ESE's works engine tuner

[Haufen]

How does anyone know it is HCCI combustion in the Ryger engine? That is what is it about the engine that makes anyone conclusively conclude it is HCCI? The people I have read about working on HCCI seem to have lots of $$$$$$$ and instrumentation up to the ying yang so they can even play with it.

There are some bigger 2 stroke race engines that win races and once they are going for a bit the spark plug is not needed, that is shutting off the ignition at full throttle won't do anything but no one is indicating it to be HCCI.

Absolutely. Besides that, HCCI needs "quite a bit" of EGR inside the combustion chamber to work. This produces residues on the piston, combustion chamber etc. even with no oil in the mixture. But the piston which had been shown to us was clean, instead.

[ken seeber]

Some say that 4 strokes are a hassle cos they need regular oil changes and that the environment can be damaged due to the incorrect disposal of the used oil. This one's done 200k km and, as you can see, all that is a non issue. You just have to question everything these days. :confused:


317543

[breezy]

[QUOTE=Haufen;1130924492]Absolutely. Besides that, HCCI needs "quite a bit" of EGR inside the combustion chamber to work. This produces residues on the piston, combustion chamber etc. even with no oil in the mixture. But the piston which had been shown to us was clean, instead.[/QUOTE

[url]http://www.researchgate.net/post/What_is_the_difference_between_a_HCCI_and_PCCI_eng ine[/url

http://www.intechopen.com/books/advances-in-internal-combustion-engines-and-fuel-technologies/homogenous-charge-compression-ignition-hcci-engines

[Lightbulb]

Absolutely. Besides that, HCCI needs "quite a bit" of EGR inside the combustion chamber to work. This produces residues on the piston, combustion chamber etc. even with no oil in the mixture. But the piston which had been shown to us was clean, instead.

From what I am understanding of HCCI so far is, EGR were used in early trials to raise the temp for ignition to occur. More recently others have been trialing other ways of raising the temp, so EGR does not need to be used. Maybe the high primary pressure is enough to mechanically do this, so very little or no intentional EGR is required for the Ryger. This will also keep it simple.
Neil

[breezy]

Absolutely. Besides that, HCCI needs "quite a bit" of EGR inside the combustion chamber to work. This produces residues on the piston, combustion chamber etc. even with no oil in the mixture. But the piston which had been shown to us was clean, instead.

www.researchgate.net/.../What_is_the_difference_between_a_HCCI_an.... worth a read..:sherlock:

http://www.intechopen.com/books/advances-in-internal-combustion-engines-and-fuel-technologies/homogenous-charge-compression-ignition-hcci-engines

i downloaded pdf at the bottom of page of above site, also clicked on next chapter.. no problems.:sherlock:

[Frits Overmars]

Curious if any of the V4 500cc 2 strokes ever tried 2 into 1 pipes? Would have improved bottom end and midrange with very minimal peak loss. Plus the sound a 2 into 1 makes... incredible! I built one for my RZ350 back in the day.I don't know of any 500 cc V-fours; I do know, as no doubt you do too, of the König boxer-4. The sound was, as you say, heavenly. The power was... well, it made hardly any more power than a good 250-twin of the same era: 75 hp on petrol :p.


http://www.intechopen.com/books/advances-in-internal-combustion-engines-and-fuel-technologies/homogenous-charge-compression-ignition-hcci-enginesThe paper proposed by Breezy happens to be one of the documents in my too-large ZIP-file, so at least you can have a start here.

[MotleyCrue]

I think I have seen HCCI in action. In karts, which were all once direct drive (no clutch), sometime a guy might spin, crash or whatever and the chain breaks. Even if the throttle may be shut, the engine revs to infinity (at least 30,001 rpm). Then the man gets out and pulls the spark plug cap off and it keeps running and we're up to 30,002 now. He then, after recovering from the HV Taser electric shock, covers the inlet tubes to the airbox. Then the engine will slow and stop. Certainly a light load, high rpm and lean condition which HCCI (ATAC ?) seems to like.


I've seen that too firsthand several times but its different conditions than WOT conditions. If the throttle on the runaway engine is opened up and then the spark plug wire is removed the engine will quit unless it has a hotspot like an overheated plug to keep it going.

[Haufen]

www.researchgate.net/.../What_is_the_difference_between_a_HCCI_an.... worth a read..:sherlock:

http://www.intechopen.com/books/advances-in-internal-combustion-engines-and-fuel-technologies/homogenous-charge-compression-ignition-hcci-engines

i downloaded pdf at the bottom of page of above site, also clicked on next chapter.. no problems.:sherlock:

Thanks for the links. So they achieved HCCI combustion up to 16 bar BMEP on a 4-stroke engine charged to 3bar absolute pressure.
So that would be 8 bar BMEP on a two-stroke engine firing every revolution and charged to 3bar absolute pressure.
With an exhaust pipe only, maximum charging is at about 1,5 bar, so that would be 4 bar BMEP.

From there on, it would be quite a way to go to the claimed 16 bar BMEP for the Ryger at full load. And the guys from the paper had most likely more equipment and instrumentation at their disposal than Harry and his supporters (which is not always necessary, but it does make life easier if you have it, for sure). So I stand by my point. Full load HCCI on the Ryger? Highly unlikely.

(Don't get me wrong, I would love to be proven wrong and then to learn and understand new things two-stroke and then to use them myself. But until that, I am a facts kind of guy, and at the moment I do not know any facts that would lead me to a different conclusion.)

[wobbly]

No V4 GP engines ran 2:1 but from my experience with World Champ Ski engines the 2:1 doesn't even come close to well designed
single pipes, no matter where you bring the headers together.
You can get a big boost in top end power by cutting the piston skirts short on the Ex side.
This creates havoc with the jetting, but once sorted it does work well.
I spent a huge amount of time on EngMod trying to replicate or even get close to twin single pipe performance on a hot road RZ350, but simply
couldn't achieve the mid, or top end, with a 2:1.
In twin snowmobiles and those adapted for small aircraft use, the best performance is achieved with a 2:1 when the Ex duration is up at 200*.
But this then seriously affects the powerband shape,as it looses a huge amount of mid power that then needs the pipe designed to get some of it back,badly compromising
the top end - just not worth it IMHO.

Edit - here is about as good as it gets, a very good aftermarket 2:1 Vs aftermarket singles.

[seattle smitty]

This doesn't pertain, except that big V-4s were mentioned, and I thought somebody here might want to look at this one:

http://www.aaenperformance.com/v4_racing_engine.asp


Here's a photo of a four-cylinder Konig like Frits mentioned (this one burned alcohol):

http://quincylooperracing.us/subpage40.html


The first big use of 2-into-1 pipes in outboarding began with alky-burning inline twin and four-cylinder Mercurys using open megaphones in the late-'50s. Makers and users of these single pipes said they had better acceleration. (EDIT--I say this not to argue the point with Wayne, but just reporting what I recall others saying at the time). Another advantage was a reduction in weight, outboards already being top-heavy, which made for a little better handling and cornering. This weight reduction became a greater factor with the advent of expansion chambers, particularly slider-pipes, in the mid-late-'60s, since the pipes and support brackets and slider mechanisms all were heavy. But by the late-'70s, many of the top racers were using one pipe per cylinder anyway. Outboards run the whole heat at WOT or nearly so, and peak horsepower may be more relatively important than it is for motorcycle roadracers who have lots of slow corners and tire traction issues.

[Frits Overmars]

... So they achieved HCCI combustion up to 16 bar BMEP on a 4-stroke engine charged to 3bar absolute pressure. So that would be 8 bar BMEP on a two-stroke engine firing every revolution and charged to 3bar absolute pressure.
With an exhaust pipe only, maximum charging is at about 1,5 bar.Where did you find that figure Haufen? The Aprilia RSW and RSA reached a cylinder pressure at exhaust closure of nearly 2.7 bar abs.

[MotleyCrue]

Where did you find that figure Haufen? The Aprilia RSW and RSA reached a cylinder pressure at exhaust closure of nearly 2.7 bar abs.

I didnt read the article too closely so far but if the 3 bar was for an auto OEM 4 stroke then the intake valve closes a lot sooner than the exhaust closes on a 2 stroke race engine so a 3 bar pressurized intake auto 4 stroke would have more than 2.7 bar pressure by the time the piston got up all the way to 80 BTDC. Exactly how much I dont know but maybe 6 bar I suppose. Not sure how 16 bar 4 stroke equates to an 8 bar 2 stroke though both having the same boost??

[MotleyCrue]

You can get a big boost in top end power by cutting the piston skirts short on the Ex side.
This creates havoc with the jetting, but once sorted it does work well.


Wobbly, do you mean cut the skirt short enough that the crankcase is connected to the exhaust port when the piston is somewhere near TDC. If so about how many degrees of duration would one shoot for as a good starting point ? I might give it a try, pistons are fairly cheap.

[jonny quest]

Wobbly, that's how I learned 2 stroke pipe building on snowmobiles. There was many a time the 2into1 outperformed individual pipes. You could be right though about 200 ex helping that.

[breezy]

Wobbly, do you mean cut the skirt short enough that the crankcase is connected to the exhaust port when the piston is somewhere near TDC. If so about how many degrees of duration would one shoot for as a good starting point ? I might give it a try, pistons are fairly cheap.

careful!! the exhaust gas temp could dry out the big end bearing...

[Flettner]

https://youtu.be/vVnOM_JZt9A


HCCI in action

The link, it' not working is it?

Just google this Lohmann Fahrrad Hilfsmotor Start durch Anwärmen

You will note that heat in the cylinder / head is nessasary and no sparkplug!

18cc ?

Can you see Ryger in there?

[husaberg]

https://youtu.be/vVnOM_JZt9A

HCCI in action

Mr Frits did mention a smaller radiator.............

[TZ350]

... http://www.highwaymanbikes.com/ I have linked some of his work before.

This is a really interesting must see place to explore.

[tjbw]

https://youtu.be/vVnOM_JZt9A


HCCI in action

The link, it' not working is it?

Just google this Lohmann Fahrrad Hilfsmotor Start durch Anwärmen

It's working, thanks. Looks like he has an exhaust leak.

[41juergen]

317534

No sorry, but under "Thread Tools" which is near the top right hand side of the page, you can "View Thread Images" and sort them into 70 per page. When you find an interesting image click on the N/A sign to see the post, there are more than 7,000 images.

When I was playing with EFI I did use a A/F meter but with a 2T there are traps as the A/F reading is seemingly rich when the trapping efficiency is not good, like when you are moving away from peak torque or well out of the power band.

The A/F meter accuracy seemed at its best when the rpm was at peak torque, every where else it indicated varying degrees of rich but was not. Frits put me on to this, the indicated richness was just air/fuel being blown through the exhaust port and lost down the pipe the remaining air/fuel that got trapped in the cylinder burnt correctly, all the air/fuel was of the correct strength for good combustion just some was not trapped and consequently lost and looked to the meter like the engine was running rich when in fact it was not.

Thank's for the feedback TeeZee!
May be than another question to the experts here: how can the fueling be tweaked with the main air jet? The tests I made showed the smaller the air jet, the smaller also the main jet needs to be (of course :yes:). And the smaller the air jet the stronger the negative pressure signal at the needle jet is... But what do I need to do when the A/F at the end of the power band goes significant leaner than in the power band (assuming that here the reading might be not too wrong)? Will a significant larger air jet together with a corresponding bigger main jet the way to go? I know that a power jet can do that, but in the power band the A/F ratio and the exhaust temps are fine.... Or is there also a reason that the lamba meter shows at the end of the power band very wrong readings?

[husaberg]

Thank's for the feedback TeeZee!
May be than another question to the experts here: how can the fueling be tweaked with the main air jet? The tests I made showed the smaller the air jet, the smaller also the main jet needs to be (of course :yes:). And the smaller the air jet the stronger the negative pressure signal at the needle jet is... But what do I need to do when the A/F at the end of the power band goes significant leaner than in the power band (assuming that here the reading might be not too wrong)? Will a significant larger air jet together with a corresponding bigger main jet the way to go? I know that a power jet can do that, but in the power band the A/F ratio and the exhaust temps are fine.... Or is there also a reason that the lamba meter shows at the end of the power band very wrong readings?

I am not Rob (TZ350)but Robinson covered it.
Remember carbs have over lapping circuits the air jet is used to compensate for the rate at which the fuelling of the main circuit is controlled by an increase in high speed airflow.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301848&d=1411461089
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301774&d=1411459844
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301773&d=1411459844
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301772&d=1411459844
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301771&d=1411459844
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301770&d=1411459844
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301769&d=1411459844



http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301764&d=1411459796
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=301763&d=1411459796

[TZ350]

Thanks Husa for the pictures of the fueling curve, I hunted high and low but could not find them. ... :niceone:

[husaberg]

Thanks Husa for the pictures of the fueling curve, I hunted high and low but could not find them. ... :niceone:

I can't figure out how to move them from the album back without posting them as images rather than attachments though.:facepalm:
All (well most) the carb stuff I have posted is here.
http://www.kiwibiker.co.nz/forums/album.php?albumid=4844

Exhausts stuff from the thread is here
http://www.kiwibiker.co.nz/forums/album.php?albumid=4854
Aprilia stuff from all over the web is here
http://www.kiwibiker.co.nz/forums/album.php?albumid=4839
Frits Overmars home phone number and bank account details are here
http://41.media.tumblr.com/227f11a825a66a5fb83255d3519d5154/tumblr_nig3y1mDsB1qcg3vgo1_400.jpg

[41juergen]

perfect, thank's a lot Husa. Some of the stuff I already know, but the Robinson book isn't in my shelf, so more to learn... :rolleyes:

[Frits Overmars]

Mr Frits did mention a smaller radiator.............My grandfather is in no way involved, Husa. In other words: drop the Mr :p.


Frits Overmars home phone number and bank account details are here
http://41.media.tumblr.com/227f11a825a66a5fb83255d3519d5154/tumblr_nig3y1mDsB1qcg3vgo1_400.jpgWould you please remove the phone number Husa? You can leave my bank account details. Thank you.

EDIT: Sh*t :shit:! That is the number of my swiss account. Please remove immediately!

[MotleyCrue]

https://youtu.be/vVnOM_JZt9A


HCCI in action

The link, it' not working is it?

Just google this Lohmann Fahrrad Hilfsmotor Start durch Anwärmen

You will note that heat in the cylinder / head is nessasary and no sparkplug!

18cc ?

Can you see Ryger in there?


Its not hard to get HCCI just hard to make it useful.

[Lightbulb]

My grandfather is in no way involved, Husa. In other words: drop the Mr :p.

Would you please remove the phone number Husa? You can leave my bank account details. Thank you.

EDIT: Sh*t :shit:! That is the number of my swiss account. Please remove immediately!

Thats just too funny you guys. You got me there Frits. The gullible test would not work on my computer. Probably time for an upgrade.

[wobbly]

Re the twin Vs single pipe testing.
The only time I have seen a single pipe beat out the twins is in a very specific application such as a freestyle jetski.
In this setup the single pipe is capable of generating alot more initial Hp below the natural powerband of the engine - and this
is exactly what is needed to do backflips etc from nil water speed.
But in enabling this to work, a huge amount of what would be regarded as normal "top end " is sacrificed.
I did experiment quite extensively with headers that had an interconnecting pipe, and even ended up trying a servo controlled
butterfly flap plate to control the interaction,but finally conceded that if I spent enough time working on the "normal " pipe design
I could get a better final result.
ie not worth the effort in the end.

Re the cutaway piston on the Ex side idea.
This was developed as a cheat in Jetski stock class racing ( yes it won several World titles as the tech guys never found it ) and the cutaway started with around 1/2
the duration of the transfers.
We spent so much time to then re calibrate the pumpers, that the duration was never changed after that.
It needed really severe reverse jetting ( that we had anyway ) but the big increase in top end power was for sure worth the risk of being thrown out of tech.

[MotleyCrue]

Re the cutaway piston on the Ex side idea.
This was developed as a cheat in Jetski stock class racing ( yes it won several World titles as the tech guys never found it ) and the cutaway started with around 1/2
the duration of the transfers.
We spent so much time to then re calibrate the pumpers, that the duration was never changed after that.
It needed really severe reverse jetting ( that we had anyway ) but the big increase in top end power was for sure worth the risk of being thrown out of tech.

So I think you are saying the exhaust port is open to the crankcase from about 30-35 BTDC to 30-35 ATDC ? With a 2:1 there likely would be a vacuum in the exhaust port at this time because of the 2 cylinders tied together with one pipe. But the AF mixture that gets pulled out of the crankcase into the exhaust port would never be returned to the crankcase (I think), so is it just the extra draw on the crankcase (that is piston plus exhaust) that makes the difference, or is the raw AF going into the exhaust port lighting off and increasing the pipe gas temp, or both, or something else. I guess what I am curious about is what is the theory behind the results.

[Haufen]

Where did you find that figure Haufen? The Aprilia RSW and RSA reached a cylinder pressure at exhaust closure of nearly 2.7 bar abs.

My bad, I had been blinded by 4-stroke simplicity when I wrote these lines.:shifty: Scavenging efficiency is about equal to boost pressure on a 4-stroke, but not on a two-stroke. Let me explain:

In the paper on HCCI they achieved HCCI combustion up to 16 bar BMEP on a 4-stroke engine charged to 3bar absolute pressure.
On a naturally aspirated 4-stroke engine, a scavenging efficiency of about 1 is common for most car engines, so that each cylinder burns about the volume it displaces.
Charge that with 1 bar above atmosphere and your engine will now burn about twice the volume it displaces.
Charge it with 2 bar above atmosphere as in the linked paper and - you guessed it - it will burn roughly 3 times the volume it displaces.
So, scavenging efficiency is about equal to absolute boost pressure for the 4-stroke.

As the formula for BMEP is not the same for 4T and 2T engines, this correlates to 8 bar BMEP on a two-stroke - and this is where I should have expressed myself more thoroughly - it correlates to 8 bar BMEP on a two-stroke which is supercharged so much that it reaches a scavenging efficiency of 3. As a good two-stroke engine with an expansion chamber exhaust pipe can reach a scavenging efficiency of 1.5, the results of the paper correlate to 4 bar BMEP on a two-stroke engine with an exhaust pipe.

And from 4 bar to about 16 bar is still a long way to go. And this is why I can not see full load HCCI on the Ryger engine.

[MotleyCrue]

As the formula for BMEP is not the same for 4T and 2T engines, this correlates to 8 bar BMEP on a two-stroke - and this is where I should have expressed myself more thoroughly - it correlates to 8 bar BMEP on a two-stroke which is supercharged so much that it reaches a scavenging efficiency of 3.

I believe this part is incorrect. Its more or less 16 bar for both, only the 2 stroke would make twice the HP at the same BMEP.


16 bar is incredibly pitiful for 2 atmospheres of boost with regular spark ignition, and HCCI is supposed to be super efficient combustion. It would be hard to even make a regular engine run so bad that it only made 16 bar with 2 atmospheres boost, (like maybe shut the ignition off for 2 out of every 3 times the plug fires). The HCCI engine must have been extraordinarily lean with a lot of exhaust gas taking up precious space too.

[wobbly]

I think that as the piston on the downstroke approaches BDC, and the diffuser starts to create a depression in the header, then the other piston is
approaching TDC and the cutaway exposes that case to this negative pressure ratio.
This increases the delivery thru the reeds around TDC for that cylinder, creating more bulk flow and carb velocity that continues for longer as that piston drops.
Then as the return wave starts to appear in the header, some of that excess mixture is returned ( or the out flow is at least slowed down ) as the cutaway piston
then closes the port on its downstroke - just as the other piston is then ( as is normal ) closing its port on the upstroke.

[Haufen]

I believe this part is incorrect. Its more or less 16 bar for both, only the 2 stroke would make twice the HP at the same BMEP.

16 bar is incredibly pitiful for 2 atmospheres of boost with regular spark ignition, and HCCI is supposed to be super efficient combustion. It would be hard to even make a regular engine run so bad that it only made 16 bar with 2 atmospheres boost, (like maybe shut the ignition off for 2 out of every 3 times the plug fires). The HCCI engine must have been extraordinarily lean with a lot of exhaust gas taking up precious space too.

Well that is yes and no I guess. I don't think the two-stroke would be able to draw the same amount of air per cycle than the four-stroke with the same boost level. But it could if you would double the boost. So the proportions regarding the charging remain as they are, I'd say.

To be able to draw the amount of air needed to achieve 16 bar BMEP (2T) with the same (lean) HCCi combustion parameters as in that paper, the Ryger would need to be able to draw 4 times the air per cycle as the RSA! I can not imagine how this can be done with an expansion chamber only.

