ESE's works engine tuner

[Flettner]

Come on Harry, word up! I'm sure I speak for everyone here

[marsheng]

Absolutely typical failure of a W big end cage -
The bearing size is non standard, none of the major factories list it, 25/32 is the norm.
25 mm solid pins are available in 60.5 and 64mm cheap as chips off the shelf.

Excuse my ignorance but what is a W big end ?

Where do I get bigend pins from? I've obviously been looking in the wrong places.

I hope the INA bearings will be better.

Maybe time to look at a YZ250 crank upgrade.

[husaberg]

The conrod is still good and I'm told to get INA conrod bearings which are
supposed to be the best. I can't find there here. Anyone got a source ?
25*31*17.



Cheers Wallace.

DT250 AND TS250 ARE THE SAME MEASUREMENTS ONLY WIDER.
TKRJ list one that is Silver plated and 25x31x16.8.
93310-424L8 25x31x16.8 GX0570G GX AG ( it will be W Type though)
http://www.tkrj.co.jp/product/m-be-bearing.html
As wobbly said it is a silly size Honda ran 25mm pins on the GP bikes as well.
Pro X Samarain and Kevin breedon offer nothing in these sizes.
Change your pin size or conrod or both.
The only other option is the specialist stuff for Maicos try one of there web pages.

Or Honda CR250 Rod kit 2002-2007

[TZ350]

page 1280 .....

(Insert long sigh here) I hate, I hate to ask this, because I know I've seen the answer somewhere, ... but could one of you skilled info-locators please once-and-for-all-time give a detailed step-by-step set of search directions here, to show us how to find something WITHIN the ESE superthread.

Seattle Smitty's original post, is the start of a short thread with many tips on how to search and find good stuff on the ESE thread or any thread for that matter.

Instead of the usual collection of useful technical stuff its maybe time to celebrate the efforts of those doing their own work tuning and interesting engine modifications. Go to the original posts to see the pictures.

hey guys im going to start a yamaha project pretty soon and split my time between it and finishing this ktm project. luckily i learned alot about welding just in the last few months on the ktm, as this yamaha will have some welding also but not near as much as the ktm. i got some ideas to accomplish things such as raising the exh floor with far less welding and heat warpage so i hope they work out like i think. once i get going ill have some pics. anyways i just wanted to see what my welds looked like today in comparison to a few months back. hopefully i can continue to learn even more as i find welding quit a bit of fun. blob of shit on the left was few months ago and the bead on the right is from today

My personal favorite is the idea of starting completely from scratch to learn something new like PeeWee's has with his welding so he can build the ultimate cylinder. I am very impressed by that.

The ports may need to be bigger yet but this is as far as i made it tonight. theres a before pic to compare. every corner was sharp as a razor

Well i got the cylinder back from the machine shop and all things considered i think it turned out well.

what you think. should be able to put some nice tea cups in now. lost count of how much filler was used but i think it was somewhere around 7 or 8 rods at 3' x 3.15mm. also took some molds of another cylinder so i have a 3D visual guide on how to make the radius twist on the front side of A as ill do a similar window shape with this other cylinder

Made a mold of the transfers today. i think what im going to do is run a bead or two on the outside of the cylinder and then use devcon on the inside wall so i can get a nice big radius through the duct. the plate attached to the cylinder bottom was nothing more than a half ass heat sink in hopes the gasket surface wouldn't pull down. one side stayed pretty flat. the other side sunk about .16mm (which is good enough for me) for you metric folks. i guess it should be more like the blue line

Blended exhaust, this is what I made for our 6.5cc engine, the reduction at the oval is 75% of the projected exhaust area. I did not take into account curvature of the liner, radius 10.19mm. The shape to oval takes place over a distance of 7mm at the shortest part, about 10 mm at the corners for the top and outer edges of the exhaust.

The pipe header is 15.0 mm diameter, and the oval is 15mm wide and 9.9 mm high. From the oval to the diameter, That part was turned as a taper from 15mm to 9.9 mm diameter. Then I just used a 3/8 endmill to make a slot through the assemble cutting an oval 9.9 x 15.
You can see from 1 picture the shape of the exhaust and the faceted looking blend, but that is the cad. Then you will see the round to the oval and the bottom area that has a small step.

I tried an adapter that was like a wire cut from the oval to the diameter 15mm header. But there was no measurable power gain or any benefit from the extra work compared to the turned taper and an oval slot put through.

