ESE's works engine tuner

[TZ350]

If you don't mind me asking what tool do you use to change the transfer port heights? I'v noted your use of the long shaft die grind bits (very helpful!) and of course the dremel with flex shaft is magic for final port shape etc but the transfer ports seem pretty hard to get at. I don't know any dentists, is there another tool/method?

Yes, I find the transfers hard to get at too. I use a battery drill and those long shaft die grinder bits and a dremmel with small ball stones.

Its not easy to make a smooth angled port roof but with care you can make a reasionable job.



The pro porters will undoubtably have better gear and make a better job, but we work with what we have.

Just have a go, this is Buckets and we are allowed to just, give it a try and learn as we go along.

Below is a post showing how we hogged the ports out, got them wrong and then filled them with Devcon to get a smooth shape and the timing we wanted, the devcon stayed in the transfer ports ok.

Rebored the cylinder and chamfered the ports before gluing up the transfer porting mistakes, actually over cutting the transfers and then gluing them back up turns out to be a real easy way to get a smooth symmetrical port.

[TZ350]

Page 240

Links and Interesting Quotes from the last 10 pages, other link lists can found on the decade pages starting with Page 80.

A handy (and cheap $16 USD) Porting Calculator from:- http://www.porting-programs.com/ is based on Blairs and Jennings work.

Some more RSA125 development info from Jan Thiel
"No pressure transducers were ever used in our engine development.
And time/aerea was never calculated.
The port timings remained practically the same during 15 years!
What we did was trying different angles and radiuses, mainly on
the transfer ducts. I think we tried 40 different types of transfer ducts
that did not chanche the time/aerea. It was all about in which direction
the charge entered the cilinder and how the tranfer streams influenced upon
each other! Also about 200 different exhaust pipes were tried. After 2004
nothing much was changed but we improved with different power jet and
ignition mapping. It seemed nearly impossible to improve the transfer ducts
any more. The exhaust ducts were CNC machined, using different programs,
mainly to reduce exhaust duct volume. Also about 100 head designs were tried"

And Kel gave me this link to a very interesting book. www.prme.nl/download/engine-1.pdf

Yes, dead right the STA numbers havnt changed at all since the theoretical work was published out of Queens in Belfast by Blair etal.

But Thiels comments about the ports is a bit misleading really.
Aprilia completely changed the whole layout from previous 3 port geometry.

Instead of the main port being right at the 72% limit, they reduced this to 68% and dropped the main transfers below the rest.This enabled the large secondary Ex ports to be added, plus gave room to pull all the transfers around and create more area with less timing.

What this lead the way with,is being shown all the time now in the sims I run, that the Ex STA means jack shit, Blow Down STA is Everything.

"I measured up the difference between the transfer height and exhaust of the 27 and 29 hp cylinders today and it is only 0.5mm" (TeeZee).

That difference is HUGE in relationship to the transfer STA, and thus its effect on the Blowdown.
For example a 0.5mm change would raise a port from say 115.8ATDC to 114.5ATDC in a 50mm stroke engine.

That is a duration change of 131 Vs 128.4 ie 2.6* - night and day, when you consider that in a KT100 kart engine changing the transfers by 0.1mm = a difference of 1.5 Hp in 18.

When you are at the outer limits of what a porting setup can achieve, then tiny differences make a big effect.

Ive been playing with engine performance and evaluation software called lesoft. Its adaptable to both 2 and 4 strokes ……. if anyone else wants to give this software a go its available free from http://www.lotuscars.com/engineering...ware-downloads Attachment 232240

Get Kev to fill in the inputs needed for my header design program I gave him a while ago, easy to make a screamer if the FXR hardware is able to be "fixed" properly.

You have to print the attachment and fill it in, scan and send to me.

www.FXR150.co.nz there are one or two more very fast 2-strokers in the pipe line.

Brens driveway test: http://www.youtube.com/watch?v=gPPq69799XI

From Koba good links of old lathes if you like such things http://www.lathes.co.uk/

Carbon Fibre Pistons http://www.techbriefs.com/component/...t/article/2258

Dont be a big girls blouse - the FXR with 48.8 stroke should be at 13000 all day, its well under 4500 ft/min and the pressure fed big ends are way less prone to cage skidding causing failure.

