ESE's works engine tuner

[Peter1962]

Keeping the oil isolated in the crankcase, and no need to premix with the fuel is a big help.

I'd really love to see a Ryger design that wasn't constrained by CIK competition regulations.

They already have some expertise in the team for direct fuel injection and power valve.


I think that Frits told earlier that a Ryger engine has no need for a power valve, which would explain Harry's choice of doing the development work on a KZ engine rather than on a MX engine.

[tjbw]

I think that Frits told earlier that a Ryger engine has no need for a power valve, which would explain Harry's choice of doing the development work on a KZ engine rather than on a MX engine.

Yes, they have something "cleverer" than power valve, but I'm not clever enough to figure it out.

It would be great to see power curve for Ryger KZ engine v the unmodified engine and also v Aprilia RSA.

[Peter1962]

Yes, they have something "cleverer" than power valve, but I'm not clever enough to figure it out.

It would be great to see power curve for Ryger KZ engine v the unmodified engine and also v Aprilia RSA.


What would be even greater is seeing Jan Thiel's masterpiece, the 2007 aprilia RSA being Rygerised, and being allowed to race in a Moto 3 grand prix. :moon:

[Frits Overmars]

Ryger. Big picture thoughts.
2. That the combustion efficiency is so much better, such that even though a percentage of the fuel is lost out the exhaust, the greater thermal efficiency of combustion offsets this. This therefore leading to an improved BSFC, brake specific fuel consumption, which may be in the order of 280 gm/kW hr. Would just love to know this, even from the RSA would be good.From memory (it's almost 10 years ago) the RSA used 20 liters of 20:1 premix per hour to produce 54 hp at the secondary gearbox shaft.


What would be even greater is seeing Jan Thiel's masterpiece, the 2007 aprilia RSA being Rygerised, and being allowed to race in a Moto 3 grand prix.I would settle for a standard RSA125 with today's tires in Moto3. Remember, the RSA had 54 hp and 70 kg. A moto3 bike has <50 hp and >80 kg.
But then of course it would't be fair. Moto3 has only 250 cc while the RSA had a full 125 cc :devil2:.

[tjbw]

What would be even greater is seeing Jan Thiel's masterpiece, the 2007 aprilia RSA being Rygerised, and being allowed to race in a Moto 3 grand prix. :moon:

Maybe it would be sacreligious to touch the masterpiece. But two stroke bikes that meet emission criteria should be allowed to race.

[MotleyCrue]

Curious as to why a 20:1 mix would be used. Is it just a longevity issue or has it something to do with mosquito control :laugh:?

60-70:1 are numbers I am more used to albeit the engines don't run wide open for more than a handful of seconds at a time. 70:1 is very clean from a sight and smell perspective, much more so than 50:1.


My personal yard equipment like weedwackers, they all get 70:1 too just so they dont stink.

[d2t]

What would be even greater is seeing Jan Thiel's masterpiece, the 2007 aprilia RSA being Rygerised, and being allowed to race in a Moto 3 grand prix. :moon:

I would think that it would't go as well as the current Ryger configuration. The RSA made use of a well placed rotary valve and highly developed cylinder characteristics. Changing the configuration would probably make it run worse! But yeah, I know what you mean. Imagine a Ryger series replacing Moto3 as a support class? Maybe if KTM adopts it, a Ryger rookies cup. ...yeah

[tjbw]

I would think that it would't go as well as the current Ryger configuration. The RSA made use of a well placed rotary valve and highly developed cylinder characteristics. Changing the configuration would probably make it run worse! But yeah, I know what you mean. Imagine a Ryger series replacing Moto3 as a support class? Maybe if KTM adopts it, a Ryger rookies cup. ...yeah
Imagine the Ryger rookies lapping faster than the main event!

[wobbly]

Why 20:1 - it makes more power, been there done that when dyno testing bean oils against synthetics in KT100 racing
where 1/10 ths of a Hp makes a difference.
Modern oils dont make gobs of dirty carbon or smoke like R30 used at 16:1 - but it smalls way better.

[MotleyCrue]

Why 20:1 - it makes more power, been there done that when dyno testing bean oils against synthetics in KT100 racing
where 1/10 ths of a Hp makes a difference.
Modern oils dont make gobs of dirty carbon or smoke like R30 used at 16:1 - but it smalls way better.

About how much more power are we talking in % between say 20:1 and 50:1 ? Is it because of less friction or better sealing or something else?


20:1 may not be too smoky at full throttle after a bit, but startup and idling ............. no wonder the emissions people hate it. 70:1 and a good oil, you only know its a 2 stroke by sound.

[Lightbulb]

I use heaps of oil in my yard machines, like chainsaws, etc Mainly because they are not used on a regular basis, and I idle them for a cool down time. My rationale for this is to have a lot of oil around the insides to stop the metal parts from rusting until the next time I use them. Although the new oil for the Stihl is only 1/2 the ratio of the regular oil, I still use it at the higher rate. Oil is cheap and I figure the more I use the longer it will last. As you can tell , the short term smoke is not an issue to me. If it was I would be buying electric or 4 stroke stuff.
Neil

[MotleyCrue]

I use heaps of oil in my yard machines, like chainsaws, etc Mainly because they are not used on a regular basis, and I idle them for a cool down time. My rationale for this is to have a lot of oil around the insides to stop the metal parts from rusting until the next time I use them. Although the new oil for the Stihl is only 1/2 the ratio of the regular oil, I still use it at the higher rate. Oil is cheap and I figure the more I use the longer it will last. As you can tell , the short term smoke is not an issue to me. If it was I would be buying electric or 4 stroke stuff.
Neil

Cheap oil is cheap and that's probably a good enough reason to run a lot of oil, but I dont use cheap oil. Never had any abnormal wear or other issues. Bean oil smells good but I dont care for the smell of any other oils and bean oil only works down to certain temps.

Maybe the oily engines will outlast their smoke loving operator, just food for thought..........in 2015

[TZ350]

Curious as to why a 20:1 mix would be used.

Apart from the truth that more oil makes more power, my other reason for running 20:1 is a practical one. When you have several helpers on the team, asking someone to mix you 3l of 45:1 is fraught with mistakes. Much easier to do what Team ESE does. Buy oil in 1L packs and fuel in 20L cans. Everyone seems to understand how to fill a 20L fuel can and immediately tip in a 1L oil pack, hardly anyone could reliably grasp the technique for making up a 20:1 fuel mix on its own.


About how much more power are we talking in % between say 20:1 and 50:1 ? Is it because of less friction or better sealing or something else?

Not sure % wise, and the potential difference is probably not universally the same, but in my experience the difference is noticeable and welcome. I guess its a number of things, less friction, less heat, better sealing throughout the engine, rings seals piston skirt.

[wobbly]

Here is an extract of mine of a dyno report I was paid to do by a customer.

"
In the test I did we narrowed it down to testing two oils for the application - a KT100 direct drive Yamaha kart engine.
This engine is run all day on the edge of destruction with egt sitting at 1280*F to get the heat in the pipe.
Without this temp it wont pull to 16000,and will be "slow".
With a new piston, we ran in, then tested on fully synthetic Elf 976 that the GP teams use.
We tested at 30 and 16:1.The lower ratio made no more power but after a severe thrashing on the dyno we pulled the cylinder and the piston had score marks all over the thrust faces.
Then we put in a new piston,with a very light hone to replicate the first test but on Elf 909.
This is castor based and we found that at 16:1 the new oil made consistently 0.3 Hp over the 30:1 and that this was 0.2 Hp up on the previous oil.
So - 0.5 Hp in an engine that makes just under 17Hp and the piston looked brand new after the test. "

Bottom line is that the oil to use is application specific, in that full synthetics are fine on unleaded or low egt temp, but crap in high temp and or racegas uses.
The castor ( or ester syn ) based oils are better in both applications but alot better when used at very high temps and rich mix ratios..

[F5 Dave]

I ran 50:1 in my trials bike. But only because you spend a lot of time going bupbupbupbup and much less time going bwaahbwaah. Well the pros might. But trials bikes are a different breed.

[MotleyCrue]

Here is an extract of mine of a dyno report I was paid to do by a customer.

"
In the test I did we narrowed it down to testing two oils for the application - a KT100 direct drive Yamaha kart engine.
This engine is run all day on the edge of destruction with egt sitting at 1280*F to get the heat in the pipe.
Without this temp it wont pull to 16000,and will be "slow".
With a new piston, we ran in, then tested on fully synthetic Elf 976 that the GP teams use.
We tested at 30 and 16:1.The lower ratio made no more power but after a severe thrashing on the dyno we pulled the cylinder and the piston had score marks all over the thrust faces.
Then we put in a new piston,with a very light hone to replicate the first test but on Elf 909.
This is castor based and we found that at 16:1 the new oil made consistently 0.3 Hp over the 30:1 and that this was 0.2 Hp up on the previous oil.
So - 0.5 Hp in an engine that makes just under 17Hp and the piston looked brand new after the test. "

Bottom line is that the oil to use is application specific, in that full synthetics are fine on unleaded or low egt temp, but crap in high temp and or racegas uses.
The castor ( or ester syn ) based oils are better in both applications but alot better when used at very high temps and rich mix ratios..


Bean oil has always been my first choice when applications permit. Still there must be a good reason why 16:1 oil makes more power. My guess is if you ran that same fuel/oil mix in a 4 stroke it would make less power than it would with no oil in the fuel (adjusting the air fuel mix to optimum in both tests), so I cant see how the oil would help combustion in either a 2 stroke or 4 stroke. Must be another reason which more than outweighs the likely loss in power from worse combustion with oil in the fuel.


I have yet to run anything severe on Redline 2 cycle alcohol oil but it mixes with everything, and I do mean every type of fuel or additive, and it is fine at cold temps. Time will tell.

[husaberg]

Bean oil has always been my first choice when applications permit. Still there must be a good reason why 16:1 oil makes more power. My guess is if you ran that same fuel/oil mix in a 4 stroke it would make less power than it would with no oil in the fuel (adjusting the air fuel mix to optimum in both tests), so I cant see how the oil would help combustion in either a 2 stroke or 4 stroke. Must be another reason which more than outweighs the likely loss in power from worse combustion with oil in the fuel.


I have yet to run anything severe on Redline 2 cycle alcohol oil but it mixes with everything, and I do mean every type of fuel or additive, and it is fine at cold temps. Time will tell.

The answer is sealing of the rings and bore is superior with the Castor oil as are the lubrication qualities in extreme aplications. It need not help the combustion at all to achieve more power, it may well (and likely does) make it worse, but regardless the net result is it consistently makes more power with less scuffing.
It does of course varnish and gunge up the engine components faster making it impractical on the street. But this is not an issue with competition engines. But you already knew that bit.

[2005bully]

Here is an extract of mine of a dyno report I was paid to do by a customer.

"
In the test I did we narrowed it down to testing two oils for the application - a KT100 direct drive Yamaha kart engine.
This engine is run all day on the edge of destruction with egt sitting at 1280*F to get the heat in the pipe.
Without this temp it wont pull to 16000,and will be "slow".
With a new piston, we ran in, then tested on fully synthetic Elf 976 that the GP teams use.
We tested at 30 and 16:1.The lower ratio made no more power but after a severe thrashing on the dyno we pulled the cylinder and the piston had score marks all over the thrust faces.
Then we put in a new piston,with a very light hone to replicate the first test but on Elf 909.
This is castor based and we found that at 16:1 the new oil made consistently 0.3 Hp over the 30:1 and that this was 0.2 Hp up on the previous oil.
So - 0.5 Hp in an engine that makes just under 17Hp and the piston looked brand new after the test. "

Bottom line is that the oil to use is application specific, in that full synthetics are fine on unleaded or low egt temp, but crap in high temp and or racegas uses.
The castor ( or ester syn ) based oils are better in both applications but alot better when used at very high temps and rich mix ratios..



Many tuners have seen how a 2 stroke engine pushed to the limits of heat and stress will perform longer and stronger with Castor oil..... The following link offers an explanation. Kermit Buller

http://frcm.org/index.php/articles/68-general1/112-castor-oil-explained

[MotleyCrue]

The answer is sealing of the rings and bore is superior with the Castor oil as are the lubrication qualities in extreme aplications. It need not help the combustion at all to achieve more power, it may well (and likely does) make it worse, but regardless the net result is it consistently makes more power with less scuffing.

Taking that further, from 80 BTDC to 80 ATDC the air fuel mix doesnt know if it is in a 4 stroke or a 2 stroke engine, its just in a confined space being compressed and burned.

Theoretically the same 16:1 fuel/oil mix should make more power in a 4 stroke than plain fuel in a 4 stroke, for the same reason as it makes more power in a 2 stroke (combustion is a bit worse but ring sealing is a lot better). That is unless ring sealing in a 4 stroke is already a lot better than ring sealing in a 2 stroke but why would that be so?

[husaberg]

Taking that further, from 80 BTDC to 80 ATDC the air fuel mix doesnt know if it is in a 4 stroke or a 2 stroke engine, its just in a confined space being compressed and burned.

Theoretically the same 16:1 fuel/oil mix should make more power in a 4 stroke than plain fuel in a 4 stroke, for the same reason as it makes more power in a 2 stroke, that being combustion is a bit worse but ring sealing is a lot better. That is unless ring sealing in a 4 stroke is already a lot better than ring sealing in a 2 stroke but why would that be so?

They conventional four strokes have pressure feed controlled lubrication, oil control rings, pressure feed cavities, they rotate, They are not fixed postion and they don't have to transverse open ports. plus normally more rings. d they don't have peteol diluting the ioled cylinder both on top and below the piston.
I can 't remember for sure but I think in a four stroke piston the top ring does 80% of the sealing the second 20%
I posted a lot of piston and ring stuff a while back that would answer your questions I guess.
(link to be added)
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130863005#post1130863005

[Lightbulb]

They used to sell upper cylinder lubricants for valves and rings years ago for 4t engines. I guess with everyone on the make it burn cleaner thing, was phased or outlawed due to emissions. That is where Harry enters the scene. Very low emissions. Material coating technologies are coming a long way.Especially in the tooling for metal removal. The coatings, have to handle high heat,and not have the material weld to it, as well as work with little to no coolant. The latest stuff in Europe is to work without the conventional liquid coolant. Anyway, I am sure that some of these coating technologies would be quite good for engine parts. There are DLC, diamond like coating on inserts for cutting ali, but also these coatings are making their way in model engines. It is only a matter of time and more research before they will become more commonly used in larger engines. Some model engines are now using an anodising process for cylinder liners, instead of hard chrome, but I have not seen a real high performance model engine with the anodised liners yet.OS have a coating on crankpins that seems to last for ever and not wear out. Some Russian engines have ceramic materials for things like gudgeon pins, being lighter and seemingly ,are not breaking. At about 1/2 the weight of a steel pin with a hardness way higher than any steel and a lower friction value. For all that though, they don't seem to have any significant advantage power wise, but maybe have a longer small end rod life.
Neil

[husaberg]

They used to sell upper cylinder lubricants for valves and rings years ago for 4t engines. I guess with everyone on the make it burn cleaner thing, was phased or outlawed due to emissions. That is where Harry enters the scene. Very low emissions. Material coating technologies are coming a long way.Especially in the tooling for metal removal. The coatings, have to handle high heat,and not have the material weld to it, as well as work with little to no coolant. The latest stuff in Europe is to work without the conventional liquid coolant. Anyway, I am sure that some of these coating technologies would be quite good for engine parts. There are DLC, diamond like coating on inserts for cutting ali, but also these coatings are making their way in model engines. It is only a matter of time and more research before they will become more commonly used in larger engines. Some model engines are now using an anodising process for cylinder liners, instead of hard chrome, but I have not seen a real high performance model engine with the anodised liners yet.OS have a coating on crankpins that seems to last for ever and not wear out. Some Russian engines have ceramic materials for things like gudgeon pins, being lighter and seemingly ,are not breaking. At about 1/2 the weight of a steel pin with a hardness way higher than any steel and a lower friction value. For all that though, they don't seem to have any significant advantage power wise, but maybe have a longer small end rod life.
Neil

The upper cylinder lubricants were mainly MoS2 Molybdenum disulphide. The oils got better they likely weren't needed anyway. but it is a very good boundary extreme situation lubricant, With hard to replicate qualities
They used to get pushed hard here for LPG vehicles but that might just have been more salesmanship. Pretty sure most in NZ over 35 you can remember the 173/186/202 Holden (or whatever it was) idling for hours on end with no oil gimmick at the A@P shows

[trevor amos]

Can it true that putting more oil put through an engine brings an increase in engine power, is it even a realistic proposition, it certainly appears counter intuitive?
I currently race an ex GP TZ250, and am a “fly-in tuner” for FactoryPro tuning and attend the nation-wide AMA road race nationals.
I have done some extensive testing, on one of our Low Inertia Eddy current dynos, with my 250 and have realized a power gain when going from 24 to 16-1 oil/fuel ratio.
A couple of key points; our dyno uses an integrated 4 gas analyzer and the dyno will hold the engine at a given rpm and record hp and all four gasses and then step up to the next rev point. It is therefore, very accurate and offers a comprehensive information down load.
I ran the bike at 24-1 and adjusted the carbs until the engine made the best hp at every point, in 1k rpm increments, until the CO was 4.5% and residual oxygen was 5.9%. The tests were then repeated with the oil content at 16-1; again, the carburation, jets and needles, were adjusted until CO and oxygen came in at the same optimum readings. At this point the power gain was 2hp!
During the tests, the initial swop over in oil content, from 24-16, caused the power to drop, the carb adjustments indicated brought about the power improvement when the same gas output readings were achieved. The oil used was Castrol A747, modern, powerful ignitions will happily fire rich oil ratios, and the benefits of better ring sealing and cooler temps can be realized.
So the answer to the question must be , yes!

I found this piece in an American bike magazine a few years back, so it would seem appropriate to post it here and it seems to confirm what Wob was suggesting?

Trevor

[Frits Overmars]

They used to sell upper cylinder lubricants for valves and rings years ago for 4t engines. I guess with everyone on the make it burn cleaner thing, was phased or outlawed due to emissions.Outlawed or not, it is common practice to run a 80:1 premix in World Superbike and Supersport foul-strokes.


Material coating technologies are coming a long way... DLC, diamond like coating DLC may look promising but there are two limitations. First of all, the surface to be treated must be super smooth, otherwise you would just be creating a diamond file.
Secondly, DLC is still temperature-limited. The safe border is moved up year by year, but I still would not use it in places where the temperature exceeds 300°C.
By the way, The C in DLC stands for Carbon, not for Coating.


Some Russian engines have ceramic materials for things like gudgeon pins, being lighter and seemingly ,are not breaking. At about 1/2 the weight of a steel pin with a hardness way higher than any steel and a lower friction value. lThose pins are among the things I'd like to try.

[MotleyCrue]

If 16:1 is better than 24:1 and 30:1, by all accounts, then the logical step would be to try more and more oil yet until there is no gain. No doubt someone has and maybe 16:1 is the optimum result from such tests. Model airplane fuel is what 5:1 bean oil or so.

