ESE's works engine tuner

[F5 Dave]

Why do you think it will fail, Dave?


Dave.

He needs a sustained 25hp from an aircooled bike that will be under load for a serious amount of time & a considerably oversquare linered arcane engine with quite a small carb. + it doesn't sound like he has the experience with small engines.

Yes it can be done. Speedpro's engine downsized to 83cc handily makes 25hp, but that is assuming a shrink ray type shrink, not just destroke it to 50cc bottom end & hope it will be as efficient.

Also there is the revs he is not talking enough to get that power I think.

I just don't see someone knocking it up in the timeframe of a magazine article. I predict a 92mph with a lot of 'gallant effort' & 'if onlys'

prepared to be proven wrong, best wishes & all.

[TZ350]

yeah I've been following that article on & off. Don't think hes got a chance,.Dave.

Why do you think it will fail, Dave?

As well as Dave's comments, did they publish any STA's for the ports, that would give us a few clues about what they might achieve, and if there is a target RPM and HP figure we could use the BMEP concept to judge if their engine performance target is possible.

Maybe it is possible, if anyone has the article, it would be interesting to know the details of their build plan then we could check it out with a bit of analysis to see what their chances are.

STA - specific time area.
RPM revolutions per minute.
HP horse power.
BMEP brake mean effective pressure.

[rgvbaz]

He needs a sustained 25hp from an aircooled bike that will be under load for a serious amount of time & a considerably oversquare linered arcane engine with quite a small carb. + it doesn't sound like he has the experience with small engines.

Yes it can be done. Speedpro's engine downsized to 83cc handily makes 25hp, but that is assuming a shrink ray type shrink, not just destroke it to 50cc bottom end & hope it will be as efficient.

Also there is the revs he is not talking enough to get that power I think.

I just don't see someone knocking it up in the timeframe of a magazine article. I predict a 92mph with a lot of 'gallant effort' & 'if onlys'

prepared to be proven wrong, best wishes & all.

I agree it certainly won't be easy but I found this on BDKs webpage, they recon just under 20hp at 10K, and 98 mph, here: http://www.bdkraceeng.co.uk/Bike5.html

A program I have that predicts top speed 1/4 mile etc also seems to think 21hp may just do it (with no wind on a nice day with no slope ) It also uses a predicted Cd.

Dave

Dave

[rgvbaz]

As well as Dave's comments, did they publish any STA's for the ports, that would give us a few clues about what they might achieve, and if there is a target RPM and HP figure we could use the BMEP concept to judge if their engine performance target is possible.

Maybe it is possible, if anyone has the article, it would be interesting to know the details of their build plan then we could check it out with a bit of analysis to see what their chances are.

STA - specific time area.
RPM revolutions per minute.
HP horse power.
BMEP brake mean effective pressure.

I did a little mock-up in EngMod, STA wise it can do about 27hp at the crank, but not sure about the inlet?

Dave

[TZ350]

STA wise it can do about 27hp at the crank ...

Thanks, being a fellow air cooled traveler and all, in my heart I would like them to succeed.

So it looks like they have half a chance, if the challenges F5Dave mentioned dont catch them out.

If your following their progress please keep us informed as I think its realy interesting.

[chrisc]

Thanks, being a fellow air cooled traveler and all, in my heart I would like them to succeed.

So it looks like they have half a chance, if the challenges F5Dave mentioned dont catch them out.

If your following their progress please keep us informed as I think its realy interesting.

I'm following their progress and will keep informed.
I thought about scanning and putting up the previous editions of the article but I don't want to piss them off. I wonder, because: you can't buy the old editions of the magazine, it may encourage you all to buy the future magazines and it's advertising for them. What you all think?

[RomeuPT]

I would like the opinion of everybody on this.

I will measure my engine primary compression (NSR 125 engine with old RS gp Cylinder), a couple years ago I have seen someone using grease to fill the exhaust and the reed cage, so oil does not exit the crankcase. What is the better way to do this? Thick grease and thick oil, so there are no leaks?

With the numbers Wobby as exposed he calculated primary comp. with the total displacement. In theory should'nt the displacement after transfer close also taken into account?

My idea is to fit a longer Rod, the crankcase is more enclosed a bit than the RS, but, because the cranck halfs have less volume than those of the RS 125 I suspect that primary Comp might be very identical. So if the value is already low I would have little possibility to play with rod lenght.

Regards

[TZ350]

What do you all think?

Ask them, and send a link so they can see were interested.

[Flettner]

Fuel injected twostroke second in national MX series. Only failures throughout the whole season were a foot peg braking off and a clutch bearing failure. EFI performed seamlessly through out the whole series. Who says EFI twostrokes can't work?
No it didn't come first but that's not the bikes fault!
It will be interesting to see how TZ's EFI works out.

[F5 Dave]

I agree it certainly won't be easy but I found this on BDKs webpage, they recon just under 20hp at 10K, and 98 mph, here: http://www.bdkraceeng.co.uk/Bike5.html

A program I have that predicts top speed 1/4 mile etc also seems to think 21hp may just do it (with no wind on a nice day with no slope ) It also uses a predicted Cd.