The oval to round is over a length of about 20 mm or so. It's not a motor bike but the idea really does work. I can't tell you why exactly that it works though. Hopefully this will be of some help to someone.

Attachment 314026

Are you trying to copy my sleek design!?

Attachment 315045

Here's the iame m50 cylinder, got it a few days ago. It's so tiny it's ridiculous!


Attachment 312254Attachment 312255Attachment 312256Attachment 312257Attachment 312258

Meassured primary volume @tdc is about 242cc, will probably end up around 250-255 if I add material to the cylinder and match the ports to my case, or around 230-235 if I weld up the case transfers. Hmm... What to do?

Attachment 312254Attachment 312255Attachment 312256Attachment 312257Attachment 312258

Meassured primary volume @tdc is about 242cc, will probably end up around 250-255 if I add material to the cylinder and match the ports to my case, or around 230-235 if I weld up the case transfers. Hmm... What to do?

Attachment 313908Attachment 313909Attachment 313910Attachment 313905Attachment 313906Attachment 313907

A “ROUGH AS GUTS” EXPERIMENT Part 1

The question is, what happens when you:
1. Get a 100 cc ARC piston port kart engine, essentially very similar and with many interchangeable parts with the Yamaha KT100S kart engine, and connect an A port to atmosphere via a filled in passage to a flanged face. Height of the port is unchanged from the original engine.
2. However, when at TDC, there is a direct passage (something we don’t want, do we?) to the crankcase via the cut-out in the side of a regular piston
3. So we weld a small piece into this side of the piston to block it off and while we are there we’ll drill a series of holes into the rear of piston to vent thru the open piston port inlet so there’ll be no great pressure fluctuations in the crankcase

Part 2 coming

Attachment 313911Attachment 313912Attachment 313913Attachment 313914


A “ROUGH AS GUTS” EXPERIMENT Part 2

4. So there’s no influence due to extraneous cylinder connected volumes in the upper cavities of the blocked off transfer passages (1 * A & 2 * B), we fill these flush with Silastic
5. Then we bolt it all together with a carb, but with no exhaust system
6. Crank it over with a few squirts of oil into the crankcase, check it out and it is all nice and oily, as one would expect with a wet sump.
7. Fill the carb with fuel only (no oil), ignition on and crank it over.

Simple really and I did say “rough as guts”.

WODDAEWESREKKON happens then?

So it's bloody impressive looking at the build over the past year.

[TZ350]

Excuse my ignorance but what is a W big end ?

It is the shape of the cage, if you look at a cross section it looks like a "W".



Flat bearing cages are preferred, preferably silver plated or better yet Peek coated.

[J.A.W.]

Scroll down this link & check out the R.E. Olds patent diagram/drawing..

http://blog.hemmings.com/index.php/2...stroke-diesel/

Mayhaps something familiar/similar there?

[marsheng]

It is the shape of the cage, if you look at a cross section it looks like a "W".



Flat bearing cages are preferred, preferably silver plated or better yet Peek coated.

Thanks I now understand.

The conrod is 132 mm eye to eye which puts it into its own category. I looked up many models and the YZ250 looked close with a length of 125mm. The stoke on the Maico is 70 and the YZ 68 so it is possible.

I found the JKJR bearings yesterday but thought that INA may be better. Bugger, as I just had a shipment from THJR last week and would have been easy to add a few in.

The problem with 'Maico' agents is, where are they made? I see several sellers of bits and on closer inspection, they are Royal rods made in Tiawan. The problem is that the so called Royal Maico 250 rods have a 22 mm pin. No Maicos I know of had a 22 mm pin.

The do however have a flat bearing cage.

Thanks for the input Wallace.

[peewee]

Attachment 315094Attachment 315095Attachment 315096

thats weird. my piston looked nearly the same after trying amsoil

[F5 Dave]

132? That's houwge, are you sure? But Japanese rodkit upgrade will get you ahead and provide cheap parts for future rebuild.

[husaberg]

Thanks I now understand.

The conrod is 132 mm eye to eye which puts it into its own category. I looked up many models and the YZ250 looked close with a length of 125mm. The stoke on the Maico is 70 and the YZ 68 so it is possible.

I found the JKJR bearings yesterday but thought that INA may be better. Bugger, as I just had a shipment from THJR last week and would have been easy to add a few in.

The problem with 'Maico' agents is, where are they made? I see several sellers of bits and on closer inspection, they are Royal rods made in Tiawan. The problem is that the so called Royal Maico 250 rods have a 22 mm pin. No Maicos I know of had a 22 mm pin.