A good ignition would be desired when lots of oil is used and there have been questions about just how good or not good some of the 2 stroke ignitions really are in comparison to automotive racing ignitions. Maybe a better ignition would lead to an optimum ratio with more oil than 16:1.

Anybody tried more oil than 16:1 ?


I run about 70:1 in both 2 strokes and 4 strokes. Personally I would never have any incentive to run 16:1 for a duration of time, but I am curious if more oil than 16:1 would do anything good for short bursts where races are just seconds long and where plug fouling would never be a concern.

[gamma500]

Hey,

friend of mine asked me to build a pipe for his yz250 2005(I think that its the same engine in newer ones).

Before I start taking the engine apart, does anyone here have the engmod2t model of this engine already?

If you got the files and are willing to share pls pm me.

[Flettner]

Hey,

friend of mine asked me to build a pipe for his yz250 2005(I think that its the same engine in newer ones).

Before I start taking the engine apart, does anyone here have the engmod2t model of this engine already?

If you got the files and are willing to share pls pm me.

Just send me the gearbox:yes:

[husaberg]

Just send me the gearbox:yes:

http://www.ebay.ie/itm/171873411622

[gamma500]

Just send me the gearbox:yes:

Maybe he won't notice anything special :cool:

[peewee]

why not use a 6sp set from a 125 or the ktm250 ?

[JanBros]

just finished going through a pile of Moto73 magazines ('76-'82) for which Frits used to write.

do you know if this engine ever ran Frits ?
https://lh3.googleusercontent.com/RE4CyJwCVzdggpwKXUCNlPlmqQ04fs7-uNwtyxzmflcLAAqupFZByuTPRT033HZn2efa0XNRn3ypcs0eMy P8P0EK_oP9Wd-yylW_WWivyp7k7DG_JoN6QU_7hgDrdtNZrHhLUUEkqh3oxAJwj FN8eyOHLQ3TAZ0rsoYoxQZ3vBk7f4K-HS7OV2t7Wgo64DgJy_dBSMNFQLq6HOlkzmUZXj4WGwXxPqkqRU LIvZLPz3ot_J5E7YltnA4yq2kxoNDYaKK_AMgi3CVaebS1oFxw SPmUR9sl0MWaRH-TsQz73RIAXhonWvEsnITYtIzJadZlwU-5LbtZggBmnrRlEtum6OhDWvW-W-qwYCd2uNF_wPxQdldo5fVaag5Q_TyDNq_k8CnmUhWjtRhAW3AI vEKDonkLIZX8aLEfOCoOJX1EjjcHmtviGjgoNGbB_ziayF8RPM OM2DAFUtxgD3IjsRNquV8UMOM-fIhRrjGDkdHqGRmcbSeFoYt7joSUdZ3Rr--RN9vGxVAKpsBQPU6Z_pOl2T13Kz7WnhehExR5g38yU5g=w779-h1051-no
https://lh3.googleusercontent.com/zZqg2lwXUFdxWk9cZXvwws8elSDqAa1phQyD5JIy8q-oObGsfuU5l2nQCxIIV8LvLk0VO_tbYrnR6rbLVUVkkK8VjNZjJ 57YZG5xE9DGgZPM623aJKzuhAj55dsxxZ63-JgRKFXq0IOUKLNzuAZ2ISaPDC0pne8H4-sJwHXIvHQ6FKKlUeRpUG8eniZNpOYpHti72Ph8GF8TQjZ5jVzR el0sVPSEg6dT2XzvZo8m2VaiST8WOEUcgjscejxQ4fz3wmOlpW yKTmHGvNm9QhmJbWyNv7wm9sh0YnFZbnZla4nAi_Zt-BHX_Fpomx7OALYATG_dGvjEFky6mhuSRsVPV9tNsOqlE8IQ5kF aI-rpjJe199eFWom-Lmwl3L7Uo9U0AQ3czFSUiE-S6j-f0b1_Il3-WynY_Ud_QyVq4OsTldETRQzS5wlDUzbfnuoC9cVh2J7eZTnjUd oOchUzw77SLziaCXNJR_0pw45IbDuKnQsiGIDyztGSDwDu9oPs E1W4b3VAxpXuAIwou4IeNOfY3qzFEQ1TqGA4Sh69czxgn0g=w7 83-h1051-no

2 "buckets" from the sixties :

Jan Thiel in action :headbang:
https://lh3.googleusercontent.com/XG_-s-5E8EmMVnlSkD29RqdCWoanGhAXZtxtVCZs-mWAYgnt-clGhKYCCGHTbmT6apvgHE7b_wQjURqxOFULKOEiYSsCHRjwMzN 52K9tKUJUwaVeEALdkdTefFW2Nutg8qEtGrnz0v8TN-FIdIJZVaA3itSqwJPWs0XDVlRkf_Sb7W0Rld-0b62Uv_RFmS8ccIVR6XgX-DEyZ1TB9G84s2ZQ6KV_AhVK9YEvhz8i0rBl7pr9dt6E0WQZBUy TExIehF9zWoP2R_ij8TBEUYsWcaUH9Kkgf5-mtH5n4VeKcy4q3LmQeBpXpy82u9M5SkUavJ0v7Wfgmo6Uq4aZl ROWZiZpBOjrgfmXt55mX57VkfJVhFtxgJs_jlVqaNwPu0XcLb6 RDEWhbarntuv5wStfWrxp2G_matKGCT0SJV-QL8mu6-jS-NdZN-g1Zsq6aKHeXyYvA5nNAWmXAcFQA1ttXPtUK0MZ0O_9XPPu8RS2 YkDlP31NFqIHaxjUlPaxoyLIN7TH6jD3K9HrkaS4wfTcyKbatQ EbJIfk6TrzbWnoV44=w1116-h860-no

very first Jamathi, but called Tansini at the time (1964) :
https://lh3.googleusercontent.com/6rcYuqoExXcFI1y5Xi7UwWuBm_YRVITCkDQ_VF67boDrdjKl4T qmeMF-E8ouO2HuMa3Ahbyj9rxFJE8D8pKfD6icsmyLHWnfzCgA42mqeS sZThLWFVT7lSCROSEQVEGYfBpZ8uPRjlcmP8m1zlPMbxQGBgh2 p65yKclg-pHVjpIV7OpLDWOAs0473d0tquZOIO-k_CylXiGha4mRQPOKXmuEVwG4c3sCcgt-LVZA9LxaTK3YCLmKSSdik2duMxkDmZS9kui0CHdFwNJkzQOjZh omk_vuxPb07rKnku5NOLY_-SCMCI3TRsnQWKxCMV68t2KCsXjJ0X7-qXCMn2elxYONT-NnmMC8J4jB5JL1n0ddUZUslJZAlB4v3iRr18FPRcPO9URtYHXH FfD-CXypt4Ca_LXpCIejp8Lnzh36yD2ZgH2sEUWyrVE2jZ6vgnO2Wv adeT31oproNwVYadmppXBbd9TCxm6tN4JWyUE_FT7ot1e21VXE 3h7f-U3pcSCv1s8J0APgJi6ZgcLdGAu5X9E4dNahR-w-mVwN8lMtrCI=w1128-h881-no

[Flettner]

why not use a 6sp set from a 125 or the ktm250 ?

Cases are already designed and cast around the YZ gearbox. No real problem as I have another YZ gearbox in the 360 engine I'm building but I just didn't want to take it apart. Just If I find another one I'll grab it, must be 2002 onwards (I think).

[Frits Overmars]

just finished going through a pile of Moto73 magazines ('76-'82) for which Frits used to write.Do you know if this engine ever ran Frits ?Not to my knowledge. I must say this took me back quite some time. Which year of publication was this Jan?

[JanBros]

Not to my knowledge. I must say this took me back quite some time. Which year of publication was this Jan?

I didn't take note of this. I went through all of the ones I have and just kept some aside I wanted to scan. putted them all back in a box and on my attic today :Oops:
but I thinck '78-'79.

[WilDun]

just finished going through a pile of Moto73 magazines ('76-'82) for which Frits used to write.
do you know if this engine ever ran Frits ?


Must say I find that one very interesting indeed, but unfortunately I didn't learn Dutch at school. However I have got the 'gist' of it all and although it would have to go through a lot of development I reckon it could be a runner. Whether or not it would make it as being a viable alternative I'm not so sure! - hope someone will have a description in English somewhere.

It would have been a good contribution on the 'oddball engines' thread (but that thread more or less got wrecked). On there, I posted the Karol Ansdale motor which in many ways is similar.
The difference here is the cylindrical outer housing in which the ring has to be shaped and can not rotate, as opposed to the spherical shape on the Karol Ansdale engine having a more normal sealing ring which can rotate. The 'scotch yoke" arrangement in this one is of course different.

I think that there was a guy who built a motor similar to this one here in Auckland (Mount Wellington) about 20 years ago.

[husaberg]

Cases are already designed and cast around the YZ gearbox. No real problem as I have another YZ gearbox in the 360 engine I'm building but I just didn't want to take it apart. Just If I find another one I'll grab it, must be 2002 onwards (I think).

This is what I found along with the other stuff re the yzf450 stuff I posted in the other thread Neil
http://www.oem-cycle.com/YAMAHAYZ250BIKEID.shtml

OEM cycles has a very good cross reference for what fits what witht the different years of all sorts of makes models and years of MX bikes

http://www.thumpertalk.com/topic/927076-yz450f-transmission-gear-upgrade-close-ratios/page-2

[Frits Overmars]

It would have been a good contribution on the 'oddball engines' thread (but that thread more or less got wrecked).Wrecked by someone who apparently made a bo-bo in his nappies, you mean? I still take an almost daily peek there hoping to find more wonderful contraptions:
http://www.kiwibiker.co.nz/forums/showthread.php/171300-Oddball-engines-and-prototypes/page607

[tjbw]

Must say I find that one very interesting indeed, but unfortunately I didn't learn Dutch at school. However I have got the 'gist' of it all and although it would have to go through a lot of development I reckon it could be a runner. Whether or not it would make it as being a viable alternative I'm not so sure! - hope someone will have a description in English somewhere.

It would have been a good contribution on the 'oddball engines' thread (but that thread more or less got wrecked). On there, I posted the Karol Ansdale motor which in many ways is similar.
The difference here is the cylindrical outer housing in which the ring has to be shaped and can not rotate, as opposed to the spherical shape on the Karol Ansdale engine having a more normal sealing ring which can rotate. The 'scotch yoke" arrangement in this one is of course different.

I think that there was a guy who built a motor similar to this one here in Auckland (Mount Wellington) about 20 years ago.

I thought at first that the internals were a bit similar to a Bourke auto ignition/detonation engine, https://en.wikipedia.org/wiki/Bourke_engine

Then I realised that it's a rotating uniflow engine with rotary exhaust!

[WilDun]

I thought at first that the internals were a bit similar to a Bourke auto ignition/detonation engine, https://en.wikipedia.org/wiki/Bourke_engine

Then I realised that it's a rotating uniflow engine with rotary exhaust!

Yes, I would be a bit worried about the amount of ring drag on the outer casing (not like the Ryger - no ring drag!)
:whistle:

[WilDun]

Wrecked by someone who apparently made a bo-bo in his nappies, you mean? I still take an almost daily peek there hoping to find more wonderful contraptions:
http://www.kiwibiker.co.nz/forums/showthread.php/171300-Oddball-engines-and-prototypes/page607

Yes, a very lonely man I think, if he stopped arguing about everything he might actually be a nice guy! The old scenario of people who like to wreck kid's sandcastles comes to mind!

But ........ one day maybe it will restart - then again is there anything old which still can be resurrected here? - in this forum, is there anything new under the sun, who knows!

[tjbw]

Yes, I would be a bit worried about the amount of ring drag on the outer casing (not like the Ryger - no ring drag!)
:whistle:

Would be interesting to see it compares with a similar engine that didn't rotate, but had a rotary exhaust valve, assuming someone could make a rotary valve that works well.

[ken seeber]

Yes, a very lonely man I think, if he stopped arguing about everything he might actually be a nice guy! The old scenario of people who like to wreck kid's sandcastles comes to mind!

But ........ one day maybe it will restart - then again is there anything old which still can be resurrected here? - in this forum, is there anything new under the sun, who knows!

Willy, I just chucked something on Oddball to maybe see if it can get going again. :2thumbsup

[peewee]

hey frits and wobbly i was trying to think what the purpose of boyesen ports is. to add inlet area but it seems like they should have a downward angle somewhere about 45*, which wouldnt be to sharp as to cause the air to hit a brick wall and go straight down . the reason i think this is because they would be responsible for filling the lowest portion of the case and the main inlet would mostly go straight in and fill up the cylinder middle section. does any of this sound like what actually happens ?

[TZ350]

.
This quote links back to the back story so far.


Many thanks to Kickaha for the GN clutch.

316505

Honda copy Monkey Bike primary gears are straight cuts which have the same C/C distance as the GP.

Another step on the way to building the Suzuki GP/NSR110 super Frankenstein engine, the crankshaft.

316848t

The GP/NSR110 crank parts.

316844

Old balance holes plugged with alloy and a Mallory slug opposite the big end. 22mm diameter 60mm long big end pin from a diesel, 115mm RD400 rod, RGV250 big end bearing and small hardened thrust washers. I made the bigger thrust washers out of material that is tough as shark shit.

316849316847

0.8mm side clearance. The flywheels are champhered to allow the wind to flow over the inner edges so the air mass can resonate into and out of the center section with less disruption, (hopefully).

316845316846

50% balance factor. The balancing was achieved by skimming the inside faces of the crank, removed 2mm each side. Plenty of crankcase volume with this baby.

Back in the 80's a friend once fitted an RD350 crank into a set of RD400 cases, lots of extra case volume with the smaller 350 flywheels. I predicted it wouldn't work, not enough crank case compression, not the done thing etc. etc.... but it worked like a charm.

[Frits Overmars]

Back in the 80's a friend once fitted an RD350 crank into a set of RD400 cases, lots of extra case volume with the smaller 350 flywheels. I predicted it wouldn't work, not enough crank case compression, not the done thing etc. etc.... but it worked like a charm.We did the same in the 80's: built TZ250 and TZ350 engines with RD400 cases and big (for the era) carbs: 38 mm for the 250; 40 mm for the 350 (because I couldn't find bigger ones).

[Frits Overmars]

hey frits and wobbly i was trying to think what the purpose of boyesen ports is. to add inlet area but it seems like they should have a downward angle somewhere about 45*, which wouldnt be to sharp as to cause the air to hit a brick wall and go straight down . the reason i think this is because they would be responsible for filling the lowest portion of the case and the main inlet would mostly go straight in and fill up the cylinder middle section. does any of this sound like what actually happens ?You want to feed the transfers directly from the inlet, so those Boyesen ports should aim straight at the transfer ducts. But as your picture shows, there is insufficient material and the studs are in the way. Hence the switch from cylinder reeds to case reeds.

[Flettner]

So Frits, you say the Ryger uses standard exhaust (and muffler?). If we are putting a lot more gas through this system then there must be a significant pressure (and temp?) increase. This must change the pipes wave length somewhat, yes. Is this how we are able to spread the power band over such a wide range? And does this pressure and temp increase the energy at which the pipe operates ie works (pumps) harder. Is this a fair question?

[MotleyCrue]

So Frits, you say the Ryger uses standard exhaust (and muffler?). If we are putting a lot more gas through this system then there must be a significant pressure (and temp?) increase. This must change the pipes wave length somewhat, yes. Is this how we are able to spread the power band over such a wide range? And does this pressure and temp increase the energy at which the pipe operates ie works (pumps) harder. Is this a fair question?

Maybe just to add to the question.

If the Ryger pipe was install on a normal top level 125 engine, would the Ryger pipe then be too short for the regular 125 to run properly (13500 peak)? I think we all know the answer to this question, but maybe not. Maybe the Ryger pipe is longer than expected for a 17000 rpm peak.

If we looked in the Ryger pipe with a flashlight would we see anything out of the ordinary as far as 2 stroke exhausts go?

[Frits Overmars]

So Frits, you say the Ryger uses standard exhaust (and muffler?).Yes, muffler too.


If we are putting a lot more gas through this system then there must be a significant pressure (and temp?) increase. This must change the pipes wave length somewhat, yes.
Is this how we are able to spread the power band over such a wide range? Let's do some math. A regular kart engine produces its maximum torque at about 12000 rpm with an exhaust gas temperature in the pipe of about 600°C ; that's 873 K.
The Ryger's max.torque rpm is 1,4 times as high. And as the Ryger uses a regular pipe (more about it further on) the waves in the pipe must travel 1,4 times as fast.
As those waves travel with the speed of sound (yes Vannik, I know, but I am talking to normal people now) the speed of sound in the Ryger pipe should be 1,4 times the speed of sound in the regular engine's pipe.
How do we accomplish that? The speed of sound is proportional to the square root of the absolute temperature but is independent of pressure or density.
So the temperature in the Ryger pipe must be 1,4 x 1,4 x 873 = 1711 K. That's 1438°C. Steel melts at 1430°C....
And if we want to rev on to 30.000 rpm, the exhaust gas temperature should be 5183°C. Steel boils at 2900°C; titanium melts at 1670°C and boils at 3287°C.
No Neil, this is not how the Ryger spreads its power band over such a wide range.

The pipe: I promised to say something about that too.
The Ryger engine is based on a regular VM kart engine and the Ryger parts are for the most part standard VM parts, including the pipe. You'll find the pipe dimensions here:
316856

[tjbw]

Yes, muffler too.

Let's do some math. A regular kart engine produces its maximum torque at about 12000 rpm with an exhaust gas temperature in the pipe of about 600°C ; that's 873 K.
The Ryger's max.torque rpm is 1,4 times as high. And as the Ryger uses a regular pipe (more about it further on) the waves in the pipe must travel 1,4 times as fast.
As those waves travel with the speed of sound (yes Vannik, I know, but I am talking to normal people now) the speed of sound in the Ryger pipe should be 1,4 times the speed of sound in the regular engine's pipe.
How do we accomplish that? The speed of sound is proportional to the square root of the absolute temperature but is independent of pressure or density.
So the temperature in the Ryger pipe must be 1,4 x 1,4 x 873 = 1711 K. That's 1438°C. Steel melts at 1430°C....
And if we want to rev on to 30.000 rpm, the exhaust gas temperature should be 5183°C. Steel boils at 2900°C; titanium melts at 1670°C and boils at 3287°C.
No Neil, this is not how the Ryger spreads its power band over such a wide range.

The pipe: I promised to say something about that too.
The Ryger engine is based on a regular VM kart engine and the Ryger parts are for the most part standard VM parts, including the pipe. You'll find the pipe dimensions here:
316856

Don't laugh, but I was thinking a pipe designed for a 180cc engine would work for a 70hp 125.

I suspect some of us would be no wiser even if we saw the full homologation pdf.

