ESE's works engine tuner

[wobbly]

Here is a pic of the oversize studs in place.Just the normal M8 threads screw into the case,with M8 female in the top.
The reeds were VeeForce replacements for Honda RS125 late model, and the rubber manifolds were used as well.

[paul gane]

Here is a pic of the oversize studs in place.Just the normal M8 threads screw into the case,with M8 female in the top.
The reeds were VeeForce replacements for Honda RS125 late model, and the rubber manifolds were used as well.

Thanks Wobbly, thats all clear now. Looks to be well worth all the effort.
Many Thanks......
P. G.

[JanBros]

Any ideas?

for some time I used my Starlane GPS laptimer as a dyno. not that it would give me HP-numbers, but it did gave me very accurate time vs speed grahps and in the end that is all that matters.
just made a "track" on the roads arround my house that included a long stretch of road that's hardly used. once passed the "starline" it started counting, then I simply stopped on the straight and did a "drag-pull", always from the same starting point.

in the starlane software you can very accuratly determine the point where speed rises from zero, and than it gives you the time between any 2 points. you can lay different runs on top of each other and compare them directly.

[koenich]

Previously MicroDyno was free but maybe it still helps: https://play.google.com/store/apps/d...owerdyno&hl=en

[shnaggs]

I have been looking for something like this also, RE. the smart phone dyno. I was under the impression that these apps needed to be hooked up to the vehicle via OBD2 port? I have PerfExprt for my car but have never used it. I will have to investigate these more. The mircrodyno looks interesting, cause it was created for 2 strokes and is capable of reading RPM via frequency.

[lohring]

Microdyno looks like it uses the same method the software on an inertial dyno uses to calculate power. That makes me wonder if it could be tricked to work on an inertial dyno.

Lohring Miller

[adegnes]

Simpledyno
https://sites.google.com/site/simpledyno/home
+ a hall sensor on the wheel and an arduino based tiny computer in your pocket should work great.

Not as quick and cheap as just an app though.

[Greg85]

That A-kit paper is from 1992. You can tell by the picture and the drawing that show the coolant hose nipple still attached to the cylinder.

Cutting the steps out increases the duct volume, which is bad. You may remember my bicycle-pump metaphor.
Filling in the steps until there is a smooth transition to the header is good.

hello frits, I would like you to tell me about your bicycle pump methapor, the theory between the difference between the up and down the good ratio case / comp following a certain volume of combustion chamber, the ex duct height also has an influence the said wobbly. thanks

[Frits Overmars]

hello frits, I would like you to tell me about your bicycle pump methapor, the theory between the difference between the up and down the good ratio case / comp following a certain volume of combustion chamber, the ex duct height also has an influence the said wobbly. thanks

Greg, I'd be glad to oblige, but I hate writing the same thing twice, so I started looking for the original 'bicycle pump' text. I gave up after 20 minutes; forum search functions never seem to do what I need.
Then I remembered that I wrote about it on another forum and I even had a fairly good idea where exactly: http://www.pit-lane.biz/t117p375-gp1...-part-1-locked.

Your question about "the theory between the difference between the up and down the good ratio case / comp following a certain volume of combustion chamber,the ex duct height also has an influence the said wobbly" is too complex for me; I do not understand what it is you are asking.

[Greg85]

Greg, I'd be glad to oblige, but I hate writing the same thing twice, so I started looking for the original 'bicycle pump' text. I gave up after 20 minutes; forum search functions never seem to do what I need.
Then I remembered that I wrote about it on another forum and I even had a fairly good idea where exactly: http://www.pit-lane.biz/t117p375-gp1...-part-1-locked.

Your question about "the theory between the difference between the up and down the good ratio case / comp following a certain volume of combustion chamber,the ex duct height also has an influence the said wobbly" is too complex for me; I do not understand what it is you are asking.

thank you frits for the links pit lane, excuse me I badly formulated my question, I would like to know if there is a report with crankcase compression and compression? I mean balancing the top and the bottom for example decompressed for not braked the piston up and decompressed the case to not brake the piston down to have the right ratio, I saw in a wobbly post and you (p1230) an image showing a calculation for chamber combustion and engmod software asks the crankase compression for that I ask you apparently it's bound as the exhaust duct height thank you( sorry Google traduction)

[RomeuPT]

I have given up trying to interpret the results from flow bench tests,as I believe its only a small part of the overall scavenging regime.
Same with using CNC Jaros type scavenging machine results - this gives the opposite effect, in that is it shows the velocity and vector directions
but takes no account of bulk flow.
The best setup is that used by DEA, a pulsed flow visualizer, but im not that rich.
Here is the best example I can give re the flow bench result.
A reed cage with a nice smooth aerofoil type splitter in front of the reed tips flows way more air than the modified cage I have developed with a thin splitter
and a flat wall,perpendicular to the flow directly under the reed tips.
Guess which setup makes way more power.
VHM show big gains in flow with a flat top piston and a timing edge radius, but the dyno result though near on 1 Hp in near on 50 is nowhere near as significant a result as you would expect.

