2 stroke thread (with occasional F1 relevance!)

[Muniix]

I was initially moderately impressed with the design concept, more conventional engineers in the industry I'd showed it to not as impressed as I was, apperently couldn't just see it for the concept ignoring everything else.

...your toasted... ..insane... ...terrible design.

<padding snipped out>



<further padding snipped>

It has a split personality to its design.


Cherry picked...

Facts to back these statements up, i've driven a Audi A3 TDI and the DSG changes up at 6,000 when you sink your foot in sport mode.

Addintionally Banks power run their modified Ford ecotec V6 diesels at 6,000, they would go faster as Gale Banks now knows. He architected the software with a 6,000rpm limit, he now regrets that decision. Talk to him he will confirm this.
...silly opinion...
Plots are for school kids... we are not in primary school here.

I think everybody gets the idea, manolis has not realised we want facts.

Marc, despite having been provided with direct feedback, it seems you are unable to check/moderate yourself, or demonstrate an acceptable level of polite discourse.. ..&, your disregard of forum norms - amounts to trolling..
..evidently you have no concept of communal decency or personal shame.. its quite a lack, & does you no credit..

Look up 'pot/kettle/black' - as a concept.. it is how you operate here.. & at a 'primary school kid' level of maturity..

Anyhow..

Obviously such CI machines as the Audi - as a sporty passenger car, are in a different class to industrial-type engines..

I specifically raised the claim on diesel combustion speed, that has nothing to do with class of engine.
How hard can it be to control an engine properly, or is auto engineering just squirt and hope for the best, and eff the consequences?
Ignoring all the hard work researches perform, insulting them by repeating claims that contradict the effort each one has done on improving on previous efforts.
One should try to turn quality up to 11.

I do note however, that Audi have withdrawn from CI competition motor sports, in which they had been granted
various 'Formula' advantages over SI engines - in order to compete.. perhaps due to VW-Audi CI emissions scandals?

& 2T CI engines are under renewed focus as 4T engine emission levels of diesel fuel particulates are targeted for bans..

I specifically asked how to
challenge a vendors repeating claims that would appear to be false, 1st attempt is all very official as I would do on a Multi million dollar project, when the vendor continues to insult everybodies intelligence by repeating same claim in all communication ignoring the published and well known knowledge, then one has to treat it for what it is, call a black kettle black.

So help me understand the issue here please, or is it just one persons opinion?

On DieselGate Emissions scandal that BMW, VW and many others were cought out on, VW not being the worse offender by any means.

I note the method to measure emissions are very different to how one would evolve the engine operation strategies to achieve high power and lowest emmisions for total distance traveled.

Whereas emmisions are measured as an absolute, go over the line in an instant you fail. Regardless if you use less total fuel or less total emmisions.

That is what was explained to me by someone I trust he said it was the way the do the test that is not real world relevant.

Would also explain why none of the developers blew the whistle on it, they could justify it to theselves because they were achieving good efficiency of he limited fossil fuel on this planet. That and that they were all doing it some worse than others, and if they didn't they would not be competitive in the industry.

Having to blow the whistle myself once on a $60m project and the Queensland Police Polaris project by putting it on the front page of the states major news paper.
Corruption, incompetance, something was going on.

when I identified the project was going to fail in the first week I started as I'd worked on the largest system in the world like it, I wrote a paper detailing exactly how and why it was going to fail what they would expect to see as it was failing. What was needed to fix it, they already had a license for it a TP monitor, but only used it to do transactions with foreign IBM Mainframe systems, so solution was zero cost, just do the system properly. They refused to take on the indispute evidence in the paper I wrote, declaring they would not use it as the first thing they stated. So I left the project, not wanting to be involved with a failing project, I've allways worked on successful projects, walking away from a well paying gig..

They stumbled on for 5 years, milking the project for $150hr, then when the money ran out QPS scanned in old unpaid fines from decades ago, grand parents where getting locked up for unpaid fines from when they were 17, raped, bashed etc. so I blew the whistle on them destroying their careers. "mummy is uncle bob going mad or did he really get rapped by a female screw and get his teeth knocked out walking in front of someone in the exercise yard on his first day in Jail, that is what he said in court under oath"

It is not me repeating falsehoods..