I agree with you on the numbers of 16 bar being lousy for 2 atm boost. But it may be really good in terms of BSFC. But much more power could be achieved by running richer and with conventional combustion. The same would be valid for the Ryger, there would be no point in running HCCI if your after hp.

[Flettner]

Its not hard to get HCCI just hard to make it useful.

Why? Just because it hasn't been done doesn't mean is can't be done. I'm sure there is a way to control it, and I'm going to have a go at it, the more I read the more interested I become. Now where is that old AG 100 engine under the bench, all I need to do is tie the gas set to it, take the plug out and volare :yes:

[MotleyCrue]

Well that is yes and no I guess. I don't think the two-stroke would be able to draw the same amount of air per cycle than the four-stroke with the same boost level. But it could if you would double the boost. So the proportions regarding the charging remain as they are, I'd say.



I think 16 bar limitation on the 4 stroke was based on having X amount of air and exhaust in the cylinder to make it run as desired, so a 2 stroke with that same X amount of air and exhaust in the cylinder should also near 16 bar, but yes it might take more boost to get that X amount of air and exhaust into a 2 stroke. A regular tuned pipe couldn't get that much into the cylinder or we'd all be riding 100+ HP 125 s with regular spark ignition that only turned 13000 rpm.

No matter a naturally aspirated HCCI making 14-16 bar doesnt exist as far as I can tell unless the Ryger has achieved it. It is fathomable that some unique condition exists allowing it at full throttle but then how would it be achieved at other conditions with just mechanical controls and likely non-moving mechanical controls.

[MotleyCrue]

No V4 GP engines ran 2:1 but from my experience with World Champ Ski engines the 2:1 doesn't even come close to well designed
single pipes, no matter where you bring the headers together.


Were you able to determine where best to bring the headers together and what sort of angle the headers would have relative to each other where they meet?

Most people I know seem to think making the headers so that they come together at the least possible distance from the port, without undue bends is best. It seems to make sense, but I have also wondered if maybe not bringing the headers together until almost the large mid section of the pipe might work so that the pipe header and a lot of the diverging section work like individual pipes and the reverse cone reflects the two.

Building it like that you could say why not just build it single pipes because it would be halfway a single pipe anyway but I was thinking for when rules insist 2:1. Maybe build single pipes and connect the stingers but I think that wouldnt fly with the rules.

[F5 Dave]

So how did Vegas go?

[sidecar bob]

It needed really severe reverse jetting ( that we had anyway ) but the big increase in top end power was for sure worth the risk of being thrown out of tech.

They call that cheating.

[136kg136ps]

Anything not specifically prohibited must be assumed legal until addressed by a rule.This gives a certain advantage to intelligent and innovative race teams. This will often draw whining from those who aren't. There is no "spirit" in rules,as this gives the power of interpretation the ability to decide a contest instead of skill on the part of the racer and team.

[wobbly]

Yep damn right, it was cheating like hell - sadly, nowhere in the rules did it say that the piston length must remain stock.
But it was the team that paid me a shit load of cash to win a world title that made the conscious decision to do so - not me.
Its only a cheat if you get caught - if you dont, then some people are comfortable and dont feel guilty every time they look at the trophy.

[wobbly]

Re Vegas - here is some cut and paste from a report on the result I did.


We were top 3 fastest thru all the sessions, but the engine guy for the team we race for didnt tighten the new sparkplug prior to qualifying.
Of course it wound almost all the way out and our pace dropped by 3/10s, enough only for 6th.
In the first heat we were up to 4th pulling in the top 3 easily within 2 laps when the 3rd place missed a gear mid bend under big pressure and spun
right in our karts path - DNF.
Means we went into the final from 12 on the grid, got to 5th place and ran out of time - track position is everything when only a few 1/10ths cover the top 5 pace.

I took the deto gauge off the dyno and ran the 0-5V output into the Pi datalogger, and was very surprised to find that after leaning down enough to get hits, that the only place
it deto'ed was the acceleration phase after 2nd, 3rd, 4th gearchanges, when dropping back to near peak power after overeving to 12200.
The 5th to 6th change stayed above peak power and didnt deto at all down into the shute.
So I fitted the new header with the deto button installed and the gearchange deto dissapeared completely.
That allowed another 3 jets leaner before it started again.

Get this - the egt at that level was 1390* F with no sign of deto or piston heat stress.
This is due to the fuel octane being too high for the com, and the fact that the SKUSA advance restrictor plate doesnt allow us to add enough static timing to create more power - only pipe heat.

I think I have worked the logic of the deto button - it creates turbulence in the top 1/2 of the duct, allowing the smooth flow along the floor to return easily up the duct and be aimed upward off
the ski jump at the closing Ex port.
This came from finding that having the floor of the oval/round transition spigot co linear with the duct floor, and all of the transition angle in the roof made best power.

So here is the jetting chart prior to adding the new header, based on safe deto level, not egt as I would usually use.
The Lambda ( in the muffler ) showed the kart was fastest at 13.8 :1 ( and it hardly varied anywhere within the usable power band ), going leaner or richer was slower on track.
We tested both VP C12 ( 108 octane ) and VP98, the 98 being both faster and easier to tune to the edge.

[steamroller]

Can anybody tell me is there a difference between a piston ring used on cast iron to a piston ring used on nickesell. Or are they both made of the same material? Thanks

[diesel pig]

Can anybody tell me is there a difference between a piston ring used on cast iron to a piston ring used on nickesell. Or are they both made of the same material? Thanks

Wiseco say you can use there standard 2-stroke ring in any bore excrept chrome bores.

[husaberg]

Can anybody tell me is there a difference between a piston ring used on cast iron to a piston ring used on nickesell. Or are they both made of the same material? Thanks

Hard and soft are needed to get along. Otherwise they wear each other out in a short space of time
If the bore is hard then the ring surface needs to be soft and visa versa. That's my understanding of it.

[mr bucketracer]

Hard and soft are needed to get along. Otherwise they wear each other out in a short space of time
If the bore is hard then the ring surface needs to be soft and visa versa. That's my understanding of it.+1 but do know cast iron on cast iron is fine to , but race engines of today? , i know my ktm125 duke had some hard cast iron sleve ?or something close.

[F5 Dave]

Well certainly soft on soft will wear like two bits of cheese rubbed together.

[husaberg]

+1 but do know cast iron on cast iron is fine to , but race engines of today? , i know my ktm125 duke had some hard cast iron sleve ?or something close.
unplated sleeves are generally cast iron. Akunar sell blanks at very reasonable prices. The rings from memory are generally ductile iron or steel. Most modern rings have a coating of some sort. The old stuff was a brittle cast iron for old low powered stuff

[ken seeber]

Virtually every performance ring you see is chrome plated on its rubbing outer surface. Chrome doesn't like being rubbed up with chrome whereas cast iron doesn't mind a rub with cast iron. So, chrome rings are ok against cast iron and Nikasil: cast iron rings are ok against cast iron or chrome bores (typically string trimmers, small Comer kart engines etc). Usually Dykes rings are cast iron so they can be used in cast iron linered kart engines ....dunno where else you might see them these days.

[Lightbulb]

Re Vegas - here is some cut and paste from a report on the result I did.

So I fitted the new header with the deto button installed and the gearchange deto dissapeared completely.
That allowed another 3 jets leaner before it started again.

Get this - the egt at that level was 1390* F with no sign of deto or piston heat stress.
This is due to the fuel octane being too high for the com, and the fact that the SKUSA advance restrictor plate doesnt allow us to add enough static timing to create more power - only pipe heat.

I think I have worked the logic of the deto button - it creates turbulence in the top 1/2 of the duct, allowing the smooth flow along the floor to return easily up the duct and be aimed upward off
the ski jump at the closing Ex port.
This came from finding that having the floor of the oval/round transition spigot co linear with the duct floor, and all of the transition angle in the roof made best power.

So here is the jetting chart prior to adding the new header, based on safe deto level, not egt as I would usually use.
The Lambda ( in the muffler ) showed the kart was fastest at 13.8 :1 ( and it hardly varied anywhere within the usable power band ), going leaner or richer was slower on track.
We tested both VP C12 ( 108 octane ) and VP98, the 98 being both faster and easier to tune to the edge.

Hey Wayne, Do you think this deto thing could work in the 2.5 cc pipe engine ? How do you attache the mushroom to the inside of the header ?
Can you send me some specs to scale one to try please ?
Thanks Neil
PS, it is only cheating if the rules say you can't do something, but make a work around that if caught is against the rules. When the rules do not specify something, then it must be legal.

[mr bucketracer]

Virtually every performance ring you see is chrome plated on its rubbing outer surface. Chrome doesn't like being rubbed up with chrome whereas cast iron doesn't mind a rub with cast iron. So, chrome rings are ok against cast iron and Nikasil: cast iron rings are ok against cast iron or chrome bores (typically string trimmers, small Comer kart engines etc). Usually Dykes rings are cast iron so they can be used in cast iron linered kart engines ....dunno where else you might see them these days.so a honda rs125 piston ring is fine with a cast iron sleave as you say ? ...thanks

[F5 Dave]

I can tell you a Kawasaki ring for electrofusion bore will wear a cast bore to the next size in one meeting.

[wobbly]

The original deto mushrooms were installed about 50mm down into the pipe header, but in the SKUSA Honda we cant touch the spec pipe.
Whereas the spigot is open except for the overall length.
I was a bit surprised that moving the thing closer to the piston still worked so well, no power loss on the dyno, but I didnt have lean enough jets
during testing to get deto happening.

As the area where the mushroom was installed was less than out in the header I simply scaled it down.
But as I said I was surprised to find that the piston killing deto only occurred after dropping back to around peak power from gearchanges, and that
the change into 6th ( with minimal rev drop ) didnt deto at all in the overev.

It would work just as well in model engines if you are getting deto that eats away the piston in the squishband, but as I see it you are running for
the longest period way into overev, not sitting on peak Hp during flight - so it may not have any useful effect.

The end of the mushroom is step threaded, and this screws into a hole with a chamfer on the outer surface where the pipe sleeve seals.
After installing it I sat it in the press and using a 90* pointed mandrel on centre, expanded the flat threaded end into the spigot chamfer.
I would have preferred to have a small boss within the spigot, but this involved way too much extra CNC time with difficult programming and special tooling.

[Lightbulb]

On an 11.4mm header pipe, does a 4.2mm diameter mushroom 0.7mm thick sound right on an oval at 2mmx1.2 holding it, the whole insert being 5.2mm high ?
Neil

[ken seeber]

I can tell you a Kawasaki ring for electrofusion bore will wear a cast bore to the next size in one meeting.

Dave, I can't answer this one directly. When I was at Orbital we had a couple of 3 cyl 1.2 litre engine plated by Kawasaki. Call it electrofusion or WESC (Wire Explosion Spray Coating). We just used regular chromed rings, so can't answer the reverse.

It is a really neat process. Wires, successively of molybdenum and high carbon steel (piano wire) of around dia 1.5 mm, were tensioned along the cylinder centreline, and given 20 kV or so. The steel particles would hit the cylinder or the previous coat, cooling instantly to become pure martensite, a very hard form of steel. This was effectively embedded in a background matrix of the moly, which acted as a from of lubricant. No chemicals, but all I remember was the impressive bang, despite the cylinder being encased in some sort of sound proof container. This was back in late 80s, so all I can really remember was the bang. Nothing wrong with that.

[jonny quest]

Wobbly, any Ryger engines in Vegas?

[wobbly]

The class for the Ryger is KZ2, being the International 125 spec class, but they have not yet received homologation status.
So no they are not at this time legal to compete.
The process is not far away from completion, and as soon as it happens I have access to the CIK homologation portal to get all the papers that
show the internal dimensions and photos for tech purposes.

[Haufen]

I think 16 bar limitation on the 4 stroke was based on having X amount of air and exhaust in the cylinder to make it run as desired, so a 2 stroke with that same X amount of air and exhaust in the cylinder should also near 16 bar, but yes it might take more boost to get that X amount of air and exhaust into a 2 stroke. A regular tuned pipe couldn't get that much into the cylinder or we'd all be riding 100+ HP 125 s with regular spark ignition that only turned 13000 rpm.

No matter a naturally aspirated HCCI making 14-16 bar doesnt exist as far as I can tell unless the Ryger has achieved it. It is fathomable that some unique condition exists allowing it at full throttle but then how would it be achieved at other conditions with just mechanical controls and likely non-moving mechanical controls.

I agree. If the engine would be able to breathe 4 times what the RSA did (and in a shorter period of time, as the peak power hp is ~17k), then we could have 16 bar BMEP in the two-stroke. This would also mean that the peak power would be about 200bar, too. That's current car-technology diesel peak cylinder pressure. So everything would have to be as rigid as in a diesel engine. And nobody wants extra weight in a race engine, especially if you can have more power and lower peak pressures if you do not use HCCI.

[Niels Abildgaard]

Dave, I can't answer this one directly. When I was at Orbital we had a couple of 3 cyl 1.2 litre engine plated by Kawasaki. Call it electrofusion or WESC (Wire Explosion Spray Coating). We just used regular chromed rings, so can't answer the reverse.

It is a really neat process. Wires, successively of molybdenum and high carbon steel (piano wire) of around dia 1.5 mm, were tensioned along the cylinder centreline, and given 20 kV or so. The steel particles would hit the cylinder or the previous coat, cooling instantly to become pure martensite, a very hard form of steel. This was effectively embedded in a background matrix of the moly, which acted as a from of lubricant. No chemicals, but all I remember was the impressive bang, despite the cylinder being encased in some sort of sound proof container. This was back in late 80s, so all I can really remember was the bang. Nothing wrong with that.

Have You written more about being at Orbital?
It is one of the places I would have liked to work at.
Last two stroke breath.

[speedpro]

Assuming of course that crank/rod geometry and piston velocity profiles are the same, then those are the numbers required. If the Ryger has some method of extracting more power from the same fuel burn then maybe not. I think it extracts that power way more efficiently, hence the smaller radiator pointing to less power being lost to the cooling system. If the emissions are reduced then possibly less or no squish area trapping unburnt fuel/air which could point to some other method to increase fuel burn rate(HCCI?). To efficiently extract useful work from that speedier burn, without trapping hot high pressure gas in the chamber where the heat is lost to the cooling system, it must be allowed to expand in a way that work is done.

[husaberg]

Assuming of course that crank/rod geometry and piston velocity profiles are the same, then those are the numbers required. If the Ryger has some method of extracting more power from the same fuel burn then maybe not. I think it extracts that power way more efficiently, hence the smaller radiator pointing to less power being lost to the cooling system. If the emissions are reduced then possibly less or no squish area trapping unburnt fuel/air which could point to some other method to increase fuel burn rate(HCCI?). To efficiently extract useful work from that speedier burn, without trapping hot high pressure gas in the chamber where the heat is lost to the cooling system, it must be allowed to expand in a way that work is done.

Ryger homologation form lists the Combustion chamber as being a semi circle
Oddly the few other homologation I have looked at say hemispherical with squish.
So I don't think its a translation issue.
it is 11cc for both so I guess this is a homologation requirement to have a caped compression ratio.
317589

[wobbly]

I dont think we can assume " crank/rod geometry and piston velocity profiles are the same ", as the Ryger has a 90mm rod with a 54.5mm stroke
and this combination is somehow capable of 30,000 rpm.
How could this be achieved with what we regard as a normal rod and crank, as its never been done previously, so something must be different.
The closest so far would be the 100cc kart engines that had around 48mm to 50mm stroke with super light components and they exploded with monotonous
regularity at 20,000 rpm and had a severely short lifespan at at that level.

And yes the KZ2 regs have a combustion space limited to 11cc in the chamber, and is measured with a plug gauge inserted and measured as 13cc to the top of this gauge.

[husaberg]

I dont think we can assume " crank/rod geometry and piston velocity profiles are the same ", as the Ryger has a 90mm rod with a 54.5mm stroke
and this combination is somehow capable of 30,000 rpm.
How could this be achieved with what we regard as a normal rod and crank, as its never been done previously, so something must be different.
The closest so far would be the 100cc kart engines that had around 48mm to 50mm stroke with super light components and they exploded with monotonous
regularity at 20,000 rpm and had a severely short lifespan at at that level.

And yes the KZ2 regs have a combustion space limited to 11cc in the chamber, and is measured with a plug gauge inserted and measured as 13cc to the top of this gauge.

I was reading something about Phil Irving the other day, it seems the first engines he designed were two stroke and he also worked on a swash plate crankshaft engine.

Irving's first engineering job started in 1922 working for the Australian engineer Anthony Michell at the firm of Crankless Engines Ltd in Fitzroy, Victoria.At the firm worked under both Michell and engineer T.L. Sherman. Irving said: "It was the greatest stroke of luck imaginable that I started work under two such eminent men..."
Its also seems it was he who drew up the EMC.

At the 1960 Isle of Man TT Races, Dr Josef Ehrlich, the owner of Ehrlich Motor Cycles (EMC Motorcycles) commissioned Irving to 'reverse-engineer' an MZ 125cc racing engine supplied by Ehrlich and to produce the working drawings of a water-cooled variant which became the 1961 EMC 125cc water-cooled single cylinder racing engine

[tjbw]

I was reading something about Phil Irving the other day, it seems the first engines he designed were two stroke and he also worked on a swash plate crankshaft engine.

Its also seems it was he who drew up the EMC.

So should Phil get the credit for the EMC boost ports,?

These were like appendices off the cylinder bore, fed by ports on the piston. I was going to say they were less usefull than an appendix, but I just noticed that wobbly spent time at EMC, and he says they increased the power!

[tjbw]

Ryger homologation form lists the Combustion chamber as being a semi circle
Oddly the few other homologation I have looked at say hemispherical with squish.
So I don't think its a translation issue.
it is 11cc for both so I guess this is a homologation requirement to have a caped compression ratio.
317589

Ryger uses the VM KZ engine head, the homologation data for that engine also says that the combustion chamber shape is "semicircle" though the drawing shows that it is flat near the spark plug. Perhaps the shape is a truncated hemisphere, with small squishband.

[husaberg]

So should Phil get the credit for the EMC boost ports,?

These were like appendices off the cylinder bore, fed by ports on the piston. I was going to say they were less usefull than an appendix, but I just noticed that wobbly spent time at EMC, and he says they increased the power!

Walter Kaden as far as I know drew up the 3rd port, or at least took credit for it design from a minion employed by MZ


Ryger uses the VM KZ engine head, the homologation data for that engine also says that the combustion chamber shape is "semicircle" though the drawing shows that it is flat near the spark plug. Perhaps the shape is a truncated hemisphere, with small squishband.
bummer thought there was something in that.

[tjbw]

Walter Kaden as far as I know drew up the 3rd port, or at least took credit for it design from a minion employed by MZ


bummer thought there was something in that.

The boost ports I am talking about were not connected to the crankcase like transfer ports. They were two isolated chambers. In theory they filled with mixture when piston was approaching BDC, then they discharged into the cylinder after they were uncovered by the piston crown.

http://rustybikes.hostingsiteforfree.com/1960emc-engine.jpg

[husaberg]

The boost ports I am talking about were not connected to the crankcase like transfer ports. They were two isolated chambers. In theory they filled with mixture when piston was approaching BDC, then they discharged into the cylinder after they were uncovered by the piston crown.

http://rustybikes.hostingsiteforfree.com/1960emc-engine.jpg

He can have those plus the half moon combustion chamber.
There is a tie in with the leaking of MZ information and Rotax as well maybe via EMC

[SwePatrick]

Sorry to bring this one up again.
But as i tend to analyze things over and over again.
I haven´t made any more dynopulls, but!
If you look at the the torquecurve, suspiciously flat huh?
My dyno is a former kartdyno and it contains an adjustable clutch, one can adjust clampingforce with turning the screws for the springs tighter.
I have verified this, at when torque flattens out, the rotationsspeed between engine and dynowheels isn´t 'locked'.
Engine revs up faster than flywheel, in short terms: clutch in dyno slips!
I have locked the clutch in engine as i didn´t want this problem *lol*
There are more power hidden correcting this. =)



A long time ago i spoked about my Honda MT5 engine.
You said i should get back to you with news.
Now i finally got some worth telling about.
I now own a dyno that´s measuring at the enginesprocket.
And this is the first pull ever with this engine in my bench.

I have spent a couple of weeks with a smaller engine to sort things out.
The small engine(66cc MT5) produced with fairly low tune in cylinder a healthy 19hp at 11200rpm with a worn out piston but with a really good register.
It was equipped with an old Autisa cylinder bored up to 45.5mm, just portmatched it to crankcase and grinded off some debris in all ports.
Keihin round throtte 27mm
'derbi design' reed.(tnx Wobbly)
Morbidelli pipe(homemade copy)

However, this was my dynomule, nothing to fancy.