[MotleyCrue]

The Ryger is full of riddles at every turn. I think somebody found Aladdins lamp and showed Aladdin their ultimate wish list.


Is the exhaust pipe an ornament or is it's regular pulsing function still needed?

Likely the pulsing function is still needed, but I wonder if it is needed all the way to 17000 (30000) rpm or if it is mainly there just for the lower revs like it would be on a regular 125 such as < 14000 rpm.

Has it ever been mentioned what rev range would be considered the actual "powerband" for the Ryger? If it peaks at 17000 then would the top of the powerband be 18-19000 rpm or does the power just hang on to a lot more rpm than that?

[Flettner]

Yes, muffler too.

Let's do some math. A regular kart engine produces its maximum torque at about 12000 rpm with an exhaust gas temperature in the pipe of about 600°C ; that's 873 K.
The Ryger's max.torque rpm is 1,4 times as high. And as the Ryger uses a regular pipe (more about it further on) the waves in the pipe must travel 1,4 times as fast.
As those waves travel with the speed of sound (yes Vannik, I know, but I am talking to normal people now) the speed of sound in the Ryger pipe should be 1,4 times the speed of sound in the regular engine's pipe.
How do we accomplish that? The speed of sound is proportional to the square root of the absolute temperature but is independent of pressure or density.
So the temperature in the Ryger pipe must be 1,4 x 1,4 x 873 = 1711 K. That's 1438°C. Steel melts at 1430°C....
And if we want to rev on to 30.000 rpm, the exhaust gas temperature should be 5183°C. Steel boils at 2900°C; titanium melts at 1670°C and boils at 3287°C.
No Neil, this is not how the Ryger spreads its power band over such a wide range.

The pipe: I promised to say something about that too.
The Ryger engine is based on a regular VM kart engine and the Ryger parts are for the most part standard VM parts, including the pipe. You'll find the pipe dimensions here:
316856

Ok, thank you, way off base.

[yesyes]

Yes, muffler too.

Let's do some math. A regular kart engine produces its maximum torque at about 12000 rpm with an exhaust gas temperature in the pipe of about 600°C ; that's 873 K.
The Ryger's max.torque rpm is 1,4 times as high. And as the Ryger uses a regular pipe (more about it further on) the waves in the pipe must travel 1,4 times as fast.
As those waves travel with the speed of sound (yes Vannik, I know, but I am talking to normal people now) the speed of sound in the Ryger pipe should be 1,4 times the speed of sound in the regular engine's pipe.
How do we accomplish that? The speed of sound is proportional to the square root of the absolute temperature but is independent of pressure or density.
So the temperature in the Ryger pipe must be 1,4 x 1,4 x 873 = 1711 K. That's 1438°C. Steel melts at 1430°C....
And if we want to rev on to 30.000 rpm, the exhaust gas temperature should be 5183°C. Steel boils at 2900°C; titanium melts at 1670°C and boils at 3287°C.
No Neil, this is not how the Ryger spreads its power band over such a wide range.

The pipe: I promised to say something about that too.
The Ryger engine is based on a regular VM kart engine and the Ryger parts are for the most part standard VM parts, including the pipe. You'll find the pipe dimensions here:
316856

What a headache :sweatdrop

[tjbw]

What a headache :sweatdrop

Yes, but what could be simpler, it seems that the VM engine to Ryger conversion kit just includes:
stepped piston, cylinder, connecting rod, spacer with valves, and perhaps ignition timing changed. Did I miss anything?

I can comprehend that the Ryger primary compression may be much more positive, with much higher primary compression ratio. This might be great for starting the engine. But to get more power than the VM engine I think you need more fresh mixture in the cylinder, and I can't imagine how the same VM exhaust can do this.

If it gets 70HP with wide powerband using VM exhaust, then wouldn't it be possible to optimise the Ryger exhaust design for even more power?

I recall that a disc valve is good for 10HP over a reed valve, based on RSA V Derbi comparison, so might we see an 80HP 125cc Ryger with disc valve?

Frits, any idea when the Ryger engine will make it's debut?

Hope we get some more Ryger details real soon, or I'll have no hair left ;)

[Yow Ling]

Maybe when the rights are sold the truth will be told ?

[F5 Dave]

Yes, but what could be simpler, it seems that the VM engine to Ryger conversion kit just includes:
stepped piston, cylinder, connecting rod, spacer with valves, and perhaps ignition timing changed. Did I miss anything?

I can comprehend that the Ryger primary compression may be much more positive, with much higher primary compression ratio. This might be great for starting the engine. But to get more power than the VM engine I think you need more fresh mixture in the cylinder, and I can't imagine how the same VM exhaust can do this.

If it gets 70HP with wide powerband using VM exhaust, then wouldn't it be possible to optimise the Ryger exhaust design for even more power?

I recall that a disc valve is good for 10HP over a reed valve, based on RSA V Derbi comparison, so might we see an 80HP 125cc Ryger with disc valve?

Frits, any idea when the Ryger engine will make it's debut?

Hope we get some more Ryger details real soon, or I'll have no hair left ;)
Try compare factory Honda and it wont be 10hp.
But there is the question of stinger diameter that increases with an increase of output. Surely the ryger would need another 3mm to not melt if a conventional engine. So can it break the rules here too?

[Lightbulb]

I think that the view of needing more fresh mixture to make more power, may not actually be the answer. I think the answer is the other way around.
You need better combustion to get less CO in the residual exhaust. Then you automatically get more effective charge from the same amount of air fuel.
It has to be that way or else it would be using more fuel and not less. For the air to mix better , it needs the most amount of time possible to mix best with the air and heating the air will help in a better dispersion. So I doubt that it uses any direct flow to any of the cylinder or ports. Neil

[trevor amos]

It might be more realistic to suggest that the disc valve arrangement offers a potential 10% advantage over the reed valve and not a blanket 10hp!

Trevor

[cotswold]

[QUOTE=Frits Overmars;1130916123]Yes, muffler too.

Let's do some math.

as you are a lot better at maths than myself and Husa, if you feel inclined, would you take a peek at my 50 page as I have some of your drawings I am assuming were for the RSA(w) 125 ? and my question is sat waiting for you

[Frits Overmars]

there is the question of stinger diameter that increases with an increase of output. Surely the ryger would need another 3mm to not melt if a conventional engine. So can it break the rules here too?Yes it can, Dave.


It might be more realistic to suggest that the disc valve arrangement offers a potential 10% advantage over the reed valve and not a blanket 10hp!Right, Trevor, as long as we're talking conventional engines. I don't think the Ryger would benefit from a disc valve.


as you are a lot better at maths than myself and Husa, if you feel inclined, would you take a peek at my 50 page ....What is 'my 50 page' ?

[Muciek]

Yes it can, Dave.

Right, Trevor, as long as we're talking conventional engines. I don't think the Ryger would benefit from a disc valve.

What is 'my 50 page' ?

It's here http://www.kiwibiker.co.nz/forums/showthread.php/160757-The-50?p=1130916458#post1130916458 .

[Frits Overmars]

It's here http://www.kiwibiker.co.nz/forums/showthread.php/160757-The-50?p=1130916458#post1130916458 .I wasn't aware of that section. Jeez! Another 20 pages to read. And heaven knows how much more sections there are here that I haven't yet discovered.
Don't hold your breath waiting for an answer Cotswold; first I want to read the lot.

[tjbw]

Yes, but what could be simpler, it seems that the VM engine to Ryger conversion kit just includes:
stepped piston, cylinder, connecting rod, spacer with valves, and perhaps ignition timing changed. Did I miss anything?
..



Oops, I missed the crankcase/inlet blanking plate in the conversion kit!

[MotleyCrue]

Its good that Frits knows all about the Ryger engine and is backing up all the claims, including some appearing seemingly impossible, because it would sound like a complete fabrication (no pun intended) without that.

[tjbw]

I think that the view of needing more fresh mixture to make more power, may not actually be the answer. I think the answer is the other way around.
You need better combustion to get less CO in the residual exhaust. Then you automatically get more effective charge from the same amount of air fuel.
It has to be that way or else it would be using more fuel and not less. For the air to mix better , it needs the most amount of time possible to mix best with the air and heating the air will help in a better dispersion. So I doubt that it uses any direct flow to any of the cylinder or ports. Neil

How about more fresh mixture at the optimum ratio (14.7?) to minimise HC emission?

I think a reason for moving the inlet from crankcase to cylinder was to facilitate some direct flow!

[Norman]

I am thinking the Ryger uses "EGR" to induce a HCCI like combustion and to lower emissions. The pipe pulse coming back to exhaust outlet after (too late) EC routes some exhaust/mix back into the inlet area? A valve (reed?) is letting exhaust go into the inlet/under piston but no fresh mix is allowed to go out to the exhaust this way due to the valve/reed? A pulse coming before EC will push into the cylinder and hold it there with help of the valves in the transfers. The alternative route for the exhaust pulse into the inlet/under piston is opened at EC and it has a certain timing through a cut out in the piston (or "something") combined with the valve/reed..? Well, how it's really done we will see one day but it is very very impressive what has been achieved! It's "a little" hard to wait I must say...:wait:

[JanBros]

Yes, but what could be simpler, it seems that the VM engine to Ryger conversion kit just includes:
stepped piston, cylinder, connecting rod, spacer with valves, and perhaps ignition timing changed. Did I miss anything?

I recall that a disc valve is good for 10HP over a reed valve, based on RSA V Derbi comparison, so might we see an 80HP 125cc Ryger with disc valve?


I don't think the stepped piston is confirmed, and it is my opinion it never will cause don't thin it's in the engine.



where would you place the disc valve to make it work ?

maybe you don't quite understand yet the main purpose of developing the Ryger and the needed solution to achieve the goal ;)

[tjbw]

I don't think the stepped piston is confirmed, and it is my opinion it never will cause don't thin it's in the engine.



where would you place the disc valve to make it work ?

maybe you don't quite understand yet the main purpose of developing the Ryger and the needed solution to achieve the goal ;)

Could put a disc valve at the current input port location, just need a 90° drive.

We live and learn ;)

[d2t]

If the spacer already has reeds that control the incoming air into the under-piston area, why would there be a need for any additional intake valve? Although I think there was a Reed cage after the carb in a Ryger photo. Maybe it blocks the return exhaust wave somehow?

[tjbw]

If the spacer already has reeds that control the incoming air into the under-piston area, why would there be a need for any additional intake valve? Although I think there was a Reed cage after the carb in a Ryger photo. Maybe it blocks the return exhaust wave somehow?

The disc valve wouldn't be an additional valve, but an alternative to the inlet reed/s, and not for the KZ engine, as the CIK regulations call for reed valves.

It would be interesting to see how the performance of disc valve intake compared with reed valve intake.

[m4r]

why make a reed block trumpet style inlet to the cylinder if you won't be using a reed block there :weird:

so having the reed at the usual place, do you actually still need the valve ring? probably not, the pre compression ratio is just not as high as you have the extra inlet volume that is added. I also think, the outlet valves in the valve ring might not have been needed at all in first place, especially not with the now increased volume. Because its only the first 60°-70° crank angle of the upward moving piston where the transfers are still open. And as the fresh mixture has just before been accelerated up the transfers in to the cylinder, it won't be flowing opposite direction immediately.

[tjbw]

why make a reed block trumpet style inlet to the cylinder if you won't be using a reed block there :weird:

so having the reed at the usual place, do you actually still need the valve ring? probably not, the pre compression ratio is just not as high as you have the extra inlet volume that is added. I also think, the outlet valves in the valve ring might not have been needed at all in first place, especially not with the now increased volume. Because its only the first 60°-70° crank angle of the upward moving piston where the transfers are still open. And as the fresh mixture has just before been accelerated up the transfers in to the cylinder, it won't be flowing opposite direction immediately.

We don't yet know the locations of reeds in Ryger KZ engine.

If you had reed inlet valve just inboard of the carb, you would still need the valve/spacer plate to complete the new primary compression chamber, isolate the fuel and air mixture from the crankcase, support lower piston, etc. It should work without additional valves. But at the moment, only the Ryger team knows the configuration that achieves 70HP.

[m4r]

We don't yet know the locations of reeds in Ryger KZ engine.

If you had reed inlet valve just inboard of the carb, you would still need the valve/spacer plate to complete the new primary compression chamber, isolate the fuel and air mixture from the crankcase, support lower piston, etc. It should work without additional valves. But at the moment, only the Ryger team knows the configuration that achieves 70HP.

thats not true, according to the earlier patent, the valve ring is a separate part! Of course you still need the "spacer" and the "lower cylinder", i didn't say you wouldn't.

EDIT: on top, not having the valve ring, would get us back on keeping the ryger hardware simple, as frits said.

[tjbw]

thats not true, according to the earlier patent, the valve ring is a separate part! Of course you still need the "spacer" and the "lower cylinder", i didn't say you wouldn't.

EDIT: on top, not having the valve ring, would get us back on keeping the ryger hardware simple, as frits said.

We don't know for sure what the Ryger internals look like.

If they include a stepped piston and valve ring as shown in the nine year old patent, then you could remove all the valves from the valve ring, use inlet reeds just inboard of the carb, and the engine would work. This would indeed keep it simple, but would the engine now give more power?

I don't know the answer, because I don't understand how they get all that power!

If you remove the valve ring you may need something that supports the lower cylinder, and aligns it with the main cylinder.

[m4r]

yes we don't know the actual ryger internals, that's right, but that doesn't stop me from thinking :cool:

forget the valve ring completely, I guess the spacer or lets call it base plate, would be fine to hold the lower cylinder, align the upper cylinder and shut off the transfers from crankcase.

Again, why would you design the new inlet in the typical reed valve style if you are not putting a reed valve inside?

316929

[MotleyCrue]

Did Frits ever say if the normal looking transfer ports in the cylinder also have normal directions of flow for A and B and C transfers?

[karter444]

Is there any advantage in running a dome top piston over a flat top piston or visa versa ,most pistons do seem to be dome top

[Lightbulb]

On testing I did with model engines, there was no gain with a domed piston and matching head over a flat top piston and matching head. But this was 6.5 cc engines. I still don't know why the MB 6.5 engines use a domed piston, I guess it looks like it makes more power as a result.
Frits may be able to comment better. To me a flat piston is the least area from the center to the edge to dissipate the heat. There may be other reason in bigger engines like trying to keep the flow adhering to the piston crown to try and cool it, just not sure. All I know is, with the limited testing I did, the domed piston was slower and made less power. CNC does not care what a shape is, it is just all just a tool path.
Neil

[tjbw]

Is there any advantage in running a dome top piston over a flat top piston or visa versa ,most pistons do seem to be dome top

There was some discussion about this here, also on pitlane and elsewhere.

IIRC domed piston can give more power, but you need a matching profile on the head. Jan Thiel found best results with 0.7mm squish clearance (on a 125cc RSA engine with domed piston).

The combustion chamber shape and compression ratio are important too.

google searches for more info:

wobbly domed piston
frits domed piston
jan thiel domed piston
ricardo domed piston

[MotleyCrue]

Did Frits ever say if the normal looking transfer ports in the cylinder also have normal directions of flow for A and B and C transfers?

Was it ever mentioned if the bore was stock, if not stock that might help with the speculating.

Every once in awhile one poster generosly puts up a Ryger summary of the main things we know, but there have been some fine points that maybe should make it to the summary list like things Frits said he wasnt at liberty to answer and some ideas that Frits avoided responding to altogether.

[seattle smitty]

The speculating a few pages back about how the Ryger might handle extra F/A and extra heat . . . does this square with Frits' hints (incl. a small radiator) about less heat being absorbed? I don't understand all the ramifications of a relatively "instant" combustion of the F/A mixture (as compared to a usual burn), but doesn't that include an ignition point much closer to TDC, with less "negative-work-effect" and less time for the engine parts to absorb that heat (and therefore more of the heat turned into useful power)? Also, does the decreased (eliminated?) use of pre-mixed oil in the F/A enable or at least assist in getting the "instant burn" to work, to light off at a precise timing? Is there a reason that HCCI would produce fewer nitrogen oxides? And wouldn't that (relatively) "instant" burn require better-than-usual F/A mixing? as well as more precise than usual spark timing? Could a conventional racing 2-stroke like Jan Theil's last Aprilia be set up to use an HCCI fuel burn (without turning it into a Ryger)? So far, in looking at internet articles on HCCI, I have only a sketchy understanding of it (about like my understanding of anything else, alas).

[m4r]

The speculating a few pages back about how the Ryger might handle extra F/A and extra heat . . . does this square with Frits' hints (incl. a small radiator) about less heat being absorbed? I don't understand all the ramifications of a relatively "instant" combustion of the F/A mixture (as compared to a usual burn), but doesn't that include an ignition point much closer to TDC, with less "negative-work-effect" and less time for the engine parts to absorb that heat (and therefore more of the heat turned into useful power)? Also, does the decreased (eliminated?) use of pre-mixed oil in the F/A enable or at least assist in getting the "instant burn" to work, to light off at a precise timing? Is there a reason that HCCI would produce fewer nitrogen oxides? And wouldn't that (relatively) "instant" burn require better-than-usual F/A mixing? as well as more precise than usual spark timing? Could a conventional racing 2-stroke like Jan Theil's last Aprilia be set up to use an HCCI fuel burn (without turning it into a Ryger)? So far, in looking at internet articles on HCCI, I have only a sketchy understanding of it (about like my understanding of anything else, alas).

there is quite a bit explained here

https://idea.library.drexel.edu/islandora/object/idea%3A901

[MotleyCrue]

If exhaust gas is purposely mixed with the fuel and air mixture, for HCCI which it seems like it is, why bother then with the usual A, B, C porting arrangement to get good cylinder exhaust scavenging which would defeat the purpose.

Why not just aim A, B, C at the exhaust port and blow as much fuel air mixture as possible right out the exhaust port forgetting the whole loop thing then stuff it ALL back into the cylinder so none of the fuel air mixture is left in the port when the port closes. On a regular engine this would go against the grain but the Ryger engine has HCCI, needs no power valve and a regular length pipe seems to work to unheard of rpm levels so somehow stuffing all the mixed up fuel, air and exhaust back into the cylinder before port closing might be realistic.

[Norman]

If exhaust gas is purposely mixed with the fuel and air mixture, for HCCI which it seems like it is, why bother then with the usual A, B, C porting arrangement to get good cylinder exhaust scavenging which would defeat the purpose.

Why not just aim A, B, C at the exhaust port and blow as much fuel air mixture as possible right out the exhaust port forgetting the whole loop thing then stuff it ALL back into the cylinder so none of the fuel air mixture is left in the port when the port closes. On a regular engine this would go against the grain but the Ryger engine has HCCI, needs no power valve and a regular length pipe seems to work to unheard of rpm levels so somehow stuffing all the mixed up fuel, air and exhaust back into the cylinder before port closing might be realistic.


A relatively sharper "cut" between the fuel/air mix and the exhaust makes it easier to control what ends up where? My guess is that blowing everything straight out and letting it all mix, and then force it back into the cylinder, will give a too high exhaust content and too little fuel/air mix ratio for high rpm operation, and misfire at lower rpm?

