ESE's works engine tuner

[SwePatrick]

New goals and challenges, winter is long in Sweden.
Summers testing went ok, but with a nagging thought, to heavy or lack of power.
I dynoed in the end when sorted out the fuel distribution 75.54hp/13280rpm and 41.6Nm/12310rpm(peak),38.8Nm at 10500rpm. (calculated crank)
Never tested it on track with that power, it was supposed to be a test now in september, but my girlfriend celebrates her 50th birthday exactly that day, one of those days one should stay at home i guess

So, why not start with winterplans early instead?



Turbo got capacity of ~280hp on 4stroke engines.
About half or a little bit more than half on twostrokes.

I want more power on the wheel then bike´s wet weight.
Much easier and cheaper to build power than loose weight

I´m building an small compact draw through carb setup, no intercooler needed when running on methanol, thereby one can concentrate on not loosing as much response.
I´m using an modified gnarly pipe as the pulses tends to get more intense when higher density(and higher temp on boost) in the exhausts, i have also tuned it further down in rpm´s to get more power early to leave the line with, when turbo is pumping it will have power upwards in rpm´s anyway.

Rgds.

[JanBros]

But you have to have a certain amount of crush on them other wise the domes spin when you are removing or fitting the spark plugs

ok, now I understand.
yes, there is a little crush, but I also make a small cut-out in the insert, and in the head I bolt a small stainless steel bolt. it's head fits the cut-out and stops the insert from turning round.

you can see the bolt on the right side at 6 o clock, and the cut out between 3 and 4 o clock.

[katinas]

Very interesting 1972

https://www.google.com/patents/US3805750

[husaberg]

Very interesting 1972

https://www.google.com/patents/US3805750

Hope it doesn't mention the patent holders name

[guyhockley]

Just an aside: Did anyone notice that the British 50cc acu freetech championship was just won by an RG50, in the original frame?

I THINK he won the road-based class, but, fair-play, that's still a 20 year old bike beating Aprilia RS50s, Derbi GPRs etc.

[Neal]

I THINK he won the road-based class, but, fair-play, that's still a 20 year old bike beating Aprilia RS50s, Derbi GPRs etc.

And the racer is as skinny as a jockey and won a few championships in his career .

[dark art]

I THINK he won the road-based class, but, fair-play, that's still a 20 year old bike beating Aprilia RS50s, Derbi GPRs etc.

Those newer aprilias and derbis are greatly overweighted, that may be the reason why is so dificult to get dry or wet weight figures online. Some time ago I read those are around 130 or 140kg.

[F5 Dave]

my RG50 I got down to 59.5kg on the kart scales with empty tank but ready to go. There were perhaps afew mods, but standard frame (well started as one.). OK maybe many many obsessive hours weighing every item.

And yes, the bike weighed 20kilos less than me.

[Frits Overmars]

Those newer aprilias and derbis are greatly overweighted, that may be the reason why is so dificult to get dry or wet weight figures online. Some time ago I read those are around 130 or 140kg.

They are overweight alright, but not that much. Sounds like you read the total weight of bike+rider.

[mike schmidt]

W. Tenney (Bill Tenney) Very sharp engineer / powerboat racer. Won a ton of championships and set a bunch of worlds records. 1930's thru early 1960's. Knew more about nitro in two stokes than everyone on this board combined. His son David is on here and has the fastest 125 hydro in the US. Just won the US National Championship.

Michael

[Nath88]

Turbo got capacity of ~280hp on 4stroke engines.
About half or a little bit more than half on twostrokes.

Turbo is an excellent idea. What makes you say the capacity will be about half? For the same power the airflow will be similar for 2 strokes or 4?

I´m using an modified gnarly pipe as the pulses tends to get more intense when higher density(and higher temp on boost) in the exhausts, i have also tuned it further down in rpm´s to get more power early to leave the line with, when turbo is pumping it will have power upwards in rpm´s anyway.

Before and after dyno will be very interesting. I always thought it would only be effective in the resonant range of the pipe, and just amplify the pipe effect. But it would be nice if it extended the power range.

[dark art]

They are overweight alright, but not that much. Sounds like you read the total weight of bike+rider.