Now to my serious MT5 engine that i´ll post a dynoscreenshot of in this post.
This engine is built to not make a ny worldrecords in torque as i want to be kind and not stress the 'under dimensioned' clutch/gearbox.
Setup:

Honda MT5 engine 5speed.(6speed breakes very easily i noticed)
132cc
6 disc clutch
MT8 crankshaft with 110mm samarin rod.(stroked to 50mm)
Kawasaki KX 125 -86 cylinder bored to 58mm(Woessner CR144 piston)
A lot of porting (199/138/138/140 durations)
Derbi design reed.
Keihin PWM 40mm, slightly modded.
Ignitech ignition, ran at the first pull(screenshot) exactly the same curve as my small 66cc engine, just raised rev,stop.
Homemade combustionchamber insert.
Homemade pipe, Actually built just with 'feeling', no calculations at all.
A lot of welding has been done to the crankcase to accept crankshaft and cylinder, Finally coated crankcase to block out some heat from gearbox.

And about the dynopull,, i hadn´t connected cooling so i just went for a quick to see if ignition worked.
When i realized it did work i let of the throtttle a bit at about ~11000rpm.
Things were much faster than the small engine, i couldn´t keep up *lol*
I also gave it full throttle at about ~8000rpm.

The weather corrections was a bit off when making screenshot, the final number is actually a little bit higher.
And remember, dyno reports in HP and Lbf-ft.

Screenshots:

https://scontent-arn2-1.xx.fbcdn.net/hphotos-xpf1/v/t1.0-9/11988653_10153462587649475_1461961640880729817_n.j pg?oh=be81ded600db0e9f1d5e6f25cd7141ad&oe=56B2F4D7

There is some tuning left as this was the first pull ever with ignitech on this engine.
Previously had PVL(458)
I aim for 40hp+ at sprocket, it was 39.09 in corrected hp in this pull and 17.xxlbf.ft in torque.
44 should be a cool number as Derbi produced that also , i got a small advantage as i got 8cc more.

Rgds
Patrick

Edit:
A picture of actual engine in dyno:
https://scontent.xx.fbcdn.net/hphotos-xpa1/v/t1.0-9/12274467_10153464260769475_4145253838700306225_n.j pg?oh=3a95267ba60fee540f20bdbc41babca5&oe=56F53B9F

[husaberg]

Sorry to bring this one up again.
But as i tend to analyze things over and over again.
I haven´t made any more dynopulls, but!
If you look at the the torquecurve, suspiciously flat huh?
My dyno is a former kartdyno and it contains an adjustable clutch, one can adjust clampingforce with turning the screws for the springs tighter.
I have verified this, at when torque flattens out, the rotationsspeed between engine and dynowheels isn´t 'locked'.
Engine revs up faster than flywheel, in short terms: clutch in dyno slips!
I have locked the clutch in engine as i didn´t want this problem *lol*
There are more power hidden correcting this. =)

Is that a Dyna trigger on the ignition?

[JustHarry]

Hi guys. i have recently(today) rooted my kr150 cylinder and piston. i put the piston in backwards and the rings got a little intimate with the exhaust port.(im sure you can imagine what that does to the cylinder wall317616317617317618) i have one option of resleving the barrel. have any of you done this before. whats involved and what sort of sleeve did you use. i have a friendly engineer neighbor so that makes doing the sleeving a little easier. what do you think?
or... is there any kr150 engine bits or parts bikes for sale around?

Cheers Harry

[TZ350]

If you look at the the torquecurve, suspiciously flat huh?

What shape were you looking for, we favor a flat curve when we can get it. Looking forward to seeing your new curve when you have the dyno clutch sorted.


Fitted a new pipe and with a little bit of fiddling found some nice wide horsepower. Rob's suggestion to increase the air correction jet diameter and up the main worked a treat.

317487


316551

There you are, 30hp and a good spread of power, a usable 4,500 rpm. Not bad for 70's technology.


316090

This is my Suzuki GP125 in its 28hp and pumper carb days, those long flat 2T torque curves are a common feature for the GP.

[Yow Ling]

Hi guys. i have recently(today) rooted my kr150 cylinder and piston. i put the piston in backwards and the rings got a little intimate with the exhaust port.(im sure you can imagine what that does to the cylinder wall317616317617317618) i have one option of resleving the barrel. have any of you done this before. whats involved and what sort of sleeve did you use. i have a friendly engineer neighbor so that makes doing the sleeving a little easier. what do you think?
or... is there any kr150 engine bits or parts bikes for sale around?

Cheers Harry

Hi Harry, you need to mention this is an early moder KR150 , the one with wire wheels.
You have a few options, buy a new cylinder from Malaysia, Indonesia or Thailand, Get it welded and replated , get a second hand one, last resort would be sleeving it. There is a guy on KB in New Plymouth that has or had KR's his user name is ride life or something his name is Alex

[husaberg]

Hi Harry, you need to mention this is an early moder KR150 , the one with wire wheels.
You have a few options, buy a new cylinder from Malaysia, Indonesia or Thailand, Get it welded and replated , get a second hand one, last resort would be sleeving it. There is a guy on KB in New Plymouth that has or had KR's his user name is ride life or something his name is Alex

Scotts brothers Bucket is based on a KR bottom end he may have a top end
looks like that's already sorted elsewhere as you were.

[SwePatrick]

What shape were you looking for, we favor a flat curve when we can get it. Looking forward to seeing your new curve when you have the dyno clutch sorted.

Yes a flat curve is what to wish for.
But i thought the abrupt stop in raising torque to an almost flat curve is a limiter.
And when i anlyzed the dyno rpm curve against the engine rpm curve i saw that, gear ratio altered from 10.3 to 10.6 just in the area where the curve flattens out.

'Locked' the dyno has gear ratio 10.3, no slippage.
This means when engine is revving 10300rpm the dyno revs 1000rpms.
And when slippage occur the engine revs 10600 and dyno revs 1000rpms.

A small value maybe, but it makes it 'not correct'.
I will sort this out and make a pull again to se what it does without slip.

rgds
Patrick

[ken seeber]

More Ryger thoughts. Reading a bit more about HCCI, perhaps there is some possibility that the rate of compression might be a factor. So then I got thinking about the recent Honda 2 stroke patent.

317621

What is that complex mechanism for, why not a simple crank? So we scaled the Honda drawing, chucked it into Solidworks, scaled the stroke to 54.5, such that we could do a direct travel vs piston travel comparison with an engine (Ryger?) that has the 54.5 stroke, 90 rod and with no significant offset of the cylinder axis or piston pin.

317622

From this, it can be seen that one side of the travels are almost identical, but there is a significant difference on the other side. Maybe this difference is what Honda was trying for, assuming (yes I know another assumption) that it was beneficial for some reason, maybe HCCI or ATAC. As the direction of rotation, it could be that the side of the Honda engine, that shows the sharper rate of travel, represents the compression stroke ie, read the plot from right to left.


Anyways, 31 days to go, unless Wobbly gets some advance info.

[tjbw]

More Ryger thoughts. Reading a bit more about HCCI, perhaps there is some possibility that the rate of compression might be a factor. So then I got thinking about the recent Honda 2 stroke patent.

317621

What is that complex mechanism for, why not a simple crank? So we scaled the Honda drawing, chucked it into Solidworks, scaled the stroke to 54.5, such that we could do a direct travel vs piston travel comparison with an engine (Ryger?) that has the 54.5 stroke, 90 rod and with no significant offset of the cylinder axis or piston pin.

317622

From this, it can be seen that one side of the travels are almost identical, but there is a significant difference on the other side. Maybe this difference is what Honda was trying for,

....



Nice work Ken.

Did you notice that the Honda con rod remains almost vertical throughout each rev, so piston sidethrust must be low too. But I wonder where the red line would be.

[Flettner]

Ok Frits, how are we going to build a continuous fuel injection system, not pulsed.
The old Hiborn mechanical fuel injection was crude at best but if we were to put a electronically controlled needle valve in place of the return "pill" it could work? Or as you have suggested a DC motor driven by pules width modulation.

[gravmax88]

Ok Frits, how are we going to build a continuous fuel injection system, not pulsed.
The old Hiborn mechanical fuel injection was crude at best but if we were to put a electronically controlled needle valve in place of the return "pill" it could work? Or as you have suggested a DC motor driven by pules width modulation.

KE jetronic:rolleyes: as used by Porsche etc or a variation.......

[Flettner]

We can do better than that can't we? I don't like the big choke thing in the inlet. I guess we could just use an airflow sensor now?

[ken seeber]

Did you notice that the Honda con rod remains almost vertical throughout each rev, so piston sidethrust must be low too. But I wonder where the red line would be.

You’re right tjbw, the rod angularity is small reducing piston side thrust friction.
There are also lots of other observations about the engine:
1. It is very under square, with a bore/stroke ratio of around 0.45:1
2. The above means that the combustion chamber can be more favourable in its shape to achieve a smaller surface area/volume ratio, enhancing efficiency.
3. It does feature a spark plug, maybe indicating that it needs this to start, something the Lohman 18 cc seemed to struggle with
4. Extremely ordinary scavenge passages, maybe not an issue with the low speed, long stroke, uniflow design
5. Crankcase compression ratio of almost zero
6. Crankcase seems to have lots of nooks and crannies for lub oil to hang up in.
7. Put a bit of effort into the cooling of piston ring belt at TDC
(with the liner being “wet” at this level), maybe because there is zero cooling of this at BDC
8. Looks to be a low speed (around 3000 rpm tops) industrial engine and expensive to make
9. Maybe, if it is ATAC, they have just gone full on to achieve the lowest BSFC ever.

[tjbw]

Re Vegas - here is some cut and paste from a report on the result I did.

We were top 3 fastest thru all the sessions,

.......

I took the deto gauge off the dyno and ran the 0-5V output into the Pi datalogger, and was very surprised to find that after leaning down enough to get hits, that the only place
it deto'ed was the acceleration phase after 2nd, 3rd, 4th gearchanges, when dropping back to near peak power after overeving to 12200.
The 5th to 6th change stayed above peak power and didnt deto at all down into the shute.
So I fitted the new header with the deto button installed and the gearchange deto dissapeared completely.
That allowed another 3 jets leaner before it started again.

Get this - the egt at that level was 1390* F with no sign of deto or piston heat stress.
This is due to the fuel octane being too high for the com, and the fact that the SKUSA advance restrictor plate doesnt allow us to add enough static timing to create more power - only pipe heat.

I think I have worked the logic of the deto button - it creates turbulence in the top 1/2 of the duct, allowing the smooth flow along the floor to return easily up the duct and be aimed upward off
the ski jump at the closing Ex port.
This came from finding that having the floor of the oval/round transition spigot co linear with the duct floor, and all of the transition angle in the roof made best power.

So here is the jetting chart prior to adding the new header, based on safe deto level, not egt as I would usually use.
The Lambda ( in the muffler ) showed the kart was fastest at 13.8 :1 ( and it hardly varied anywhere within the usable power band ), going leaner or richer was slower on track.
We tested both VP C12 ( 108 octane ) and VP98, the 98 being both faster and easier to tune to the edge.

Wobbly, thanks for Vegas report, and well done.

What would be the effect of the det mushroom on egt at the det mushroom location if you didn't change jets?

I think local egt would increase, and mixture returned to the cylinder would be warmer, this combined with the turbulance you mentioned resulting in a more homogeneous mix.

[Frits Overmars]

Ok Frits, how are we going to build a continuous fuel injection system, not pulsed.
The old Hiborn mechanical fuel injection was crude at best but if we were to put a electronically controlled needle valve in place of the return "pill" it could work? Or as you have suggested a DC motor driven by pulses width modulation.I developed the continuous injection idea for a 6,5 cc model engine that revs past 35.000 rpm, so no chance in hell that I would ever find an injector that's quick enough. I decided upon a gear pump driven by a pulse width modulated electromotor and a spring-loaded injection nozzle that I posted here before. As flow sensors, MAP sensors, Lambda sensors and the like are all too big for this engine, and as it's an unthrottled (always WOT) engine, I planned to use only an engine rpm / pump rpm lookup table. Crude as this would be, it would be an improvement on the present carburation system that depends on a pre-set (before flight) needle and exhaust pressure.
Of course such an rpm/rpm lookup table is totally insufficient if you want any throttle control and rideability.

[Yow Ling]

Ok Frits, how are we going to build a continuous fuel injection system, not pulsed.
The old Hiborn mechanical fuel injection was crude at best but if we were to put a electronically controlled needle valve in place of the return "pill" it could work? Or as you have suggested a DC motor driven by pules width modulation.

why not just pwm an injector ?

[TZ350]

A couple of years ago I copied down a long and very interesting thread on the restoration of a Saxon-chassis TZ from the NATS forum. I was given permission to put a copy of that PDF file on my website so that everyone can download it.

http://www.eurospares.com/graphics/chassis/SaxonYamaha.pdf

It is about 22MB in size.

cheers,
Michael

Interesting Post/Link.

[TZ350]

I developed the continuous injection idea for a 6,5 cc model engine.

An Ecotrons EFI system for really small engines:- http://www.ecotrons.com/products/uav-engine-efi/

[TZ350]

Page 1390 :niceone:


Fritz sent these through a couple of weeks ago but it's taken some time to get them up.


http://kiwibiker.co.nz/images/DKW-Jawa-KTM-Ossa-Rumi-Fath-Stredor-Seel-Hessels-carbs-CRP.zip
http://kiwibiker.co.nz/images/Honda-Suzuki-Yamahai.zip
http://kiwibiker.co.nz/images/Jamathi-Piovaticci-Bultaco-Garelli-Kreidler.zip

EngMod2T and simulating pipe designs.



TeeZee,the older version used a completely different pipe modelling code. In this setup we found that 50* gave the best correlation to dyno tested powerbands, and was a source of real frustration for Neels who hates " fudging " numbers with a passion.


He came across a new thesis that modelled an RSW and this included a new pipe simulation technique, and this has been written into the new code. Now the pipe wall temp makes a huge difference ,and much more accurately represents the real world wall temp average over the pipes length.


When you have temp varying with rpm, this overrides the temp at max power entry, and I found in Beta testing that 325 and 425 worked very accurately. In a situation like the Aprilia model where a powerjet is switched off past peak, 450 is needed at peak rpm to get correlation
but is too hot for our "normal" sims.




As some of you know I have been developing my 300cc NSR. Its going really well except the pipes are cracking and braking all the time. They are SS no surprise. They really do cool very quickly and obviously heat fast as well. I was wondering if lagging the pipes for the first 300mm is a good idea to keep a bit of heat in there and not let them cool so fast. Will this help with the cracking yah reckon.


Years ago on pre 95 rs hondas guys used to put beads of high temp red silacon around the chambers to take the zing out of them to stop cracking , the promblem was the rubber mounts but it did work not to bad but looked crap



I'm not sure how the SS works as I've never had a SS pipe. As with nearly everything I've owned, if the pipe was cracking the cure was to mount it so it was free to move around while still supported. You probably already on to that idea.




...anybody who has tried this, tell me about expansion chambers made of aluminum, examples of which I saw on the French site. Since, I assume, they'd have to be made thicker than steel, does the weight savings balance the drawbacks? I assume the big drawback is heat-loss, but maybe that could be largely addressed with a ceramic coating. What alloy and thickness has worked (if any has worked)?



Don't do it. There is no weight saving, aluminium (aluminum to you) pipes won't work without an internal ceramic coating, and they will crack despite the increased thickness. Aluminium does that.


Titanium works great for pipes if you use the right grade . But stainless steel is almost as good, cheaper and easier to weld.



hey wobbly let me ask something. in EngMod 2T, where it asks for the flow width of the window. if the duct exit and window are the same size and there is no kicker or radius turn at the duct exit, its rather easy to figure the flow width.


But like most cylinders, there is either a kicker or a radius turn just as it enters the cylinder. is there a easy way to get a close approximation of the flow width in this situation ?


Green arrow would be the flow width if both duct walls went parallel into the cylinder. but what if there was a radius or kicker. Would it still be as simple as the blue arrow suggests or is it more complicated than that ?



Where you have an angled exit on one wall like that I use a combination of the flow and chordal width. In reality the port flow area will be very close to the chordal width, as when the flow exits the duct its effective area will be less than a straight flow port, but more than the flow area measured vertically as you have drawn it. In between approximation is the chordal width as I have shown.



Imagine that you have a collection of coins. The diameter of the largest coin that you can shove through the window from within the cylinder bore, is the dimension you are looking for.



Well its sort of like I said, with parallel walls the coin will push into the duct and give you the exact "flow width".


With one wall angled a smaller coin will push into the port, but this gives a smaller flow width, and in this case its the chordal port width. Neels (EngMod2T) code asks for the actual "flow width" and even he says you need some judgement to approximate this where weird angles are involved.


You will know when TubMax is too high ( around 980*C ) as the program will scream DETONATION at you.


On a DynoJet you will need around 12.5% multiplier ( down ) to go from indicated crank Hp in EngMod to RWHp when testing your average racebike.


ONLY a 1 mm change, that is enough to completely ruin any engine - 0.1mm should be an ONLY to everyone - in a KT100 0.05mm in any port size can ruin an engines power.



You will make more power if you have a transition from the 23.7 duct outlet ( this will of course be oval ) up to the 26 pipe diameter ( round ) ie no steps at the joint face.
This is usually around 25 to 30 long and will be the slip joint spigot - this can be inserted into the pipe in front of the header as part of the header length %.






Hi Wob, this is getting into deeper water than I am used to. I worked hard playing with the ignition to get a flat TubMax (squish end gas temperature), but was I doing the right thing, is Ief's red line on this graph more appropriate? I just don't know what a good TubMax graph should look like.



EngMods TubMax is a reflection of the % of fuel energy retained in the unburned end gases trapped in the squishband. The shape of this curve is affected by a myriad of elements but the biggest factor is the real ignition timing.


In a race engine the results are supremely useful for juggling the ignition timing to fix any major anomalies that can produce low bmep at one point or several in the usable powerband. Where you are running what i would call "normal" numbers for timing - say 28* at the bottom of the range and 15* at peak then some further retard to get heat in the pipe for overev capability ,the curve shape will be close to that of the torque produced, a flattened bell.


ie low 900 rising to high 900*C at peak torque then dropping away again as more of the combustion heat energy is dumped into the pipe. You have to be careful of part throttle deto at the beginning of the powerband, and then of course if the temp starts hovering at 1000* in the high power range you will get DETO lighting up on the screen.


To drop the temp it is easy enough to simply retard the timing - but more power may often be had by adjusting the stinger, or reducing the com/squish velocity. Then re-running the Turbulent model to account for the differing flame propagation speed through the chamber due to squish turbulence changing the combustion delay numbers etc.


These factors are just as important, sometimes more - than the "raw" ignition timing number at any rpm point. Each end of the bell curve can be tipped, by use of a powervalve for example,or a solenoid powerjet that is simulated by a change in A/F ratio past peak power.



A huge part of Neels efforts to recreate reality in EngMod2T’s sim results is all around the code needed to model the wave action within the pipe.


A 2T lives and dies on the correct timing and amplitude of the particle flow down the pipe, much as a 4T lives and dies on the intake tracts influence. The latest code change that now has an accurate model of the actual wall temps effects has got the results even closer, without the demon fudge
factors Neels hates with a passion.


The only caveat i would add is that there is still some leeway for idiocy to creep in, and still get a result that seems fine ie 25* diffuser angles. Go back to the old texts and you will find that very early on in the development of expansion chambers it was found that the angle that gave the best energy recovery ( amplitude Vs period ) of the depression communicated to the Ex port during the scavenging phase was 16* included.


This is now modified somewhat in that we can and do have up to 6 different cones. All interacting and changing the shape of the negative pressure ratio plot as seen at the port face when the piston is around BDC, but as is human nature we always think more must be better - even with single malts.


Just keep in mind that any energy used in the diffuser, must then reduce the energy available to be used in the reflection phase - there is only a finite ( and ever decreasing ) energy level available that starts when the piston cracks open the port.

[SwePatrick]

Formula 1 injectors..
Those that they used when their engines revved above 20k

4 of those might work, but they´re to big.
If you use one injector every fourth revolution.

How am i thinking?

4 stroke seqvential injection, one squirt per cycle(720 degrees)
2 stroke, one squirt per cycle.

That would mean one injectors can deliver fuel to an twostroke for 10000rpm.
Just multiply them the get one to squirt every fourth cycle(the second one the cycle after that, the third one on next and the last one on the last, then start over) to get 'closed time' enough to be able to give an exact 'open time'.