I still think that aome key aspects points towards ATAC/HCCI combustion, but still spark induced flame front combustion at certain rpms and loads? The believed relatively high pre compression, valve arrangement, lubrication principle and other parts of the Ryger concept are not very unlikely the last things needed to take the earlier 1980's-90's low emission ATAC/HCCI assisted like combustion intentions all the way.

[Frits Overmars]

Is there a reason that HCCI would produce fewer nitrogen oxides?Yes, the burn temperature does not rise quite so high with HCCI.


Could a conventional racing 2-stroke like Jan Thiel's last Aprilia be set up to use an HCCI fuel burn?Jan had practically reached that state. The Aprilias had to be jetted too rich, otherwise they wouldn't listen to the quickshifter's ignition cut-out and keep on running without a spark.

[MotleyCrue]

My guess is that blowing everything straight out and letting it all mix, and then force it back into the cylinder, will give a too high exhaust content and too little fuel/air mix ratio for high rpm operation, and misfire at lower rpm?



I do believe there is a way to make that work. A spark plug might not light off a charge with a high exhaust content but HCCI is not a spark event, not at all.

[jonny quest]

Yes, the burn temperature does not rise quite so high with HCCI.

Jan had practically reached that state. The Aprilias had to be jetted too rich, otherwise they wouldn't listen to the quickshifter's ignition cut-out and keep on running without a spark.

So the 54hp dyno run isn't really the numbers the bike ran with on the track? Meaning, it was jetted max effort on dyno. But track configuration was 1 to 2 hp less to make everything work for the rider?

[Lightbulb]

It will be a good day when Frits can respond to my comments.
Neil

[steamroller]

Hi people,

I have a KR150 motor that runs a balance shaft that I would assume would run smoothly. We have put a CNC barrel on it based off a Honda RS125, and now run a 125 piston in it. The motor however now vibrates really badly.

Any suggestions? Is there a ratio to how much weight we should take off the balance shaft to compensate for the 125 piston?

[husaberg]

Hi people,

I have a KR150 motor that runs a balance shaft that I would assume would run smoothly. We have put a CNC barrel on it based off a Honda RS125, and now run a 125 piston in it. The motor however now vibrates really badly.

Any suggestions? Is there a ratio to how much weight we should take off the balance shaft to compensate for the 125 piston?

I will post a link but are you 190% sure it is timed correctly?

attached is a file that explains how the maths work std.

post the weight of the new piston and bearing and the old piston and bearing.
Neil has designed them so I am sure he will give you a simple rule of thumb as will Frits.

[steamroller]

I will post a link but are you 190% sure it is timed correctly?

That was my first thought can not find much about them but my mate did have a motor so just went off that one

[husaberg]

That was my first thought can not find much about them but my mate did have a motor so just went off that one

A guess is you have lowered the reciprocating weight of the piston assembly and also raised the Revs, (plus changed the frame) id say you will have adjust the balance factors on both the crankshaft and the balancer weights.

[steamroller]

A guess is you have lowered the reciprocating weight of the piston assembly and also raised the Revs, (plus changed the frame) id say you will have adjust the balance factors on both the crankshaft and the balancer weights.

Had it on the track today with out one in; it mint down low and up top but mid range its bad

[41juergen]

Frits, if I remember correct you have made an own design of piston pin plugs, made out of PEEK may be? I'm looking for some plugs for my engine and would have access to (standard, means not GFK reinforced) PEEK but no good idea about the design. So if you allow me to ask you if you could give me an idea (or may be sell that idea :- ) )how that plugs would need to look like. Of course I would be able to design "some" plugs but I'm afraid if they would fail (and most probably the first design(s) will) that the engine will be destroyed...:(
wbr from Hanau
Juergen

[jasonu]

Hi people,

I have a KR150 motor that runs a balance shaft that I would assume would run smoothly. We have put a CNC barrel on it based off a Honda RS125, and now run a 125 piston in it. The motor however now vibrates really badly.

Any suggestions? Is there a ratio to how much weight we should take off the balance shaft to compensate for the 125 piston?

Post a few pictures please.

[F5 Dave]

Regan, as a simple experiment, disconnect the balancer. See where that moves the vibration.

[TALLIS]

I have a KR150 motor that runs a balance shaft that I would assume would run smoothly. We have put a CNC barrel on it based off a Honda RS125, and now run a 125 piston in it. The motor however now vibrates really badly.

Any suggestions? Is there a ratio to how much weight we should take off the balance shaft to compensate for the 125 piston?

I balance my shaft with two large low slung weights. I guess you wouldn't know anything about that. But yes the bike was great on pipe but mid corner was givin some bad vibrations. very good platform to start with.

[MotleyCrue]

If exhaust gas is purposely mixed with the fuel and air mixture, for HCCI which it seems like it is, why bother then with the usual A, B, C porting arrangement to get good cylinder exhaust scavenging which would defeat the purpose.

Why not just aim A, B, C at the exhaust port and blow as much fuel air mixture as possible right out the exhaust port forgetting the whole loop thing then stuff it ALL back into the cylinder so none of the fuel air mixture is left in the port when the port closes. On a regular engine this would go against the grain but the Ryger engine has HCCI, needs no power valve and a regular length pipe seems to work to unheard of rpm levels so somehow stuffing all the mixed up fuel, air and exhaust back into the cylinder before port closing might be realistic.

The fish arent biting so I cant tell if it is over the top, or if it is hitting too close to home to be officially commented on.:laugh:

[breezy]

so the emissions tested at 5000rpm, if an engine /exhaust system is designed for full power, maybe 10,000 plus. with this engine good emissions results seem wrong. the exhaust only works proper at 10,000 rpm ish.... as the super charging effect is best at 10,000 rpm ish. . the stuffing back of fuel pulled into the exhaust header can only be pushed back best at its designed length....at lower rpm it doesn’t work , it hits the rising piston and probably goes out the stinger as unburned fuel.. no good for emissions..... so could having a port in the piston below the rings on the exhaust side allowing this fuel to return into the area below the piston at the lower rpm be of benefit,:sherlock: if the pressure below the piston at that point is lower than the returning pressure wave from the exhaust wouldnt it just love to pour into that space...?? wouldnt we be in the area of diverging / converging areas. and whilst increasing speed of pressure flow not increasing bulk flow.( my interpertation of a previous post with info from wobbly).

[MotleyCrue]

so the emissions tested at 5000rpm, if an engine /exhaust system is designed for full power, maybe 10,000 plus. with this engine good emissions results seem wrong. the exhaust only works proper at 10,000 rpm ish.... as the super charging effect is best at 10,000 rpm ish. . the stuffing back of fuel pulled into the exhaust header can only be pushed back best at its designed length....at lower rpm it doesn’t work , it hits the rising piston and probably goes out the stinger as unburned fuel.. no good for emissions..... so could having a port in the piston below the rings on the exhaust side allowing this fuel to return into the area below the piston at the lower rpm be of benefit,:sherlock: if the pressure below the piston at that point is lower than the returning pressure wave from the exhaust wouldnt it just love to pour into that space...?? wouldnt we be in the area of diverging / converging areas. and whilst increasing speed of pressure flow not increasing bulk flow.( my interpertation of a previous post with info from wobbly).

Seems to make some sense to me, except Frits said looking in the exhaust port we wouldnt see anything unusual moving the piston top to bottom. I think thats what he said, but I am not sure, those little tidbits of info are spread out all over the place and my memory is not the best.

Also with HCCI and a lean mixture (I'd bet they use a lean mixture as well as exhaust and ultra retarded timing to make the HCCI work), any fuel air mixture that does not get put back into the cylinder or crankcase through the exhaust port might actually burn in the pipe. Might. If it does then emissions would still be good and fuel economy while not perfect would still be better than for a regular two stroke due to the recycling effect.

Even if this is not in the Ryger engine, I think it still has some merit, blow the motherload as directly as possible into the exhaust port through the cylinder then stuff it all back in somewhere, some into the cylinder and some into the crankcase, % of what goes where depends on rpm. Probably with this setup the regular size stinger could support 70 HP which seems to be what the Ryger is using.

Thing is at severe overrev nothing gets stuffed back into the crankcase but instead fuel air mixture gets pulled out of the crankcase into the exhaust. If there is enough raw fuel air mixture sitting in the port when the exhaust opens next time around it could light off and make the pipe work better by sort of exploding down the pipe reaching the converging cone sooner so the pipe sort of works at insane revs. Maybe there is a point of balance reached.

[mr bucketracer]

Regan, as a simple experiment, disconnect the balancer. See where that moves the vibration.we did , was better without it , good up stairs but mid range was ugly , just put it back in and took a pot luck guess at machineing meat of the weights, still vibrating but 50% better as a guess over what it was

[TZ350]

316960

My pick is that the balance shaft and crankshaft should each be 50% of the reciprocating mass (piston assembly plus upper conrod). So that at mid stroke the balance shaft and crank balance out each other and at TDC and BDC together they balance out a 100% of the reciprocating mass.

Early on Thomas demonstrated how to balance a single cylinder crankshaft. Some of the early posts below.


Looking at the connecting rod it is easy to see that the Big End goes round and round and is all rotating mass. And the little end goes up and down and is all reciprocating mass.


Pic-1 Find the weight of you're Reciprocating Mass.


Then Balance Factor C = A/B ........


The KISS method of balancing a single cylinder 2 or 4-stroke. Its all in the pictures:-

And a bit more to think about:


The percentages quoted are "mass".

The forces generated by the reciprocating mass increases linearly as a function of the rate of reciprocating.

The force generated by the rotating mass increases as a square of the rate of rotating.

Therefore, even though at standstill the rotating mass only exerts a force equal to say 60% of that exerted by the mass of the reciprocating parts, as the engine speed increases the forces generated by the rotating parts increases at a greater and greater rate and eventually equals the force being generated by the reciprocating parts. If engine speed continues to increase the forces generated by the rotating parts will exceed the forces generated by the reciprocating parts. The forces mathematically only equal each other at a single engine speed. We want that speed to be close to the operating speed.

On a single the forces at 90deg to the cylinder bore are unopposed regardless of the % used as there is no force generated by reciprocating parts to oppose them. 90deg V-twins are wonderful.


Reminds me of Phill Irvings comments on page 107 " It is quite useless to postulate any particular balance factor as being the ideal; so many considerations enter into the matter.............................do not be misled into rebalancing your engine just because one of your pals with an entirely different machine thinks he has some magic formula"

"Suck and See" seems to be a big part of getting the engine balancing right.

[husaberg]

we did , was better without it , good up stairs but mid range was ugly , just put it back in and took a pot luck guess at machineing meat of the weights, still vibrating but 50% better as a guess over what it was

Might be a good idea to take a squiz at the crank as well Scott.

[speedpro]

I've also found having the engine solidly mounted helped. My theory at the time was that the original slightly flexible engine mount allowed the engine to get a "buzz" going. When solidly mounted it couldn't get the whole bike "buzzing". As has been said there is no real slid magic % as there are lots of factors affecting the vibrations. You should be reducing counterbalance on both the crankshaft and the balance shaft. In the direction of piston travel the masses act in unison but at 90 degrees they counteract each other. If you remove mass from only one then you will be altering that counteraction which is at 90 degrees to piston travel. Irrespective of piston weight and rpm they probably should remain at about the same ratio.

[Frits Overmars]

Frits, if I remember correct you have made an own design of piston pin plugs, made out of PEEK may be? I'm looking for some plugs for my engine and would have access to (standard, means not GFK reinforced) PEEK but no good idea about the design. So if you allow me to ask you if you could give me an idea (or may be sell that idea :- ) )how that plugs would need to look like.For what engine, Jürgen? Jan Schäffer of Langtuning or Martijn Stehouwer of Emot might be able to supply you with the type of piston plug you need.
Re the material: it'd not PEEK. I wish; the stuff I finally found most suitable is a lot more expensive.
The pics show the plugs in a FOS-piston and a comparison of the Pankl RSA-piston pin and a FOS-plug.
316978316977316979

[41juergen]

For what engine, Jürgen? Jan Schäffer of Langtuning or Martijn Stehouwer of Emot might be able to supply you with the type of piston plug you need.
Re the material: it'd not PEEK. I wish; the stuff I finally found most suitable is a lot more expensive.
The pics show the plugs in a FOS-piston and a comparison of the Pankl RSA-piston pin and a FOS-plug.
316978316977316979

Thank's a lot Frits, will contact both. They are for a TZ250 4DP (the Vee 2 engine from 1995) with a 16mm diameter piston pin ....
Juergen

[jfn2]

hello 41juergen:
When you contact these people could you ask them what size they do make the plugs for and tell us? Thanks jfn2

[TZ350]

.

Yes, contact details for piston pin plugs would be very welcome.

[Moooools]

Hi Everyone,

I have seen a bit of the discussion around crank balance going on, so I got motivated to port my MATLAB balance script into excel to make it a bit more accessible.

So far the sheet is for a single cylinder without a balance shaft only.

It finds an optimum balance factor based on minimizing the difference between horizontal and vertical RMS crankshaft vibration.
I am definitely not sure if this is the right way to go about it but if you get a chance to play around with it then provide some feedback and I might be able to make some improvements.

It just needs piston weight, con-rod total weight, con-rod big end weight, con-rod length and stroke to make it go.
Things are explained slightly more in the spreadsheet.

Most of what I got out of it was shorter conrod = more required balance factor.

Have fun.

Follow this link and click' Download through your browser' (The file was too big for KB to handle at a whopping 4.2MB)

https://mega.nz/#!dY4SlDCA!Q59zSe1YnoXTnw1Q8mDBL-jGNHwrP1G_aWHpo228Zuk

[Sketchy_Racer]

Hi Everyone,

I have seen a bit of the discussion around crank balance going on, so I got motivated to port my MATLAB balance script into excel to make it a bit more accessible.

So far the sheet is for a single cylinder without a balance shaft only.

It finds an optimum balance factor based on minimizing the difference between horizontal and vertical RMS crankshaft vibration.
I am definitely not sure if this is the right way to go about it but if you get a chance to play around with it then provide some feedback and I might be able to make some improvements.

It just needs piston weight, con-rod total weight, con-rod big end weight, con-rod length and stroke to make it go.
Things are explained slightly more in the spreadsheet.

Most of what I got out of it was shorter conrod = more required balance factor.

Have fun.

Follow this link and click' Download through your browser' (The file was too big for KB to handle at a whopping 4.2MB)

https://mega.nz/#!dY4SlDCA!Q59zSe1YnoXTnw1Q8mDBL-jGNHwrP1G_aWHpo228Zuk

Hey Moools,

Cool work there. In regards to balancing, how did you go about doing the balancing on your 450? Not 2t sorry guys but still very interesting.

Did you manage to come up with a mathematical solution or was there a bit of fudge factor?

Cheers,

Sketchy

[Grumph]

Without going into the file can you tell me if there's a factor incorporated for cylinder inclination ?

[Moooools]

Hey Moools,

Cool work there. In regards to balancing, how did you go about doing the balancing on your 450? Not 2t sorry guys but still very interesting.

Did you manage to come up with a mathematical solution or was there a bit of fudge factor?

Cheers,

Sketchy

It was essentially this times 3. Each piston Conrod got added up separately and the crank was ignored (because the 4 cylinder crank is inherently balanced) the weight was modelled in a similar way to how I modelled the balance factor here.

So no fudge factor at all really. I took the numbers off of the screen and put it into the bike. The hard/fudgy bit was working out what numbers to use. On the 450 I used the crossover point between front view and top view RMS rotational vibrations. Came out to a 55% balance factor for the counterweight or something.


Without going into the file can you tell me if there's a factor incorporated for cylinder inclination ?

It assumes that 'vertical' is along the cylinder axis and 'horizontal' is perpendicular to that and also perpendicular to the crankshaft axis. The effects of gravity are not modelled as they are very, very small compared to the other things going on. So no matter which way up your engine is this model will work the same. I just use the terms horizontal and vertical for ease of communication.

[husaberg]

It assumes that 'vertical' is along the cylinder axis and 'horizontal' is perpendicular to that and also perpendicular to the crankshaft axis. The effects of gravity are not modelled as they are very, very small compared to the other things going on. So no matter which way up your engine is this model will work the same. I just use the terms horizontal and vertical for ease of communication.

What Grumph was trying to communicate is horizontal cylinder engines such as an old Honda step through and an Aermacchi vibrate in another plane altogether
The balance factors used on them are totally different altogether than a vertical cylinder. He has no doubt learnt this from experience.

[Moooools]

What Grumph was trying to communicate is horizontal cylinder engines such as an old Honda step through and an Aermacchi vibrate in another plane altogether
The balance factors used on them are totally different altogether than a vertical cylinder. He has no doubt learnt this from experience.

Well I didn't know about the different balance factors in those engines. Learn something new every day.

I can say with relative certainly however that this has nothing to do with the engine cylinder orientation alone. The forces due to gravity are just too small. My guess is that it is likely a lot more to do with how they were mounted to the bike, and interacted with the very bendy (in the vertical direction) chassis. It might have been better to sacrifice a bit of balance in the 'cylinder axis' direction in favour of balancing the the vertical (with respect to bike) forces, and reduce overall vibration within the engine-bike system.

[Flettner]

What Grumph was trying to communicate is horizontal cylinder engines such as an old Honda step through and an Aermacchi vibrate in another plane altogether
The balance factors used on them are totally different altogether than a vertical cylinder. He has no doubt learnt this from experience.

What you are saying is balance factor in a (non balance shaft) single is a compromise anyway, so you can either have the engine shake up and down or forward and aft OR a compromise of both. On a TT500 for example the shake is bias compromised forward and aft so although they seem relitively smooth at the handlebars they are in fact vibrating forward and aft a LOT.
In a lie down engine the compromise bias I guess would be the other way round, assuming it's running in a bike.

[husaberg]

Well I didn't know about the different balance factors in those engines. Learn something new every day.

I can say with relative certainly however that this has nothing to do with the engine cylinder orientation alone. The forces due to gravity are just too small. My guess is that it is likely a lot more to do with how they were mounted to the bike, and interacted with the very bendy (in the vertical direction) chassis. It might have been better to sacrifice a bit of balance in the 'cylinder axis' direction in favour of balancing the the vertical (with respect to bike) forces, and reduce overall vibration within the engine-bike system.
The chassis and the mounting and harmonics or resonance of the chassis and materials all play a part. Steel is a better damper than Aluminium for instance. but I believe its the direction of the vibes and how they are mitigated as why the Laydowns are balnced to different factors.



What you are saying is balance factor in a (non balance shaft) single is a compromise anyway, so you can either have the engine shake up and down or forward and aft OR a compromise of both. On a TT500 for example the shake is bias compromised forward and aft so although they seem relitively smooth at the handlebars they are in fact vibrating forward and aft a LOT.
In a lie down engine the compromise bias I guess would be the other way round, assuming it's running in a bike.