Back in the day, had the old model with steel frame, single sided swing arm and was acceptable, maybe 90/95kg stock. The Al frame model they use in UK might be around 90-100kg when new. Newer models, seem to be the same bike as the RS4 125 4stroke but with a 50cc engine.
No listed weights anywhere, someone must know someone who ones one

http://www.aprilia.com/en_EN/models/...ikes/road/rs4/

[SwePatrick]

Turbo is an excellent idea. What makes you say the capacity will be about half? For the same power the airflow will be similar for 2 strokes or 4?



Before and after dyno will be very interesting. I always thought it would only be effective in the resonant range of the pipe, and just amplify the pipe effect. But it would be nice if it extended the power range.

It´s a small rule of thumb here in Sweden when turbocharging snowmobiles, use a turbo with twice the capacity then you aim for, i actually dunno why but having a clue.
You blow out boost through exhaust.
Even thou i try to balance the pressureratios and it isn´t blowing out boost, i´ll just have the bonus of extra capacity

Yes it´ll boost the pipe´s area, but 'after' the pipe as in my case having whole lot durations it´ll keep on filling the cylinder but with less effect of the pipe ofcourse.
One has to see what the pipe actually does.
It increases the VE with the pumping in a certain area.
This is also what the turbo does, but in a bigger area.
The pipe i use should have a long 'overrev' from what i have measured, the end cone/baffle is 'wild' 8 degree for example, this often let´s a small engine rev to the skies but with less power ofcourse.
If my ideas work, my powercurve will be looking quite odd for a twostroke.
Kind of a wide ayers rock with falling torque curve instead.
As long as i get my 100hp to the wheel somewhere in the usable rpm area i´m happy.

Started the bike the other day, no silencer *yuck*
Sounded like it didn´t give a damn about the fact it sat a turbo in the end of the pipe.
Same throttlerepsonse as before maybe even better as pipe tunes at lower rpm.
Looked at the turbo and it seemed to spin hard, couldn´t hear any boost thou.

I´m waiting for silencer to show up before i can evaluate some more, i got neighbors sadly enough *lol*

Rgds.

[katinas]

W. Tenney (Bill Tenney) Very sharp engineer / powerboat racer. Won a ton of championships and set a bunch of worlds records. 1930's thru early 1960's. Knew more about nitro in two stokes than everyone on this board combined. His son David is on here and has the fastest 125 hydro in the US. Just won the US National Championship.

Michael

Thanks, and looks like he was very romantic person

https://www.google.com/patents/US2612749

[dtenney]

I see a couple of my fathers patents have shown up on this thread. It was interesting growing up in the Tenney house. Rather than talking sports or politics, we discussed 2 cycle engines. He had many patents in 3 disciplines.....2 cycle engines, Pulse jet engines and fog generation. During WW-2 my father was stationed at Curtis-Wright field in Dayton, Ohio. While there, the airbase received some parts from a V-1 Buzz bomb engine and my father was given the task of building a US version....which he did successfully.

Post the war he sold a model pulse jet engine under the Dynajet brand name. As you would imagine the demand for tis type of product is not too large. At the same time my father figured out that you could actually use the Pulse jet engine to create fog...fog that could be used for carrying insecticides and for a smoke screen. Building pulsejet based foggers and engine powered foggers became a primary business for 40 plus years.

In addition, to building foggers my father was extremely active in boat racing. In the late 50"s he began importing the British Anzani race motor to the US. These motors, running megaphones and up to 40-50 percent nitro were monsters in their day. The test tank for the outboards was outside of the kitchen of our family home. You can imagine the noise. It is a good thing that we lived in the country.

In addition to foggers, my fathers other main line of business was 2 cycle R&D work. The "eye brow" port patents referred to above are an example of that. To showcase the effectiveness of the ports, my father built a single cylinder engine where the "eye brow" ports could be opened and closed manually on the dyno. The results were dramatic. He spent many years defending his "eye brow" patent versus the big Japanese companies, but the amount of legal resources they had simply dwarfed the legal resources he cold muster. Thus, in the end the patent was sold to Yamaha for a relatively small sum of money.

Lesson learned...patents are nice but are very hard to defend.

It is great to see that this web site is helping to keep 2 cycle engines relevant in todays world. The content of this thread is amazing.

In the US I race boats where we use 2 cycle engines and the only rules are bore and stroke based. This is a great play ground for those that like to develop and race 2 cycle engines. Special thanks to Guiseppe Rossi and Carlo Verona(VRP) for helping to keep our sport of Pro(Alky) boat racing alive. They build engines that dominate the sport today.