, and carbs. I also ran coolant under the crankcase, which I hope was worth something because it was a pain in the ass to do. Partially because I am a fair-at-best welder.



I connected the webbed pockets as a maze and then capped the pockets.

That is an interesting setup how you cool the case. I'm working on the same idea on my RZ with taking a smaller amount of water coming from the pump leading through the case and than back to the radiator... Have you already run the engine with that case cooling, did you found significant gains?
Juergen