Correct my understanding is as well as the it being a compromise in regards to the rev at which the engine is static balanced to run at what is deemed by the rider as being acceptable.
The direction at which the vibrations occurred ie for or aft or up or down (and are balanced to mitigate) are also is important in how the vibrations are actually perceived by the rider.

[Moooools]

What you are saying is balance factor in a (non balance shaft) single is a compromise anyway, so you can either have the engine shake up and down or forward and aft OR a compromise of both. On a TT500 for example the shake is bias compromised forward and aft so although they seem relitively smooth at the handlebars they are in fact vibrating forward and aft a LOT.
In a lie down engine the compromise bias I guess would be the other way round, assuming it's running in a bike.

That is a nice explanation. I would presume that the stiffer your chassis gets (read: more modern) the more the balance shifts towards an outright compromise between fore-aft and up-down.





Correct my understanding is as well as the it being a compromise in regards to the rev at which the engine is static balanced to run at what is deemed by the rider as being acceptable.
The direction at which the vibrations occurred ie for or aft or up or down (and are balanced to mitigate) are also is important in how the vibrations are actually perceived by the rider.

I can understand the perception that engine balance changes through the RPM range given a set static balance. I think everybody has had a bike that shakes at X rpm. However all major engine vibrations increase with RPM^2. There is no change to the balance. The perceived change in balance through the RPM range is all a function of how the engine resonates with the chassis. By changing the compromise between fore-aft and and up-down vibrations with the balance factor, for instance, you might excite different frequencies in the chassis. A chassis might have a 100Hz natural frequency for and aft and a 200Hz natural frequency up and down. If you shifted the balance factor to produce more fore aft and less up down you might reduce excitement to the 200Hz chassis frequency and start exciting the 100Hz chassis frequency. It would then feel like the engine vibrates at low RPM, when in reality it is just the chassis vibrating at lower RPM.

[Tim Ey]

Hello everyone.
As discussing balancing factors at the moment is a thing:

I agree with Husa - different cylinder angle needs different balancing factors.
A friend of mine got used to this fact while mounting a rotax 100ccm kart engine horizontal. It nearly ribbed the bike to pieces. After rotating the Engine to standing Position, it ran pretty smooth.

I know an "old dog" Kart Tuner who says for a horizontal mounted cylinder, a Balancing Faktor of 20-35% might be the best option. From benchmarking serveral engines, also he knows that modern Motocyles like the Honda RS125 or some "Agriculture" 125cc Engines got the Factors around 66-74%

My questions:
1. How is a chainsaw ballanced? ;)
2. How do I balance a V2 Engine like the RS250? Do I deal with it like the cylinders are two single engines? I know that there are some forces which might be killing itself. Also I know where I have to read to get an scientific answer, but I wanted to know if anyone of you guys got experience with it.

Cheers
Tim

P.S.
Frits, do I read your drawing correctly - I do not see any clips in there?! Is only the Cap holding the wristpin in tis place? :eek5:

[husaberg]

Hello everyone.
As discussing balancing factors at the moment is a thing:

I agree with Husa - different cylinder angle needs different balancing factors.
A friend of mine got used to this fact while mounting a rotax 100ccm kart engine horizontal. It nearly ribbed the bike to pieces. After rotating the Engine to standing Position, it ran pretty smooth.

I know an "old dog" Kart Tuner who says for a horizontal mounted cylinder, a Balancing Faktor of 20-35% might be the best option. From benchmarking serveral engines, also he knows that modern Motocyles like the Honda RS125 or some "Agriculture" 125cc Engines got the Factors around 66-74%

My questions:
1. How is a chainsaw ballanced? ;)
2. How do I balance a V2 Engine like the RS250? Do I deal with it like the cylinders are two single engines? I know that there are some forces which might be killing itself. Also I know where I have to read to get an scientific answer, but I wanted to know if anyone of you guys got experience with it.

Cheers
Tim

P.S.
Frits, do I read your drawing correctly - I do not see any clips in there?! Is only the Cap holding the wristpin in tis place? :eek5:

I think the factors if we take both those figures you posted away from 100 percent there is a direct correlation with cylinder angle from vertical.
Hondas offset crankpins four stokes ie Hawk /Bros /Revere/Transalp used a simple formula which I wlll post it .....here tomorrow. That made them balanced like a 90 degree v twin
The two strokes whether V 2 or v4 also do as well I will post ......something tomorrow

[Frits Overmars]

I agree with Husa - different cylinder angle needs different balancing factors.So do I. Vibrations in the horizontal plane (i.e. in the riding direction) are much less annoying to the rider than vertical vibrations, so engines with a horizontal cylinder get a balance factor of less than 50%; 30% may be a good value. Engines with vertical cylinders get about 60%. But these factors also depend on frame stiffness.
For example a kart chassis is about as stiff as a wet newspaper in the vertical direction, so kart engines get about 70% balance factor to minimize the vertical vibrations.
Note: all of the above is null and void for engines with a balance shaft.


How do I balance a V2 Engine like the RS250? Do I deal with it like the cylinders are two single engines?More or less; you treat a 90° V-2 like two single cylinder engines that were both equiped with a balance shaft.


Frits, do I read your drawing correctly - I do not see any clips in there?! Is only the Cap holding the wristpin in tis place?That's right. It saves some weight. But it requires that the caps' protrusions are precisely matched to the clip grooves in the piston.
In the past people have fitted caps that were designed for a Vertex piston, in a Kreidler piston. The wrist pin diameters were the same but the clip grooves weren't,
so a cap worked loose. The material of the cap is such that the cap could disappear without doing any harm to the piston or the cylinder, but then the wrist pin started moving sideways, damaging the cylinder.

[Haufen]

How do you remove those caps? Can they be re-used?

[JanBros]

1. How is a chainsaw ballanced? ;)


as a chainsaw is only supposd to run at max rpm or very close to it, it's pretty straightforward I would say : balance it so that it vibrtas the least at (close to) max rpm. all the other rev's do not matter much.

[Frits Overmars]

How do you remove those caps? Can they be re-used?The decent way would be to blow the first one out using compressed air but you can also pry it out with an awl; the second one is easily pushed out from the inside with a screwdriver through the wrist pin. They are re-usable.

[AndreasL]

Thanks for the link and your work Moooools.

One thing though...

Wouldn't it be more convenient if the small end of the con rod was the one to be weighted?
This is a easy thing to measure with the crank still put together. Big end is not...

Maybe I have got it all wrong and if so, dont put any attention to this post. ;)

I really need to sit down and see if I can get the effect of the cylinder angle in to excel.
Would be nice to have.

Maybe not exactly the same thing but any way...
TZ did some very good work documenting the process starting at page #70.
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1129264719#post1129264719

[Grumph]

Finally got back to this thread to see the talk about balancing. Yes, i asked because of personal experience. Horizontal cylinders in my experience require the reciprocal balance factor of those which are vertical. Aermacchis use around 25% Vs an upright single which is usually in the 65-75% range.

I disagree with Frits - vibration in the vertical plane is usually more acceptable to a rider (motorcycle not kart..) The figures talked about will give just this.
The only big engine i have experience with that broke this rule is the TR1 Yamaha 1000cc V twin. On checking the balance factor on it, it's down below 50% hence shakes fore and aft. On the road this translates to an odd "stretching out under you" feeling remarked on in period road tests.

So Mooloos, I'd build in a question to your data input - above or below an inclination angle of 45 degrees...And adjust the end result to reflect that.

But yes, there's still an awful lot of suck it and see involved....

[wobbly]

Sorry Grumph but your figures ( correctly ) directly contradict what you are saying about rider perception.
A Norton Manx is balanced to 80% as this extra bob mass reduces the vertical shake at the bars by opposing the piston inertia force
in the plane of the cylinder axis.
A kart engine is around 70% as this again reduces the vertical buzz that the frame cannot resist.
A horizontal cylinder needs only 35% as this generates more for and aft shake the rider does not sense as bad vibes at the bars.
The angled cylinders on say a RZ or TZ need high 50 % as they have a shake vectors in both planes and need cancellation for both
cylinder axes components - then the added complexity of having 100% primary cancellation in the cylinder vertical plane is ruined by
the addition of a rocking couple along the same axis.
The rocking couple is the same as the secondaries, nothing can be done to ameliorate them, apart from a balance shaft.
So - the numbers all indicate the need to reduce the vertical component of any out of balance forces, as it is this that a humans senses detest most.
If you read my analysis ( a personal fail of the first order ) of an RZ running at 90* phasing ( in Oddball Engines ) , and translate this into an even fire TZ750 the effects are the same.

Just to add another note on vibrating up and down,here are next years signings for Yamaha MotoGP

[Grumph]

We may have to agree to disagree, Empirically, the horizontal singles balanced to less than 50% still vibrate in a vertical plane - ie at right angles to the cylinder axis. If you balanced a manx to the same factor, I'd pick it would be very unpleasant cos it would shake at right angles to the cylinder axis - fore and aft. Which the mounts aren't designed for...
The reason for upright singles being around 65-75% for road motors is because historically this was the best compromise with the modified bicycle frames they had.
i'm not going to go to the guillotine for my opinions. lol. i'm quite prepared to be shouted down by those with the experience to argue.

[Lightbulb]

Frits,
Some where on the Kiwi biker you mentioned about the way a high speed
engine runs with very little acceleration from the tdc to ex opening,
but that the remaining piston momentum from ex open to bdc is where
energy is put into the stroke cycle.
Have you done or do you have any information about rotational
acceleration of 2 stroke single cylinder engines ?
What is the difference between an engine having about 192 deg of exhaust
timing compared to an engine with 196 deg exhaust timing for making top
end power?
I am asking these, as I have an old 1992 2.5 cc engine. It can turn the
same prop my 2011 engine does, but but will run 1100 rpm more. Working
backwards, the 2011 engine at 39000 to 39100 is about right for the pipe
length and 192 deg exhaust timing. The 1992 engine, turns that prop at
40200, but because of the 195.4 deg, should be doing about 39750 rpm
with it's pipe. The older engine is running 450 rpm in the over rev
situation.
If I have a hall effect sensor, am I likely to see something between the
two different engines, ?
Will I be able to see a loaded engine state and an under loaded engine
state if I recorded these and graphed the rotation from 4 points ?
Lots of questions I know,
Thanks for your time and input.
Neil

[wobbly]

Grumph - For fucks sake what drugs are you on " in a vertical plane - ie at right angles to the cylinder axis ".
A Norton Manx cylinder is vertical, the cylinder axis is therefore vertical - you get free blowys for life as well if I am wrong.
These are balanced at 80% - ask Ken McIntosh.
This reduces the vertical shake by opposing the piston ( vertical ) inertia forces, and stops the bars from shaking up and down.
Its like being a Greeny, how the hell can you save the planet when you are off it most of the time.

And in answer to Neils question about the piston acceleration from TDC to EPO.
Frits analysis was based on an a calculation with an error of over a factor of 2 regarding peak cylinder pressure in the Aprilia.
I certainly dont want to even begin to second guess, or criticize Frits in public, but the assumptions leading from this error are plainly wrong
as i alluded to previously in this thread.

The answer re EPO is that down at 190 we have huge superposition that allows a very wide band of usable torque production.
But ultimately this approach finally runs into good old physics, and is simply incapable of generating sufficient blowdown to even begin to approach
the peak numbers able to be generated at 200*.
BUT - To make this scenario work over a usable broad band every trick in the bag is needed, a servo PV and PWM powerjet along with digital ignition enabled spark retard.
All the things you dont have.

[Moooools]

So Mooloos, I'd build in a question to your data input - above or below an inclination angle of 45 degrees...And adjust the end result to reflect that.

But yes, there's still an awful lot of suck it and see involved....

Hmmm, the outputs would be a bit too subjective I think. I will get a plot going of horizontal vs Vertical vibrations so that you can correlate an existing engine vibration 'feel' to a ratio between vertical and horizontal vibrations.

Will do a balance shaft too. But have to get through a few exams first. Unfortunately balancing only takes up 5 pages of content out of 300 or so in my next exam so not much of an excuse to keep working on the spreadsheet.

[Grumph]

Grumph - For fucks sake what drugs are you on " in a vertical plane - ie at right angles to the cylinder axis ".
A Norton Manx cylinder is vertical, the cylinder axis is therefore vertical - you get free blowys for life as well if I am wrong.
These are balanced at 80% - ask Ken McIntosh.
This reduces the vertical shake by opposing the piston ( vertical ) inertia forces, and stops the bars from shaking up and down.
Its like being a Greeny, how the hell can you save the planet when you are off it most of the time.


While I have ridden bikes where the balance was so bad you were off the planet most of the time, i don't think you saw the point i was making.
I said, if you balanced a manx (upright cylinder) to the same factor as a horizontal cylinder motor, it would shake at right angles to the cylinder axis...IE fore and aft. i can tell you as fact that a horizontal single balanced to 25% still has a vertical (in relation to the ground, ie at right angles to the cylinder axis) vibration. The trick is getting it to an acceptable level - as is the case with whatever cylinder configuration you choose to use.
I'm well aware of the factor Ken uses as i've discussed more than one of Kens cranks with Barry Lynch here who has done a few....

I'm out of this argument. carry on.

Edit - If sammy miller ever brings the F model Horizontal single manx out here, we must ask him what the balance factor is....and if he wants a blowy...

[Flettner]

as a chainsaw is only supposd to run at max rpm or very close to it, it's pretty straightforward I would say : balance it so that it vibrtas the least at (close to) max rpm. all the other rev's do not matter much.

I think with chainsaws they just rubber/spring mount them (from the handle) as much as possible. You know, just let the bugger shake!

[mr bucketracer]

i must ask brian thomas

[husaberg]

I think with chainsaws they just rubber/spring mount them (from the handle) as much as possible. You know, just let the bugger shake!

Back in the old days before the antivides there was a fair few people who lost fingers from the saws not from the chain but from the vibration destroying the blood supply to the fingers they used to call it white finger or wimpy fist.
People operating Jack hammers used to get it as well but those things were at least designed to vibrate.
https://en.wikipedia.org/wiki/Vibration_white_finger
http://www.sticksite.com/raynauds/whitefingers.jpg

[wobbly]

Sure thing, you are out, but the bottom line is that vertical shake reduction really is the aim of the balance factor
chosen to work with the chassis natural resonance.
Saying vertical shake is a non issue is simply bollocks.
And in all cases of a near vertical cylinder this necessitates a highly overbalanced crankshaft ( around 80% Manx, less for a "road " single ) to nullify the vertical component.
You disagreed with Frits on this and I am fully defending his assertions.
So I have now also disagreed with him about his graphical analysis of rod force resultants, due to combustion pressure magnitude Vs mechanical inertial forces.
Im cringing awaiting the sky falling in on my head.

[steamroller]

Sure thing, you are out, but the bottom line is that vertical shake reduction really is the aim of the balance factor
chosen to work with the chassis natural resonance.
Saying vertical shake is a non issue is simply bollocks.
And in all cases of a near vertical cylinder this necessitates a highly overbalanced crankshaft ( around 80% Manx, less for a "road " single ) to nullify the vertical component.
You disagreed with Frits on this and I am fully defending his assertions.
So I have now also disagreed with him about his graphical analysis of rod force resultants, due to combustion pressure magnitude Vs mechanical inertial forces.
Im cringing awaiting the sky falling in on my head.

Time for your pills i hope that brings you back down to earth

[TZ350]

Page 1360 ....

Some of the F5 50's that people have built.


14.6 is the most i'v heard off , dave is a master

Team ESE have dynoed a few 50's when I can find the original posts I will paste them below.

Fixer 13.6 hp


The ESE boys might have only half a clue, but it's a good half. And they have a functioning dyno now. With the addition of a small aluminium plate to raise the barrel, a small mod to the exhaust manifold and a little fiddling with the ignition timing, my Aprilia RS50 with it's Conti pipe and Doppler top end has gone from 10hp to 13.6hp. Woo hoo! Evidence below:

297225

Cotswald touching 14



Thanks Tee Zee for letting me put the 50 on your Dyno, ... happy with the nearly 14, could you post the graph for me as I forgot to take a photo in my haste to get home and strip the bee atch.
Sure,

310162

There you go.

Gigglebutton ... Av gas Red line, NOS Blue line.


237930237929

After a bit of a thrash on the dyno....... Red is the old curve, Blue new.
Well worth the hours worked on it. Next step a better ignition. Thanks guys

Buckets4me 14hp


288388 288389

There are a few F5 projects on the go, this is Buckets4me and his RG50. And as far as the Team goes, his pretty much sets the bench mark.

NedKellys 12hp


NedKellys 50.
294606294602

11.0 red line is Ex opens 87 deg atdc duration 186 deg and Frits pipe.
12.0 blue line Ex opens 81 deg atdc duration 186 deg and Fritz pipe.

And a very clever F4 bike.

<iframe width="560" height="315" src="https://www.youtube.com/embed/tCxZ6YYAcao" frameborder="0" allowfullscreen=""></iframe>


Big day today bike is running up real nice . Would like to thank all gpr boys for this build really nice work :yes:

317224

I very much admire the work that has gone into this bike and engine.



Check with TZ, so long as the results are posted on KB he always seems happy to run the dyno (DynoJet) for a 2T Bucket.We will bring it would be good to see what it's at riding it i think it will be round 25 at this stage just don't want it to blow to bits

If you are bringing it up for the 2 hour I would be very happy to help you run it up on the dyno.

Below are post links to some of the development work done making the cylinder for this very clever bike.

You will have to click on the link to view the whole post and pictures, they are worth a look.


... hope to have it running in the next week or so.
315108315109315110


Barrel and sleeve together, Head needs a spark plug tap put down it and then adjusted for height.


Mostly milled till I got to the angled fins, then I just cut them out on the bandsaw for that classic GPR homebuilt look...


Meanwhile... Sleeve has sprouted wings.


Yep folks, still a happening thing, and I can see an end in sight now too.


Latest developments are 6 fins, these will snap fit into grooves machined around the barrel for good engagement. Then welded down the fins seam, or welded to the exhaust port, depending on their placement.


We are having a crack at a two stroke conversion GPR125.