No one has managed to get "ringless" pistons to work in a normal sized bore on petrol, but a company I work for has a patent on a trapped piston ring that allows a T port with no bridge. See http://www.wipo.int/pctdb/en/wo.jsp?WO=2005121608

Posted before but still interesting. http://www.madsci.org/posts/archives...3778.Ph.r.html

The normal ignition takes care of the ionisation channel; then as soon as the current starts to flow, the Emot-set sends a big extra current through this channel. It looks like this: http://www.youtube.com/watch?v=7BfQuxyWN90

Here is a test I did ages ago when I was pissed at having to pay $140 for shorty RS125 plugs - and more for the cap..
The test shows 4 different 10.5 plugs in a 3 time Nationals winning 125 kart engine,and each curve is a 3 run average.
Red is B105EGV .
Lime is Denso TAE01-32 ( later Honda replacement for the NGK shorty)
Brown is NGK R6252K - 10.5 ( kawasaki 125 special)
Orange is NGK R6120A - 10.5 Shorty Iridium as sold by Honda.
The trick plug is worth a couple of Hp , this can be bought now as a normal length plug with the Iridium center and Platinum Earth as NGK R7376 for about 1/2 the price, and uses a normal plug cap.

I spent months learning how to do real nice blown pipes when I worked for JL in England and we were contracted by ZipKart to do some special pipes for the British Superkart GP at Silverstone.No matter what I did I couldnt get the same power as the hand made cone pipes.
The problem is that no matter how you do it, the changes in area are "smeared" together, especially around the mid section.
Finally we decided to make the curved header part only as a blown section, as this is very time consuming when welding alot of sections together.
This combination actually made 1.5 Hp per pipe more ( only the front pipe is curved on a Superkart).
If you look at Honda factory bikes the pipes are pressed in 2 halves and have very sharp "corners" where the angles change.
And the last GP pipes I had anything to do with - the 250 KTM, were made this way.

The powerjet carb is controlled by the Ignitech with a combination of throttle position and rpm in a "truth table".
In general the solenoid is activated with 12V ( no fuel flowing) below 4000 rpm and 75% throttle on the TPS.

Above 75% and around 12400 rpm it is activated again to lean off the fuel curve over the top of the pipe.
Looks like you will be able to reverse the fuel exit, blocking off the hole on the throttle bore side, and take off fuel from the outside bung, thru a needle jet and into the top of the venturi next to the slide.

Well funilly enough that (concave dome) Kawasaki piston gave rise to the idea of a toroid shape. I think they were trying to get the plug closer to the centre of the combustion area, but of course it shagged the squish action as well as the transfer flow regime. The toroid shape does everything right and there is no reason to use anything else.

There are over 1,200 images on this thread, to find the interesting ones use “Thread Tools”, then “View Images” near the top of this page. You can view the images 70 at a time from the beginning. It’s a quick way to find some of the interesting posts too.

[koba]

Yes, I find the transfers hard to get at too. I use a battery drill and those long shaft die grinder bits and a dremmel with small ball stones.

Its not easy to make a smoth angled port roof but with care you can make a reasionable job.



The pro porters will undoubtably have better gear and make a better job, but we work with what we have.

Just have a go, this is Buckets and we are allowed to just, give it a try and learn as we go along.

Here is a post showing how we hogged the ports out, got them wrong and then filled them with Devcon to get a smooth shape and the timing we wanted, the devcon stayed in the transfer ports ok.

Have I mentioned I have lust eyes for old lathes?

Here is a pic of the one I've used most, It belongs to the old mans mate and is pretty old. It has the old flat leather belts and some of the tooling used on it he bought back from the second world war.

Edit: good link if you like such things http://www.lathes.co.uk/

[Yow Ling]

Have I mentioned I have lust eyes for old lathes?

Here is a pic of the one I've used most, It belongs to the old mans mate and is pretty old. It has the old flat leather belts and some of the tooling used on it he bought back from the second world war.

Edit: good link if you like such things http://www.lathes.co.uk/

in the 70's there was a tv show called Logans run, was it inspired by this lathe ?
the lathes site is the last word if you are reasearching old machinery, doesnt havre much east european stuff though

[koba]

in the 70's there was a tv show called Logans run, was it inspired by this lathe ?
the lathes site is the last word if you are reasearching old machinery, doesnt havre much east european stuff though

I'm a bit young to know... younger than both!

Yeah, there is definatley plenty more stuff from around the world.

[wobbly]

Just one thing to add here re the screamer 100 engines we are looking at building.
To make the sort of power we are looking for, we have to use around 200* of Exhaust timing.
This works with a TL of around 800mm to give power up to the 14000 mark.
But this timing and pipe length is a resonance mismatch.
For it to work, and rev that high, we HAVE to use a solenoid powerjet, to get heat into the pipe ( along with pulling out timing to near TDC ).
This combination will not run above the power peak on a normal carb.
To get power and revs with a "normal" carb requires a timing of around 83* ATDC and a tuned length of around 830, but this seriously limits the blowdown STA and thus the power that can be achieved.