[Frits Overmars]

An Ecotrons EFI system for really small engines:- http://www.ecotrons.com/products/uav-engine-efi/
This 'real small EFI system' would double the size and the weight of the engine if the injector could cope with the revs, which it can't.


Formula 1 injectors.. Those that they used when their engines revved above 20k. 4 of those might work, but they´re to big. If you use one injector every fourth revolution.It might work on a test bench. But the aim is to get the plane off the ground which would become rather difficult with the battery that those four injectors would require. And the whole idea becomes academic when you realize that the total weight of the plane would exceed the permissible maximum.
(There is a damn good reason for a maximum weight; I've witnessed the destructive energy of an F3D model plane hitting something at 360 kmh).

[senso]

why not just pwm an injector ?

Injectors are inductive, and slow to respond, its "easy" to pulse 10A or 20A at 50Khz for example, but the injector wont even move with such frequencies.

[Yow Ling]

Injectors are inductive, and slow to respond, its "easy" to pulse 10A or 20A at 50Khz for example, but the injector wont even move with such frequencies.
Would a piezo diesel injector work?

[FastFred]

.

30,000 rpm = 500 Hz

[Flettner]

A small constant spray system would be useful, for confined spaces within the engine.
You know the Hilborn system? Gear pump connected to the engine, simple, the faster the engine spins the more fuel supplied. There is a return system to the fuel tank with a jet in it, the bigger the jet the less fuel the rest of the system sees. There is some crude fuel control system for idle and low speed running also. I'd imagined that if you inserted an electronic control on this return "jet" you could control fuel flow throughout the rev range. Just like a normal EFI engine the ECU would need lots of inputs like TPS, temp, RPM, etc.

[ief]

I f... one takes a (not so good) carb, placed on a bike with X size (main) jet. Now we flow the carb and we find the jet size goes down...

Does this automaticaly mean better emulsion or is that not to say?

[Frits Overmars]

You know the Hilborn system? Gear pump connected to the engine, simple, the faster the engine spins the more fuel supplied. There is a return system to the fuel tank with a jet in it, the bigger the jet the less fuel the rest of the system sees... I'd imagined that if you inserted an electronic control on this return "jet" you could control fuel flow throughout the rev range.A bypass-jet will make the system sensitive to the viscosity of the fuel. The obligatory fuel for the model engine I was working at contains 20% castor oil, making its viscosity quite temperature-dependent, playing havoc with needle settings. I wanted to eliminate this dependence so I decided against a bypass.
Connecting the gear pump to the engine would give a fuel flow that rises linearly with engine rpm but that is not what's needed, so I chose to decouple the fuel pump rpm from the engine rpm and regulate the pump rpm via the afore-mentioned lookup table.

[senso]

.

30,000 rpm = 500 Hz

I know, but in a 4 stroke at even 10000 rpm the injector is only working at 83.3Hz, a much lower frequency, and at 10k rpm you are already into "exotic" parts and not stock parts from a car or motorcycle.

[Flettner]

Poor little engine, HCCI test unit. It's going to get a hiding. AG 100 Yamaha, just arrived on my floor.

[Peiter]

Excuse me for the interruption guys but I am amazed by those rpms..

http://youtu.be/yqz2YU7QzEc

[wobbly]

But at 18,000 a 50cc with 39mm stroke has only 23M/Sec mean piston speed, less than an RSA at 13,000.
Its only just getting going.

[FastFred]

.30,000 rpm = 500 Hz
I know, but in a 4 stroke at even 10000 rpm the injector is only working at 83.3Hz, a much lower frequency, and at 10k rpm you are already into "exotic" parts and not stock parts from a car or motorcycle.

TeeZee posted some injector math for his 2T


Performance Fuel Systems has great technical articles about fuel injectors http://performancefuelsystems.com/tech.htm
(http://performancefuelsystems.com/tech.htm)

An injector does not instantaneously snap open, it take a finite amount of time to reach full flow. 2ms (2 thousandths of a second) is the rule of thumb, below that, the flow is mostly non-linear and erratic.

Thankfully its better on the closing side as the fuel injection pressure helps with closing the injector’s needle valve so closing is much more rapid than opening.

A little math ..... 8,000 rpm / 60 = 133 rps x 360 deg = 48,000 deg sec / 1000 = 48 deg/ms

So at 8k rpm the crank turns 48 degrees in one mille second or 96 degrees in the time it takes to open the injector properly (ie 2ms).

2ms @ 8k rpm = 96 deg of crank rotation
2ms @ 10k rpm = 120 deg of crank rotation
2ms @ 12k rpm = 144 deg of crank rotation
2ms @ 14k rpm = 168 deg of crank rotation

So if at 12k rpm it takes 144 degrees (2ms) to get the injector fully open and another 72 degrees (1ms) to deliver sufficient fuel then the injectors pulse width is 3ms and it is energized for 216 degrees which is way more time, than the transfer port is actually open.


30,000 rpm = 500 Hz = 2ms for 360 deg of crank rotation. Just not enough time for conventional Pieco (small) injectors.

[husaberg]

TeeZee posted some injector math for his 2T



30,000 rpm = 500 Hz = 2ms for 360 deg of crank rotation. Just not enough time for conventional Pieco (small) injectors.

Which is why some used GP tems that experimented with Fuel injection in the nineties huge pressure (45 bar from memory)and a duel system that feed on intermintent engine revolutions.

[Flettner]

A bypass-jet will make the system sensitive to the viscosity of the fuel. The obligatory fuel for the model engine I was working at contains 20% castor oil, making its viscosity quite temperature-dependent, playing havoc with needle settings. I wanted to eliminate this dependence so I decided against a bypass.
Connecting the gear pump to the engine would give a fuel flow that rises linearly with engine rpm but that is not what's needed, so I chose to decouple the fuel pump rpm from the engine rpm and regulate the pump rpm via the afore-mentioned lookup table.

I guess so, but seeing as you have a computer on board, just give it a fuel temp sensor so as to take account of viscosity changes?

[Flettner]

Which is why some used GP tems that experimented with Fuel injection in the nineties huge pressure (45 bar from memory)and a duel system that feed on intermintent engine revolutions.

You don't want pulsed injection anyway ultimately.

[SwePatrick]

I dunno if posted before, Ryger plot ;)

http://citsengine.com.au/?page_id=64
https://www.youtube.com/watch?feature=player_embedded&v=ndWWHzE1Eek
https://www.youtube.com/watch?v=U4LksAgmYSo&feature=player_embedded

[husaberg]

You don't want pulsed injection anyway ultimately.

Not sure with the overlapping that it would ultimately be pulsed much at that speed and pressure.
Cagivas system is detailed in here they are out of order. (But they can be scrolled through.)
http://www.kiwibiker.co.nz/forums/album.php?albumid=4844&attachmentid=302540
Looking through it wasn't Cagiva that used the skip a stroke alternating injection someone did but I can't remember who?
Incidentally Moto Guzzi had a mechanical direct injection in the 1930's via air.
http://www.kiwibiker.co.nz/forums/newreply.php?do=newreply&p=1130654830

[crbbt]

I like the idea of continuous flow injection.

Would it work with port injection?

Or would you need a second solenoid/rotary valve to close the nozel when the transfer ports are closed?

I've just started learning programming at uni. Seems logical haha

[Lightbulb]

Frits, years ago, F2D control line combat motors used to have direct fuel continuous injection into the backplate of the engine. It was supplied with a bladder made from surgical tubing,(still being used today). Anyway, when they went to the 4mm restricted venturi engines, they have been able to make more power but putting the fuel into the venturi at a constant flow from the bladder. So the fuel is now pulsed with the air. It is still set by a guess of how much richer it needs to be before it gets into the air. I'm not sure what the real answer is, but being able to control the flow is one thing, but a mechanism for measuring the engines parameters is another. We saw a system back in 2007 , but the guy was having problems with the system in certain situations. It turned out that a lean of peak situation would fool the engine management and it never recovered once it happened. They also had issues when getting over the lean stage when piping up and getting it going on the line.
Neil

[speedpro]

What about continuous injection to an injector, with variable pressure, feeding through a disc controlled port/opening. This would give the control through the variable pressure and the timing of the pulse through the disc. With the disc controlled port closed the fuel would have to have a return path to the tank on the injector side of the disc valve as you wouldn't want the fuel flow to be interrupted but kept constant for any given pressure. Sounds a bit complex when I think about it but easily doable, maybe even by a suitably positioned port into the crankcase through the standard disc valve. The disc would not control the fuel flow, only whether it entered the crankcase and when.

[SwePatrick]

Well...

Today i did a couple of pulls.
First i made the clutch not being able to slip cause i found that it was correct that dyno slipped.

317666

Then i mounted pvl ignition instead as ignitech is still bugging me.
Made a pull with mild ignition, therefor peak torque is lower.


317667

Then i though i´d aim for 42hp at sprocket.
Adjusted ignition a little bit tougher, well..
The engine sounded really nice, really really nice i should say. ;)

Made one more pull,,, *BAM*!!!
Dynoshaft broke *lol*

317668

Is this the baddest mt5 engine ever or what? ;)



Yes a flat curve is what to wish for.
But i thought the abrupt stop in raising torque to an almost flat curve is a limiter.
And when i anlyzed the dyno rpm curve against the engine rpm curve i saw that, gear ratio altered from 10.3 to 10.6 just in the area where the curve flattens out.

'Locked' the dyno has gear ratio 10.3, no slippage.
This means when engine is revving 10300rpm the dyno revs 1000rpms.
And when slippage occur the engine revs 10600 and dyno revs 1000rpms.

A small value maybe, but it makes it 'not correct'.
I will sort this out and make a pull again to se what it does without slip.

rgds
Patrick

[Frits Overmars]

Frits, years ago, F2D control line combat motors used to have direct fuel continuous injection into the backplate of the engine. It was supplied with a bladder made from surgical tubing,(still being used today).That is more or less what we see in F3D. The fuel is contained in a rubber bladder; the bladder itself is contained in a tank. Pressure from the exhaust pipe (about 1,2 bar abs) is fed in between the tank and the bladder, squeezing the fuel out of the bladder. This cruel continuous injection has the advantage of increasing the fuel flow when the engine power and the pipe pressure rise. The downside is that there is no fuel flow at all until the engine is running, so how do you start it?
Every F3D flier has a circular brand on his index finger from keeping the tailpipe closed while spinning he engine :D.

[teriks]

Every F3D flyer has a circular brand on his index finger from keeping the tailpipe closed while spinning he engine :D.
Mostly so after you stall the engine for some reason and are in a hurry to get it up and running in time for takeoff..

[2005bully]

Frits...

There is a very simple non conventional 2 stroke mechanical fuel injection patented by a Barry Holtzman. Its concept may be applicable for your project...
The unit I had was very compact, yet able to feed a 125cc on methanol. It was roughly the dia of an ink pen and somewhere around 20 mm long. It screwed into a 3mm hole drilled
in the cylinder wall, which was located so the piston uncovered it about 60 degrees atdc. Output of the injector pump was plumbed into the crankcase. Engine compression was sufficient to operate the pump for starting purposes.
In operation each injection pulse is directly proportional to the pressure of the previous power stroke. It functioned remarkably well. I ended up sending it to a customer for testing and never got it back.

The patent number is US 6725845 B2

Here is a link to Google patents.... https://www.google.com/patents/US6725845?dq=Barry+Holtzman&hl=en&sa=X&ved=0ahUKEwiL06eNz77JAhVIZCYKHbzDBhsQ6AEIIzAB

Kermit Buller

[wobbly]

Hey Kermit, in my view that idea is absolute genius, I hope Miss Piggy gave you what you deserved.

[Flettner]

https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQrJgsvld1yHDE0lgRyOSprv8myfpiRw mRJWaTgGFkeIC_E45A2Pw
Frits...

There is a very simple non conventional 2 stroke mechanical fuel injection patented by a Barry Holtzman. Its concept may be applicable for your project...
The unit I had was very compact, yet able to feed a 125cc on methanol. It was roughly the dia of an ink pen and somewhere around 20 mm long. It screwed into a 3mm hole drilled
in the cylinder wall, which was located so the piston uncovered it about 60 degrees atdc. Output of the injector pump was plumbed into the crankcase. Engine compression was sufficient to operate the pump for starting purposes.
In operation each injection pulse is directly proportional to the pressure of the previous power stroke. It functioned remarkably well. I ended up sending it to a customer for testing and never got it back.

The patent number is US 6725845 B2

Here is a link to Google patents.... https://www.google.com/patents/US6725845?dq=Barry+Holtzman&hl=en&sa=X&ved=0ahUKEwiL06eNz77JAhVIZCYKHbzDBhsQ6AEIIzAB

Kermit Buller

Didn't Maytag washing machines have a similar system? They used to run twostrokes before electric. Could you imagine the lady (opps washer person) of the house firing up the Maytag, must have been quite an event.

I think they used some sort of crank case pump to feed the fuel in, it was a form of fuel injection.

Imagine opperating that!!!! O the noise, the smoke, the vibration :gob:

[Ocean1]

I think they used some sort of crank case pump to feed the fuel in.

Crank case pressure driven diaphragm pumps, pretty common in chainsaw type applications.

I'm struggling to remember details of a fueling system for a 2T rock drill which had to run at any angle...

[Flettner]

http://www.herculesengines.com/maytag/[06_13_00][20_08]_09.jpg
There is a better image

Unbeliveable, wonder if they use HCCI as well?

[teriks]

Frits...

There is a very simple non conventional 2 stroke mechanical fuel injection patented by a Barry Holtzman. Its concept may be applicable for your project...
The unit I had was very compact, yet able to feed a 125cc on methanol. It was roughly the dia of an ink pen and somewhere around 20 mm long. It screwed into a 3mm hole drilled
in the cylinder wall, which was located so the piston uncovered it about 60 degrees atdc. Output of the injector pump was plumbed into the crankcase. Engine compression was sufficient to operate the pump for starting purposes.
In operation each injection pulse is directly proportional to the pressure of the previous power stroke. It functioned remarkably well. I ended up sending it to a customer for testing and never got it back.

The patent number is US 6725845 B2

Here is a link to Google patents.... https://www.google.com/patents/US6725845?dq=Barry+Holtzman&hl=en&sa=X&ved=0ahUKEwiL06eNz77JAhVIZCYKHbzDBhsQ6AEIIzAB

Kermit Buller
Now that looks like it has some potential!

[Flettner]

Crank case pressure driven diaphragm pumps, pretty common in chainsaw type applications.

I'm struggling to remember details of a fueling system for a 2T rock drill which had to run at any angle...

I had the occasion to be out the back of Siberia some years ago. The Russians had chainsaws with Villiers type engines. I was interested to see that the way the chainsaw was tilted was to tilt the carburetor as well. Butterfly screws and a revolving connecting angle manifold, wow!
Can't remember how the fuel tank worked?

http://img.auctiva.com/imgdata/4/6/8/8/3/1/webimg/486613319_tp.jpg

Wonder what thats used for, relieving friction around the houes? Clearly I'm bored

[Frits Overmars]

Frits...There is a very simple non conventional 2 stroke mechanical fuel injection patented by a Barry Holtzman. Its concept may be applicable for your project... The unit I had was very compact, yet able to feed a 125cc on methanol. It was roughly the dia of an ink pen and somewhere around 20 mm long. It screwed into a 3mm hole drilled. in the cylinder wall, which was located so the piston uncovered it about 60 degrees atdc. Output of the injector pump was plumbed into the crankcase. Engine compression was sufficient to operate the pump for starting purposes. In operation each injection pulse is directly proportional to the pressure of the previous power stroke. It functioned remarkably well. The patent number is US 6725845 B2.Here is a link to Google patents.... https://www.google.com/patents/US6725845?dq=Barry+Holtzman&hl=en&sa=X&ved=0ahUKEwiL06eNz77JAhVIZCYKHbzDBhsQ6AEIIzABI love the simplicity of this idea. I fear that the resonant frequency of the spring-piston-spring system (46-50-44 in the patent drawing) may be too low for our 600 Hz (36000 rpm) model engines but I will certainly give it some more thought.

[MotleyCrue]

Crank case pressure driven diaphragm pumps, pretty common in chainsaw type applications.

I'm struggling to remember details of a fueling system for a 2T rock drill which had to run at any angle...

The Holtzman set up uses pressure in the cylinder above the piston so the amount of fuel squirted in is directly related to the load on the engine or at least that is what I remember from 15 or 20 years ago. The magazine tests seemed favorable at the time but I don't think it has been in use for years (could be wrong) so it must not have been all that great.

[Tim Ey]

Hello everyone!

I have a question concerning auxiliary exhaustports:
If you have plugged your wristpin and are on the quest for more exhaust TA - why not make the ports wider than 100% of the Bore?
I have the picture of Frits in mind where the auxiliary ports do not aim directyl to the bore center but more to the C-Port.

I can imagine that the scavenging will not work properly as the A Ports will shoot straight in the auxiliary ports, also the returning fresh gas mixture might swirl the cylinder a lot more than in an "conventional" engine...

So... Has anyone made an computer fluid dynamic of this and it seems to be bullshit? Or why was it never (?) done before?

cheers!
Tim

[teriks]

I love the simplicity of this idea. I fear that the resonant frequency of the spring-piston-spring system (46-50-44 in the patent drawing) may be too low for our 600 Hz (36000 rpm) model engines but I will certainly give it some more thought.
My main concern is what happens if, or rather when, you end up on the lean side of peak power/cylinder pressure.
I'm fairly confident that the resonance frequency can be raised enough with clever design though.

[MotleyCrue]

I think the Holtzman mechanical feedback loop could be tricked into the wrong mixture under certain conditions. The idea of a simple mechanically controlled injection is intriguing though.

Thing is carbs are always a compromise in one way or another yet they do a very good job and in such a simple way.

[SwePatrick]

Mended the dyno today.
Did a couple of pulls.
Brand new sparkplug to read out mixture, really spot on.
Tested a couple of times to se if it was happy with more ingnition, no.
The setting that broke the shaft seems best.
And,, this is the end of the road with this engine, now just racing it left to do.

What about the power then?
Yes!!, i reached 44hp on sprocket.
And at 11400 there is above 27Nm
Only thing i´m not happy with is the dip at ~7500rpm, but I designed the pipe not to build any lowdown torque so i guess i have to deal with it.
Ignitech can sort it out.

screenshot:

https://scontent-arn2-1.xx.fbcdn.net/hphotos-xfp1/v/t1.0-9/12294868_10153483387869475_4629612856784284052_n.j pg?oh=6ad1219eb86c07750f7fe4f481a1e08d&oe=56DF2927



Well...

Today i did a couple of pulls.
First i made the clutch not being able to slip cause i found that it was correct that dyno slipped.

317666

Then i mounted pvl ignition instead as ignitech is still bugging me.
Made a pull with mild ignition, therefor peak torque is lower.


317667

Then i though i´d aim for 42hp at sprocket.
Adjusted ignition a little bit tougher, well..
The engine sounded really nice, really really nice i should say. ;)

Made one more pull,,, *BAM*!!!
Dynoshaft broke *lol*

317668

Is this the baddest mt5 engine ever or what? ;)

[wobbly]

Re the idea of increasing the Aux ports wider than 100% of the bore.
This was tested even better than CFD - Jan did it with the RSA on the dyno, lost power.
I believe due to any advantage gained from the extra blowdown area is offset by the much longer path length for the Ex wave
when its past 1/2 way in the bore, and this smears out the pulse amplitude entering the header.

I was asked about Aux ports and spigot design in a PM, and as I cant add pics to a PM, here is the welded duct on a KTM250
with 75% area at the face - 52mm wide by 32mm high, considerably reducing the duct volume in the cylinder just short
of going sonic in EngMod ( PS the floor is 4mm above BDC ).
I added the male spigot, so that the oval to round transition could be made smoothly before entering the pipe header.

[FastFred]

Mended the dyno today. Did a couple of pulls. Brand new sparkplug to read out mixture, really spot on. Yes!!, i reached 44hp on sprocket. And at 11400 there is above 27Nm

44hp, well done, party time ... :wari:

[MotleyCrue]

SwePatrick,

Cool. Did you ever post any pics showing your ports? Maybe you did but this thread is so big I have only read a fraction of it. If you did please point us to that for a refresher.

[2005bully]

My main concern is what happens if, or rather when, you end up on the lean side of peak power/cylinder pressure.
I'm fairly confident that the resonance frequency can be raised enough with clever design though.