[husaberg]

Here is the Honda formula used on the narrow angle twins ie Bros and so forth.
Honda incorporated this split-crankpin technique in both the VT-series and in the RS750 dirt-track racing engine, Bros, Hawk GT, Steed, Africa twin. and so forth.
In order to find the correct crankpin offset angle, we subtract twice the cylinder vee angle from 180.
Thus, in the case of a 52-degree vee angle Bros , we subtract (2 X 52) = 104 from 180 to get a 76-degree angle between the two offset crankpins.
317024317022317023

The 45 degree V angle one is this 90 degrees offset.
317021

[ken seeber]

Frits,
Some where on the Kiwi biker you mentioned about the way a high speed
engine runs with very little acceleration from the tdc to ex opening,
but that the remaining piston momentum from ex open to bdc is where
energy is put into the stroke cycle.
Have you done or do you have any information about rotational
acceleration of 2 stroke single cylinder engines ?
If I have a hall effect sensor, am I likely to see something between the
two different engines, ?
Will I be able to see a loaded engine state and an under loaded engine
state if I recorded these and graphed the rotation from 4 points ?
Neil

Neil,
I think you a referring to the effect of crankshaft cyclic speed change and the possible effect on the true openings and durations. Not to sure about a Hall effect sensor, but an optical type might be more suitable. Well out of my knowledge in this area. At Orbital we used to mount a 360 T encoder wheel, say around dia 300) on the crank, triggered with a RS optical sensor, for in-cycle data logging. To me, I think that if you were to compare the crank position vs time over a single rotation, one would need this number of teeth to give sufficient resolution, plus of course a suitable storage oscilloscope or acquisition system. With this info, one could then compare the EO, TO event tgimings to the crank position. Then it might be that a 192 deg duration might be less or more than this value.
One key thing though, is the inertia of the crank and associated rotating bits eg flywheel, or in your case, the prop. An infinite flywheel would show no cyclic speed variation. This raises the question as to whether the engine actually run with an infinite flywheel.

Piston plugs. Here is a pic of a type that we have made. Not a body of revolution, but one shaped(3D) to the adjacent skirt profile, therefore requiring indexing. This used a material more expensive than PEEK. Results of this type have been shown previously in this thread, with good results. Surface finish looks so shitty in the pic, but it was done on a manual in a special fixture......I'll call them oil retention grooves. :weird:

317029

[wobbly]

OK I have taken the meds, but anyone trying to get past me saying vertical vibes are a non issue is dreaming.
Same as the last time I went off when someone tried to assert "we dont have time to blip the downchange in a bucket ".
The response then ,as it is now, bullshit.

[seymour14]

Best thing about this world is no two people do the same things, if we did. what a boring shithole we would live in.

We'll stick to winning, there's plenty else you lot can do...:innocent:

[mr bucketracer]

OK I have taken the meds, but anyone trying to get past me saying vertical vibes are a non issue is dreaming.
Same as the last time I went off when someone tried to assert "we dont have time to blip the downchange in a bucket ".
The response then ,as it is now, bullshit.here we go again:violin:

[lodgernz]

Here is the Honda formula used on the narrow angle twins ie Bros and so forth.
Honda incorporated this split-crankpin technique in both the VT-series and in the RS750 dirt-track racing engine, Bros, Hawk GT, Steed, Africa twin. and so forth.
In order to find the correct crankpin offset angle, we subtract twice the cylinder vee angle from 180.
Thus, in the case of a 52-degree vee angle Bros , we subtract (2 X 52) = 104 from 180 to get a 76-degree angle between the two offset crankpins.
317024317022317023

The 45 degree V angle one is this 90 degrees offset.
317021

Interesting. If I remember correctly, Phil Irving said somewhere many many years ago that 76* was the perfect angle for a V-twin.

[FastFred]

We'll stick to winning, there's plenty else you lot can do...:innocent:

317033

Its all about winning, you Morons!

317035

Ok, so there can only be one winner, but lots of us can Party and you are invited ..... :D

317034

Party - Party well at least a few beers with friends anyway.

[wobbly]

Winning, its great.
Especially when you go pole, win 5 of 5 and are nearly 2 secs a lap faster than the whole field.
Dennis Sharlett on my TZ400 destroying the Pre 82 field and the lap record ( along with pre 89 F3 ) at the Shorai.

[seymour14]

Winning, its great.
Especially when you go pole, win 5 of 5 and are nearly 2 secs a lap faster than the whole field.
Dennis Sharlett on my TZ400 destroying the Pre 82 field and the lap record ( along with pre 89 F3 ) at the Shorai.

Good on Dennis.

Were you in the sidecar?

[steamroller]

OK I have taken the meds, but anyone trying to get past me saying vertical vibes are a non issue is dreaming.
Same as the last time I went off when someone tried to assert "we dont have time to blip the downchange in a bucket ".
The response then ,as it is now, bullshit.

HA HA the only thing that blips is your big head. what did you say about any thing around 30 hp at 10500 rpm you would suck them off :killingme time to pay up boy

[wobbly]

So smartarse show us the dyno chart showing an aircooled 125 making anything like that power at 10500.
And no I wasnt in the sidecar I was in the pit tuning the thing.

[seymour14]

So smartarse show us the dyno chart showing an aircooled 125 making anything like that power at 10500.
And no I wasnt in the sidecar I was in the pit tuning the thing.

Good for you, but don't take credit for others ability to win because of their talents.

Dennis also rode a bike at Greymouth last year with an engine that we helped to build, and won all three races. We don't claim those as our own.

If I was too, I could bleat on about world titles and national titles as well, but most of us on these forums could say the same also.

I come in here to try and glean some knowledge, but most the time I see write ups that just sound like team talk up, so end up having to try and solve it ourselves.

My advice to this thread is to start talking in common language, preferably English, and speak laymens terms. Most of us are doers, not talkers.

[mr bucketracer]

Good for you, but don't take credit for others ability to win because of their talents.

Dennis also rode a bike at Greymouth last year with an engine that we helped to build, and won all three races. We don't claim those as our own.

If I was too, I could bleat on about world titles and national titles as well, but most of us on these forums could say the same also.

I come in here to try and glean some knowledge, but most the time I see write ups that just sound like team talk up, so end up having to try and solve it ourselves.

My advice to this thread is to start talking in common language, preferably English, and speak laymens terms. Most of us are doers, not talkers.this is the new Zealand way , well said

[steamroller]

So smartarse show us the dyno chart showing an aircooled 125 making anything like that power at 10500.
And no I wasnt in the sidecar I was in the pit tuning the thing.

How are your 117 hp 400cc 2t going thats right they only made 98 and would not last a day on the track great job .

[wobbly]

Still no 30 Hp @ 10500 dyno chart for a 125, and not one statement of of facts about the 400 correct.
Sadly I wont be back to pass on any of my big headed knowledge as its obviously all wrong.
See ya.

[TALLIS]

Still no 30 Hp @ 10500 dyno chart for a 125, and not one statement of of facts about the 400 correct.
Sadly I wont be back to pass on any of my big headed knowledge as its obviously all wrong.
See ya.

Hmmm... seems to think he can dish it out but not take it. Funny that, people who are always right aye.

[steamroller]

Still no 30 Hp @ 10500 dyno chart for a 125, and not one statement of of facts about the 400 correct.
Sadly I wont be back to pass on any of my big headed knowledge as its obviously all wrong.
See ya.

can give it but can not take it a

[FastFred]

317038

Hey guys, this is not the thread.

[kel]

show us the dyno chart showing an aircooled 125 making anything like that power at 10500.

Can we clarify what "anything like" actually means. On second thoughts please don't, we are already at 28hp at 10.5 and don't want to stop development. Im not sure I could sleep at night knowing you might turn up at the door wanting to honour your offer.

So steamy - you're up here this month for the 2hr, bring the aircooler with you, we all want to see what it can deliver on the dyno

[FastFred]

Check with TZ, so long as the results are posted on KB he always seems happy to run the dyno (DynoJet) for a 2T Bucket.

[seymour14]

Can we clarify what "anything like" actually means. On second thoughts please don't, we are already at 28hp at 10.5 and don't want to stop development. Im not sure I could sleep at night knowing you might turn up at the door wanting to honour your offer.

So steamy - you're up here this month for the 2hr, bring the aircooler with you, we all want to see what it can deliver on the dyno

Cheers guys, I think the boys would like that. Two hours on a bucket, hell, I could barely last one at the BOB! You must be Supermen!!

[steamroller]

Check with TZ, so long as the results are posted on KB he always seems happy to run the dyno (DynoJet) for a 2T Bucket.

We will bring it would be good to see what it's at ridding it i think it will be round25 at this stage just don't want it to blow to bits

[peewee]

thought some people might be interested in these cylinders im working on. frits i know you liked them yamahas :laugh:. im not sure what the hell the person who designed this casting was thinking as you can see the exh bottom is low and wide so ill correct that while im at it. the C seems to be tilted farther forward than what ive seen before. its angled forward 45* from the rear cylinder wall. is this normal practice nowdays ? i miscalculated on this first cap so ill have to make a new one then trace it on some paper and trace that on some tube and cut 3 more.

[peewee]

wouldnt let me put more than six photos

[mr bucketracer]

How are your 117 hp 400cc 2t going thats right they only made 98 and would not last a day on the track great job .like wobble said you got it wrong , made 96 in the end:baby:

[2T Institute]

thought some people might be interested in these cylinders im working on. frits i know you liked them yamahas :laugh:. im not sure what the hell the person who designed this casting was thinking as you can see the exh bottom is low and wide so ill correct that while im at it. the C seems to be tilted farther forward than what ive seen before. its angled forward 45* from the rear cylinder wall. is this normal practice nowdays ? i miscalculated on this first cap so ill have to make a new one then trace it on some paper and trace that on some tube and cut 3 more.

What on earth you doing to those poor athena cylinders:lol: The exhaust port needs lowering on those badly to say they are 'peaky' is an under statement but they don't need help making hp 421cc is over 90hp with those

[husaberg]

Interesting. If I remember correctly, Phil Irving said somewhere many many years ago that 76* was the perfect angle for a V-twin.
76 in the Honda case was just a co-incidence to do with the 52 degree v angle.
Irvings formula /Theory something I think to do with Max velocity of the other piston rather than just mid stroke. I posted an article way way back. A few Triumphs and so forth have been done at 76 degrees. The jury's out on whether its better or the same than a 90/270 set up, but its still far better than a 360 set up anyway.
I will see how good the Kiwibiker search function is and see if I can find it. (I did)317050

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130144843&highlight=degree#post1130144843

here is a few balancing links on stuff already posted on KB
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130833549&highlight=phil+irving#post1130833549
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130142401&highlight=phil+irving#post1130142401

[peewee]

theyre not athenas but i believe theyre loosely based on that casting. the timings are low. around 182/122 i think but i havent checked yet. these are also sitting at 65mm bore right now but ill probly have to go to 65.5 so theyll straighten up. athena bores start at 68mm i believe. i believe theres a few other differences also. now if i could get them around 100hp with methanol i would feel all the effort was worth it. totall cc will be around 391-397 depending how the bore cleans up

[TZ350]

thought some people might be interested in these cylinders I am working on.

Good work, great to see the development as it progresses.

[peewee]

i think most people were only getting power somewhere in the 80's range with them cylinders on a +4 crank but i think i can do better. ill give it a hell of a shot anyways

[Lightbulb]

Thanks Ken and wobb for the input and thoughts.
We did a test today with a single hall effect sensor, and a micro data logger.
We used a 1 mhz timer,and a 64 mhz processor,writing to a micro sd card,
writing at 500kB/sec
The engine is a 2.5 cc Profi glow plug engine with a tuned pipe, on a bench run.
So the result was showing the engine running at 39100 rpm on a 100 cycle average.
However, looking at each individual cycle, there is a variation in some at only 30 rpm difference,
while others are at 400 rpm difference per cycle and oscillating up and down a little.
While some have a 400 change,then it seems stable for like about 6 or so then a big decline ,
then semi stable again, then another jump etc.
Is it possible that these variances are just due the nature of model glow plug engines and the inconsistency
of the very crude carb that it has.?

Here is a picture of the sort of thing I am talking about. This is during the what seemed to be a stable part of the run from a regular model optical tacho from the prop.
The second picture shows the starter turning over at about 6k then the glow plug driver is connected and showing the start of the engine itself.

[41juergen]

So I got a feedback from Martijn as well as from a colleague of Jan. Conclusion is for small displacements like the 50cc the plugs work for a racing setup, means some (low) risk that they may come loose during the race. But for bigger piston pins like in a 125cc cylinder they don't recommend to use these as they might fail. Frits can you confirm that?
So may be two other ways to do that:
a) Ken's proposal looks promising to me, would you share / sell these? :-)
b) weld some end caps onto the piston pin, may be via laser welding. But Martijn mentioned that the welding material is crucial (people reported the caps were falling off).
Juergen

[Frits Overmars]

for bigger piston pins like in a 125cc cylinder they don't recommend to use these as they might fail. Frits can you confirm that?No I can't, and I don't remember either Martijn or Jan using 125 cc-size plugs.


...weld some end caps onto the piston pin, may be via laser welding.Like the Pankl welded pins used by Aprilia, shown in my picture on page 1357. But they were hideously expensive; fitting and removing the clips wasn't easy, and they did not really form a closed piston surface.

[tjbw]

76 in the Honda case was just a co-incidence to do with the 52 degree v angle.
Irvings formula /Theory something I think to do with Max velocity of the other piston rather than just mid stroke. I posted an article way way back. A few Triumphs and so forth have been done at 76 degrees. The jury's out on whether its better or the same than a 90/270 set up, but its still far better than a 360 set up anyway.
I will see how good the Kiwibiker search function is and see if I can find it. (I did)317050

That's a doc by Brian Whooley?

Here's "Vic Willoughby's view on 90° rephased crank": http://www.xs650.org.au/Technical%20Info/smoothness.htm

Some other info on that Yamaha XS650 club site, including http://www.xs650.org.au/Technical%20Info/vtwin.html (this may already be here on KB)
Also, http://www.xs650.org.au/Downloads/Downloads.htm simple engine vibration model (needs Java)

[lodgernz]

76 in the Honda case was just a co-incidence to do with the 52 degree v angle.
Irvings formula /Theory something I think to do with Max velocity of the other piston rather than just mid stroke. I posted an article way way back. A few Triumphs and so forth have been done at 76 degrees. The jury's out on whether its better or the same than a 90/270 set up, but its still far better than a 360 set up anyway.
I will see how good the Kiwibiker search function is and see if I can find it. (I did)317050


Ah, that's right, thanks Husa. Irving's article was about parallel twins, not V-twins. Like George Bush, I "mis-remembered"...

[ken seeber]

Thanks Ken and wobb for the input and thoughts.
We did a test today with a single hall effect sensor, and a micro data logger.
We used a 1 mhz timer,and a 64 mhz processor,writing to a micro sd card,
writing at 500kB/sec

Neil,
Not sure what your plots indicate other than there are overall engine speed variations with time.
I was trying to make the point, and I think this is what you were alluding to, that over a crank cycle, the engine will not run at a constant speed, but it will speed up and slow down thru the cycle. This being the case, the port durations, whilst maintaining a constant number of degrees, will in fact vary in time, due to the cyclic speed variation.
A couple of numbers: At 39,000 rpm, the crank rotates 650 times per sec, ie a rotation takes 0.0015 sec.
If, as I suggested earlier, one had a 360 T encoder wheel and this signal was logged against time, one could have three (or more really) basic scenarios. (Note the 360T is a bit arbitrary, but something I am familiar with, and could be less (less accuracy) or more (more accuracy). I guess it somewhat depends on the capacity of your acquisition system.) See the attached sketch.

317067

One can see, exaggerated, the different scenarios, and the effect on port durations. Could turn out to be ¾ of 5/8 of stuff all, but would be interesting to know. The key variable I think, being crank inertia.

[FastFred]

317068

Spied at Team ESE Headquarters, the home of "The House of Speed" and other interesting Bucket racing stuff.

This soon to be a race bike was addressed awaiting pickup by Bike-Trans for delivery to another part of the country. Where its reported that the new owner is going to work some magic on it. 70cc turbocharged maybe.

[TZ350]

317071

For those that want to try stroking their motor, you could have a custom pin made by Worb5 http://www.worb5.com/vespa_lambretta_scooter_tuning_EN/crankshaft_conrod_bigend_smallend_crankpin_fillcir .html

[husaberg]

Ah, that's right, thanks Husa. Irving's article was about parallel twins, not V-twins. Like George Bush, I "mis-remembered"...

A guy in Aussie built one into a triumph I guess that was what Brian Wolley was replying to. I don't have the article as its at my olds.
The 90 degree crank might be better but the 76 is still better than the 360 crank anyway.
reading the article it seems Irving's calculations made an assumption about the rod length being twice the stroke anyway.


That's a doc by Brian Whooley?

Here's "Vic Willoughby's view on 90° rephased crank": http://www.xs650.org.au/Technical%20Info/smoothness.htm

Some other info on that Yamaha XS650 club site, including http://www.xs650.org.au/Technical%20Info/vtwin.html (this may already be here on KB)
Also, http://www.xs650.org.au/Downloads/Downloads.htm simple engine vibration model (needs Java)

Yeah I linked a few somewhere
From memory it was a reply to and article where a guy had done a 76 degree crank where Irving theory was quoted by Woolley.

[richban]

317068

Spied at Team ESE Headquarters, the home of "The House of Speed" and other interesting Bucket racing stuff.

This soon to be a race bike was addressed awaiting pickup by Bike-Trans for delivery to another part of the country. Where its reported that the new owner is going to work some magic on it. 70cc turbocharged maybe.

Hey what the what! That is my new secret 50 project. Well not really secret. Kindly picked up by TZ for me. Yes as I no longer own a 4 stroke bike my 2 stroke addiction is complete. A 50 A 125 and A 300. The plan for the 50 is hp. I really want to get stuck in and get it going well. Should be fun. I will start with a FOS pipe and simple mods and see where that leads me. What I am not sure about is the best exhaust duration for the 50. Anyway can't wait.

[Tim Ey]

317071

For those that want to try stroking their motor, you could have a custom pin made by Worb5 http://www.worb5.com/vespa_lambretta_scooter_tuning_EN/crankshaft_conrod_bigend_smallend_crankpin_fillcir .html

I know two guys who made bad experiences with the worb5 excenter stuff...
both wanted to reduce stroke, but they mounted the excenter the wrong way...
If you buy them, dont let them fit your crank :-)

[41juergen]

Thank's for the feedback Frits.

So Ken would you sell us your idea? :yes:

[husaberg]

Thank's for the feedback Frits.

So Ken would you sell us your idea? :yes:

Howard Gifford Pitlane part two
http://www.pit-lane.biz/t3173p740-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-2-locked


It is no secret what to use. DuPont makes a product called Vespel SP. I have used it and it works quite well at temperatures up to 500 degrees F and yes sir it is super expensive. SP-22 is the material of choice for pin plugs in that it has a thermal expansion rate that is identical to that of cast aluminum.
[Vous devez être inscrit et connecté pour voir ce lien]
Dernière édition par Howard Gifford le Jeu 10 Jan 2013 - 8:46, édité 1 fois


At the price DuPont charges for even a small sample piece I doubt you will sell much of it at a profit. If anyone wants any plugs made I can make a limited amount but at around $120.00 a plug I doubt anyone will be beating on my door with orders.
By the way I have a mint condition 1990 944 Turbo for sale Frits if your'e interested


Jan I will let you know how they stand up in a race situation. They seem quite good on the dyno but we do not do sustained runs on the dyno so I will find out shortly . I havent seen any big gains on the dyno either but with our auxillary exhaust communicatinbg with the transfewrs at tdc you would think that they can only help.
I tried machining two pieces out of aluminum that were bolted together by an allen screw. They had a locator pin and were curved on the belt sander to match the profile of the piston. They worked well also but they were heavier than I liked. The Vespel plugs weigh 4 grams each so weight is not a concern. I just wish I could give them a proper test on the track before I determine weather they are worth the bother.
Yes the cost is silly for the material and they are difficult to hold properly to machine so Im hoping they will become unnecessary. Especially since Frits promised to come to Canada to wring out some more «hp out of my motor.

