ESE's works engine tuner

[cotswold]

Thanks to Rob and Culley I have made a start on porting the cases. It's amazing how much metal is removed.

The first picture is the disc valve cover

2nd The standard cases and what I'm aiming for

3rd half way there

4th Nearly finished just need to glue up the back of the left hand case to be able to put the rear port in

5th is what happens when you get carried away

The last is the left overs

[cotswold]

Robert junior wants to know whats gone wrong with his crf250?

Attachment 275198Attachment 275199Attachment 275200Attachment 275201

any clues as to why it locked up in top gear on him?

Too many parts?

[wobbly]

Actually Lozza is right - here is tomorrows job.
Fully expalins the dark area over the exhaust - a heap is short circuiting.

[TZ350]

TeeZed those transfer dividers apper to be the wrong way around, they are pointing AT the exhaust port.

Good spotting, yes they do, now that's weird ..... I better have another look.

[TZ350]

The rear faces forward, I think this is right but I think it could benefit from having a hook in it.



I had tried to have the front of the B ports aiming straight across the barrel but they are more forward than I thought.

[TZ350]

Thanks Wob

Actually Lozza is right - here is tomorrows job.
Fully expalins the dark area over the exhaust - a heap is short circuiting.

Ok so the front of the A's need to sweep back some more.



Wob I intended to have the front of the Bs directly inline with each other across the bore, is that a good idea.

[husaberg]

Attachment 254336CRECY ..... sleeve valve 2-Stroke, one of the most powerfull internal combustion engines ever made.

A quick Google (and display "Images") brings up some interesting info.

Really? How many ponies are in there? 3000? This will teach you to be more careful with your remarks, TeeZee

Arrrr words and the games we play with them ... ... Glad I said "one of the most powerfull", actually its a bit of a tiddler compaired to yours. I wanted to say aero engine but that would have given the game away. Maybe I should have just said "big grunty engine compaired to a Morris Minor".

Attachment 254373Attachment 254370 development was heading towards 5,000 bhp


There are various numbers bandied about, but this from Wiki.

The progress of jet engine development overtook that of the Crecy and replaced the need for this engine. As a result the project was cancelled in December 1945 at which point only six complete examples had been built, however an additional eight V-twins were built during the project. Crecy s/n 10 achieved 1,798 horsepower (1,341 kW) on 21 December 1944 which after adjustment for the inclusion of an exhaust turbine would have equated to 2,500 horsepower (1,900 kW).^[11] Subsequent single-cylinder tests^[12] achieved the equivalent of 5,000 brake horsepower (3,700 kW) for the complete engine. By June 1945 a total of 1,060 hours had been run on the V12 engines with a further 8,600 hours of testing on the V-twins.^[13] The fate of the six Crecy engines remains unknown.

Here a bit of history on disk valve engines, yes there is a 2 stroke cosworth in there , near the bottom, the Junkers torpedo engine is pretty interesting too

http://www.douglas-self.com/MUSEUM/P...aryValveIC.htm

ok i was reading a old book today and came upon reference to a project in the late 70's or early 80's it was the Excalubur project it was secribed as one of the most ambitious projects since ww2 to produce a racing motorcyle engine that was Cross head design piston with a Sub-head primary compression and sleeve piston arrangement in a totally balanced configuration.
the 125cc versions target was 50HP at around 22000rpm.
i had a bit of a google search and the only half way acceptable references to Excalibur i find are to the rossi like powerboat..
but with the sub head i find these anyone know about the project i guess Frits may..............
i guess it is the mix of the Creasy and the ones below?



http://www.marinediesels.info/Basics...scavenging.htm

[wobbly]

Yep, the front wall of the B port should be perp to the bore CL.
The rear should hook and intersect 1/2 way between bore centre and the boost face, with a big rad in the corner right to the bore.

[TZ350]

Thanks Wob

I went back through the thread pictures and found this one.

[TZ350]

I wanted to fit another piston that has the ring gap in a better place.



FarmerKen put me onto this 86 YZ125 piston with a dome. I had been using the flat top piston because that made it easy to form the squish with a flat copper plate. But I guess now is the time to change.



The dome is good in lots of ways, one of them means that I can have a head shape like Frits and Wob suggest for leaded fuel.



Because of the dome I have to take 2.5cc out of the head, so its easy for me to get that flat dome head shape.



The purists mighten approve but this is the quick and dirty way of measuring the crown angle using the cross slides angle adjustment. And disapproving purists certainly don't want to know how I cced the head as I opend the chamber up but in the end it worked out real well.



A big thanks to Gigglebutton for letting me use his lathe.



If I need to go there later, there is enough material left to carve a toroid head and lower the compression a bit more for unleaded.

[husaberg]

Thanks Wob

I went back through the thread pictures and found this one.

not sure if this was the rotax or aprilia

[TZ350]

Thanks Husa ...

[husaberg]

I thought I'd ask the smart people here a question if I may. I've been planning to build a dyno and have been working on design and finding materials. Yesterday I happened across this:

It's an old Heenan Froude water brake. Funny, it's been sitting in my machinists shop the whole time we were talking inertia dyno design ideas and he never mentioned it until yesterday when we were at another shop having one of his race car motors dyno'd lol.
I was wondering if, say money were no object LOL, would I be better off converting this with a modern load cell, sensors and software or should I stick to my original plan of an inertia dyno. Or maybe there's a third option I haven't thought of?
TIA

My first brake (we're talking 1978) was a Heenan & Froude, same as yours, only a larger version.
The main problem was that its torque absorbtion curve was less steep than the torque curve of a racing two-stroke. So either the engine rpm would be stuck at a point somewhere in the torque dip, or it would shoot right past max. torque rpm, past max. power rpm and even past max. mechanical safe rpm.
A partial solution was to triple the water pressure in the whole system, but stabilizing engine rpm via the brake's handwheel remained a hell of a job.
My advice: stick to your original plan of an inertia dyno.

Dead right Frits.
All the water brake dynos I have seen that worked well with high output 2Ts needed additional inertia,to enable the operator,or the software
to adjust the valving quick enough to get anything like a consistent load .
Even the best well adjusted PID loop control goes bananas trying to hang onto the rate of change a good 2T produces.

i am the messenger remember..............
i can't say i totally agree with the article but it is interesting i will post Berts air paddle dyno photo later.

Notice in the picture Bill Lacey responable for the last single cylinder win in the senior Manx 1961 against the MV4's no less (ok so they broke) (Hailwood plain bearing big end and Jag rod) holder of many records pre ww2 war as a rider/tuner (he preferred to be called engineer)on his own bikes.he also worked on GP car engines.

[Yow Ling]

Seeing as F4 is way too fast , F5 is dominated by the 50cc zealots from Wellington, if i have any chance of ever winning a title I will need to create my own class F6

49cc single speed pre 1960 that should narrow the field a bit

Heres my entry, after reading in depth about small frontal area , light weight skinny tyres I have arrived at this formula



maybe some of the senior bucket guys like speedpro can shed some of their wisdom as he can probably remember them when they were new

[TZ350]

I love it ...