The do however have a flat bearing cage.

Thanks for the input Wallace.

There is a longer rod for the YZ250 130mm length 1989 is the year this was std in.
its a common mod for Late YZ's.


I have also seen some Euro sites where they sell stuff for VMX.
I could try and did out a few old mags.
But seeing as you are an engineer I would build your engine around common stuff I will try and get the measurements on the YZ250 89 rod.

[marsheng]

[QUOTE=husaberg;1130894540]There is a longer rod for the YZ250 130mm length 1989 is the year this was std in.
its a common mod for Late YZ's.


The YZ250 looks like a great option. Slightly wider big end and the bike was rated at 48hp so this should work well.

I'll look into that.

The small end is 23 compared to the Maico 22 but I'm sure I can find a bearing for this.

Thanks again.

[husaberg]

[QUOTE=marsheng;1130894563]

There is a longer rod for the YZ250 130mm length 1989 is the year this was std in.
its a common mod for Late YZ's.


The YZ250 looks like a great option. Slightly wider big end and the bike was rated at 48hp so this should work well.

I'll look into that.

The small end is 23 compared to the Maico 22 but I'm sure I can find a bearing for this.

Thanks again.

But wait
PS I have no idea what the odd one is from.

[manolis]

Hello Kiwi

Hello Husaberg

The volume above the exhaust ports (post #9172):



seems difficult to be scavenged (lots of residual gas).
Reasonably it will operate much hotter than the conventional 2-strokes.

The exhaust valve:



is simpler but, as the sleeve valve, has several issues: hot (it is a metal grid, like a radiator, through which all the exhaust gas passes, it abuts heavily – and moves at the same time - onto the cylinder head, it requires sealing means at various points, it requires strong actuation mechanism. What about the spark plug?


Here is an unconventional rotary valve:



(more at http://www.pattakon.com/pattakonPatRoVa.htm )

The compression –combustion – expansion pressure loads heavily two opposite surfaces / fronts of the rotary valve. But the force on the one front counterbalances the force on the other front (through the hub) leaving nothing to the bearings.

The lower cylinder wall can be full of ports (transfer or exhaust, depending on what the rotary valve is for).


For asymmetric intake without reed or disk valves, the PatATi approach can be used:



Youtube video at http://www.youtube.com/watch?v=aXvRaVqiHxs





(more at http://www.pattakon.com/pattakonPatAT.htm )

In the PatATi a properly shaped connecting rod in cooperation with a properly shaped piston opens and closes asymmetrically intake ports on the cylinder liner.




The PatRoVa rotary valve better fits with 4-strokes:

Youtube video at http://www.youtube.com/watch?v=6Q-EGdeS0ws




(the underneath mechanism:



shwon better in the following drawings:





is unconventional only because it was available when the PatRoVa prototype was made.

(before reading at http://www.pattakon.com/pattakonPatTwo.htm think what the trottle with the lever in the last drawing is for).

Objections?
Questions?

Thanks
Manolis Pattakos

[husaberg]

Hello Kiwi

Hello Husaberg

The volume above the exhaust ports (post #9172):


seems difficult to be scavenged (lots of residual gas).
Reasonably it will operate much hotter than the conventional 2-strokes.

The exhaust valve:



is simpler but, as the sleeve valve, has several issues: hot (it is a metal grid, like a radiator, through which all the exhaust gas passes, it abuts heavily – and moves at the same time - onto the cylinder head, it requires sealing means at various points, it requires strong actuation mechanism. What about the spark plug?



(before reading at http://www.pattakon.com/pattakonPatTwo.htm think what the trottle with the lever in the last drawing is for).

Objections?
Questions?

Thanks
Manolis Pattakos

The Grate sliding valve was a muse

I could not be worse than a poppet valve and look what they have been developed into.
I do really enjoy your animations.
That cutaway piston I posted was actually raided from one.

This one I do like. but maybe with the top end crosshead guided?


The rotary valve prototype is interesting not unlike the Coates and the Aussie (Deane) only done differently.
The prototype engine is fashioned/fabricated together in the manner of the Autounion f1 engines. neat

I do like the creasy engine Why?
Because after only a few rushed years they were better and more reliable than a conventional engine development only stopped because the turbines were better again.
With some devolvement R&D and modern metallurgy who knows.
I added it in as I could see no other reason for the "Twist" in Ryger

[breezy]

Manolis... great post, excellent animations