Very good observation. My intended use of the Holtzman injector was on a clutched fixed gear race kart engine. Unlike most 2 strokes with a transmission, these engines typically operate in an rpm range starting at the torque peak, (point of clutch engagement) followed with all the overwind one can generate. The injector worked remarkably well at all points before torque peak. Then it abruptly stopped pulling with virtually no overwind. After much trial and error I reasoned that since the amount of fuel supplied for each power stroke was determined by the previous combustion event, once the resonances became out of phase and the cylinder pressure dropped a down-ward spiral of lower pressure combustion events followed. Kind of became self governed at the point of peak power.... After quite a bit of trial and error with springs and Bellevue's I moved on to other projects. But kept it in the back of my mind for an application where the engine was operated at rpm's before the power peak.. Current emissions standards have changed everything 2 stroke,, But imagine if you could go back to the early days of chainsaws and weed-eaters, WOW what a slick solution. Self governed, Self compensating for any altitude, and much simpler than any carburetor. Hats off to Barry Holtzman. :woohoo:

One other question raised from working with this unit I hope to answer in due time.... Would it work to use the input from a pressure sensor located in the same position as the Holtzmans injector, as the main input for EFI fuel mapping? Kermit Buller

[TZ350]

Honda MT5 engine 5speed.(6speed breakes very easily i noticed), 132cc, 6 disc clutch, MT8 crankshaft with 110mm samarin rod.(stroked to 50mm), Kawasaki KX 125 -86 cylinder bored to 58mm (Woessner CR144 piston), A lot of porting (199/138/138/140 durations), Derbi design reed. Keihin PWM 40mm, slightly modded. Ignitech ignition, homemade combustionchamber insert. Homemade pipe, Actually built just with 'feeling', no calculations at all.A lot of welding has been done to the crankcase to accept crankshaft and cylinder, Finally coated crankcase to block out some heat from gearbox.


44hp on sprocket, and at 11400 there is above 27Nm Only thing i´m not happy with is the dip at ~7500rpm, but I designed the pipe not to build any lowdown torque so i guess i have to deal with it.

317695



44hp from 135cc with a good usable spread of power, congratulations. :niceone:

The power dip, we get that too with our different engines, I think it is where the pipe is working against the cylinder and messing up the carburation, we can sometimes improve it with tuning.

317693317694

[MotleyCrue]

I am looking at removing the aluminum divider entirely, between A and B ports in a cast iron sleeve engine bore 75mm. Does the aluminum divider do anything other than direct and guide the air ? That is, does it also provide any important strengthening/stiffening to the cast iron liner or the aluminum that forms the inside radius of the transfers ? Essentially if I remove the divider will it cause any harm when the engine is run other than mess up the airflow ? I know this is kind of a novice question but I have never needed to remove the entire aluminum divider before, I have always just reshaped dividers.


I will need to replace the divider entirely because its all wrong but its replacement will be epoxy until I get what I want shapewise and I was also going to run it without any divider before doing the epoxy divider just for curiosity's sake, but I'm not curious enough to want to risk damage.

[wobbly]

The ring will probably pop out into the huge transfer holes, and wreak havoc - as there will be no guide radi to ease the ring back into the piston groove.
With no support due to the Ex port hole, as well as the huge transfers, the small areas actually holding the ring in a roundish shape, will be worn very quickly - tears will follow.

[MotleyCrue]

The ring will probably pop out into the huge transfer holes, and wreak havoc - as there will be no guide radi to ease the ring back into the piston groove.
With no support due to the Ex port hole, as well as the huge transfers, the small areas actually holding the ring in a roundish shape, will be worn very quickly - tears will follow.

Actually I wouldn't be taking the cast iron divider out of the cylinder wall between the A and B, just the aluminum divider which runs down through the transfer passageway, so the rings would still have the usual contact with the cylinder wall. I just wasn't sure if the aluminum divider was there for any other reason than flow reasons.

[wobbly]

Sorry misread that then, but I have twice seen unsupported cast dividers break off as well.
The ring pressure approaching BDC as the Ex radi push the ring back into its groove, means the narrow septums are subject
to high loading, and with no support from behind the cyclic load means they fail - quickly.

[Lightbulb]

What happens if you have a carb of some form introducing some fuel into the incoming air prior to the main carb ?
Is there any advantage to having a mix of air that has a small amount of fuel already mixed with it ?
The idea is that the initial amount of fuel has time to mix with the air before it gets to the carb to help make a better air
fuel mix for the engine .
Neil

[SwePatrick]

44hp, well done, party time ... :wari:

Yes! i´m still in shock ;)

[SwePatrick]

SwePatrick,

Cool. Did you ever post any pics showing your ports? Maybe you did but this thread is so big I have only read a fraction of it. If you did please point us to that for a refresher.

Here´s a pic in between pulls, when checking state after i blown reedplates though the carb *lol*
I hope you can see it, it is linked to my facebook page.

https://scontent.xx.fbcdn.net/hphotos-xlf1/v/t1.0-9/12299197_10153484548739475_1390424316559050539_n.j pg?oh=6128d8d05cd2504412771af55d85623e&oe=56DB84D6

Since pic below i have ported a bit more at the boreskirt at the intake side, smoothen it out and made the passages down in crankcase more smooth.

https://scontent.xx.fbcdn.net/hphotos-frc3/v/t1.0-9/s720x720/1900097_10152049453229475_1865876644_n.jpg?oh=8fca 89b3a213a2eba98ec2e5a0e4f100&oe=57218673

[J.A.W.]

Actually I wouldn't be taking the cast iron divider out of the cylinder wall between the A and B, just the aluminum divider which runs down through the transfer passageway, so the rings would still have the usual contact with the cylinder wall. I just wasn't sure if the aluminum divider was there for any other reason than flow reasons.

A major function of rings is heat transfer, & that heat so transferred has to be carried away through the cylinder wall/sleeve..

If the aluminium sleeve support is removed, then so is its heat sink/transfer - duty/functional capability..
& thus allowing formation of a potential hot spot location - to flare off lubricant & promote a nip up..

[MotleyCrue]

Sorry misread that then, but I have twice seen unsupported cast dividers break off as well.
The ring pressure approaching BDC as the Ex radi push the ring back into its groove, means the narrow septums are subject
to high loading, and with no support from behind the cyclic load means they fail - quickly.

Thanks. I guess what I'll do then is leave some decent thickness of aluminum right behind the cast divider then eliminate the rest of the divider further down the transfer passageway and build up a new sectional replacement there with epoxy.

The epoxy will not disintegrate with fuel it stays hard as a rock, but it always seems that every epoxy eventually lifts off the base metal (aluminum) sooner or later. Small screws and rough surfaces help and keep the epoxy from going into the engine, but is there anyway to keep it from lifting off the base material? It just seems that the oil gradually gets in under the epoxy maybe by capillary action and at some point the epoxy lifts. Maybe some kind of sealant that keeps the oil from getting under the epoxy ?

[SwePatrick]

Yes..
You can 'paint' above the epoxi to get a seal.
Just need to find a really resistant paint.

[jfn2]

wobbly:
Do you have any more comments or pics of the ktm250 exhaust (in port or portmap) of the work you did? Thanks Jeff

[seattle smitty]

I had the occasion to be out the back of Siberia some years ago. The Russians had chainsaws with Villiers type engines. I was interested to see that the way the chainsaw was tilted was to tilt the carburetor as well. Butterfly screws and a revolving connecting angle manifold, wow!
Can't remember how the fuel tank worked?


One of the dusty boxes buried in the back of my shop contains a Titan 40 chainsaw, circa about 1952, IIRC. Rotary valve through the crank, crossflow cylinder and deflector piston, worm-drive, and a float-type carburetor. The blade-bar and drive section rotates in the manner you describe, affixed by a big ring-clamp that is very quickly released for re-orienting the bar to keep the powerhead and carb upright. I believe Titan was the first or one of the very first makers of gasoline powered chainsaws, at first big 2-man saws for logging, later one-man saws like this one that I have (see the ring-clamp on the sixth row of photos):

https://www.google.com/search?q=titan+40+chainsaw&biw=1331&bih=559&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwigq_Ka28LJAhVFyWMKHSdRCUgQsAQIIw


As usual with Google images, only the first few rows of photos apply to the subject you asked for.

My saw was the first chainsaw for the Smith family, bought by my dad from a neighbor, many times second-hand. A big, heavy brute by modern standards. Before he got it, I had cut a lot of trees on the property with a bow-saw, cut them down, cut them into logs for the fireplace, split the logs with sledge and wedge. Amazing how much you can get done when you're young, with energy to spare, a strong back, and a weak mind.

Maybe a year after the Titan 40, Dad found a couple of early-to-mid-'50s Sears "David Bradley" chainsaws, also very much used. Also cross-flow, with VERY early reedvalve into crankcase induction, and very early little pumper carburetors (so no more need to rotate the bar). The blade-drive was geared-down to about half engine speed (I think there were direct-drive versions, too). The reeds on these saw engines were few and TINY!! The powerheads were made by Power Products, a name well known to the first generation of kart racers; Power Products kart motors fought it out with McCullough, West Bend, and maybe a few others I don't now recall. Here are some of the saws (I have a couple of these):

https://www.google.com/search?q=1956+david+bradley+chainsaw&biw=1331&bih=559&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwidl-TP3sLJAhUN0WMKHdVzB0UQsAQIGw#tbm=isch&q=1953+david+bradley+chainsaw

. . . and the PP kart engines:

https://www.google.com/search?q=power+products+kart+engine&biw=1331&bih=559&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjazaPc4cLJAhVHxGMKHSf3DksQ_AUIBygC

[seattle smitty]

Some of you might get as big a laugh as I did from this offering by a gal on a van enthusiasts' site. There aren't a whole lot of girls/women directly involved in motorsports, and many of those are only drivers/riders of machines that are built and maintained by the men in their family. But the gals who do get grease under their nails, some of whom have real mechanical ability, tend to be very interesting individuals in other ways as well. I love this one for her comment about mis-laying tools:

Annaleigh,


(QUOTE) "Yes tools!!! I could spread out a white sheet, sit in the middle of it, open my tool box and lay each tool out as I inventory them on paper. Having never moved, when putting the tools back in the box, 3 or 4 would be missing . . . " (end Quote)

[wobbly]

Here are some more pics of the road racing KTM250.
It has a long rod from an earlier model with a Wossner flat top single ring piston from CR250, needed an 8mm plate under cylinder
that corrected the case com, and got ports close - still needed 2 days of grinding as the ring pinned on centre enabled huge B ports.
The reed is a VF4 off a late model KTM and the inlet length is tuned to 10,000 rpm with a 42mm bored SPJ carb of late model RS250 to use the
solenoid PJ for overev power.
This has a screw adjustable powerjet on a CNC carb bowl.
I cut off the kickstart gear housing to get the intake dead straight.
Water route has been changed with CNC head and has bronze insert.
The Aux ports were welded then made triangular and twice the area around to bore centre, Ex port floor and corner rads are welded.
Port setup is with B,C highest and set in EngMod for 72 Hp on Avgas.
Servo driven PV is used as it drops over 1500 rpm into 5th gear due to MX gearbox ratios.

[TZ350]

Old air cooled Suzuki GP100 soon to be a 30+hp water cooled 110cc six speed Suzuki GP-NSR Frankenstein engine. Backstory.
The whole build can be seen by following the backstory posts like a trail of bread crumbs.

The Dry Sump and Gear Oiler, not to sure how well this idea will work so I am going to try it on the old air cooled engine first.

317734 317736

The oil spray bar. The oil level in the crankcase will be minimal and well below the gears and clutch hub. The bulk of the oil will be held in a sump tank.

The oiler drops oil onto the gear pairs, I sure hope the oil mist generated will find its way to the gear bearing surfaces and the ball races.

317738 317737

The oiler lubricates the clutch hub gear through a small hole near the end of the spray bar and the end of the tube sprays oil onto the outside of the clutch hub itself, some of it will hopefully dribble down to the output shafts plain bush bearing. There is a new hole in the input shaft to lubricate the clutch hub bearing. The input shaft hole was a challenge as the shaft is as hard as the hobs of hell. Thankfully Chambers found a way of doing it with Dremel and diamond bit.

317735

Oil is feed to the spray bar and up the inside of the gear box input shaft to lubricate the clutch hub and release bearing.

317733

As well as the dry sump and gear oiler I am trying a longer rod for more crankcase volume.

The motor was going together really well until I fitted the cylinder. Then I found the fatter rod was jamming around TDC. Now the cases need relieving, bugger, I have to take them apart again.

[jfn2]

Wobbly:
Thank you for the pics and reply. If I may, a question about the intake length. It looks a bit long and is the long red spacer block just a transition from the round carb to the square reed? Another question, from the 4mm build-up at the bottom of the exhaust port, are you adding 4mm of fill the whole length of the port or is it 4mm at the port window and tapering to 0mm at the spigot end? I am building a 250 KTM now for hill climbing and very interested in what you did.Thank you, Jeff

[wobbly]

No,and no.
The intake length isnt long at all, just remember that the "normal " 250 intake is the same as a 125 - simply so the carb can fit in behind the suspension etc.
How can that possibly be correct for an engine that peaks all of 2000 rpm lower.
The built up Ex floor is full length, as the roof is set by the PV blade, and that is flat to begin with.
The red block is simply a spacer to adapt the differing bolt patterns and get the length correct.
The round to squarish transition is done in the manifold rubber.

[bucketracer]

The Dry Sump and Gear Oiler, not to sure how well this idea will work so I am going to try it on the old air cooled engine first.

Interesting project, really sort of getting out there. TeeZee I think the later TZ250 and TZR had a similar gearbox oiling system but I can't find any pictures of it, I will keep looking, hopefully someone has one and can post a few pictures of the gearbox oil circulation system.

[karter444]

Wobbly
as the exhaust floor and lower corners have been welded do you think that you could widen the A port or make the angled bridge more vertical ie make the a port more rectangular in shape .
Whats the ideal width for the bridge between the B and C port now that it doesn't support the ring gap
cheers

[TZ350]

Interesting project, the later TZ250 and TZR had a similar gearbox oiling system, hopefully someone has one and can post a few pictures of the gearbox oil circulation system.

It would be great to know more about it, I would love to see a few pictures, it would be very helpful to know if I am on the right track with the way I am setting up the dry sump oiling system.

[husaberg]

It would be great to know more about it, I would love to see a few pictures, it would be very helpful to know if I am on the right track with the way I am setting up the dry sump oiling system.

Not totally sure as I have never had one apart but pretty sure the NSR250 has a pumped gearbox oiling system.
later
http://edetuckracing.blogspot.co.nz/2011/09/on-sunday-6th-september-2011-i-finally.html


Interesting project, really sort of getting out there. TeeZee I think the later TZ250 and TZR had a similar gearbox oiling system but I can't find any pictures of it, I will keep looking, hopefully someone has one and can post a few pictures of the gearbox oil circulation system.

Not a great article as it only mentions it briefly but there is a pic of the cluster.
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130251631&highlight=reverse+cylinder#post1130251631
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130252650#post1130252650

Try a Parts fiche or a manual for either the TZ TZR or RS250 or NSR250.
http://www.risingsuncycles.com/pdf_partsbooks.htm

[TZ350]

Thanks Husa, its encouraging that both Honda and Yamaha did it. If anyone has one apart I would love to see some photos or more information on how the oil holes are arranged for oiling the gears.

[JX.]

Someone was interested of my engine so I'll post info of it.
Back in the days when I bought my Derbi with 50cc (D50B0) Engine, I wanted to tune it of course. Started from small things such as exhaust, cdi, carb...
Then I wanted to rebuild/tune an engine with more power.

Bought used engine for 30€
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/Varaosa%20kone/IMG-20141210-WA0077.jpg
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/Varaosa%20kone/IMG-20141210-WA0055.jpg
The gearbox was in perfect shape, crank was full of rust, no cylinder, clutch is too used.

Then the rebuild started, first I wanted to make sure that there is no steps in begin of transfers with the new 80cc cylinder (50mm Bore, 40mm stroke)
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/REBUILD/An2GYsd9QDEdiqyoqv8HMFe94i8T.jpg
Fixed:
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/REBUILD/20150315130513.jpg

https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/REBUILD/Doppler_ENDRC.jpg
I had my old crankshaft already disassembled because the 18mm crankpin had snick on it as you can see in the picture.
No problem, bought new rod for it and assembled it.
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/REBUILD/20150321074734.jpg

Repainted & smoothed
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/REBUILD/20150328103103.jpg
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/RE-REBUILD/20150910112416.jpg
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/REBUILD/20150330123211.jpg

Result:
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/RE-REBUILD/20150911_192926.jpg
https://dl.dropboxusercontent.com/u/40317680/Images/Derbi/JX_TOPIC/REBUILD/photoshop.jpg
Specs:

Engine: Derbi D50B0
Carb: Oko PWK 28mm
Reedvalve: VForce3
Intake manifold: Honda CR85
Cylinder: Airsal "80cc"(50mm bore) with stock 183* exhaust port
Crankshaft: Doppler Endurance(40mm stroke) with Malossi conrod(90mm) and SKF C3 Tn9 bearings
Ignition: MVT Digital Direct (250g flywheel, Digital), NGK B9EG sparkplug)
Exhaust: Voca Racing "80cc" carbon


https://www.youtube.com/watch?v=fcegoze3F60

So there is a lot of improving to do with the cylinder for example, I do not have any exp. with Nikasil plated cylinders, I've tried once to increase the timing of exhaust port in my old seized cylinder with Dremel and high RPM but at the end the plating chipped a bit. I'm not sure if I should try again with diamond bits. I was thinking to increase the exhaust timing to 196*, reshape the exhaustport and enlarge/finish the exhaust channel.

[TZ350]

Interesting project, great pictures. On the very few plated cylinders I have ported I marked the height I wanted then using a Dremel with a pink stone. I ground the cylinder edge of the port up to the line.

I ground it as if it was a big chamfer for the rings. That way the plating had a chamfered edge to it for the ring. Then I worked on the inside of the port like you normally would. The plating lasted long enough for dyno testing and then if the cylinder was any good I had it re plated.

Another approach has been to raise the barrel until the exhaust port timing is where I want it and then fill the top of the transfers with Devcon epoxy glue until the blowdown time area between the exhaust and transfers was correct for the anticipated rpm and power output. The bottom edge of the transfer is lowered and given a big chamfer. The head is spigoted down into the cylinder to get the correct squish. For the plating and port edges a Dremel with pink ball and taper stones works well.

I like your work.

[wobbly]

The whole idea of filling the floor and the bottom corner rads was to reduce the short circuiting from the A port, so widening this
I didnt want to do.
As it turned out by widening and raising the B ports, there was plenty of transfer STA ( easy with a long stroker ) so it wasnt needed.
I made the bridges next to the boost port the same as the A/B at 3mm.
The EX side walls are angled from the narrower width below TPO out to 70% bore,and with the big width of the Aux top edges it was again easy to
get plenty of blowdown STA to match the 72 Hp transfers due to tons of bore area in the long stroke configuration.
The only issue with the 72mm stroke is that spinning it to 11,000 is sacrilege on the big end life, so the whole thing is designed to run to 10500 max
with plenty of power on the upside to help acceleration when dropping low in revs after the big gearchange splits of the MX ratios.
Alot cheaper than getting special gears made.

[husaberg]

Thanks Husa, its encouraging that both Honda and Yamaha did it. If anyone has one apart I would love to see some photos or more information on how the oil holes are arranged for oiling the gears.

Aprilia GP bikes has a pressure feed gearbox I believe as well, Frits might shear it details (get it)
There is a few pics. from a brief look arround at other systems. it looks like there is very similar systems used, to what you have designed.
First pic is some form of us style Honda crusier, second is a Honda V4. third is a F650 BMW, Forth is a random generic pic

I think both the Honda and Yamaha feed through the center of the shafts with a gear pump not sure if the autolube pump will have enough flow? what is the fully open flow rate of the one you are using?
Pitbikes and CRF50 have nice little gear pumps that drive straight of the primary gear. I have a Takakawa uprated one here somewhere, you are welcome to it if you want it.
317747317746

Page 39 onwards here Rob
http://www.slideshare.net/EvanDeCiren/techgp-94-yamahatz125-94-tz250

[Frits Overmars]

Interesting project, really sort of getting out there. TeeZee I think the later TZ250 and TZR had a similar gearbox oiling system but I can't find any pictures of it, I will keep looking, hopefully someone has one and can post a few pictures of the gearbox oil circulation system.Will you settle for a 1968 Yamaha RA31A (17000 rpm 125 cc W-four)? Click 3 times on the picture and you'll see the row of oil bores in the upper case.
317748

[TZ350]

The Dry Sump and Gear Oiler, not to sure how well this idea will work so I am going to try it on the old air cooled engine first.