This is his FB page
https://www.facebook.com/people/Gifford-Brothers-Hydroformed-Pipes/100004979745390



Jan Thiel Pitlane aluminium piston pin plugs

Yes, we tried that, and it worked.
First the pin was honed on the inside, and a piece of aluminium was pressed in.
The pin expanded a bit through the pressing-in.So we fitted smaller needles. Then it worked quite well, but it was a bit heavy.
We also tried magnesium, but that worked loose.
Then welding the pin was tried, that was lighter.
But sometimes there were reliability problems, the welded-on caps came loose.This caused massive engine failure.
Finally we had our pins made by Pankl in Austria. These were 100% reliable.


these guys I am pretty sure did the plastic ford engine.
http://www.solvay.com/en/media/press_releases/20150518-Polimotor.html
317086


Mr. Holtzberg’s efforts to change that can be traced at least to 1969. Reading a magazine article at the public library in Hackensack, N.J., he learned of a new plastic said to be tough enough to withstand the harsh conditions inside engines. He obtained a sample, made a piston with it and installed it in the engine of a friend’s Austin Mini.
The plastic piston lasted 20 minutes.

Mr. Holtzberg pressed on. During the 1970s, he made and sold plastic pistons — now with aluminum crowns to withstand the heat inside the cylinders — and connecting rods to racers. In 1979, he founded Polimotor — shorthand for polymer motor — to develop a plastic-intensive engine.

The first Polimotor, a clone of the Ford Pinto 2.3-liter 4-cylinder, used plastic for the block, piston skirts, connecting rods, oil pan and most of the cylinder head. Bore surfaces, piston crowns and combustion-chamber liners were iron or aluminum. The crankshaft and camshaft were standard metal components.

Shortly after Mr. Holtzberg’s first engine successfully ran, an article in Automotive Industries, a trade magazine, inquired, “What...a Plastic Engine?” Two years later, Popular Science featured a Polimotor on its cover. By then, Mr. Holtzberg had progressed to a second-generation 300-horsepower design weighing 152 pounds; a stock Pinto engine made 88 horsepower and weighed 415 pounds.

To prove that his plastic powerplant was durable, Mr. Holtzberg campaigned a Lola racecar in the International Motor Sports Association’s Camel Lights series. Amoco Chemical provided financial backing to promote its Torlon plastic resin. The only mishap during half-a-dozen 1984 and 1985 races was the failure of a connecting rod, a part purchased from an outside supplier.

In spite of his successes, Mr. Holtzberg roused little attention. “Ford was technically interested,” he recalled. “The Popular Science article gave them plenty of free publicity, but they actually contributed nothing to the Polimotor project.”

Read more: http://blogs.internetautoguide.com/6...#ixzz1vZ5kX1cR

http://blogs.internetautoguide.com/6584915/industry-news/plastic-engines-can-composite-materials-be-used-to-make-engines/index.htm

[tjbw]

Neil,

... over a crank cycle, the engine will not run at a constant speed, but it will speed up and slow down thru the cycle. This being the case, the port durations, whilst maintaining a constant number of degrees, will in fact vary in time, due to the cyclic speed variation.
A couple of numbers: At 39,000 rpm, the crank rotates 650 times per sec, ie a rotation takes 0.0015 sec.
If, as I suggested earlier, one had a 360 T encoder wheel and this signal was logged against time, one could have three (or more really) basic scenarios. (Note the 360T is a bit arbitrary, but something I am familiar with, and could be less (less accuracy) or more (more accuracy). I guess it somewhat depends on the capacity of your acquisition system.) See the attached sketch.

317067

One can see, exaggerated, the different scenarios, and the effect on port durations. Could turn out to be ¾ of 5/8 of stuff all, but would be interesting to know. The key variable I think, being crank inertia.

That would also be useful, for comparing the effect of converting an engine to HCCI.

If instantaneous combustion results in an acceleration after TDC, can that be damped by anything in the drivetrain other than a larger flywheel?

[Frits Overmars]

If instantaneous combustion results in an acceleration after TDC, can that be damped by anything in the drivetrain other than a larger flywheel?Sure, a transmission shock absorber in the primary gear, in the clutch or in the rear wheel hub.

[m4r]

this came up on facebook (https://www.facebook.com/1456266058034401/photos/pb.1456266058034401.-2207520000.1446660486./1506101056384234/?type=3&theater) today, looks like a stepped piston


317087

[Ocean1]

this came up on facebook today, looks like a stepped piston

Stepped or not the displayed face looks conical. Assume it's the combustion face... have you ruled out a fully floating piston yet?

[ief]

Long shot but anyone went to the trouble to model a puch maxi and/ or tomos a35 in engmod and want to share the pack file?

[MotleyCrue]

Yesterday Jan Thiel wrote

"I have absolutely nothing to do with it.
And I would have to see a powercurve before I believe any 125cc engine gives
70HP and revs to 30.000!"

Thats a bit unexpected I think.

[ken seeber]

Thank's for the feedback Frits.

So Ken would you sell us your idea? :yes:

Our situation on the plugs is this. The one in the pic did work, but was a prick to install and was destroyed on removal. As with any such plug, as Frits said, its dimensioning is strongly dependent on the position of the piston circlip groove relative to the piston skirt face plus piston pin offset plus the geometry of the bore beyond the circlip (different manufacturers had slight variations in this area ranging from an enlarged diameter to a stepped bore, to suit their processes.

Since that time, we have come up with a snazzy locating arrangement, but this is still subject to the circlip/bore details as above. For us, we are holding back on this until the Ryger thing comes out as there might be a relevance there and/or it might very quickly kill existing style engines and we all have to think again about a new direction and/or things might just revert back to the status quo.

56 days to go. :yawn:

[2T Institute]

theyre not athenas but i believe theyre loosely based on that casting. the timings are low. around 182/122 i think but i havent checked yet. these are also sitting at 65mm bore right now but ill probly have to go to 65.5 so theyll straighten up. athena bores start at 68mm i believe. i believe theres a few other differences also. now if i could get them around 100hp with methanol i would feel all the effort was worth it. totall cc will be around 391-397 depending how the bore cleans up

They look identical except for the athena logo. Where did you get them from?

[breezy]

Wobbly, by removing oil from the fuel used in the 2 t engine, what impact would that have on transfer flow/ scavenging patterns?

[husaberg]

Wobbly, by removing oil from the fuel used in the 2 t engine, what impact would that have on transfer flow/ scavenging patterns?

Less carbon deposits ...................:msn-wink:

[F5 Dave]

An upset sheik?

[polinizei]

this came up on facebook (https://www.facebook.com/1456266058034401/photos/pb.1456266058034401.-2207520000.1446660486./1506101056384234/?type=3&theater) today, looks like a stepped piston


317087
I don't belive its a typical stept piston.
You wouldn't grap a round body outside the 12 and 6 o'clock position. Also Frits gave the hint, we wouldn't see any thing special through the exhaust port.

[m4r]

I don't belive its a typical stept piston.
You wouldn't grap a round body outside the 12 and 6 o'clock position. Also Frits gave the hint, we wouldn't see any thing special through the exhaust port.

guess why you wouldn't see anything special through the exhaust port :msn-wink:

Edit: He is probably holding it at what is left of the piston skirt to cover the exhaust


317108

[breezy]

An upset sheik?

ahhhh of course..:laugh::laugh:

[d2t]

we are holding back on this until the Ryger thing comes out as there might be a relevance there and/or it might very quickly kill existing style engines and we all have to think again about a new direction and/or things might just revert back to the status quo.

This!

With details just beyond the horizon, makes me wonder if there's any reason to try new things in regards to existing configurations as any positive steps may be trumped by the Ryger design. The answer is nothing is certain. Aside from karting, there's no garuntee other racing organizations will even allow the Ryger-style engines to compete if they make 100% of the current field obsolete. So, yes, there's still reason to try new designs but with 2016 rapidly approaching, it may be worth delaying such efforts as they usually involve considerable development time/cost.

[Flettner]

guess why you wouldn't see anything special through the exhaust port :msn-wink:

Edit: He is probably holding it at what is left of the piston skirt to cover the exhaust


317108

Yes I agree.

[WilDun]

guess why you wouldn't see anything special through the exhaust port :msn-wink:

Edit: He is probably holding it at what is left of the piston skirt to cover the exhaust



Geez - it took a helluva long time for people to come to that realisation!;) - but, there's a little bit more to finish the jigsaw :scratch:

Then, ............ as always, I could be wrong!

[ken seeber]

Yes I agree.

Fletto, do you agree with this one as well?

And the good news is that it will just fit into our current boxes. :soon:

317124

[Lightbulb]

Where did you find that Ken ? , that looks about right to me.

[polinizei]

....With the KF and KZ classes gaining popularity, STRIKE became the Australian distributor for the Italian made Meteor pistons and commenced delivery of these in early 2013.

http://www.strikeproducts.com.au/whatsnew.asp

[jonny quest]

2 sets of rings. Just saying

[Flettner]

Fletto, do you agree with this one as well?

And the good news is that it will just fit into our current boxes. :soon:

317124

There you go, just build the rest of the engine around that. Did you want a cylinder to go with that order?

[breezy]

00000000000

[breezy]

guess why you wouldn't see anything special through the exhaust port :msn-wink:

Edit: He is probably holding it at what is left of the piston skirt to cover the exhaust


317108

that looks very weak.... mechanically

[breezy]

Fletto, do you agree with this one as well?

And the good news is that it will just fit into our current boxes. :soon:

317124

a few years back i had a wiseco piston i used to run back to front to keep the piston ring pegs from falling over the exhaust port. it was a piston port engine and i had removed some of the skirt to extend the inlet timing on the other side of the piston.. on one occasion i put the piston in wrongly with this inlet piston side such that at tdc the exhaust port didn’t fully close. it may have been a coincidence, but the engine ground to a halt after about 300 yards. big end seizure!! big end cage disintegrated and my brand spanking new conrod turned blue!!:no::no:

[tjbw]

Fletto, do you agree with this one as well?

And the good news is that it will just fit into our current boxes. :soon:

317124

Nice mock-up, wink wink

[Lef16]

I can't remember from where I have this photo on my computer,from Jan Thiel's facebook page I think....
It could be ryger,the piston fits........................
317130

[MotleyCrue]

Here's what I think about the powerband. The Ryger engine will make good torque over the usual rpm that the normal exhaust pipe works at, then at the medium high rpm 13.5-14 k to 15.5 -16k rpm scavenging will be mediocre just like any engine off the pipe but torque will be propped up instead of falling off a cliff because the HCCI will keep a good burn going even with mediocre scavenging. The small exhaust port and small for the rpm size stinger help with this.

Then at high rpm nearing 17000 rpm the pipe will start working again (also factoring in a slightly lower exhaust temperature because of the HCCI). Do the math and at some super high rpm any pipe will actually start working again because though the first reflection off the converging cone arrives way too late to be useful the second reflection from the converging cone will arrive just on time when the exhaust port is closing on the cycle after that. Cool beans. All you got to do is span the rpm gap between the 2 good torque engine speeds. This cant be done without HCCI to prop up the torque through the nasty engine speed zone that exists between the 2 good engine speeds explaining why no one else has done it.

The second peak torque engine speed would be about 40-50% higher than the first peak torque engine speed and in between the 2 speeds is the bad zone that is very much propped up with HCCI and a stinger smaller than the rpm would suggest.

[Frits Overmars]

Do the math and at some super high rpm any pipe will actually start working again because though the first reflection off the converging cone arrives way too late to be useful the second reflection from the converging cone will arrive just on time when the exhaust port is closing on the cycle after that. Cool beans.Secondary pulses can work when the revs are too low for the pipe. The first reflection pulse will come too early, followed by a second suction pulse and a second stuffing pulse that may arrive just in time before the exhaust port closes. But when at ultra-high revs the first reflection comes too late to do some useful stuffing, the next combustion will be weak, the next emerging pulse will be weak, the combustion after that will be even weaker and the gas dynamics will collapse completely.

[MotleyCrue]

Secondary pulses can work when the revs are too low for the pipe. The first reflection pulse will come too early, followed by a second suction pulse and a second stuffing pulse that may arrive just in time before the exhaust port closes. But when at ultra-high revs the first reflection comes too late to do some useful stuffing, the next combustion will be weak, the next emerging pulse will be weak, the combustion after that will be even weaker and the gas dynamics will collapse completely.

At normal peak torque rpm the primary pulse would be approximately 180 degrees after exhaust opening and the secondary approximately 360 degrees after exhaust opening, at higher revs this becomes greater and is no good (example 220 and 440) as you mentioned, but at even higher revs things get better again when the primary is 270 degrees after exhaust opening and and the secondary is 540 degrees after exhaust opening. 540 degrees is when the exhaust port is closing on the next cycle. The secondary pulse from the previous cycle stuffs the cylinder during exhaust port closing instead of the primary pulse on the current cycle.

That's how I see it, 2 torque peaks , one at normal speed for the pipe and the other at 40-50% higher speed. A torque hole in the middle rpm between the 2 peaks that gets propped up as well as possible. Hot exhaust to extend good torque revs as much as possible past the first torque peak rpm then when the gas dynamics crash the exhaust gets much cooler and the second torque peak would start to mature at less than the 270/180 = 1.5 x difference in rpm between peaks, then fully mature as the revs climbed further and the exhaust once again got hotter.

[WilDun]

Ahem,
Excuse me ....... What has happened? - pregnant pause, no recent posts! - on the ESE thread?? - I can't stand the suspense just got to say something.

TZ seems to have gone on holiday, Wobbly has thrown a Wobbly, Flettner has become overloaded with experiments, Frits is preparing for the Ryger onslaught in the new year, Motley Crue is trying his best, ........ me? well I'm just hanging around, still trying to get my head around how a two stroke works but now I am more confused than ever.
Did I hear it right? a two stroke doesn't need oil in the petrol anymore? - how come? .......... last I heard, it was a pint of oil to a gallon of petrol! I must have missed something but I'm too tired to go back over it all again. :facepalm:

Think I'll just have another beer!

[lodgernz]

Still no 30 Hp @ 10500 dyno chart for a 125, and not one statement of of facts about the 400 correct.
Sadly I wont be back to pass on any of my big headed knowledge as its obviously all wrong.
See ya.

Thanks a lot guys. Once again petty personal issues ruin it for everyone.

[SwePatrick]

Still no 30 Hp @ 10500 dyno chart for a 125, and not one statement of of facts about the 400 correct.
Sadly I wont be back to pass on any of my big headed knowledge as its obviously all wrong.
See ya.

Can´t take any negativity?
Just ignore them.
And continue.

[G10]

I don't think the piston that's been shown a few posts back is the answer to the Ryger puzzle, if it displaces 125 cc's on the top it only displaces about 85 cc's on the underside to pump the incoming charge. There must be more to the puzzle.

[WilDun]

Thanks a lot guys. Once again petty personal issues ruin it for everyone.

Well, I'm sure most people here don't take the posts personally - most of us understand that it's often hard to get things across in the written word, not as easily as it would be in face to face conversations, also we often don't really know what the person we are having a discussion with is really like.

Of course some people are more adept at getting things across in print than others - then in this forum it is possible to revise what you have said and perhaps change what could be construed as offensive to something less offensive.

Just come back Wobbly, many people did listen to you and the fact is, humans don't always agree and never will - understand that, don't get bogged down in small time controversy, just contribute, there are a lot of other interested people here too you know and if they don't like what you say, so what, most of them just won't comment if they disagree or don't understand!

Think you've got problems? think about Obama, Putin, and of course John Key having so much hassle with all those murderers, rapists, sex offenders and above all minor offenders incarcerated in Christmas Island!

No, you don't really have a problem ! :bash:

BTW. If any of you think I'm talking shit, please don't tell me that, I'd rather not know! :laugh:

[WilDun]

I don't think the piston that's been shown a few posts back is the answer to the Ryger puzzle, if it displaces 125 cc's on the top it only displaces about 85 cc's on the underside to pump the incoming charge. There must be more to the puzzle.

I don't think that it's all that important that it has a smaller displacement, it's probably good at lower revs but I think that harmonics take over at the higher revs - that's what I'm led to believe, but don't quote me, others can explain it no doubt.

Also, as regards pumping (or over pumping) issues - this is being restricted only by competition rules and so does not apply to two strokes in the wider world, some free thought can be applied there (ie if the higher moral ground of the four stroke world doesn't step in to scupper it!).
I'm really talking about stepped pistons in general of course, not that particular setup.

I realize of course that this is essentially a bucket racing forum and they do have rules, but just don't let that narrow our thinking!

[breezy]

Ahem,
Excuse me ....... What has happened? - pregnant pause, no recent posts! - on the ESE thread?? - I can't stand the suspense just got to say something.

TZ seems to have gone on holiday, Wobbly has thrown a Wobbly, Flettner has become overloaded with experiments, Frits is preparing for the Ryger onslaught in the new year, Motley Crue is trying his best, ........ me? well I'm just hanging around, still trying to get my head around how a two stroke works but now I am more confused than ever.
Did I hear it right? a two stroke doesn't need oil in the petrol anymore? - how come? .......... last I heard, it was a pint of oil to a gallon of petrol! I must have missed something but I'm too tired to go back over it all again. :facepalm:

Think I'll just have another beer!

317196


i think they've all gone mate!!:weep::weep:

[WilDun]

i think they've all gone mate!

No, not on this thread! they'll all be back again - just a little bit of a hiccup! ...... and it gives me the opportunity to say something too, whereas previously I just couldn't keep up! :sweatdrop

Anyway if you turn the camera round 180 deg. you'll see a lot more coming in!

[ken seeber]

Ahem,
Excuse me ....... What has happened? - pregnant pause, no recent posts! - on the ESE thread?? - I can't stand the suspense just got to say something.


Willy, well done. I thought of doing something starting like “Just doesn’t seem the same….,” but I didn’t.

So, let’s get down to the matter. Turns out I’m a bit different at times. It also turns out there is a little bit of a difference in everyone, including all you guys out there. If we were all the same all around the world, the place would be a mess.

I think everyone was really enjoying the thread (easily tolerating the differences in us all) and contributing in all levels of ways. Some more abrupt, some more bragging, some wrong, some clearly wrong, some not quite so wrong in their words, but really, who gives a shit? The fact is that it was enjoyable and that a good load of info was being shared and commented on.

I say well done to the bunch of bucketeers who started this wonderful thread originally in 2008 and let it build up to where it is now (current perturbation aside). However, I miss Frits, Wobbly, TZ350, Hooser etc, etc and I want them back and back now. This thread is quoted and contributed to by many people all around the world. It’s great.

