ESE's works engine tuner

[husaberg]

TeeZee, I saw no "Delete" box at all. (I have endless problems with this laptop, this steaming pile of dog-doo, possibly because its running Win 8.1. A local kid, computer whiz, says he's going to help me convert to some form of Puppy Linux; I hope that helps me).

Edit post then press advanced. You should have enough posts by now for this function to be enabled.

[breezy]

"Lower operating temperatures of all power-connected engine parts, cylinder and pistons, Harry Ricardo showed that as long as the clearance between sleeve and cylinder is adequately settled, and the lubricating oil film is thin enough, sleeves are 'transparent to heat'."

this is a quote i came across from hours of surfing Harry Richardo information..., if i can find the source again, i will post.

[wobbly]

I built a Mac 101 sometime last century with 4 carbs.
Two were on the "bottom" of the crankcase feeding thru pyramid reeds, and one on each side feeding thru plate reeds into
the transfer cavity's.
Who knows if it needed that much intake area, and yes it was real easy to "port" the cylinder by simply removing the transfer cover plugs
and squaring up the round drilled holes with small files.
This was also the time I made my first pipe for a 2T engine, having discovered everything known to man about racing twostrokes in the little red book.
I could never get it to run properly though, it would be fine outside the powerband and crap inside, or visa versa.
Then I discovered the Vevey rear cone concept, added a progressive linkage so each pair of carbs opened independently, and it finally won an open title.
Would love to find that thing, just to remind me how dumb I was.
Also prompts me to remind you guys that in here, the vast majority of people have big trouble getting a conventional 2T anywhere near its real potential.
But we are now discussing all manner of weird arse ways of making what is really a simple system, way more complicated ?

[Flettner]

I built a Mac 101 sometime last century with 4 carbs.
Two were on the "bottom" of the crankcase feeding thru pyramid reeds, and one on each side feeding thru plate reeds into
the transfer cavity's.
Who knows if it needed that much intake area, and yes it was real easy to "port" the cylinder by simply removing the transfer cover plugs
and squaring up the round drilled holes with small files.
This was also the time I made my first pipe for a 2T engine, having discovered everything known to man about racing twostrokes in the little red book.
I could never get it to run properly though, it would be fine outside the powerband and crap inside, or visa versa.
Then I discovered the Vevey rear cone concept, added a progressive linkage so each pair of carbs opened independently, and it finally won an open title.
Would love to find that thing, just to remind me how dumb I was.
Also prompts me to remind you guys that in here, the vast majority of people have big trouble getting a conventional 2T anywhere near its real potential.
But we are now discussing all manner of weird arse ways of making what is really a simple system, way more complicated ?

You are absolutly right Wayne but isn't interesting anyway? I like looking into engines just like you described above.

[breezy]

this is a quote i came across from hours of surfing Harry Richardo information..., if i can find the source again, i will post.

T S M uniflow ... noticed this web site via google,,, wonder if its up and running?

[Flettner]

No, have a look at the bucket foundry posts there you will see the cases for the sleeve engine as of yesterday. I'm hoping by the end of today to have them ready to cast. These same cases will also have the FOS / variants fitted and run as well. It has provision for a balance shaft. Flettner = Uniflow, same person.

[seattle smitty]

[QUOTE=wobbly;1130811832] . . . Also prompts me to remind you guys that in here, the vast majority of people have big trouble getting a conventional 2T anywhere near its real potential . . . (QUOTE]

Who? ME???? And why do you think I'd want to be reminded, Wobbly?LOL. Throwing water on our fun, that's cold, man!! Has your Christmas spirit departed already?LOL

An old-timer who has hung four carbs on a McCulloch (and some of us used to grind bridges between ports entirely out, rather than squaring them) ought to have some empathy for our weird speculations, LOL. Come on, Wobbly, pg. 1074, #16109. Tell me it's stupid, whatever, I want to hear whatever you think of it.

Yeah, getting the timing right, getting the carburetion spot-on, getting everything lock-wired, and getting a perfect start and beating the pack to the first turn . . . that actually would pay off better than having the craziest engine in the pits, but 2-stroke guys aren't just racers, we're gear-heads, wild-eyed maniacs with rotary files. It's often an incurable condition.

I'm 21 hours and 10 minutes into the new year and haven't screwed anything up yet!!!

[peewee]

hey wob im sure some how theres a way to determine the correct size of carb for any specific engine but i dont have any idea how to figure it out. on engmod STA page it lists a recomended size of carb. do you see any reason i shouldnt use ( or atleast start with) the carb size it recomends ? also what happens when the carb is to big for the engine ?

[F5 Dave]

C`mon Smitty you come across as a bit aggressive and we actually like having Wob on here. Don't piss on him.

[breezy]

T S M uniflow ... noticed this web site via google,,, wonder if its up and running?

ok...., when i read on about the efi bike it started to sound familiar. ... best of luck . you managed the efi so i recon youll be sucessfull with this.( just flicked through the posts... where was i when this was going on, cant believe ive missed so much)

[Frits Overmars]

This doesn't have to be a sleeve whose finished I.D. forms the cylinder bore. It can made as a ring, sitting in a wide slot just barely below the exhaust ports... You could have this ring-sleeve rotate rather than move up and down, to reduce the port area...(sorry I can't make a sketch).