317734 317736

The whole build can be seen by following the backstory posts like a trail of bread crumbs.


Grumph gave me the original ideas of what to do.


Will you settle for a 1968 Yamaha RA31A (17000 rpm 125 cc W-four)? Click 3 times on the picture and you'll see the row of oil bores in the upper case.

317748


Thanks Frits


There is a few pics. from a brief look around at other systems. it looks like there is very similar systems used, to what you have designed.

I think both the Honda and Yamaha feed through the center of the shafts with a gear pump not sure if the autolube pump will have enough flow? what is the fully open flow rate of the one you are using?

Thanks Husa

317750

This one shows the gear bearings being directly lubricated as well as the gear teeth. And it is maybe something I can try to do with the water cooled NSR/GP six speeder. I would have to have the shafts annealed so I could drill them then re hardened, might be worth doing.

317749

Hi Husa, yes my air cooled test engine is more like this one where just the gear teeth are directly lubricated and everything else is just good luck. I am not sure if Frits's RA31A Yamaha is more like the first or second oiling system.

317751

The current plan is to have the oil drain back into a 1L mini bike fuel tank and pump it up to the gear box gears with a small 1-2L/min water fountain pump or a diaphragm pulse pump or maybe both in series for volume and pulsed flow. Or maybe the auto lube pump could be replaced with a mini bike oil pump like the one Husaburg posted a picture of.

[Frits Overmars]

.. my air cooled test engine is more like this one where just the gear teeth are directly lubricated and everything else is just good luck.
I am not sure if Frits's RA31A Yamaha is more like the first or second oiling system.Yamaha did not rely on luck back then. I couldn't find an appropriate photo of the RA31A's multipoint lubrication system, but here's a picture of the identical system on its bigger brother, the 250 cc RD05A four-cylinder. By the way, my all-time favorite Yamaha, the simple RD56 twin, already had a similar system (click 3 times to enlarge).
317752 317753 317754

[TZ350]

a few pictures of a 1970's water cooled 4 cylinder rotary valve 125cc Yamaha road racer, 42 RWHP at 18,000rpm photoed by Chambers at the classic meet.

317756

Certainly nothing is left to chance with the engine auto lube system.

[husaberg]

317756

Certainly the nothing left to chance with the engine auto lube system.

Its almost spaghetti
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=258589&d=1330253931
258589
I can't help musing that of you are going the spray bar technique with a low pressure and output pump Rob, it might be best to have the pump feeding both ends?




The current plan is to have the oil drain back into a 1L mini bike fuel tank and pump it up to the gear box gears with a small 1-2L/min water fountain pump or a diaphragm pulse pump or maybe both in series for volume and pulsed flow. Or maybe the auto lube pump could be replaced with a mini bike oil pump like the one Husaburg posted a picture of.
If you you a aluminium resivour finned it will cool better plus plasic isn't a fan of heat, you can also even spray/splash some cool oil onto the back of the crankcase wall.
One pump should be more than enough KISS

[TZ350]

If you you a aluminium reservoir finned it will cool better.

I have been toying with the idea of making a catch tank out of a piece of finned turbo intercooler pipe.

317759

If I put a sleeve over the finns and blow air through it with a fan then I could have a really good air cooled catch tank.

317760

I also have one of these auto trans coolers that I could fit a fan to. Ok for the 110cc NSR water cooler but just none to sure about the legality of using it on the 125 which must be air cooled.

[J.A.W.]

[QUOTE=husaberg;
I can't help musing that of you are going the spray bar technique with a low pressure and output pump Rob, it might be best to have the pump feeding both ends?


If you you a aluminium finned tank - it will cool better, you can also even spray/splash some cool oil onto the back of the crankcase wall.
One pump should be more than enough KISS[/QUOTE]



Yam RZ500 road bikes used a pumped lube cassette type trans..
H1/H2 Kaw triples ran a collector cup feeding oil to the hollow output gear shaft - from the primary gear/clutch oil splash.

Perhaps a simple plunger oil feed pump - could be rigged up - to be worked by swing arm movement?

Or an even simpler.. gravity feed from a tank..
It would take a fair while to fill the trans case 'sump' - up to gear level - anyhow, likely - longer than most races..

[husaberg]

I have been toying with the idea of making a catch tank out of a piece of finned turbo intercooler pipe.

317759

If I put a sleeve over the finns and blow air through it with a fan then I could have a really good air cooled catch tank.

317760

I also have one of these auto trans coolers that I could fit a fan to. Ok for the 110cc NSR water cooler but just none to sure about the legality of using it on the 125 which must be air cooled.

https://www.google.co.nz/search?q=round+heat+sink&biw=1920&bih=953&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjH8_-1zsbJAhWlHaYKHT2DD5YQsAQIGQ#

[peewee]

Wobbly:
Thank you for the pics and reply. If I may, a question about the intake length. It looks a bit long and is the long red spacer block just a transition from the round carb to the square reed? Another question, from the 4mm build-up at the bottom of the exhaust port, are you adding 4mm of fill the whole length of the port or is it 4mm at the port window and tapering to 0mm at the spigot end? I am building a 250 KTM now for hill climbing and very interested in what you did.Thank you, Jeff

i had a bunch of photos how to fill in the exh floor. dont confuse me with a professional welder though as it was my first go :laugh:. youll want to have a idea ahead of time what the exh exit area should be, that way youll know how much of the floor to fill in. or what i did was just over fill it then grind it down to where it needed to be

[AndreasL]

Sorry if I'm sounding a bit negative...but haven't we been through "the cooling fan"-theories here before?

Ok, this is a different situation but not to much.

Love the finned cooling tank idea. With that you probably improve the cooling some WITHOUT making your system more complicated/heavy/expensive.

With the "coolers/fan/pump" solution you may improve the cooling some more. But to what cost in performance? I say cost since I believe the weight increase will make a slower bike.

All of the above stated if the gear box don't really needs the extra lube/cooling.
Or finding a loophole in the regs for air cooled engines running the gear box with a oil cooler to make a oil cooled engine a'la Porsche. I know you have thought about that before.

Ones again, I hope this come out right. I don't like to offend anyone.
But I'm a believer in spending resources were they make the biggest impact.
Then it's fun to just play around with different ideas, that's what make us come up with new solutions to old problems.

[wobbly]

Today I would use CFD to show the flow rate from the oil pump entering the spray bar over the gears, but back when I did the BSL
we made a small jig with a variable speed drive to the TZ250 gearbox pump.
This gave a good indication also of the gear ratio needed to drive the thing off the clutch input shaft.
It took 3 goes with varying sizes of the 6 orifices to get near equal discharge rates feeding the bar from one end only.
The pump inlet filter housing was at the lowest point of the case, that had a small sump with a cover that helped access for the CNC machining process.
Its cover was finned, but probably wasnt helped much by the proximity of the bottom pipe.
If doing it again I really like the idea as used by Honda in the NSR of feeding the pumped oil into the gear shafts,this way the oil floods out of
the support bearings,or if its a fixed gear then out thru the gear itself.
But I think they dropped oil onto the output shaft gears via a cast in slot with spray holes as well.

[jonny quest]

What is the advantage of an oil pump to the trans?

[wobbly]

A TZ350 ( with dry clutch ) has 1700mls of oil thrashing around all over the clutch primary and the all the gears.
The BSL500 had only 150mls and the spray bar directed a continuous small amount onto the clutch gear,the
transfer gears and the input shaft gear set.
At any one time less than 1/2 the oil was being used to lubricate these parts, the rest was in the sump around the pump
intake filter, and was well below any of the gears "dipping ".
Exactly the same effect as dry sumping a 4T crankcase.

[jonny quest]

I'm used to MX bikes, wet clutch.

I figured that was the deal... but the trans spins so slow compared to crank, curious as to what the actual gain is with an oil pump.

[TZ350]

Sorry if I'm sounding a bit negative...but haven't we been through "the cooling fan"-theories here before?

Yes true we have, but the fan idea keeps being attractive to me because you can greatly increase the cooling efficiency of an air cooled anything if you can purge the hot air trapped deep in the roots between the fins.


Curious as to what the actual gain is with an oil pump.

I am curious too, so it is one of the reasons I am re cycling the old air cooled motor which I have dyno data for. I will fit the old air cooled motor to the new chassis for testing before I put the super duper 110cc NSR/GP motor into the new frame.

317769

Apart from any potential performance gain from a dry sumped motor I basically have to do it because the motor is so heavily tilted down at the front in the new frame that all the gear box oil will flood the rotary valve area and leave the gears dry, so I have to pump it back over the gears to lubricate them. And if your pumping oil around you might as well run it through an oil cooler too. And if you have an oil cooler you might as well make it as efficient as possible with a fan to shift air through it. Anyway that was the thinking. But with Wobbly pointing out that 150ml of oil was enough for the BSL 500 I will re think how big a catch tank I need.

[karter444]

has anyone had problems with JB metal weld falling out . I need to reangle an A port from its current 9* to 25* without changing the port height so need to fill the roof and then grind to correct angle
cheers

[AndreasL]

Yes true we have, but the fan idea keeps being attraktive to me because you can greatly increase the cooling efficiency of an air cooled anything if you can purge the hot air trapped deep in the roots between the fins.

Don't you think some clever ducting to i.e. the finned pipe used as a catch tank would give enough air flow, even at the low speed tracks?

I really like what you are doing TZ and I'm looking forward to new posts about the 110cc.

[lodgernz]

has anyone had problems with JB metal weld falling out . I need to reangle an A port from its current 9* to 25* without changing the port height so need to fill the roof and then grind to correct angle
cheers

DevCon Liquid B. Sit the cylinder on a wedge at the angle you want the port roof to be, then tip some DevCon in. No grinding required. Think hard before you pour though...

[wobbly]

You can do the same with Devcon F putty.
Plaster enough into the corner to get the fill needed, sit the cylinder on the angle in an oven set at around 50 to 70*C.
As the cylinder and epoxy warm up if flows out nicely flat and the elevated temp then starts the setting process much quicker.
If you are filling a large amount you can drill and fit in small PK screws so the protruding heads are captured with the epoxy.

[husaberg]

I am curious too, so it is one of the reasons I am re cycling the old air cooled motor which I have dyno data for. I will fit the old air cooled motor to the new chassis for testing before I put the super duper 110cc NSR/GP motor into the new frame.


Apart from any potential performance gain from a dry sumped motor I basically have to do it because the motor is so heavily tilted down at the front in the new frame that all the gear box oil will flood the rotary valve area and leave the gears dry, so I have to pump it back over the gears to lubricate them. And if your pumping oil around you might as well run it through an oil cooler too. And if you have an oil cooler you might as well make it as efficient as possible with a fan to shift air through it. Anyway that was the thinking. But with Wobbly pointing out that 150ml of oil was enough for the BSL 500 I will re think how big a catch tank I need.

With the KR250 or 350 (I forget which) racing at Daytona one year. Kawasaki lowered the gearbox oil level as they found the hot oil was causing power fade but heating up the rear wall of the crankcase (pretty sure that came from Cameron)
Of course re the oil levels there is no reason not to separate the oil from the primary drive and the gearbox, Conversely there is actually plenty of very good reasons to actually do this.:msn-wink:

http://www.cycleworld.com/2015/09/18/more-on-gearbox-lubrication-technical-editor-kevin-cameron-insights-on-engine-performance/

[ken seeber]

There's a bit of an interesting read on transmission oiling in the forum deracehelden. Can't seem to be able to post the link to the exact section, but if you go to:

http://translate.google.com.au/translate?hl=en&sl=nl&u=http://www.deraceheldenvanweleer.nl/index.php%3Fwap2&prev=/search%3Fq%3Dderacehelden%26biw%3D1335%26bih%3D817

Then go to Full version, then Overall engine talks, then Jan Thiel Pt 14, then to Page 44, read from Bravo down

Bit of a struggle with the Dutch to English translation, but it certainly indicates there are gains to be made from having less oil or, alternatively, removing a hydraulic viscous brake from the transmission.

[jonny quest]

TZ350. IF your daring, warm up your test bike fully on the dyno. Get your baseline.

Drain transmission of oil.

Make a dyno run.

You should be able to make a run without hurting anything. I'm about 99% positive no harm will come.

Reason I'm so sure? I built a CRF150 for a customer, it has separate oil chambers for the crank and trans. This was a new motor that was completely stripped down. Oil was put in crank side, but my helper didn't realize there was a separate spot for the trans.

Kid ran 2 full motos with no oil in trans. Only thing that happened was one of the gears started to squeel when freewheeling from it not being in engaged position when not in that particular selection.

After realizing it didn't have any oil, I took it all apart. Only thing I had to do was buff shaft a bit. No parts had to be replaced.

[lodgernz]

Opinions please:
How much horsepower would a 150cc 4T bucket have to produce to do 178Km/Hr on a 2.4Km race circuit? Presumably on the straight, which might be 0.7Km.

[Frits Overmars]

Opinions please:
How much horsepower would a 150cc 4T bucket have to produce to do 178Km/Hr on a 2.4Km race circuit? Presumably on the straight, which might be 0.7Km.My guess: 29 rear wheel-hp. A bit much for a 150 cc foul-stroke, isn't it?

[husaberg]

Opinions please:
How much horsepower would a 150cc 4T bucket have to produce to do 178Km/Hr on a 2.4Km race circuit? Presumably on the straight, which might be 0.7Km.

24hp plus super aerodynamics. or a water cooled cylinder and ..............................
Note this was the 130cc rules days Speedpro and Kicka will have memories of this one being destroyed in a crash at Wigram.

317781

[kel]

Opinions please:
How much horsepower would a 150cc 4T bucket have to produce to do 178Km/Hr on a 2.4Km race circuit? Presumably on the straight, which might be 0.7Km.

The RS/KE125 bucket weighs 70kg and puts out 29+ dynojet rear wheel hp. Taupo track 2 is 2.2km long and the bike ain't getting close to 178km/h. The NSR300's at 70hp maybe pull 180km/h, so that's my answer 70hp! :drinkup:

[JanBros]

a more accurate translation from the oil-post on Racehelden Ken :

Measuring the loss in an engine block (50cc) is a simple matter. leave the connecting out and drive the crankshaft with a small electric motor. Preferably a DC motor (no starter-motor, these are a series motor and run wild). Let it run for a while , a few thousand revolutions is sufficient, and measure the power consumed (absorbed current voltage times). Measure the block without oil and then fill to the the desired oil level, with or without heated oil. I have this test done once a few years ago. The (loss) of power was approximately with heated oil (approximately 24 volts and 5 amps) just over 125 Watts or 0.2 horsepower. Only true for a directly driven bank and not on a chassis dynamometer. Doing the same experiment on a chassis dyno you will obviously lose a lot more power and therefore need a significant larger drive motor. Mind you there are a lot more "parameters" as innertia of the drum, chain, tire pressure, etc. I believe that some of the test bench operators estimate the los of power somewhat on the high side, perhaps to get higher figures of power at the crankshaft.

and Frits' response :

Bram, a large part of the power loss in the transmission is caused by the mutual friction of the gears. That friction is proportional to the torque that is on the gears.
If you drive the gearbox drives with a two horsepower electric motor, these losses are much smaller than when 20 hp has to be transferred.
For that same reason, the measurement of the power outlet after an acceleration run is rather pointless, because then the full engine power (including the associated frictional losses) are no longer present.

Point two: the power of an electric motor is only equal to the amount of power when the motor efficiency is 100%. which off course it isn't; it's efficiency is not even consistent across the rev range. So measuring power-losses isn't saying enough about the actualy delivered output.

[Frits Overmars]

Thanks Jan, you're doing much better than Google Translator. Only under 'Point two' a couple of words got lost in translation.
It should read: "the absorbed power of an electric motor is only equal to the delivered amount of power if the motor efficiency is 100%... etc."

[lodgernz]

My guess: 29 rear wheel-hp. A bit much for a 150 cc foul-stroke, isn't it?


24hp plus super aerodynamics. or a water cooled cylinder and ..............................


The RS/KE125 bucket weighs 70kg and puts out 29+ dynojet rear wheel hp. Taupo track 2 is 2.2km long and the bike ain't getting close to 178km/h. The NSR300's at 70hp maybe pull 180km/h, so that's my answer 70hp! :drinkup:

Interesting. At the CAMS Southern Classic Festival at Levels last weekend, several F4 bikes were clocked at over 170, one of them at 178.
They probably had fairings on, and of course the best riders in the country, but I'd love to see inside those engines.

[richban]

The NSR300's at 70hp maybe pull 180km/h, so that's my answer 70hp! :drinkup:

This one is not going very fast at the moment. I melted a piston on the practise day. I may have found the problem. Checking the igntech we noticed that it was map switching to the B advance map after 10k. Lets just say we have never used the b advance map and it would have been retarding the ignition rather a lot. rookie mistake.

Oh and its more like 85 and 205kph on Manfield.


317804317803

[Buddha#81]

Interesting. At the CAMS Southern Classic Festival at Levels last weekend, several F4 bikes were clocked at over 170, one of them at 178.
They probably had fairings on, and of course the best riders in the country, but I'd love to see inside those engines.

Really? That's a bit optimistic. Mid to high 150's at best! Being FXR's filled the first three spots, speed is cancelled by reliability. I was third and my top speed all weekend was is 134kph. At 178 they would have been running away from the RG150's and Ninja 250's which simply wasn't happening. Fark my RD350 was only running mid 160's

[kel]

This one is not going very fast at the moment.

I see the problem, you need one of those new 178km/h bucket engines :lol:

[diesel pig]

Interesting. At the CAMS Southern Classic Festival at Levels last weekend, several F4 bikes were clocked at over 170, one of them at 178.
They probably had fairings on, and of course the best riders in the country, but I'd love to see inside those engines.

That's because who ever set up the Mylaps for the event put in the wrong track length 4km instead of the actal 2.4km so all the average speeds are wrong not just the F4s

[lodgernz]

That's because who ever set up the Mylaps for the event put in the wrong track length 4km instead of the actal 2.4km so all the average speeds are wrong not just the F4s

AHA!!! That explains it. Phew, I was just about to toss it in.

[karter444]

tig torch advice
I wanted to learn a new skill so decided I wanted to be able to weld up my own barrels mainly exhaust ducts etc . On advice from a welding supplier purchased a TM 24 torch , the smallest available , 80 amp air cooled , the head is about 25 mm high great for right up inside an exhaust duct .It completed about 15 mm of welding and got so hot the rubber insulator melted and the head came loose on the shaft .
Next option was to modify a tm 17 torch head that I already had , rated at 150 amps I shortened it down and fitted the very short ceramic shroud and the collet from the tm 24 . This torch ended up about 30 mm high , still ok to just get into the duct .while the torch itself was ok the rubber insulator once again melted .welder is set to 80 amps and barrel is preheated
2 questions that I have , do I need to just spend the money on a water cooled tm 24 torch , or is there a coating available so the rubber insulator can be removed that will take the heat and also insulate it electrically
cheers

[husaberg]

This one is not going very fast at the moment. I melted a piston on the practise day. I may have found the problem. Checking the igntech we noticed that it was map switching to the B advance map after 10k. Lets just say we have never used the b advance map and it would have been retarding the ignition rather a lot. rookie mistake.

Oh and its more like 85 and 205kph on Manfield.


Rich could you do some pics on how the gearbox oiling system set works, please.
Ps I see the problem, you have no crankshaft.

[richban]

Rich could you do some pics on how the gearbox oiling system set works, please.
Ps I see the problem, you have no crankshaft.

Sure.Will be up in the shed later. Don't worry I now have 2 cranks. Just need seals and I am back racing this weekend. fingers crossed.

[Yow Ling]

Interesting. At the CAMS Southern Classic Festival at Levels last weekend, several F4 bikes were clocked at over 170, one of them at 178.
They probably had fairings on, and of course the best riders in the country, but I'd love to see inside those engines.

I guess you are looking at the Mylaps, the speeds are way wrong, they are supposed to be the average lap speed, at Ruapuna the avg is around 100km, I think they (the timing company) entered the wrong track length

OK I see Diesel Pig sorted that out earlier

[Ocean1]

tig torch advice
I wanted to learn a new skill so decided I wanted to be able to weld up my own barrels mainly exhaust ducts etc . On advice from a welding supplier purchased a TM 24 torch , the smallest available , 80 amp air cooled , the head is about 25 mm high great for right up inside an exhaust duct .It completed about 15 mm of welding and got so hot the rubber insulator melted and the head came loose on the shaft .
Next option was to modify a tm 17 torch head that I already had , rated at 150 amps I shortened it down and fitted the very short ceramic shroud and the collet from the tm 24 . This torch ended up about 30 mm high , still ok to just get into the duct .while the torch itself was ok the rubber insulator once again melted .welder is set to 80 amps and barrel is preheated
2 questions that I have , do I need to just spend the money on a water cooled tm 24 torch , or is there a coating available so the rubber insulator can be removed that will take the heat and also insulate it electrically
cheers

How long are you working at those amps? You may find the handpieces are rated for those amps for a 60% duty cycle and using it inside an enclosed space is only going to shorten that.

