ESE's works engine tuner

[TZ350]

I know Frits has posted some dimensions for a fantastic pipe in this thread before but buggered if I can find it.

Here you go, and looking forward to some pictures as the build progresses.

[TZ350]

Engmod > Giving it a go myselfs on the little tomos engine, now engmod keeps telling me something exceeds the grid mesh or something, inlet or exhaust pipe to long or short but no mather what I change (nothing weird as far as I can see) it won't go away

Anyone else stumbled into this?

Can you post the pack file or at least screen shots of the Engmod pages and I will see what can be done to get it working.

[F5 Dave]

Its seams the 50cc arms race has well and truly kicked off across the north island of NZ.

I had my first taste of 50 racing on the weekend. As I have said in another thread. I have never had so much fun going so slow. And by slow I mean proper slow on a near stock RS50. The only tools I took to the track were a tyre gauge and a hand pump. Refreshing after a few rounds of racing the NSR300.
Anyway! Its now time to play. And as there is this little event coming up next year. (THE F5 GP). Its time to put the bike on a diet and TRY to double or triple the power.

I will post some pics as I go and share the info here. I know Frits has posted some dimensions for a fantastic pipe in this thread before but buggered if I can find it. Q Moderator of all things internetberg.

What I would like to know is if I wanted to make 18hp. "And who wouldn't" What would the lowest rpm that this might be possible? I know there are quite a few factors to consider but if someone on here has tuned a 50 to that level? It would be nice to know the rpm that it made that power.

About 11, 000 should be enough if you employ normal practice.

Speedpro I'm leaving the door open here but I'll kick off at 80cc. Any advance?

[TZ350]

for 2 years now, I'm into moped-cross. MX with automatic scooters/mopeds. rules are simple : 2 working brakes, needs to be 50cc and engine and frame must be from the same model (so no automatic in a Honda MTX frame for example), great great fun.

Looks great, I would be keen to see more posts as you develop them for more power. I love how you have arranged the pipes and the mid pipe muffler stinger.

[Yow Ling]

What I would like to know is if I wanted to make 18hp. "And who wouldn't" What would the lowest rpm that this might be possible? I know there are quite a few factors to consider but if someone on here has tuned a 50 to that level? It would be nice to know the rpm that it made that power.

Jan Thiel has , but he doesn't come here too often

[peewee]

Frankly, if you don't race or tune 2-strokes, you have no business to be reading this thread, let alone posting on it.

sorry alittle late but ive been working a million hours it seems. some racers probly only ride the machine and know jack shit about the rest of the bike so you would have to narrow down the criteria further. in many places like north america, a 2t tuner simply meens a person who adjusts carburetors, again you would have to narrow things down even further. maybe all the way down to only the folks who do their own work, design their own parts, build their own stuff to the best of their meens, of course proof would be required as talk is cheap now days. ive always thought this section of the site should be private, with proof of past or current projects theyve done. this should keep out 99% of the trouble makers and lurkers who are likely just stealing the info, copying it and passing it off as their own brilliant ideas. you listening moderators ?

while im thinking of it i managed to find a bit of time today to finish the exterior on one of the cylinders

[jasonu]

sorry alittle late but ive been working a million hours it seems. some racers probly only ride the machine and know jack shit about the rest of the bike so you would have to narrow down the criteria further. in many places like north america, a 2t tuner simply meens a person who adjusts carburetors, again you would have to narrow things down even further. maybe all the way down to only the folks who do their own work, design their own parts, build their own stuff to the best of their meens, of course proof would be required as talk is cheap now days. ive always thought this section of the site should be private, with proof of past or current projects theyve done. this should keep out 99% of the trouble makers and lurkers who are likely just stealing the info, copying it and passing it off as their own brilliant ideas. you listening moderators ?

while im thinking of it i managed to find a bit of time today to finish the exterior on one of the cylinders

Does being shiny make it go faster?