I only repeat the challenge until they acknowledge it.

It is not me with;

"disregard of forum norms - amounts to trolling..
..evidently you have no concept of communal decency or personal shame.. its quite a lack, & does you no credit.."

What words are ok, clearly these ones have been used;
Nonsense, i'm sure others like this have been, so how is preschool different.

[Muniix]

Cancelled out by the extra engine speed needed, lack of turbulence, heat loss etc. You are cherry picking information again to support a silly opinion that doesn't stand up to challenge.

Manolis claimed the availability of 30% higher revs as a benefit of the slow piston motion not a necessity. It is circular to argue that the extra speed is needed, then claim that the slow piston motion causes loss of turbulence when in fact at 30% higher revs the piston motion near TDC is the same and therefore produces the same turbulence.

Anyway, as I stated previously, turbulence is simply designed-in, after the architecture, piston motion and engine speed have been determined. There is no loss of turbulence.

Your language puzzles me. Where is the need call someone's opinion "silly"? Especially when it is not silly at all. "Doesn't stand up to challenge"? You have not provided any evidence to support your "challenge". In fact your "challenge" is as weak as water.

This plot :
http://www.pattakon.com/tempman/pre_comp.GIF
shows that during most of the compression and the expansion, the piston of the PatOP moves, more or less, as fast as the piston of the conventional, and that during the end part of the piston stroke the piston of the PatOP “stops” and gives time to the combustion.

Plots are for school kids, engineers use graphs of actual data. Post data, we are not in primary school here.
Anyway, this is where all the turbulence dissapates nearly completely.

More unnecessarily derogatory language. The plot does exactly what the poster claims. It illustrates the piston motion - EXACTLY! No need for experimental data. Some mid-level trigonometry is all that's required to verify the accuracy of the plot.

A split personality engine is going to reveal split personality responses to its analsys, that is a given.

An engine that consideres all the relevant issues and attempts to integrate a solution with minimal compromises. A whole of system solution, ...

... as apposed to a design with split personalities leading any analysis to confusion due to which personality your inherrent confirmation bias puts you on.

Confusion rules supreme.

Would love to run some gramatical analsys over comments, but I fear typos, lack of domain specific knowledge and terminology would make it pointless.

[J.A.W.]

Marc writes:
"Its not me."
But it is.. so do yourself a favour - try this: https://psychology-tools.com/autism-spectrum-quotient/

[Muniix]

Marc writes:
"Its not me."
But it is.. so do yourself a favour - try this: https://psychology-tools.com/autism-spectrum-quotient/

I'm not the one disrespecting the hard work and efforts of researches who stand on the shoulders of giants in the field. I gave a specific example the most referece powertrain research on the effects of variable inertia on vibration and fuel use was dismissed by manolis as shown by his respose below;

"Thanks for the PDF. It is strange how many "specialists" write "papers" for such a simple problem.

That is not what other researches think!!!

Creating the most accurate models for simulation of powertrains.

Something he has never attempted to do, why because it would highlight issues in his designs he would rather not know about.

He thinks something he wrote in dos decades ago is superior!!! Likely he has never heard of test driven development, let alone behavior driven development where you actually test behaviour against reality.

My simulations are TDD with BDD and when the software is modified all tests are run automatically, checking a simulation against published exerimental data.

He didn't know that with floating point calculation;

0.1 +0.2 != 0.3

and dismissed the known issues of using a financial math library for scientific purposes.

You can guess how many systems I've had to fix because of incompetant people implementing them, it is a lot!!

I make sure they can never do damage again, cause pain to anyone else, disaster and waste. It is a duty, to rid the world of such people, if they refuse to learn, they have to be eliminated.

Your score was 21 out of a possible 50.
Scores in the 0 - 25 range indicate little or no Autistic traits.

Answered as accurately as I could.

There are some good sites to asses bias, confirmation bias i've learned techniues how to eliminate.

As a developer constantly improving ones craft, you are constantly learning how people work to create effective solutions and identify human biases, strengths and weaknesses.