Let’s just get it going, keep it going and get the “missing in action” guys back. Please.

Cheers

[WilDun]

Willy, well done. I thought of doing something starting like “Just doesn’t seem the same….,” but I didn’t.
I want them back and back now. This thread is quoted and contributed to by many people all around the world. It’s great.
Let’s just get it going, keep it going and get the “missing in action” guys back. Please.
Cheers

Yes Ken, well spoken, I didn't manage to list all of the guys of course (sorry Husa, Smitty and the dozens of others).
Funny how even the slightest "nudge" can upset the whole applecart somtimes - all very hard to figure out.
So you guys had better sort that miniscule "tiff" you had, you don't even have to apologise or feel silly, just come back as if nothing happened and think of others in future.
As they say "shit happens" , it gets swept up and the stink disappears in no time!

I might add that it's very hard to know who is in contact with who in the PM's etc. and so I may have missed out on a lot.
People like myself who don't have a lot of personal contact through the Bucket Racing etc. with a lot of the guys, tend to be out of the "loop" (dare I even call it "clique") and so seem to be a bit behind in the latest developments, especially in this fast moving and perhaps sometimes confusing thread - but I agree that it has been great up till now despite its failings. - worthwhile resurrecting again and long may it reign!

[gamma500]

I really hope that this thread will continue, I've been reading this almost daily since 2010. I have learned so much, thanks to everyone!

[mr bucketracer]

Thanks a lot guys. Once again petty personal issues ruin it for everyone.just for you i will come back , but i'm a do'er not a talker so hope thats ok with you , and i don't go fuck you i'm the best ! i like to learn new things , and even if i'm not on the same wave lenth i don't like been told i a fucken wanker or want ever , ok! sick of this shit !

[ken seeber]

Ryger confession time. Yep, the stepped piston I posted a few days ago was a mock-up.
317198

Sort of a joke, but, more seriously, another contribution as to what might be inside the Ryger.
Some time ago, I did a range of sketches, one being as below.

317199

Following that, after we found out it has a 90 rod and the piston skirt can be seen at all time after EO, we started thinking along these lines again. We then created a scale schematic layout of the engine based on all the knowns. To this then we added a stepped piston version that might comply, as is shown below:

317200

From that, we just created the mock-up out of scrap and an hour of my time. One big question was, would the piece of skirt just break off? Well, referring to a spreadsheet we did on piston forces and accelerations, we can see at 30k, the peak acceleration is around 350,000 met/sec^2.

317202

Then looked at the skirt.

317201

From this the force acting on the shaded area (or base of the skirt) can be calculated. From F=ma, = (12.5/1000)* 350,000 = 4375 N. Given this force, acting on the area of 220 mm^2, the stress can be calculated from Stress = F/area = 4375/(220^10-6) = 19.9 Mpa = safe, given the UTS might be around 300 MPa. Hope I’m not fundamentally wrong here.
This is all based on no shock loads, no side thrust etc. In fact, given all this it could be simply made much thinner (less weight, less area = same stress), not too sure though if it could go to beer can thickness (Heineken of course?)

What it all tells is that we have no idea really, but all it does is to put some scale to a range of possibilities and raises more questions & points:

1. How the valving works?
2. Does the reduced under-piston working volume cause issues?
3. Although the volume is less, the primary compression ratio (formerly crankcase compression ratio) can be much, much higher.
4. Maybe this is adequate for starting and low speed running, but then maybe das dynamics, 24/7,HCCI, take over and do the trick
5. Maybe the exh port doesn’t go to BDC, allowing for a much shorter piston skirt and possibly another transfer port under the exhaust
6. How does the rest of the engine, particularly the rest of the piston, the rod and its bearings, survive the 30k, notwithstanding nice lubricating conditions?

52 days to go

Better do some real work.

[husaberg]

I found a rather interesting variable speed electric water pump.
I even have a couple here now thanks to a benefactor
Its used on all manner of BMW's as the primary water pump.

The specs are 2kgs and 125 liters /minute.

Quoting the pump specs more than 7500 liters per hour with back pressure of 450mbar'
317204
Pin 1 is battery voltage
Pin 2 is PWM signal
Pin 3 is a test/BSD signal
Pin 4 is Ground

Supplying +12volts to Pin 1 AND pin 2 (and grounding pin 4) should make it run full speed after a 'timeout' period of about 3-10 seconds. To vary speed based on PWM input on Pin 2, you need at least 3ms of an inturrupted high pulse in order for it to awake the pump. Keep that in mind when you decide on the PWM frequency and/or your duty cycle percents.

It needs a controller to operate in variable speed mode but I am pretty sure something could be bodged up with a 555 circuit and a piggy back. Or an Arduino circuit.
http://www.nomad.ee/micros/pwm555.html

or
https://www.maximintegrated.com/en/app-notes/index.mvp/id/3530
http://www.reichelt.de/ICs-MAX-1000-9201/MAX-6653-AEE/3/index.html?ACTION=3&GROUPID=5470&ARTICLE=115924&OFFSET=16&SID=14VVq3JawQATYAAHPOtpM0258660c7c3713fe135246538 1224c40&LANGUAGE=EN

http://www.tecomotive.com/download/manual_tinyCWA.pdf
The manual for this controller gives out the important specs

[TZ350]

TZ seems to have gone on holiday,

No not on holiday, the thread moves on faster than I can make stuff and post about it, I am just getting left behind a bit, that's all.

I have been working with Chambers on his RG50's for F5, trying some new ideas but we are having trouble cracking 14hp, still we will get on top of that. I hope to get the final parts needed from Flettner soon to complete the NSR110 engine. I am also putting the old fuel injected 125 air cooled back together. I have unfinished business with the EFI thing. And have to finish the NSR rolling chassis to test the new motor. Sort of busy but nothing new to post about.

[WilDun]

No not on holiday, the thread moves on faster than I can make stuff and post about it, I am just getting left behind a bit, that's all.

That's good and it explains why Flettner is so busy!

I'm now looking at Ken's stuff to see what he's been doing. I did learn a bit about mechanics (forces, loads vectors and stuff) long ago, but it all escapes me now and I'm too lazy to try to understand it all so I'll just look at the pictures and work on hunches (as you do). :niceone:

[Sketchy_Racer]

Ryger confession time. Yep, the stepped piston I posted a few days ago was a mock-up.
317198

Sort of a joke, but, more seriously, another contribution as to what might be inside the Ryger.
Some time ago, I did a range of sketches, one being as below.

317199

Following that, after we found out it has a 90 rod and the piston skirt can be seen at all time after EO, we started thinking along these lines again. We then created a scale schematic layout of the engine based on all the knowns. To this then we added a stepped piston version that might comply, as is shown below:

317200

From that, we just created the mock-up out of scrap and an hour of my time. One big question was, would the piece of skirt just break off? Well, referring to a spreadsheet we did on piston forces and accelerations, we can see at 30k, the peak acceleration is around 350,000 met/sec^2.

317202

Then looked at the skirt.

317201

From this the force acting on the shaded area (or base of the skirt) can be calculated. From F=ma, = (12.5/1000)* 350,000 = 4375 N. Given this force, acting on the area of 220 mm^2, the stress can be calculated from Stress = F/area = 4375/(220^10-6) = 19.9 Mpa = safe, given the UTS might be around 300 MPa. Hope I’m not fundamentally wrong here.
This is all based on no shock loads, no side thrust etc. In fact, given all this it could be simply made much thinner (less weight, less area = same stress), not too sure though if it could go to beer can thickness (Heineken of course?)

What it all tells is that we have no idea really, but all it does is to put some scale to a range of possibilities and raises more questions & points:

1. How the valving works?
2. Does the reduced under-piston working volume cause issues?
3. Although the volume is less, the primary compression ratio (formerly crankcase compression ratio) can be much, much higher.
4. Maybe this is adequate for starting and low speed running, but then maybe das dynamics, 24/7,HCCI, take over and do the trick
5. Maybe the exh port doesn’t go to BDC, allowing for a much shorter piston skirt and possibly another transfer port under the exhaust
6. How does the rest of the engine, particularly the rest of the piston, the rod and its bearings, survive the 30k, notwithstanding nice lubricating conditions?

52 days to go

Better do some real work.

I'd imagine that it is not so much the force trying to tear the skirtlet off which would be the biggest problem. I would have thought that it would be the bending moment that the eccentric skirt would create through the rod as it accelerates.

So as I understand it the bore is 54mm so for simplification I'll assume the moment to be centered in the bore so ((54/2)/1000)*4375=118.125Nm

That's a hell of a moment for a long slender rod to bear!!

[Frits Overmars]

Thanks a lot guys. Once again petty personal issues ruin it for everyone.


Well, I'm sure most people here don't take the posts personallyI'm equally sure Wobbly did and I can understand why.


...I miss Frits, Wobbly, TZ350, Hooser etc, etc and I want them back and back now.I never left, Ken. It's just that I can't comment on everything, especially not on your posts :p.


So you guys had better sort that miniscule "tiff" you had, you don't even have to apologise or feel silly, just come back as if nothing happened and think of others in future.I think that did not come out the way you meant it, Will. The way I see it, Wobbly has nothing to apologize for. He has shared a tremendous amount of hard-gained knowledge here and to me he is one of the pillars of this forum.

[m4r]

I'd imagine that it is not so much the force trying to tear the skirtlet off which would be the biggest problem. I would have thought that it would be the bending moment that the eccentric skirt would create through the rod as it accelerates.

So as I understand it the bore is 54mm so for simplification I'll assume the moment to be centered in the bore so ((54/2)/1000)*4375=118.125Nm

That's a hell of a moment for a long slender rod to bear!!

how much force is left on the skirt, if we have a lower cylinder that could take a lot of guidance?

[AndreasL]

The way I see it, Wobbly has nothing to apologize for. He has shared a tremendous amount of hard-gained knowledge here and to me he is one of the pillars of this forum.

Agree!

I wouldn't been i.e running sims in EngMod without Wooblys help. That's for sure.

[Tim Ey]

He has shared a tremendous amount of hard-gained knowledge here and to me he is one of the pillars of this forum.

Totaly agreed!
This thread brought my thoughts in different directions and I made some very good experiences with advices from wobbly! (For example the divider in a reedvalve worked really good)
Besides I would not use EngMod2T without wobblys shared experiences and knowledge about that program.
@wobbly:
If you will not come back it would be a great loss for all of us - one way or the other I have to say: Thank you very much.

[MotleyCrue]

This forum is pretty mild for backstabbing compared to some. If all you guys (and myself) posted the crazy ideas that have been posted on here in the last few months you would be hacked to death on some forums. Looking forward to more great technical posts by Wobbly and all others.

[jasonu]

I have been working with Chambers on his RG50's for F5, trying some new ideas but we are having trouble cracking 14hp, still we will get on top of that. I hope to get the final parts needed from Flettner soon to complete the NSR110 engine. I am also putting the old fuel injected 125 air cooled back together. I have unfinished business with the EFI thing. And have to finish the NSR rolling chassis to test the new motor. Sort of busy but nothing new to post about.

What are you going to do after lunch???:niceone:

[nine-thirtysix]

The way I see it, Wobbly has nothing to apologize for. He has shared a tremendous amount of hard-gained knowledge here and to me he is one of the pillars of this forum.

Totally true. This thread is followed by an enormous amount of people. And there are less than a handful who have so many proven results to share.
So to loose just you Wobbly would be a real shame! So please give yourself a jerk and tutor us oncemore.

[sidecar bob]

Good for you, but don't take credit for others ability to win because of their talents.

Dennis also rode a bike at Greymouth last year with an engine that we helped to build, and won all three races. We don't claim those as our own.

If I was too, I could bleat on about world titles and national titles as well, but most of us on these forums could say the same also.

I come in here to try and glean some knowledge, but most the time I see write ups that just sound like team talk up, so end up having to try and solve it ourselves.

My advice to this thread is to start talking in common language, preferably English, and speak laymens terms. Most of us are doers, not talkers.

Iv only just discovered this wee chucklefest.
I also fielded a bike at the Shorai with a top rider on it & an engine that Grumph had quite a hand in.
Sure, it stayed together & made the numbers, but I take no credit for where it finished apart from putting it together, the results belong to the rider.
Heres a pic im not sure what to think of, https://www.facebook.com/carlcoxmotorsport/photos/pb.1496677837235805.-2207520000.1447275525./1686527688250818/?type=3&theater Ken McIntosh (McIntosh Suzuki fame, google it) copying down my spring numbers.
I hope it helps make his bike faster, as it owes them 100k more than mine owes me & the two bikes were on very similar lap times. Does that make me the awesome one?

Great riders, the cheapest way to make dodgy old shit go fast.



You're behind me because I hired the best rider.
I bought 50 boxes of Heineken & drank one every time I enjoyed my race bike.
Sorry, all gone.

[WilDun]

I'm equally sure Wobbly did and I can understand why.
I think that did not come out the way you meant it, Will. The way I see it, Wobbly has nothing to apologize for.

Yes Frits , I can understand why too - but it wasn't aimed solely at Wobbly, it was just a general statement to everyone really, (ie. have a debate, but don't dive overboard if the boat starts to rock!). - serves no purpose at all and severely affects others, - I do see your point though!

PS I did actually reword this one too, so as not to be misunderstood! :rolleyes:

[WilDun]

how much force is left on the skirt, if we have a lower cylinder that could take a lot of guidance?

That makes sense and the piston can not tilt as in a normal arrangement. Anyway, by the same token, you would get a similar effect with a normal piston arrangement where there were large windows in the skirt and that doesn't seem to cause any problems.

Oh,and Wobbly, at least a lot people know and appreciate your work, - just think of me, not even one person in my family takes any interest at all in my workshop, my foundry efforts, or my bike stuff! - best encouragement I ever had from them was "uh, yeah" :violin:

[nodrog]

.... Ken McIntosh copying down my spring numbers......

that's Lols, is he planning on getting jay to ride it?

[trevor amos]

The world wide web of two-stroke enthusiasts needs you Wob, and really appreciate all that you contribute in helping others. Don`t let a few brain-deads mess with you.

Cheers, Mate

[WilDun]

The world wide web of two-stroke enthusiasts needs you Wob, and really appreciate all that you contribute in helping others. Don`t let a few brain-deads mess with you.

Cheers, Mate

Trevor, no 'brain deads' there by any means, simply just different points of view, could be easily resolved.

[Grumph]

Trevor, no 'brain deads' there by any means, simply just different points of view, could be easily resolved.

Quite so...I've apologised to TZee for inadvertently setting Wob off on a rant. I still don't understand why he did though...I've publicly disagreed with him and Frits before and may well again. Arguments are second nature to me - the old man (AMIMechE) turned it into an art form. I don't go behind peoples backs, what you see is what you get. I backed out of that argument, I thought before anyone would have got upset, but apparently not so.

What Wob contributed was worth reading. Some of my contributions may be also, a matter of opinions.

To my knowledge I've not done Wob any direct harm. Thus the rant came as a surprise to me. And mildly offensive.

[sidecar bob]

Quite so...I've apologised to TZee for inadvertently setting Wob off on a rant. I still don't understand why he did though...I've publicly disagreed with him and Frits before and may well again. Arguments are second nature to me - the old man (AMIMechE) turned it into an art form. I don't go behind peoples backs, what you see is what you get. I backed out of that argument, I thought before anyone would have got upset, but apparently not so.

What Wob contributed was worth reading. Some of my contributions may be also, a matter of opinions.

To my knowledge I've not done Wob any direct harm. Thus the rant came as a surprise to me. And mildly offensive.

Really, do you have to apologise to people on this thread if you disagree with them. Holy Shit That's one king sized ego!!!
Sometimes we're just better off without those kind of people in our lives, although it may not seem so at the time.

[FastFred]

Really, do you have to apologize to people ...

317215

Good manners are always appreciated.

[TALLIS]

Second thoughts

[wobbly]

Im just about to leave for the World Karting champs in Vegas to try win it for the 3rd time, and will start posting again when I get back.
And no I wont be in the sidecar with one of the best kart drivers in the World- I will be full time looking at data and tuning his engine and chassis.
As he couldn't win it without that help,and I for sure couldnt drive 1/2 as well.

The only two times I have gone off on this forum is when reading absolute rubbish passed off as an attempt at fact.
1 - " Vertical bar shaking isnt bad " - but why does every engineer set the balance factor to try and reduce it to a minimum.
2 - " There is no time to blip the downchange on a bucket " - funny that all the worlds fastest shifter karters find time in less than 1/2 the braking distance -
and do it for the same reason all good bike racers do, reducing the ill effects of the downchange on the chassis.

And as for the childish personal abuse and piss taking, well many others have said to me - ignore it, but my response is to say "fuck off " or contribute something
useful to the forum, as I have tried to do.

And to cap off what was received by a couple as being a big headed wank on my part, well here is a pic of Dennis doing what he does best.
The reason for the wank - I built the chassis, designed the engine &, the pipes in EngMod - then made them, so yes I am the proud builder
of the fastest Pre 82 in the country - not just talking eh.

[richban]

And to cap off what was received by a couple as being a big headed wank on my part, well here is a pic of Dennis doing what he does best.
The reason for the wank - I built the chassis, designed the engine &, the pipes in EngMod - then made them, so yes I am the proud builder
of the fastest Pre 82 in the country - not just talking eh.

All I can say to that is you should put me on that next time and with the added weight I bring, there will be no wheelie issues.:innocent:

[sidecar bob]

Cool, I built mine too, It cost ten percent of what the only bike barely ahead of it cost.
So how much did some poor cunt have to pay you for that? We all know chequebooks win races.

[FastFred]

I think this is the story, its Trevor Discombs bike, he was a very good rider in the 70 and 80's on TZ's. Even had a sponsorship deal with Air NZ. He had to give it away when a Kiwi Fruit venture went sour and he needed to put all his energy into financial survival.

And now that he is 74 (I think), 70 plus anyway, and things have come right for him he has had the ultimate TZ put together for a grand last fling, I can relate to that. He rode it at Philip Island last year. And He can still peddle it competitively, as witnessed at Puki and HD. Not sure how much of the background I have got right but I think that is the story.

Trevor appears twice on the AMCC roll of honer (1974) http://www.mnz.co.nz/docs/default-source/about-us/roh-1970-1979-final.pdf?sfvrsn=2

Anyway whatever, he is someone who is enjoying a little pride of ownership in his bike. Back in the day he prepared his own bikes and they were always very well presented and now he is still getting out there and doing it, I take my hat off to him.

[kel]

Oh for goodness sake Sideshow Bob has found his way back. I thought we left him deep in the woods ...


I bought 50 boxes of Heineken & drank one every time I enjoyed my race bike.
Sorry, all gone.

But that is funny :laugh:

[nodrog]

..... my response is to say "fuck off " or contribute something
useful to the forum, .....

OK -

its Dennis Charlett not Dennis Sharlett




...... so yes I am the proud builder
of the fastest Pre 82 in the country ....

Junior.