[peewee]

when the welds are grinded flat with the burr it just goes shiny on its own. clean aluminum i suppose. u never welded anything i guess . but it is gonna be alot faster than with the pencil dick sized aux ports. sorry i offended you some how. perhaps your a lurker stealing info ?

[MotleyCrue]

Here you go, and looking forward to some pictures as the build progresses.

I am not familiar with the build but I had a simple maybe stupid question, on the top drawing the diameter tapers down then back up again like a nozzle not far from the piston, is this due to rules specifying the diameter or is it there to generate a stronger wave action?

[Lightbulb]

I agree on lowering the transfers if possible.
For what its worth, I have had best luck with my F3D's running the transfers at 125°-130° and exhaust at around 194°-197°.
My, now dead, all time favorite cylinder had plenty of blowdown thoug:
Attachment 317311
Why that particular cylinder outperformed everything else I have tested since I will probably never know.
The way i set it up it was a bit tricky to get on the pipe though, at least if you ask Rob about when he called for me in Melnik ages ago.
-There's more to it than port areas for sure, most of it quite difficult to measure in such small scale.

Thanks guys for the input.
I know that every so many piston /liner sets, you will get one that goes exceptionally well. Yet when you look at roundness, rate of taper from exhaust to tdc, taper from bdc to bottom of the liner etc, you will find nothing.
There will be fast liner sets with out of round liners, by as much as 0.01mm , you will get fast ones that are round to less than 0.001mm. Some will have more taper, some will have less taper. I think the best ones are the ones where the actual port machining is just right. As cutters dull, the ports get smaller. I have seen where the bottom of the exhaust port was widened by 0.1mm and it dropped a whole lot of power.
So I will try some stuff , and will report what works. No point posting what does not work, cause I don't have enough time to type those up.
Neil

[richban]

I am not familiar with the build but I had a simple maybe stupid question, on the top drawing the diameter tapers down then back up again like a nozzle not far from the piston, is this due to rules specifying the diameter or is it there to generate a stronger wave action?

Yeah I was wondering about that as well.

[TZ350]

There is a good reason for it, I will see if I can find Frits original Post.

[TZ350]

... folks who do their own work, design their own parts, build their own stuff to the best of their meens, past or current projects they've done.

Yes, its great to see the work others are doing, I would love it if more people posted about the progress they are making on their projects.

[TZ350]

... on the drawing the diameter tapers down then back up again like a nozzle not far from the piston, is this due to rules specifying the diameter or is it there to generate a stronger wave action?

Yeah I was wondering about that as well.

Here you go ...

A suggestion was made to smooth out the step in the adaptor and try it again. Instinctively, this seemed likely to produce a positive result. In fact it wasn't. The result was worse in every respect. There was less peak power and the powerband was narrower!
Tim

Tim, right now you may be more interested in ' All that you wanted to know about the Aprilia RS50'. Here are some numbers to play around with. Exhaust pipes don't come any simpler than this, but don't let that fool you; this pipe was good for eight championships. Just don't show it to the Poms; year after year they keep trying to beat those Dutch 50 cc bikes .



About the step in the exhaust duct: if there is a step and you remove it, you lose power. I think the main reason is that in removing the step you increase the duct volume. The Malossi cylinder I experimented with has no step at all, but as you can see in the pipe drawing, the exhaust duct is quite narrow. That works.

[Lightbulb]

As a geometric compression ratio, I am at about 16.5:1 or so, sometimes lower sometimes higher, depending on the density altitude. Slowly we are starting to find a correlation to compression and the number of head shims in an engine and the density Altitude, but seems that the RAD % is making more sense in tuning, especially for the needle valve position.
But as we go faster, it seems to change a little, as more load is on the engine the more fuel it can handle, and it seems that it actually seems that it needs more compression to get it to run properly. That maybe why Alex runs a 19:1 compression ratio, and may well be the only way to get them to run at over 290 k's and then they use the fuel to assist in the cooling of the engine, not just the air.
Neil