Do you think this would work on the V-force 2/3? flatening the fins?

Do you have any simple PDF/paper regarding Aerodynamics for motorcycles? Something like newbie concepts etc?

Cheers

[peewee]

thank you frits for the links pit lane, excuse me I badly formulated my question, I would like to know if there is a report with crankcase compression and compression? I mean balancing the top and the bottom for example decompressed for not braked the piston up and decompressed the case to not brake the piston down to have the right ratio, I saw in a wobbly post and you (p1230) an image showing a calculation for chamber combustion and engmod software asks the crankase compression for that I ask you apparently it's bound as the exhaust duct height thank you( sorry Google traduction)

i believe the crankhouse compression ratio should be around 1.32 (+/- .02). compression ratio above the piston will depend alot on the fuel type and perhaps even engine cubic capacity since small engines seem to tolerate high ratios better. maybe less piston surface area has something to do with it ?(standard low grade petrol, racing petrol, , e85, methanol, nitro etc)

[Frits Overmars]

I would like to know if there is a report with crankcase compression and compression? I mean balancing the top and the bottom for example decompressed for not braked the piston up and decompressed the case to not brake the piston down to have the right ratio.

No, balancing the pressures above and below the piston is not a point of consideration. You want a downward-moving piston to push on the con rod as much as possible, so you do not want the crankcase pressure to slow down a downward-moving piston. But after BDC the piston must be accelerated upwards, which requires negative work via the con rod; now you want the crankcase pressure to help accelerate the piston as much as possible.
In short: when the piston is moving down, you want a low crankcase pressure, i.e. a large crankcase volume, and when the piston starts moving upwards, you want a high crankcase pressure. But when the crankcase volume is small, the crankcase pressure will drop fast because of the rising piston, so that is one more argument in favour of a large crankcase volume.
However, all the above factors are unimportant against the requirement for mixture transfer: a large crankcase volume from which the exhaust pipe can suck up as much mixture as possible.

Above the piston, things are much simpler. Let's just look at an engine without ignition and combustion. On its way towards TDC the piston is slowed down by the compression pressure, so this pressure is applying negative energy. But after TDC that same compression pressure is accelerating the piston downward, applying just as much positive energy. In short: compression pressure above the piston is energy-neutral.

Of course, with combustion, things become more biased: a low compression ratio equals a low expansion ratio, leaving more energy in the exhaust gas. And this energy is used by the exhaust pipe in the same way that a turbo would: the more the better.

[Greg85]

No, balancing the pressures above and below the piston is not a point of consideration. You want a downward-moving piston to push on the con rod as much as possible, so you do not want the crankcase pressure to slow down a downward-moving piston. But after BDC the piston must be accelerated upwards, which requires negative work via the con rod; now you want the crankcase pressure to help accelerate the piston as much as possible.
In short: when the piston is moving down, you want a low crankcase pressure, i.e. a large crankcase volume, and when the piston starts moving upwards, you want a high crankcase pressure. But when the crankcase volume is small, the crankcase pressure will drop fast because of the rising piston, so that is one more argument in favour of a large crankcase volume.
However, all the above factors are unimportant against the requirement for mixture transfer: a large crankcase volume from which the exhaust pipe can suck up as much mixture as possible.

Above the piston, things are much simpler. Let's just look at an engine without ignition and combustion. On its way towards TDC the piston is slowed down by the compression pressure, so this pressure is applying negative energy. But after TDC that same compression pressure is accelerating the piston downward, applying just as much positive energy. In short: compression pressure above the piston is energy-neutral.

Of course, with combustion, things become more biased: a low compression ratio equals a low expansion ratio, leaving more energy in the exhaust gas. And this energy is used by the exhaust pipe in the same way that a turbo would: the more the better.

thank you frits for your answer, ok in summary have a large crankcase volume I think around 1.33 for a reed valve is a good base as the said pewee. after us in karting we have a volume respected 13cc minimun so by calculating the theoretical compression ratio is effective it is far from arrived like the RSA which was 14.88: 1? the question is how to do more power with a low rate compression? by increasing the trapping effiency of the cylinder? a better combustion chamber? exhaust adjustement? what do you think about frits? thanks

[Greg85]

i believe the crankhouse compression ratio should be around 1.32 (+/- .02). compression ratio above the piston will depend alot on the fuel type and perhaps even engine cubic capacity since small engines seem to tolerate high ratios better. maybe less piston surface area has something to do with it ?(standard low grade petrol, racing petrol, , e85, methanol, nitro etc)

hi peewee yes single cylinder 125cc and benzin sans plomb 98 total yes you're right it takes a high compression ratio but in karting we have a minimum volume respected 13 cc volume chamber, a low compression ratio, so yes I think be a good base 1.32 1.33 crankcase compression ratio thanks for answer peewee