Preventing spent gases from entering the transfers is the main purpose. That will only work if the blowdown phase is lengthened, so the transfers must be lowered. Smitty, I am trying to picture your proposal in my mind, but I have a hard time doing that without a drawing.

A hinged piece(shaped to fit up into the transfer port roof as close to the bore as possible),hinged at the outside radius where there is more meat in the cylinder.

I envisage something like a "comma" shaped piece lying horizontal forming the roof of the transfer port. It would pivot on a shaft through the part that would normally be the top part of a written comma. In the position with the comma fully raised it would form a smoothly contoured transfer duct outer wall and port top/roof. Pivoted to a lower position obviously the roof slope would decrease as would the proximity to the cylinder wall.

I'll get back to this further on.

One could even retrofit a conventional existing cylinder to test out various mounting methods.Just make the comma, grind out a recess in the transfer port roof, figure a way to have it rotate around a pin and then on to actuation.

This may actually do some good to the power characteristics of a conventional engine. Maybe even a lot of good.

What also is abundantly clear is that there is stuff all room between the floor of the exhaust and the roof of the transfers... Still, I have the feeling that right now there are lots of dudes on the case at present.

I enjoy that same feeling. I love brainstorming with you guys!

With my ring-sleeve, if you make it move up and down, you only need two pushrods, one on either side, ganged together outside the cylinder.
And although your comma-valves are not "in" a high temp environment, they are very close to one, could pick up a lot of heat, could transfer that heat to the intake charge.

Without the moveable part that metal would be in direct contact with that same exhaust floor....so it should be actually be cooler than originally.

That's right. The temperature of the original transfer roofs would be like that of the A-transfer roofs in a conventional cylinder with auxiliary exhausts.
Keeping the roofs cooler will improve cylinder filling and deto resistance.

have a look at the bucket foundry posts there you will see the cases for the sleeve engine as of yesterday. I'm hoping by the end of today to have them ready to cast. These same cases will also have the FOS / variants fitted and run as well. It has provision for a balance shaft. Flettner = Uniflow, same person.

Some person! I wish you would live around the corner instead of around the world. Could you give us a link to those posts Neil? It would save me some time.
It may amuse you guys to know that I've spent more time on this forum than on all other forums put together over the whole year (2015, that is ).
While 'm on the subject: best wishes, everybody!



The comma shape can definitely be made. But for my purpose, preventing spent gases from entering the transfer ducts, and functioning as throttles, I see a problem. Because my transfer ducts are tapered towards the cylinder bore, the commas must be tapered too. But because of their swinging motion this means that in certain comma positions gaps will arise between the side walls of the commas and the side walls of the transfer ducts. There will also be gaps between the inward tips of the commas and the cylinder bore. Spent gases entering the volume above the lowered commas can still enter the transfer ducts via these gaps.

What I'm thinking about right now, is something along the lines of the sketch below. On the left you see the current situation; on the right I've added curved yellow 'fingers', bolted to a red ring that can slide up and down. It's all still far from perfect; the red ring gets in the way of the inlet flow, although maybe it can be shortened at the inlet side, and I haven't given its guidance much thought yet either.

[seattle smitty]

C`mon Smitty you come across as a bit aggressive and we actually like having Wob on here. Don't piss on him.

No, no, I was pulling his leg, Dave!! Wobbly, you knew that, right?? Dave, nobody values Wobbly's generosity here more than I do, or needs it more. I'll go back to that post and put in some LOLs and smiley faces (the emoticons weren't working yesterday, for me). Maybe my tone there didn't translate from Merkin to Kiwi.

[husaberg]

Some person! I wish you would live around the corner instead of around the world. Could you give us a link to those posts Neil? It would save me some time.
It may amuse you guys to know that I've spent more time on this forum than on all other forums put together over the whole year (2015, that is ).
While 'm on the subject: best wishes, everybody!

.

Sleeve valve crank case patterns. Bit of a half assed way to build them but too bad this is how it's going to be. Note the cavity to house the balance shaft. Gearbox is YZ250.

Not Neil but this is the thread.
http://www.kiwibiker.co.nz/forums/sh...post1130811501

[peewee]

can any engmod experts give me some advice. on the subsystem screen where it says edit engine, edit exh port, edit transfer port, edit inlet port etc etc, when i try to click on edit exh type and data a box pops up that says 'this exhaust system is meant for a 0 cylinder engine', when i click OK it makes me stay on the subsystem screen and wont let me go the the exh pipe screen. i was going to contact neels about it but figured i would ask here first in case its a simple problem. ive used engmod for other engines and never had this problem.

also when i click exit program to close the whole program another box pops up that says 'error in exhaust sytem file'. ive never even gone to the exhaust file yet on this particular engine. i put in all the general engine data and all the exh port, transfer and inlet port data. i was just now getting around to putting in the exh pipe data but it wont let me get there because the box keeps poping up

[Flettner]

http://twostrokemotocross.com/forum/...lk/yz-250-efi/

http://twostrokemotocross.com/forum/...2196/#msg52196

So that's how it's done? Do these links work?