ESE's works engine tuner

[aljaxon]

Hi,
I tried to adapt the wobbly pipe, #39123, designed for aljaxon to LT= 825mm for my model.
I adjusted the pipe to have the same inlet for a better comparison.
I tried to keep the angles and dimension ratios as much as possible.
I was interested in how close I am to the characteristics of the wobbly pipe, which can be seen on the graph.
I assume that aljaxon could expect a similar characteristic on his moped at lower RPM.

Attachment 354396

out of the 5 pipes ive made since october for this bike the lower "fat" one is the best pipe. stupidly fat 4.7 x belly to ex port area. using the wobbly duct geometry to start things off. ive left the dims off the lower pipes first part but they are the same as the above pipe. the too sharp rear cone doesnt mess things up because i am told the energy has all been used up by the diffusers sharp angles. its annoying because when i stick to the "rules" i get a lesser pipe.

[Gradella23]

wob, i have a question regarding the tm head insert with squish band cooling that you posted some time ago.
You said that this gave a slight improvement, bringing the water near the squish but keeping the chamber hot.

but isn't the water substantially stagnant inside the holes? also in a rapid cfd simulation this is what looks more likely.
Wasn't it better with a continous 3-4mm groove around the same zone? maybe that might have caused some structural issues?

thanks!

[skako]

skako, you can test this one ?
.................................................. ...............................

I need more info in my inbox.

[wobbly]

The water is forced to flow around the annular ring above the drilled cooling holes.
Heated water in the holes naturally migrates toward the cooler water above and is being continuously recycled.
The annular ring is a compromise between beam strength and water flow capability.
This setup gave substantially less background deto level on the dyno , and on track allowed probably 2 jets or 30*C extra egt without deto.

[TZ350]

Just for info I discovered Avejas is advertising his deto knock sensor box again on Ebay - havnt seen it for ages.
Ive used dozens of the things for over 10 years , they work perfectly.
You can order the 0-5V output for data logging - as well as add an ouput that shorts to ground when deto is happening.
This is great with an Ignitech input that retards a setable amount when its grounded.
The Bosch sensor with an 8mm hole can be got for nothing from wreakers or new on Ebay as well.


https://www.ebay.com/itm/18573910441...3Avlp_homepage

would this work with say an rd350A with powerdynamo (vape) ignition? or even a single cylinder moped? im not that bothered if it doesnt do the retard under grounding with every ignition stystem. as long as i get a good early knock detection in order to have enough time to shut off. where does the sensor get mounted? cyl cyl head or crankcase?

[F5 Dave]

As you were. I'd thought there was problems with Air-cooled. I'd modded to water cooled for everything by then.
Still have to make special head bolts and be careful with torque evenly.

Sorry if I put you crook.

[Gradella23]

The water is forced to flow around the annular ring above the drilled cooling holes.
Heated water in the holes naturally migrates toward the cooler water above and is being continuously recycled.
The annular ring is a compromise between beam strength and water flow capability.
This setup gave substantially less background deto level on the dyno , and on track allowed probably 2 jets or 30*C extra egt without deto.

thanks, on cfd it's not easy to weight the natural convection from the holes to the upper cool flow, but you absolutely have a point here.

Have you tried the deeper annular ring solution? maybe half the depth of the holes for example.
Is it really critical from a strenght perspective? worth trying?

[katinas]

Tested this similar squish cooling type, but without holes. Flow rise up from the cylinder and then arranged down to squish area by cover deflector and then rise to outlet near spark plug.
Both piece made from 7075, but still not cracking.

[philou]

a test of Mota simulator automatic exhaust optimization feature.

this could be an additional function to bring to engmod

[rgvbaz]

a test of Mota simulator automatic exhaust optimization feature.

this could be an additional function to bring to engmod

Hi,

Just to note: the pipe in the latest video at Mick's isn't the same as the one in the video about the Mota optimiser. I'd like to build that one at some point to see how the inverse baffle will work in reality.

Cheers

Dave

[wobbly]

Inverse angle rear cones have never worked , unless its some very very weird application or particular effect being sought.
A generality I know but I tried several variations in Dynamation before Neels came along.
This geometry makes a high amplitude return wave very early in the plugging process with the piston closer to BDC where it should be still evacuating.

[skako]

skako, you can test this one ?

Édit : 13 mm leak tube for 50cc o_0 it will break. the oil film in the cylinder will burn on the exhaust side

Hi,
Here I tried to adapt Philou suggestion.
The simulation and the drawing for comparison are on the graph.


I also tried to adjust the A.I. pipe design for my 50cc model. Simulations for comparison are on the graph.


I still think that the FOS pipe can be adjusted well for engine.

[F5 Dave]

Hi,

Just to note: the pipe in the latest video at Mick's isn't the same as the one in the video about the Mota optimiser. I'd like to build that one at some point to see how the inverse baffle will work in reality.

Cheers

Dave

So why still the low revs?

Old road 125s did 25hp and managed 100mph. To do it with only 20 you'll need a great fairing and tiny rider I'd expect with spot on gearing and some luck.

Or, just attn to the crank bearing /rod choice and rings that cope with the revs without fluttering, push revs up 2000 rpm and 25hp will be easy. You're not building a high mileage bike are you?

[rgvbaz]

So why still the low revs?

Old road 125s did 25hp and managed 100mph. To do it with only 20 you'll need a great fairing and tiny rider I'd expect with spot on gearing and some luck.

Or, just attn to the crank bearing /rod choice and rings that cope with the revs without fluttering, push revs up 2000 rpm and 25hp will be easy. You're not building a high mileage bike are you?

Hi Dave,

Yeah, I'm certainly not there yet. Going by the previous attempt in Practical Sports Bikes I need at least another 3-4 hp. They had real issues pulling top gear so I'm contious of moving peak too high and reducing the power range.

I'll have a look at the STA available at a higher rpm.

I'm currently on a dykes ring piston. I'd like to swap to something single ring but the 12mm piston pin and 54.5mm bore are an issue. I do have a early RM rod that will fit the crank and would use a 14mm piston pin piston (CR125 1984?)

So many different things to try 😀


Cheers

Dave

[TZ350]

I did try " fixing " the T port by having the outer edges the highest , to ameliorate the huge difference in duct lengths the T suffers from.

Our interpretation of Woblys idea of having the outer edges of the T port the highest.

Not sure if this is correct, Wob and the Dyno will tell us soon enough I guess.