ESE's works engine tuner

**diesel pig** · 7th May 2013, 22:04

This isn't really anything to do with this thread per say but I reckcon that if anybody has tired what I am going to ask about it would be the people on this thread.
Talking with my old man about the programmable ign it is hard work out what's happening with the engine all the time with the curves and powerjet and what nots
in relation to the power curve. So we wondered if we made a graph starting with a dyno HP curve and then overlaying it with ign advance curve and powerjet off
and on times and other things the programmable ign is doing it using the revs as the common baseline maybe easier to "see" what is going on. Since this would take some work I thought I would ask has
anybody done this? was any help?

**gamma500** · 8th May 2013, 04:43

Originally Posted by wobbly

Here are some engine dyno shots.
SportDevices software is very easy to setup and use, so is 3rd dyno I have built using it.
Gives appox 10 second run time from 8,000 to 15,000 in 4th gear with 46Hp.
Had everything from 50cc scooter to 100Hp RZ500 on it, repeatable to 1/10ths of Hp easily.
And the engine is at my easily accessed level of crippledom.

Thanks Wobbly!

What is the diameter of the inertia wheel shaft?

**wobbly** · 8th May 2013, 08:25

The top shaft with the sprockets/starter gear and the overun clutch is 30mm.
The main shaft is 40mm, and the bearings for this have no trouble supporting the 80Kg odd static load.

**TZ350** · 8th May 2013, 19:00

Originally Posted by diesel pig

Talking with my old man about the programmable ign it is hard work out what's happening with the engine all the time with the curves and powerjet and what nots in relation to the power curve.

So we wondered if we made a graph starting with a dyno HP curve and then overlaying it with ign advance curve and powerjet off and on times and other things the programmable ign is doing using the revs as the common baseline.

Click image for larger version.

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I have not actually done what your trying to do with the graph before myself, but because my ignition advance on WOT covers pretty much the same range as the hp, ie 0 to 30 on the Y axis I mocked up this EngMod2T dyno graph to see what it might look like.

Yellow for ignition advance and blue for power jet on/off.

My graph has the power jet shutting off just past max power to compensate for the natural enriching effect as the air velocity increases through the carb.

And over advancing the ignition at the bottom on WOT is for enhancing drive out of corners, retarding back to normal at peak torque and extra retarding of the ignition past peak power rpm to dump more heat into the pipe for extending the over rev.

I know its just a mockup but graphing manualy WOT ignition and the power jet onto a dyno graph printout could be fairly doable.

**Grumph** · 8th May 2013, 19:54

Originally Posted by diesel pig

This isn't really anything to do with this thread per say but I reckcon that if anybody has tired what I am going to ask about it would be the people on this thread.
Talking with my old man about the programmable ign it is hard work out what's happening with the engine all the time with the curves and powerjet and what nots
in relation to the power curve. So we wondered if we made a graph starting with a dyno HP curve and then overlaying it with ign advance curve and powerjet off
and on times and other things the programmable ign is doing it using the revs as the common baseline maybe easier to "see" what is going on. Since this would take some work I thought I would ask has
anybody done this? was any help?

Do it Neil, bring it along on Saturday and let's all look at it.....

**husaberg** · 8th May 2013, 23:31

Some random Yam TZ125 Crankcase (first 3 pics) is it an illusion or is the main bearing oiling holes actually proud?
Re the Crankcase crankshaft shielding. I have seen Wob do something similar to the Yam cases shielding before. Which i presumed at the time was for primary comp on Yow's RG100.I guess that's not what its entirely for?

For giggles i have thrown in Some NX4 cases.(last 3 pics)

Maybe if Wob feels so inclined he can post a pic or the of the NSR125 inlet and crankcase mouth.

**RomeuPT** · 9th May 2013, 11:37

Hi everybody.

Wobbly, can you say the port timings of a typical Honda 125 A-Kit?

Is there any radius raising the exhaust time like on Aprilia?

Many many thanks

**2T Institute** · 9th May 2013, 16:07

Originally Posted by RomeuPT

Hi everybody.

Wobbly, can you say the port timings of a typical Honda 125 A-Kit?

Is there any radius raising the exhaust time like on Aprilia?

Many many thanks

Something like
Exhaust 80-83
A transfer 113-115
B 113-115
C 117-119

Open ATDC

No radius I don't think HRC were that clever or go hold of an Aprilia cylinder long enough to copy.

**wobbly** · 9th May 2013, 17:26

In reality only factory engineers have ever seen a real A kit cylinder - let alone actually measure one.
But the B kit parts available to teams are a very different setup to the customer bikes.
Several close copies have been made and the setup is Ex 80 with dead flat top edge,A Tr 114.2 B Tr 115.5 Boost 115.8.
The high Exhaust port is difficult to get the powerjet and ignition timing working properly.
But the added blowdown makes alot more power in overev.
Here is a B Kit power curve.

**rgvbaz** · 9th May 2013, 18:28

Originally Posted by 2T Institute

Something like
Exhaust 80-83
A transfer 113-115
B 113-115
C 117-119

Open ATDC

No radius I don't think HRC were that clever or go hold of an Aprilia cylinder long enough to copy.

I had a measure up of a RS 125 cylinder once, It had the a big radius on the top of the exhaust port (like the RSA) and high axial angles on the A transfers. The one thing I did note was that every transfer and the top of the exhaust duct were finished with a file with the score lines in the direction of the gas flow... This is something I saw mentioned by Frits on here, finishing ports with hand tools.

It wasn't a HRC cylinder mind, but a Seel cylinder.

Cheers

Dave

**chrisc** · 9th May 2013, 21:35

Rob, this was the link I was talking about this evening. You posted it back on page 230.

http://www.dirt-bike-tips-and-pics.c...o-strokes.html

and here's another one. The second one talks a lot about injection

http://www.dirt-bike-tips-and-pics.c...sociation.html

**TZ350** · 9th May 2013, 21:47

Thanks ....

**RomeuPT** · 10th May 2013, 01:14

Originally Posted by 2T Institute

Something like
Exhaust 80-83
A transfer 113-115
B 113-115
C 117-119

Open ATDC

No radius I don't think HRC were that clever or go hold of an Aprilia cylinder long enough to copy.

The "crapy" information I have in shows that the good cylinders come with the A transfer much higher, like a 1mm or so than the B transfer. Giving about 136/137º for A and 133/132 for B.

In the photo there are the values to top of cylinder, if we give 0,7 squish deck making tdc 0,7mm below top of cylinder than the transfer timings are way above 130, giving 26,5, 40,5 and 41,5mm from the top of ports to tdc.

**wobbly** · 10th May 2013, 07:46

Crappy info for sure.
Assuming a 0.7mm deck then that cylinder has the Ex @ 81, combined with a 112 main transfer it would then have so little blowdown that a stock customer bike would be way faster.
All of the RS125 types have the A port between 0.5 and 1mm higher than the B, but I can assure you no GP race winners would have had anything like 112 on the transfers.

**RomeuPT** · 10th May 2013, 08:29

Originally Posted by wobbly

Crappy info for sure.
Assuming a 0.7mm deck then that cylinder has the Ex @ 81, combined with a 112 main transfer it would then have so little blowdown that a stock customer bike would be way faster.
All of the RS125 types have the A port between 0.5 and 1mm higher than the B, but I can assure you no GP race winners would have had anything like 112 on the transfers.

Thanks for this info.

It leaves my experience and knowlegde a bit against each other.

Regards