May be that for that application you do need a water cooled handpiece. These look reasonable: http://www.trademe.co.nz/business-farming-industry/industrial/manufacturing-metalwork/welders/auction-993191072.htm

[lodgernz]

A question for anyone who knows about pipes: Is it feasible to make the tailpipe de Laval nozzle out of aluminium alloy? Any idea of the temperature at the tailpipe of a 50?

[TZ350]

TZ350. IF your daring, warm up your test bike fully on the dyno. Get your baseline.

Drain transmission of oil.

Make a dyno run.

You should be able to make a run without hurting anything. I'm about 99% positive no harm will come.

Its a good idea, I think you could be right, pity I didn't think of it when I still had the old horizontal motor chassis, the new chassis has the motor steeply angled down at the front and would be totally un-suitable. Maybe someone else with a more conventional layout might be game to try the experiment and post the results here.

[bjorn.clauw.1]

Hello, i have been a silent reader on this forum for a long time and now I cannot control my curiosity. I was wondering if someone had any news about the 'ryger' type engine. First time I heard of this engine and the specific claim of 30000rpm my mind flashed 'forced induction'. Seeing the pictures and no immediate devices to provide this I have to believe the system has to function like the old dkw engines from around 1930. (At least the principle must apply).


Link to dkw engine: http://www.kfz-tech.de/ZweitaktmotorA.htm

http://www.kfz-tech.de//Bilder/Kfz-Technik/Zweitaktmotor/DKW-Laderm02.jpg
The left 'piston' is actually a pump, but what if it was a real piston. Would explain the aluminium riser plate on the ryger.

I am very interested in your thoughts about this. I just like mechanical mysteries.
If this was allready mentionend in the thread I am sorry for reposting.

[breezy]

Hello, i have been a silent reader on this forum for a long time and now I cannot control my curiosity. I was wondering if someone had any news about the 'ryger' type engine. First time I heard of this engine and the specific claim of 30000rpm my mind flashed 'forced induction'. Seeing the pictures and no immediate devices to provide this I have to believe the system has to function like the old dkw engines from around 1930. (At least the principle must apply).


Link to dkw engine: http://www.kfz-tech.de/ZweitaktmotorA.htm

http://www.kfz-tech.de//Bilder/Kfz-Technik/Zweitaktmotor/DKW-Laderm02.jpg
The left 'piston' is actually a pump, but what if it was a real piston. Would explain the aluminium riser plate on the ryger.

I am very interested in your thoughts about this. I just like mechanical mysteries.
If this was allready mentionend in the thread I am sorry for reposting.


makes you wonder why the patent hasnt appeared... perhaps its not brand new and is made up of several old patents and the patent people wont see it /cant see it as a brand new idea..???

[bjorn.clauw.1]

Found interesting piston in some old cache page in google. Does anybody know if this is from an existing engine? My guess would be no. Looks like dkw principle to me.

Would explain how they are able to get mixture above the piston at such high rpm, also dampening the piston forces on the downstroke at high rpm.
Would also explain riser plate and shorter rod.
Still not sure how they reduce emmisions, oilfree 'mixture' or making sure no fresh mixture escapes through the exhaust port?

[teriks]

Found interesting piston in some old cache page in google. Does anybody know if this is from an existing engine? My guess would be no. Looks like dkw principle to me.

Would explain how they are able to get mixture above the piston at such high rpm, also dampening the piston forces on the downstroke at high rpm.
Would also explain riser plate and shorter rod.
Still not sure how they reduce emmisions, oilfree 'mixture' or making sure no fresh mixture escapes through the exhaust port?
Ken here knows quite a lot about that piston ;)
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130919423#post1130919423

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130920630#post1130920630

[bjorn.clauw.1]

Ken here knows quite a lot about that piston ;)
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130919423#post1130919423

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130920630#post1130920630

So this is a repost :sweatdrop
Gotta love this forum, others are still guessing while a member here is making sketches and material analysis of the piston.

Thanks teriks for sharing these post. (And Ken for the reading pleasure this afternoon) ;)

[bjorn.clauw.1]

Some interesting ideas in those posts. Was going to post some drawings of my own but then i found the following 3d rendering. https://youtu.be/7UfMPi-jUz8

(So I do not need to hurt your eyes with my drawing skills)

[SwePatrick]

I dunno if posted before, Ryger plot ;)

http://citsengine.com.au/?page_id=64
https://www.youtube.com/watch?feature=player_embedded&v=ndWWHzE1Eek
https://www.youtube.com/watch?v=U4LksAgmYSo&feature=player_embedded


guys.. check this regarding Ryger.
I think all your answers are here.

[wobbly]

The 3D rendering all makes sense from the info we have seen in the original patent, except for one small point.
How does a conventional 54.5mm stroke crank with a 90mm rod spin to 30,000 rpm.
I have said this before several times,its never been done before - so why is it now suddenly possible, some other trickery hasnt been revealed to us yet.


PS - re TIG torches.
You need 150A to do anything worthwhile, such as inside an Ex duct, or welding up a cylinder head insert.
This is only achievable at a continuous rating with a water cooled hand piece, air cooled just cant get rid of this amount of current especially in a confined space.

[bjorn.clauw.1]

Hello Wobbly,

What do you think is the limiting factor. Mechanical or piston moving faster than flame front?

_tig torch advice:
Spot on with torch advice. Aluminium (cerainly large pieces) suck the heat away from point where you're welding. So you need to input a lot of heat to get your puddle. Also, I like to preheat cilinders on an electric heater plate to 300° fahrenheit. This reduces the time to get the weld started.

[wobbly]

The issue is purely mechanical stress levels at 30,000 rpm with a 54.5mm stroke.
Even worse is the super short rod that will put severe side load on the piston support rod thru the plate.
This rpm gives a mean piston speed of 55 M/Sec, and today with current technology,approaching 30 is considered extreme.
From the reading I have done, flame front propogation speed isnt an issue, and anyway the Rygers peak Hp rpm is only 17,000
so its outright combustion efficiency at 30,000 isnt going to affect that result.

[TZ350]

<iframe width="560" height="315" src="https://www.youtube.com/embed/kjJ1iYtg_OM" frameborder="0" allowfullscreen=""></iframe>

.......... :drinknsin

[bjorn.clauw.1]

https://m.youtube.com/watch?v=SkJd7LL24ec

Driving it :drool:

[karter444]

thanks for the advice on tig torches

I have just seen the small tm 24 watercooled 180 amp torch heads on Ali express, they can be purchased for US $8.00

CHEERS

[Flettner]

thanks for the advice on tig torches

I have just seen the small tm 24 watercooled 180 amp torch heads on Ali express, they can be purchased for US $8.00

CHEERS

$8.00, ask yourself, buy a decient one.

[Larry Wiechman]

As stated previously, a water cooled torch is the only way to go. Push LOTS of water through it. A square wave TIG machine with the ability to offset the balance is a plus. A helium/argon gas mix (or straight helium $$$$) will generate higher temps for a given amperage.

[peewee]

At $8 I suspect it may be from china. 25/75 or 50/50 gas mix works fine. On small cylinders you may even be OK with straight argon. You just have to try and see. Helium is expensive, at least where I'm at so I wouldn't use it unless you need it. Expect some warpage and have a plan how to fix it

[breezy]

Hello, ive just read a post on another site in which the poster said" we dropped the compression right down as it enabled the bike to rev higher". is this correct, less compression easier to rev? less forces on the piston/ conrod/bearings maybe less heat?

once you have your engine on the pipe maybe a conservative 9500rpm with all its momentum would being able to vary the compression (lower) at this peak make it rev more?
has anyone have any views on this, come across anything, on the net, relating to this? thanks, nigel.

[Frits Overmars]

Hello, ive just read a post on another site in which the poster said" we dropped the compression right down as it enabled the bike to rev higher". is this correct, less compression easier to rev? less forces on the piston/ conrod/bearings maybe less heat? once you have your engine on the pipe maybe a conservative 9500rpm with all its momentum would being able to vary the compression (lower) at this peak make it rev more?
has anyone have any views on this, come across anything, on the net, relating to this? thanks, nigel.Less compression = less expansion = more heat and energy left in the exhaust gases when the exhaust port opens = higher exhaust pipe frequency.

[dark art]

I had thinking some time ago, in making a dry sump gearbox. My mental version of it, was to use a electric pump (widely availabe for cars) to feed a catch tank and then, gravity feed. The main reason was to try to make a normal wet sump when the electric pump wasn´t pumping. In my head at the time it would be easy to implement, the only main area of concern being the clutch lubrification.

The reason for this idea is because I bought a second hand bike, a nsr75, wich the previous owner filled the gearbox sump to the very top. First time I rode it it will hardly pull the 3rd gear on a small straight, very underpowered. After the 5min ride I discovered I had oil in everyplace behind and below the engine, even in brakes. :mad:
As soon as the oil level was normal, the bike could pull 5th gear on the same straight. Didn´t check the hp at the time, obviously, but at leat 50% of the total power was lost in oil pumping out of the cases :lol:

[breezy]

Less compression = less expansion = more heat and energy left in the exhaust gases when the exhaust port opens = higher exhaust pipe frequency.

Frits, thanks for reply.. could you extend this as higher exhaust pipe frequency = extending useful range of exhaust pipe = increased rpm ?:scratch:

[SwePatrick]

Hello, ive just read a post on another site in which the poster said" we dropped the compression right down as it enabled the bike to rev higher". is this correct, less compression easier to rev? less forces on the piston/ conrod/bearings maybe less heat?

once you have your engine on the pipe maybe a conservative 9500rpm with all its momentum would being able to vary the compression (lower) at this peak make it rev more?
has anyone have any views on this, come across anything, on the net, relating to this? thanks, nigel.

to test this, pour some high octane fuel (not alcohol) like 116octane or something in the tank.
this fuel burns slower and leaves more heat in gasses, this will heat up the pipe more, and might give you more rev.

[trevor amos]

I suppose one must pose the inevitable question, what is regarded as a high or low compression number within the context of ,say a good 125cc engine? The actual number of a ratio tells us nothing of the actual quantity of mixture contained in the combustion chamber at the point of ignition. If there is little in there, squeeze the hell out of it! Perhaps the real answer is a variable ratio that progressively lowers at escalating, higher rpm that provides for improving cylinder filling! Avgas reacts better to a high ratio, unleaded though faster burning is averse to high cr. So what is high and what is low in compression ratios?

Trevor

[bjorn.clauw.1]

Is there any patent information allready available? (Ryger offcourse :msn-wink:)
If not, I may have found something.

[wobbly]

The amount of energy available to the combustion process is finite.
How it is distributed is dependent upon the CR , the ignition timing and the squish velocity.
As you raise the com, more energy within the A/F mixture is transferred to the surrounding metal ( head/piston/cylinder wall ) and to raising the gas pressure earlier within the cycle.
Thus less remnant heat energy is available to the wave process within the pipe.
Same for ignition timing, spark of the mixture earlier and the same thing as above occurs.
Then lastly we have squish velocity - as this is raised the turbulence within the combustion space is increased - thus raising the burn speed, with the same effect as advancing the timing.

With regard to compression ratios in a ( normal tech - not Ryger ) 125, this is entirely fuel and end use dependent.
For what we regard as unleaded ie pump gas of the 95/98 octane range we can use around 13.5 to 14.5 :1, the higher number is common for MX where throttle response is favored over
outright peak Hp numbers, and thus the bmep is lower compared to say a road race designed engine spec.
This comes back to the effective dynamic compression created within the combustion space by the entire engines design specifics.
And for what we regard as leaded race gas ie Avgas the numbers are 15.5 to 16.5:1.
Go up to 110 leaded rocket fuel ( or C12/C14 ) then 17.5:1 is commonplace.

As the com is dropped, then more heat is seen in the header pipe as measured by an egt, and this extra heat is created thru the entire rev range - thus as usual, no free lunch ie greater
mach number of the gas speed from the higher local temp means better overev, at the expense of course of bottom end.
This can to some extent be ameliorated by winding in advance lower in the rev range - but as many have found,this can create havoc on part throttle use off the powerband.

Re the Ryger patent info - we already know how the top end "works " from an existing published paper, but we still have no idea at all about the 30,000 rpm capable sealed bottom end.

[trevor amos]

Many thanks wobbly, As always an authoritative account of what is actually happening and thus what is required with our `home tuned`engines, information based upon the reality of what is from an expert who has been there and done it!

Regards, Trevor

[jasonu]

Is there any patent information allready available? (Ryger offcourse :msn-wink:)
If not, I may have found something.

Post what you have. Doesn't matter if someone has already posted it.

[bjorn.clauw.1]

http://worldwide.espacenet.com/publicationDetails/biblio?CC=WO&NR=2007142512A1&KC=A1&FT=D&ND=3&date=20071213&DB=EPODOC&locale=en_EP

inventor is also person who requested the ryger trademark.

http://trademark.markify.com/trademarks/ctm/ryger/014093306

[Lightbulb]

That was posted here before sometime in October I think.
Supposedly there is a newer patent, but I have not found it yet.
It may well be that the technology can't be patented or else it is something
that they do not want to patent but protect from another means.
Neil

[TZ350]

Sorry Henk, didn't catch the first "three way". However, got the second bit of "passing on the German autobahn" later on.

<iframe width="560" height="315" src="https://www.youtube.com/embed/ICbJbi3reNQ" frameborder="0" allowfullscreen=""></iframe>


Great racing, hot action, it's what Bucket racing is all about, and the race was led by a bike running a tuned Suzuki TF125 farm bike engine, in fact there were two front running 2T's with home tuned TF125 engines. Go the 2T's.

[AndreasL]

A "70cc RSA by Jan Thiel"!

https://www.facebook.com/photo.php?fbid=1037079113022065&set=a.1037078373022139.1073741839.100001599594953&type=3

[TZ350]

here's some footage of the second session


https://www.youtube.com/watch?v=v_kk74wPT1A&feature=youtu.be

And some more Bucket Racing from Team GPR.


To cheer you up, here comes the first A-Grade race.
https://youtu.be/vTIuLYigUfg


Here we go folks, another video. I thought I was uploading the third B-Grade race, but it looks more like a game of pinball...
https://youtu.be/Fdk7YUwSfK4

And photos.



The 2 hour! Album here: https://www.flickr.com/photos/sonscc/albums/72157659118320303

https://farm6.staticflickr.com/5735/23236824691_f3b4df7f25_b.jpg (https://flic.kr/p/BpmNqt)

[kel]

Caution, bucket racing can be hazardous to your health
Hopefully Brian was OK


https://www.youtube.com/watch?v=3JEwqXeR7Mw&feature=youtu.be

[TZ350]

Photos are up from round 1. Click here for the full album (https://www.flickr.com/photos/sonscc/albums/72157659734847064)

https://farm1.staticflickr.com/732/23473243001_615e814ed7_b.jpg (https://flic.kr/p/BLfvme)



Round 1 of the 2015 North Island Series. Mr Bucketracer from Team GPR leads the pack.

[mr bucketracer]

i don't know if i want to race again after seeing this picture

[Tim Ey]

Hey there everyone.
I have a Problem. I have calculated some exhausts for a friend with a 50ccm engine.
Aircooled, 30mm Carb, 196° Exhausttiming, 128° Transfers

I have calculated the exhaust using blairs lenght formula and my gut feelings for the exhaustgas temperature.
After several exhausts and times of dynoing the engine, the former endresult is this

317929
Not bad for a 50cc engine. The Problem is: This exhaust has a tuned length of 578,5mm which equals a Exhaustgas Temperature of 430°C. (edit 400°C)
Insane low...
Can anyone tell me where my mistake is? Is this normal for 50cc engines?

cheers
Tim

[JanBros]

I have calculated the exhaust using blairs lenght formula
Can anyone tell me where my mistake is? Is this normal for 50cc engines?


can't realy help you, but I have a feeling Frits will answer that the answer to your question lies in the other sentence I quoted

[sonic_v]

Hey there everyone.
I have a Problem. I have calculated some exhausts for a friend with a 50ccm engine.
Aircooled, 30mm Carb, 196° Exhausttiming, 128° Transfers

I have calculated the exhaust using blairs lenght formula and my gut feelings for the exhaustgas temperature.
After several exhausts and times of dynoing the engine, the former endresult is this

317929
Not bad for a 50cc engine. The Problem is: This exhaust has a tuned length of 578,5mm which equals a Exhaustgas Temperature of 430°C.
Insane low...
Can anyone tell me where my mistake is? Is this normal for 50cc engines?

cheers
Tim

That is very short for an engine peaking at 14,600 rpm. 660 mm would be closer to the mark. What sort of ignition timing are you running?

[peewee]

has anyone tried this process for transmission gears and shafts ? http://www.cryoheat.com/motorsports/

[wobbly]

Cant help with the pipe question because of insufficient collateral info, apart to say its miles too short.
What is the ignition curve.
What is the egt in the header.
Does the Blowdown STA match with the Transfer STA for peak power at 14660.
The pipe is well out of sync with the port, as is shown by the huge torque hole at 12,000, so something is seriously wrong.
Post a pic of the pipe design, as who knows what the the length % are after the usual cut and try on the dyno scenario, where the tuned length
that you found to "work " was only "right " as it was fighting elements of the design that were not remotely right for the peak rpm.

Edit - and 18 Hp at 14660 is only 11Bar BMEP so its hardly "good " for an engine reving that high - again pointing to something being very wrong.

Re Cryo treatment
Works very well for Jap gearboxes where for production purposes they do the absolute minimum heat treat required for the hardness needed.
As it helps to complete the martensite conversion process.
Also helped the old Rotax 256 twin that liked to spit out the small diameter 3rd gearwheel that was way over-stressed for the application.
And done it for years in aircooled KT100 racing, where it helps to stabilize the bore shape when they get very hot - especially when we used clutch pipes and
were up against that engines thermal limit the whole time.
But in my opinion micropolishing and the microblue process would achieve more if you are confident in the gear strength and heat treatment.

[TZ350]

Morgan Engineering and Sheetmetals :- http://www.morganeng.co.nz/ here in Penrose Auckland is setting up to do Micro Polishing and there is another process too, maybe its MicroBlue.

[TZ350]

Page 1400 ...


Interesting supercharged 2T:- http://www.odd-bike.com/2014/02/dkw-supercharged-two-strokes-force-fed.html Carb Tuning. http://www.3cyl.com/mraxl/manuals/carbtune/carbtune.htm


The "downdraft" Keihin FCR carbs such as:- http://www.ebay.com/itm/KEIHIN-FCR-39-CARBURETORS-FZR-YZF-750-1000-EXUP-OWO1-CBR-ZX7-ZX9-ZX10-ZX11-GSXR-/271340133101?hash=item3f2d21daed:m:m71ve_LHls3ZDnT Daf-9G9A&vxp=mtr

Can one of these carbs be made to work on a 2 stroke engine? They are pretty steep even with the bowl flat and very steep when the bowl is inclined. They are relatively expensive even for one and I need two, so if it's not doable I don't want to waste all that money, but getting the carbs very steep would solve a lot of other problems.


Mine pwm carb is at it's limit, if i alter the angle a little bit steeper it starts to drip from ventilation. Maybe one could make a deeper bottom plug on bowl and make the jets reach longer into that plug, then lower float level.

PWM and some newer PWK´s (Airstriker?) has a new separated idle system from low speed jet. It runs through the choke system instead, throttle is resting dead on the floor, air runs through the choke hole instead.
You adjust the idle with turning the choke knob.

Really neat feature actually =) http://www.pbase.com/jdjetting1/image/43260810



TeeZee: I remember you did some tests on the dyno some (100 ) pages back. Do you still know which page you showed the results? And do you had a chance to use a A/F meter at that time? Juergen

No sorry, but under "Thread Tools" which is near the top right hand side of the page, you can "View Thread Images" and sort them into 70 per page. When you find an interesting image click on the N/A sign to see the post, there are more than 7,000 images.

When I was playing with EFI I did use a A/F meter but with a 2T there are traps as the A/F reading is seemingly rich when the trapping efficiency is not good, like when you are moving away from peak torque or well out of the power band.