Dave

Dave

I've assumed 25hp as that's what derestricted UK 125s seemed to need to break 100 in old mag tests (going from a foggy & not hugely invested interest). they weren't building a stream liner, just a std bike.

Sorry TZ seem to have misplaced the older mag with BMEP estimates. If BDK were able to get almost 20hp out of a 93cc aircooled at only 10,000rpm then it exceeds anything I've touched so I'll have to shut my mouth, but I'd want to see it on a known dyno & smelt the petrol before I paid out any sort of bet.


oh yeah in mag they are running a 26mm oko.

[husaberg]

He needs a sustained 25hp from an aircooled bike that will be under load for a serious amount of time & a considerably oversquare linered arcane engine with quite a small carb. + it doesn't sound like he has the experience with small engines.

Yes it can be done. Speedpro's engine downsized to 83cc handily makes 25hp, but that is assuming a shrink ray type shrink, not just destroke it to 50cc bottom end & hope it will be as efficient.

Also there is the revs he is not talking enough to get that power I think.

I just don't see someone knocking it up in the timeframe of a magazine article. I predict a 92mph with a lot of 'gallant effort' & 'if onlys'

prepared to be proven wrong, best wishes & all.

Not familiar with the bike or magazine, but if they want 100MPH why do they need 25 HP? NSU achieved 121 mph with only 12.8hp (50cc supercharged with a wankel? i think supercharger) in the 1950's with clever aerodynamics.

Anyway something i didn't know until i glanced at a book today was Wankel also supposedly did design or work on a disk valve engine for a torpedo in WW2 disk valve foul stroke.

Left: Cross-section of a Junkers Jumo KM8 disc-valve engine, enclosed in its torpedo casing.
The disc valve is visible on the right side of the engine, just above the piston.

The engine had eight liquid-cooled cylinders of 90mm bore by 85mm, stroke arranged as a V-8 with a 90deg angle. The total swept volume was 4.34 litres and the compression ratio was 6.6 to 1. Output was 275 HP at 3650 rpm. It ran on a mixture of petrol, oxygen, and its own exhaust gas- the latter presumably to dilute the oxygen to a manageable content.

A production order for 100 engines was issued towards the end of WW2 but was never completed. A prototype was examined by British and American intelligence engineers, who concluded it was "a progressive trend in automotive development." It would appear they were wrong.

http://www.douglas-self.com/MUSEUM/P...ValveIC.htm#fw

Above: Longitudinal section through one cylinder bank of a Junkers Jumo KM8 disc-valve engine.
The disc valves are fitted between upper and lower cylinder heads. They had teeth on their periphery, and formed two gear trains without the need for idlers or extra gearwheels. The train of valve discs was driven by bevel gears from the crankshaft, with splined connections to allow valve timing to be altered.


In 1951 NSU became interested in Wankel's rotary engine project, and he joined them. It seems very likely he was involved in the design of the Froede rotary valve shown above.

NSU allegedly hired him for his disk valve sealing expertise for engines, for 2 stroke development which later lead to the Wankel rotary engine.

Walter froede was at the time NSU head of research.

[TZ350]

Fuel injected twostroke second in national MX series.

Only failures throughout the whole season were a foot peg braking off and a clutch bearing failure.

EFI performed seamlessly through out the whole series. Who says EFI twostrokes can't work? No it didn't come first but that's not the bikes fault!

It will be interesting to see how TZ's EFI works out.

Excelent result ... OK, so now we know, home brew 2-stroke fuel injecting at the sharp end of competition is a real possiblity and reliable to boot.

Thank you for helping me out with my own EFI project.

[F5 Dave]

Not familiar with the bike or magazine, but if they want 100MPH why do they need 25 HP? NSU achieved 121 mph with only 12.8hp (50cc supercharged with a wankel? i think supercharger) in the 1950's with clever aerodynamics.
. . ..

If you read my post form 10 min ago you'll see its supposed to be a street sleeper Moped, not a tricky speed tool.

[husaberg]

If you read my post form 10 min ago you'll see its supposed to be a street sleeper Moped, not a tricky speed tool.

No it doesn't and neither does Robs?


okay the other one might (No not really) but i was adding the NSU and junkers stuff...........

I guess the post time and order is decided when you submit a reply rather than when you hit reply to Quote?

[TZ350]

Got me a nice new 10mm ball end milling cutter today.



Its great for digging holes and leaves a nice radius on the back of the newly excavated transfer ducts.



Hopefully I will have better directional control of the flow streams this time.

Following Wobblys mantra of "Low and Wide".

The plan is to make the transfers as wide as possible and open the main port at 116 and the secondary's and boost at 117.5 ATDC.

With 1ex, 73% wide, that opens 80 deg ATDC. STA's and EngMod2T simulation at 83% combustion efficiency. Transfer Port Details.