Humans are not good at certain things. So one has to implement strategies to improve quality and the outcome.

[Muniix]

If you can get some pressure and temperature sensors in useful places, then sampling them with a cheap analyser, seeed studio have a cheep analyser that can be programmed with high sample rate, Infineon have crank angle sensor released this year and other sensors, from that you can get a better understanding of what is going on. A Sensata cylinder pressure only sensor would really help and not as expensive as a Kistler sensor though only good for 15k samples a second.

Thanks, but I suspect what you suggest is beyond my capabilities. Never say never though, depends on the progress I make and where I may end up with it.
For now, I want to reduce UBHC to a level I can pass a UK MOT test. If I can achieve that then I can sling one of the Mercs into a currentish road car (otherwise it's pre 1975 or build from scratch) and do mpg comparison tests between standard and modified. This I suspect will be for my own benefit only - I doubt that it can be commercialised.

What I was refering to was this;
The DSO Nano V3.

https://m.seeedstudio.com/detail/1358

You can download the manual pdf document to check it out.

The forums available will help you use it and people are active on there to help.

For under US$100 you get this;

The DSO Nano V3 is a pocket-size compatible 32bit digital storage oscilloscope. Based on ARM -M3, it’s equipped with 320*240 color display, SD card, USB port and recharging function. It’s compact, simple to operate; meets the basic demands of school lab, electric furniture repairment and electric engineering.
Features

Portable and lightweight

Color display

Waveform storage and playback

6 triggering modes

200Khz Analog Bandwidth

Complete measurement markers and signal characteristics

Built-in Signal Generator

Accessories available

Open Source

Specification

Display: 2.8'' color TFT LCD

Display Resolution: 320x240 Display Colors 65K

Analog Broadband: 0 ~ 200kHz

Max. Sampling Rate: 1Msps 12 bit

Sampling Storage Depth: 4096 points

Transverse Sensitivity: 1uS/Div~10S/Div(1-2-5 stepping)

Vertical Sensitivity: 10mv/Div~10V/Div(x1 probe) 0.5V/Div~10V/Div(x10 probe)

Input Resistance: >500KΩ

Max. Input Voltage: 40Vpp（x1 probe）400Vpp(x10 probe)

Coupling Mode: DC

Triggering Mode: Auto，Normal，Single，None

Auto Measurement: Frequency, cycle, duty, Vpp, Vram, Vavg, DC voltage; Vertical Precise Measurement Cursor; Horizontal Precise Measurement Cursor; Rising/Falling Edge Trigger; Triggering Cursor; Triggering Sensitivity Cursor; Hold/Run

Inbuilt Test Signal: 10Hz~1MHz(1-2-5 stepping)

Waveform Storage: build-in 2Mbyte

PC Connection Interface: Connection through USB

You could get it to sample a sensor on trigger of crank position or a condition. Could be worth the expense, can't hurt the wallet much and likely you can use it for many thins once you get used to it.

We used to pay tens of thousands for such equipment.

Seeed Studio have a very good reputation. I have not used of these, it does seem very useful for the cost.

Interfaces to your pc via usb, where you can upload the data and do useful things with the digital data.

[Pinger]

Thanks Manolis and Muniix for earlier replies to questions I asked.

Thanks also Muniix for the info on Seeed Studio kit. For now, I'm waiting for a low cost analyser with which I intend to try and get a grip of UBHC at various transfer port opening times (on the Zenoah). It isn't designed for high temp though so I will have to collect exhaust gas and allow it to cool before measurement is possible. No problem for idle (first priority) but instantaneous under load (when I get to that) will be more problematic so possibly then more sophisticated data capture will be in order.
Really though, I'm just an amateur tinkerer who wants to civilise a touch the worst traits of the simplest of 2T for my own use. I had hoped that what I am investigating could be commercialised but as a 'concept' I'm beaten to the draw (assisted scavenging and Primivus(?)). Which only leaves full scale production of a unit ready to do immediate service as say, a range extender - but we all know what an undertaking that is. So back to amateur tinkering.
I'm hopeful I can get some gains from what I'm working on but am realistic enough to know there are no guarantees and that I need hard measurement to make my case. By next week (hopefully) I will have a better idea. Then it's either further refinement and transfering to the larger Mercury motors, or... Or if it doesn't work, a decision to accept that as fact or push further to ascertain why.
I appreciate the help and advice from this forum so far - and imagine I'll be asking quite a few more questions yet!