And I use a 182MC right angle head ,available from C C Speciality in the States, for porting the transfers - but I hate it with a passion.

[k14]

Just one thing to add here re the screamer 100 engines we are looking at building.
To make the sort of power we are looking for, we have to use around 200* of Exhaust timing.
This works with a TL of around 800mm to give power up to the 14000 mark.
But this timing and pipe length is a resonance mismatch.
For it to work, and rev that high, we HAVE to use a solenoid powerjet, to get heat into the pipe ( along with pulling out timing to near TDC ).
This combination will not run above the power peak on a normal carb.
To get power and revs with a "normal" carb requires a timing of around 83* ATDC and a tuned length of around 830, but this seriously limits the blowdown STA and thus the power that can be achieved.

And I use a 182MC right angle head ,available from C C Speciality in the States, for porting the transfers - but I hate it with a passion.

Glad you cleared that up, I was just going to bring that up...

[RMS eng]

Just one thing to add here re the screamer 100 engines we are looking at building.
To make the sort of power we are looking for, we have to use around 200* of Exhaust timing.
This works with a TL of around 800mm to give power up to the 14000 mark.
But this timing and pipe length is a resonance mismatch.
For it to work, and rev that high, we HAVE to use a solenoid powerjet, to get heat into the pipe ( along with pulling out timing to near TDC ).
This combination will not run above the power peak on a normal carb.
To get power and revs with a "normal" carb requires a timing of around 83* ATDC and a tuned length of around 830, but this seriously limits the blowdown STA and thus the power that can be achieved.

And I use a 182MC right angle head ,available from C C Speciality in the States, for porting the transfers - but I hate it with a passion.

200* and 14000 rpm will be hard work to get a fast lap time on kart track,

[wobbly]

Well here is a set of curves for a hot customer RS125in green, the other two curves are 200* and short pipe, what is called the A Kit spec..
One is with the PV working - the other locked up.
Note it makes over 40 Hp from 11500 to 14000 and peaks at 50.
This sort of fat spread doesnt even need a close ratio box, and if you tanslate this sort of performance to the 100cc with the PV working, it would make the MB100 of MIkes or NoMates RG100 look sick - and since when did Nomates ever get beaten at Mt Welly when he didnt bugger it.

[RMS eng]

Well here is a set of curves for a hot customer RS125in green, the other two curves are 200* and short pipe, what is called the A Kit spec..
One is with the PV working - the other locked up.
Note it makes over 40 Hp from 11500 to 14000 and peaks at 50.
This sort of fat spread doesnt even need a close ratio box, and if you tanslate this sort of performance to the 100cc with the PV working, it would make the MB100 of MIkes or NoMates RG100 look sick - and since when did Nomates ever get beaten at Mt Welly when he didnt bugger it.

NoMates is a good rider,but hasn't been to the track for a while,he may have to work for a win with one of the 21 hp derbi 80 s.have to keep an eye out for a RS100 A kit.

[Buckets4Me]

NoMates is a good rider,but hasn't been to the track for a while,he may have to work for a win with one of the 21 hp derbi 80 s.have to keep an eye out for a RS100 A kit.

wont take him long to knock a N D off the track
and we all know he will do it and what the outcome will be (oh wait thats why he hasn't been back for so long)

[wobbly]

Nigel NoMates has a crushed vertebrae in his back, and had sent his cylinder away for plating on the cast iron, that is why he hasnt raced for a while.
But as I say ,the new engines having the same sort of spread as the A Kit RS125, but peak at say 33Hp, then that will give the lie to 200* and 14000 being hard to ride.

[jasonu]

since when did Nomates ever get beaten at Mt Welly when he didnt bugger it.

Or knock his competitors off...

[TZ350]

Raised transfers from 116 blue line to opening 114 ATDC red line.



I was expecting to maybe lose something off the top because of the reduced blow down, and fatten the bottom end but this is the other way??????

Must have done something wrong.......



Fiddling with the ignition curve and jetting I can get a bit more out of the curve higher up but the bottom is still stubbinly weak.

It sure is easier to lose hp than gain it.

[TZ350]

Got it..........



First ever dyno graph posted of a Bucket cracking 30rwhp

Air cooled, rotary valved 1978 Suzuki GP125 Engine on a DynoJet dyno.