The A/F meter accuracy seemed at its best when the rpm was at peak torque, everywhere else it indicated varying degrees of rich but was not.

Frits put me on to this, the indicated richness was just air/fuel being blown through the exhaust port and lost down the pipe the remaining air/fuel that got trapped in the cylinder burnt correctly.

All the air/fuel was of the correct strength for good combustion just some was not trapped and consequently lost and looked to the meter like the engine was running rich when in fact it was not.


Maybe Wobbly or Frits may know the answer to this. ... Curious if any of the V4 500cc 2 strokes ever tried 2 into 1 pipes? Would have improved bottom end and midrange with very minimal peak loss. Plus the sound a 2 into 1 makes... incredible! I built one for my RZ350 back in the day.


No V4 GP engines ran 2:1 but from my experience with World Champ Ski engines the 2:1 doesn't even come close to well designed single pipes, no matter where you bring the headers together.

You can get a big boost in top end power by cutting the piston skirts short on the Ex side. This creates havoc with the jetting, but once sorted it does work well.

I spent a huge amount of time on EngMod trying to replicate or even get close to twin single pipe performance on a hot road RZ350, but simply
couldn't achieve the mid, or top end, with a 2:1.

In twin snowmobiles and those adapted for small aircraft use, the best performance is achieved with a 2:1 when the Ex duration is up at 200*.
But this then seriously affects the powerband shape,as it looses a huge amount of mid power that then needs the pipe designed to get some of it back,badly compromising the top end - just not worth it IMHO.

Edit - here is about as good as it gets, a very good aftermarket 2:1 Vs aftermarket singles.


Were you able to determine where best to bring the headers together and what sort of angle the headers would have relative to each other where they meet?

Most people I know seem to think making the headers so that they come together at the least possible distance from the port, without undue bends is best. It seems to make sense, but I have also wondered if maybe not bringing the headers together until almost the large mid section of the pipe might work so that the pipe header and a lot of the diverging section work like individual pipes and the reverse cone reflects the two.

Building it like that you could say why not just build it single pipes because it would be halfway a single pipe anyway but I was thinking for when rules insist 2:1. Maybe build single pipes and connect the stingers but I think that wouldn't fly with the rules.


Re Vegas - here is some cut and paste from a report on the result I did.

We were top 3 fastest thru all the sessions, but the engine guy for the team we race for didn't tighten the new spark plug prior to qualifying.

Of course it wound almost all the way out and our pace dropped by 3/10s, enough only for 6th.

In the first heat we were up to 4th pulling in the top 3 easily within 2 laps when the 3rd place missed a gear mid bend under big pressure and spun right in our karts path - DNF.

Means we went into the final from 12 on the grid, got to 5th place and ran out of time - track position is everything when only a few 1/10ths cover the top 5 pace.

I took the deto gauge off the dyno and ran the 0-5V output into the Pi data logger, and was very surprised to find that after leaning down enough to get hits, that the only place it deto'ed was the acceleration phase after 2nd, 3rd, 4th gear changes, when dropping back to near peak power after overeving to 12200.

The 5th to 6th change stayed above peak power and didnt deto at all down into the shute. So I fitted the new header with the deto button installed and the gearchange deto disappeared completely. That allowed another 3 jets leaner before it started again.

Get this - the egt at that level was 1390* F with no sign of deto or piston heat stress. This is due to the fuel octane being too high for the com, and the fact that the SKUSA advance restrictor plate does not allow us to add enough static timing to create more power - only pipe heat.

I think I have worked the logic of the deto button - it creates turbulence in the top 1/2 of the duct, allowing the smooth flow along the floor to return easily up the duct and be aimed upward off the ski jump at the closing Ex port.

This came from finding that having the floor of the oval/round transition spigot co linear with the duct floor, and all of the transition angle in the roof made best power.

So here is the jetting chart prior to adding the new header, based on safe deto level, not egt as I would usually use.
The Lambda ( in the muffler ) showed the kart was fastest at 13.8 :1 ( and it hardly varied anywhere within the usable power band ), going leaner or richer was slower on track.

We tested both VP C12 ( 108 octane ) and VP98, the 98 being both faster and easier to tune to the edge.


The original deto mushrooms were installed about 50mm down into the pipe header, but in the SKUSA Honda we cant touch the spec pipe. Whereas the spigot is open except for the overall length.

I was a bit surprised that moving the thing closer to the piston still worked so well, no power loss on the dyno, but I didn't have lean enough jets
during testing to get deto happening.

As the area where the mushroom was installed was less than out in the header I simply scaled it down. But as I said I was surprised to find that the piston killing deto only occurred after dropping back to around peak power from gear changes, and that the change into 6th ( with minimal rev drop ) didn't deto at all in the overev.

It would work just as well in model engines if you are getting deto that eats away the piston in the squish band, but as I see it you are running for
the longest period way into overev, not sitting on peak Hp during flight - so it may not have any useful effect.

The end of the mushroom is step threaded, and this screws into a hole with a chamfer on the outer surface where the pipe sleeve seals.
After installing it I sat it in the press and using a 90* pointed mandrel on centre, expanded the flat threaded end into the spigot chamfer.
I would have preferred to have a small boss within the spigot, but this involved way too much extra CNC time with difficult programming and special tooling.


Ok Frits, how are we going to build a continuous fuel injection system, not pulsed.

The old Hiborn mechanical fuel injection was crude at best but if we were to put a electronically controlled needle valve in place of the return "pill" it could work? Or as you have suggested a DC motor driven by pules width modulation.


I developed the continuous injection idea for a 6,5 cc model engine that revs past 35.000 rpm, so no chance in hell that I would ever find an injector that's quick enough. I decided upon a gear pump driven by a pulse width modulated electromotor and a spring-loaded injection nozzle that I posted here before.

As flow sensors, MAP sensors, Lambda sensors and the like are all too big for this engine, and as it's an unthrottled (always WOT) engine, I planned to use only an engine rpm / pump rpm lookup table. Crude as this would be, it would be an improvement on the present carburation system that depends on a pre-set (before flight) needle and exhaust pressure.

Of course such an rpm/rpm lookup table is totally insufficient if you want any throttle control and rideability.


Frits... There is a very simple non conventional 2 stroke mechanical fuel injection patented by a Barry Holtzman. Its concept may be applicable for your project...

The unit I had was very compact, yet able to feed a 125cc on methanol. It was roughly the dia of an ink pen and somewhere around 20 mm long. It screwed into a 3mm hole drilled in the cylinder wall, which was located so the piston uncovered it about 60 degrees atdc. Output of the injector pump was plumbed into the crankcase.

Engine compression was sufficient to operate the pump for starting purposes. In operation each injection pulse is directly proportional to the pressure of the previous power stroke. It functioned remarkably well. I ended up sending it to a customer for testing and never got it back.

The patent number is US 6725845 B2 Here is a link to Google patents.... https://www.google.com/patents/US6725845?dq=Barry+Holtzman&hl=en&sa=X&ved=0ahUKEwiL06eNz77JAhVIZCYKHbzDBhsQ6AEIIzAB

Kermit Buller


Hey Kermit, in my view that idea is absolute genius, I hope Miss Piggy gave you what you deserved.


Hello everyone! I have a question concerning auxiliary exhaust ports:

If you have plugged your wrist pin and are on the quest for more exhaust TA - why not make the ports wider than 100% of the Bore?

I have the picture of Frits in mind where the auxiliary ports do not aim directly to the bore center but more to the C-Port.

I can imagine that the scavenging will not work properly as the A Ports will shoot straight in the auxiliary ports, also the returning fresh gas mixture might swirl the cylinder a lot more than in an "conventional" engine...

So... Has anyone made an computer fluid dynamic of this and it seems to be bullshit? Or why was it never (?) done before? cheers! Tim


Re the idea of increasing the Aux ports wider than 100% of the bore.

This was tested even better than CFD - Jan did it with the RSA on the dyno, lost power. I believe due to any advantage gained from the extra blowdown area is offset by the much longer path length for the Ex wave when its past 1/2 way in the bore, and this smears out the pulse amplitude entering the header.

I was asked about Aux ports and spigot design in a PM, and as I cant add pics to a PM, here is the welded duct on a KTM250 with 75% area at the face - 52mm wide by 32mm high, considerably reducing the duct volume in the cylinder just short of going sonic in EngMod ( PS the floor is 4mm above BDC ).

I added the male spigot, so that the oval to round transition could be made smoothly before entering the pipe header.



wobbly: Do you have any more comments or pics of the ktm250 exhaust (in port or portmap) of the work you did? Thanks Jeff


Here are some more pics of the road racing KTM250. It has a long rod from an earlier model with a Wossner flat top single ring piston from CR250, needed an 8mm plate under cylinder that corrected the case com, and got ports close - still needed 2 days of grinding as the ring pinned on centre enabled huge B ports.

The reed is a VF4 off a late model KTM and the inlet length is tuned to 10,000 rpm with a 42mm bored SPJ carb of late model RS250 to use the solenoid PJ for over rev power.

This has a screw adjustable powerjet on a CNC carb bowl. I cut off the kickstart gear housing to get the intake dead straight. Water route has been changed with CNC head and has bronze insert.

The Aux ports were welded then made triangular and twice the area around to bore centre, Ex port floor and corner rads are welded.

Port setup is with B,C highest and set in EngMod for 72 Hp on Avgas.

Servo driven PV is used as it drops over 1500 rpm into 5th gear due to MX gearbox ratios.


Wobbly: Thank you for the pics and reply. If I may, a question about the intake length. It looks a bit long and is the long red spacer block just a transition from the round carb to the square reed?

Another question, from the 4mm build-up at the bottom of the exhaust port, are you adding 4mm of fill the whole length of the port or is it 4mm at the port window and tapering to 0mm at the spigot end? I am building a 250 KTM now for hill climbing and very interested in what you did.Thank you, Jeff


No,and no. The intake length isn't long at all, just remember that the "normal " 250 intake is the same as a 125 - simply so the carb can fit in behind the suspension etc. How can that possibly be correct for an engine that peaks all of 2000 rpm lower.

The built up Ex floor is full length, as the roof is set by the PV blade, and that is flat to begin with.

The red block is simply a spacer to adapt the differing bolt patterns and get the length correct.
The round to squarish transition is done in the manifold rubber.


Hello, i've just read a post on another site in which the poster said" we dropped the compression right down as it enabled the bike to rev higher". Is this correct, less compression easier to rev? less forces on the piston/ conrod/bearings maybe less heat?

once you have your engine on the pipe maybe a conservative 9500rpm with all its momentum would being able to vary the compression (lower) at this peak make it rev more?

Has anyone have any views on this, come across anything, on the net, relating to this? thanks, nigel.


Less compression = less expansion = more heat and energy left in the exhaust gases when the exhaust port opens = higher exhaust pipe frequency.


I suppose one must pose the inevitable question, what is regarded as a high or low compression number within the context of ,say a good 125cc engine?

The actual number of a ratio tells us nothing of the actual quantity of mixture contained in the combustion chamber at the point of ignition.

If there is little in there, squeeze the hell out of it! Perhaps the real answer is a variable ratio that progressively lowers at escalating, higher rpm that provides for improving cylinder filling! Avgas reacts better to a high ratio, unleaded though faster burning is averse to high cr. So what is high and what is low in compression ratios? Trevor


The amount of energy available to the combustion process is finite. How it is distributed is dependent upon the CR , the ignition timing and the squish velocity.

As you raise the com, more energy within the A/F mixture is transferred to the surrounding metal ( head/piston/cylinder wall ) and to raising the gas pressure earlier within the cycle. Thus less remnant heat energy is available to the wave process within the pipe.

Same for ignition timing, spark of the mixture earlier and the same thing as above occurs. Then lastly we have squish velocity - as this is raised the turbulence within the combustion space is increased - thus raising the burn speed, with the same effect as advancing the timing.

With regard to compression ratios in a ( normal tech - not Ryger ) 125, this is entirely fuel and end use dependent. For what we regard as unleaded ie pump gas of the 95/98 octane range we can use around 13.5 to 14.5 :1, the higher number is common for MX where throttle response is favored over outright peak Hp numbers, and thus the bmep is lower compared to say a road race designed engine spec.

This comes back to the effective dynamic compression created within the combustion space by the entire engines design specifics. And for what we regard as leaded race gas ie Avgas the numbers are 15.5 to 16.5:1. Go up to 110 leaded rocket fuel ( or C12/C14 ) then 17.5:1 is commonplace.

As the com is dropped, then more heat is seen in the header pipe as measured by an egt, and this extra heat is created thru the entire rev range - thus as usual, no free lunch ie greater mach number of the gas speed from the higher local temp means better overev, at the expense of course of bottom end.

This can to some extent be ameliorated by winding in advance lower in the rev range - but as many have found,this can create havoc on part throttle use off the powerband.

Re the Ryger patent info - we already know how the top end "works " from an existing published paper, but we still have no idea at all about the 30,000 rpm capable sealed bottom end.

[ken seeber]

Page 1400 ...

but wait, there's more useful stats.......

It's been going for 7 years 16 days = 2555 days which @ 20986 posts = 8.16 posts per day

Well done...a belated happy birthday and a happy 8th Xmas to ESE

And also 17 days to go for the big spreading of the Ryger legs :eek5:

[F5 Dave]

And the big secret is.
Sex lube.
Good for a 125 to 30,000 at 20:1, and a 14yr olds right hand to 40,000.

[TZ350]

317936

Where all good Buckets start.

A bunch of TF125 farm bike engines just waiting for a good home .... http://www.trademe.co.nz/motors/motorbikes/parts-for-sale/wrecking-bikes/auction-995371499.htm

Two seriously good TF125 powered bikes bracketing a fast FXR150:- https://www.flickr.com/photos/sonscc/23067575493/in/album-72157659734847064/

[Holeshot]

No doubt this is the best thread on the net. Reading from page 1, im still back in 2009 and page 64, but i will catch up eventually. Thank you all for this incredible thread.

[F5 Dave]

Heck, I feel like I'm still back in 1997. Welcome anyway.

[wobbly]

Previously I said I would post pics of the mods done to the TZ400 that won at the Shorai Challenge, so here are some of the modified head
and new water circuit.
From the pump water enters the rear of the cylinder below the welded on top plate, this forces flow around over the transfers then up into the front of
the head via holes on each side of the Ex duct.
This water is then forced to flow around the inserted head, and out at the highest point, with an auto air bleed back to the top of the crossflow rad.
The 3G3 - 6 port cylinder has an intake bridge added with a boost port cut on each side and ported to suit the Banshee 58mm stroker crank and special single ring
Wossner 66mm Blaster pistons.
After plating the 6mm welded on plate was reduced 2.8mm so that all the squish is in the cylinder with no step on the insert face.
It runs 16.2 :1 com on Avgas with 40mm Lectron HV carbs that are period legal- running into CR125 Reedblocks from VeeForce.
This makes the cylinder the same configuration as the TZ500 factory engine as run by Roberts - pre 82

[FastFred]

No doubt this is the best thread on the net. Reading from page 1, im still back in 2009 and page 64, but i will catch up eventually. Thank you all for this incredible thread.

Check out page 1000 it has a lot of accumulated info there and a bit of a directory to other good stuff on the thread.

[MotleyCrue]

Wobbly, thank you for posting your pics.

I had a few questions about the Lectron carb.

I see it is a Fast by Gast carb and as far as I know they only run 4 strokes there. Did FBG or Lectron set up the carb for a 2 stroke, or did you just buy it as a 4 stroke carb then reconfigure it for a 2 stroke engine, and if so was it difficult?

I have thought about getting Lectrons, I know they come up once in awhile on ebay off of a 2 stroke engine but I can get them easier and cheaper if they come off a 4 stroke engine. There doesn't seem to be much info around as to how difficult it would be to configure them for a 2 stroke. Lectrons don't have a bunch of circuits so it seemed like maybe it wouldn't be too hard, maybe just a needle change, but they cost a lot so I wouldn't want to just end up having them sit on the shelf.

Some people say Lectrons are better than Mikuni and Keihin, but others disagree, what do you think?

[wobbly]

I got one of the carbs off Ebay and it just happened to be an FBG, nothing special about it, they just jet them to suit.
Make sure you get the HV version with the venturi behind the slide.
The only thing to correct or set is the float needle size for gravity or pump feed, the main needle and the powerjet size.
Thing is they flow alot more air size for size than a Mik or Keihin, and the venturi then gives way better part throttle response than
what you would expect from the carb size.
Looking at the Lambda on the dyno they have a really linear A/F ratio, a Mik or Keihin is all over the place as the circuits overlap.
On the TZ400 I started out with a 4-2 needle and a 75 powerjet, this was too lean on top, and needed a 95 powerjet to settle at 650C at full noise.
This is too big, so I went up to a 6-2 needle and the powerjet dropped into the 60 range - that gave a spot on fuel curve to suit that engine.
Only problem I had is that the Frepin frame has the tank very low and close to the carbs, thus the fuel head is minimal above the bowls unless the tank was near full.
The stock gravity needle and seat is a 3mm, so I got the special option 3.6 and this stopped it leaning out as the fuel level in the tank became low.
They do an add on air bell as well that dramatically improves air flow.

[Holeshot]

Check out page 1000 it has a lot of accumulated info there and a bit of a directory to other good stuff on the thread.

Will do thank you sir. I dont want to clutter your thread with my thank you responses. I will lurk awhile. Im constantly sidetracked studying xlnt information and links that were previously posted. Since i started from page 1 this explains my slow progress to catch up to current posts. You guys are all the best company. Thank you.

[J.A.W.]

Wobbly, thank you for posting your pics.

I had a few questions about the Lectron carb.

I see it is a Fast by Gast carb and as far as I know they only run 4 strokes there. Did FBG or Lectron set up the carb for a 2 stroke, or did you just buy it as a 4 stroke carb then reconfigure it for a 2 stroke engine, and if so was it difficult?

I have thought about getting Lectrons, I know they come up once in awhile on ebay off of a 2 stroke engine but I can get them easier and cheaper if they come off a 4 stroke engine. There doesn't seem to be much info around as to how difficult it would be to configure them for a 2 stroke. Lectrons don't have a bunch of circuits so it seemed like maybe it wouldn't be too hard, maybe just a needle change, but they cost a lot so I wouldn't want to just end up having them sit on the shelf.

Some people say Lectrons are better than Mikuni and Keihin, but others disagree, what do you think?


Paul Gast sure does do 2T Lectrons, as he has for decades.. see here.. www.fastbygast.com/H-2%20parts.htm

& they do work, if a bit pricey, but when limited by regs which forbid late 2T carbs, they are the go - as Wobbly has proven..
Mind you, rocking up with a PG H2 race mill in your bucket - might just raise a few eyebrows..

[J.A.W.]

Wobbly, thank you for posting your pics.

I had a few questions about the Lectron carb.

I see it is a Fast by Gast carb and as far as I know they only run 4 strokes there. Did FBG or Lectron set up the carb for a 2 stroke, or did you just buy it as a 4 stroke carb then reconfigure it for a 2 stroke engine, and if so was it difficult?



Yeah, I should've noted, if you go in to 'tech tips' on the FBG site, you can read some Lectron function/set-up info..

[J.A.W.]

Wobbly, thank you for posting your pics.

I had a few questions about the Lectron carb.

I see it is a Fast by Gast carb and as far as I know they only run 4 strokes there. Did FBG or Lectron set up the carb for a 2 stroke, or did you just buy it as a 4 stroke carb then reconfigure it for a 2 stroke engine, and if so was it difficult?

I have thought about getting Lectrons, I know they come up once in awhile on ebay off of a 2 stroke engine but I can get them easier and cheaper if they come off a 4 stroke engine. There doesn't seem to be much info around as to how difficult it would be to configure them for a 2 stroke. Lectrons don't have a bunch of circuits so it seemed like maybe it wouldn't be too hard, maybe just a needle change, but they cost a lot so I wouldn't want to just end up having them sit on the shelf.

Some people say Lectrons are better than Mikuni and Keihin, but others disagree, what do you think?



You could contact Dave at http://www.twostrokeperformance.com.au - he offers the Lectron set up for 2Ts, & ask him how they compare..

[MotleyCrue]

Paul Gast sure does do 2T Lectrons, as he has for decades.. see here.. www.fastbygast.com/H-2%20parts.htm

& they do work, if a bit pricey, but when limited by regs which forbid late 2T carbs, they are the go - as Wobbly has proven..
Mind you, rocking up with a PG H2 race mill in your bucket - might just raise a few eyebrows..

Interesting, everytime I see anything on the internet about FBG its always to do with big powerful 4 cylinder 4 strokes. To be honest I never heard of an H2 and never clicked on the H-2 tab on the FBG site before.