[manolis]

Hello all.


The following “slides” are from the balance.exe program (it is written in QuickBasic, it requires DOS environment and it is available at http://www.pattakon.com/pattakonEduc.htm ) and explain, among others, how the balance.exe program calculates what it calculates and what it can do.



























The balance program is based on Newton’s laws and on simple geometry / physics.


For those who know what Fourier Analysis means, do play with it.


For those who want to add balance shaft in a strange or typical arrangement engine and check the results (the remaining free inertia forces, moments and torque), it is more than easy.

If anybody can find errors, please let me know.

If anybody wants to transfer it to Visual Basic, please let me know (to give him the code).


Thanks
Manolis Pattakos

[Muniix]

Marc writes:
"Its not me."
But it is.. so do yourself a favour - try this: https://psychology-tools.com/autism-spectrum-quotient/

I'm not the one disrespecting the hard work and efforts of researches who stand on the shoulders of giants in the field. I gave a specific example the most referece powertrain research on the effects of variable inertia on vibration and fuel use was dismissed by manolis as shown by his respose below;

"Thanks for the PDF. It is strange how many "specialists" write "papers" for such a simple problem.

That is not what other researches think!!!

Creating the most accurate models for simulation of powertrains.

Something he has never attempted to do, why because it would highlight issues in his designs he would rather not know about.

He thinks something he wrote in dos decades ago is superior!!! Likely he has never heard of test driven development, let alone behavior driven development where you actually test behaviour against reality.

He brought up where the researcher found errors in another researchers published work with phase convention. Then gives me a spreadsheet with the exact same issue! The crank rotation was backwards, then makes a statement that I'm wrong, no he's ass about didn't know it or check and declares himself right. Now what conclusion can one draw from this behaviour? Are they thorough, careful, check their work before saying someone else is wrong.

My simulations are TDD with BDD and when the software is modified all tests are run automatically, checking a simulation against published exerimental data.

He didn't know that with floating point calculation;

0.1 +0.2 != 0.3

and dismissed the known issues of using a financial math library for scientific purposes.

You can guess how many systems I've had to fix because of incompetant people implementing them, it is a lot!!

I make sure they can never do damage again, cause pain to anyone else, disaster and waste. It is a duty, to rid the world of such people, if they refuse to learn, they have to be eliminated.

Your score was 21 out of a possible 50.
Scores in the 0 - 25 range indicate little or no Autistic traits.

Answered as accurately as I could.

There are some good sites to asses bias, confirmation bias i've learned techniues how to eliminate.

As a developer constantly improving ones craft, you are constantly learning how people work to create effective solutions and identify human biases, strengths and weaknesses.

Humans are not good at certain things. So one has to implement strategies to improve quality and the outcome.

[henry]

Manolis: the advantages of the increased dwell at TDC of your engine are an obviously important claim. The most significant challenge for diesel engine manufacturers today appears to be control of NOx and particulates. Do you know of any research that would suggest that the longer mix and burn you anticipate would help, or hinder, or make no difference to the pursuit of lowering these emissions?

On related point, given this slow approach to TDC is there a possibility that the specific point of combustion initiation might vary more than a more conventional design? I assume that the combustion actually starts over a range of pressure/temperature values and in your design these seem likely to occur over a wider range of crank angle. Might this have noise and vibration repercussions?

[63l8qrrfy6]

From an official data base source: http://www.marinecouncil.org.au/engine-database/

Two engines compared, 250hp class S.I.,outboard motors:

1, 2T cylinder ported, crankcase scavenged DI - Evinrude G2.
2, 4T OHC variable valve timing fuel injected - Honda.

Both are premium CARB 3-star emissions rated: HC/NOx & CO, respectively.

1, Evinrude 2T; HC/NOx 12.2; CO 48.7.
2, Honda 4T; HC/NOx 13.2; CO 91.7.

HC is hydrocarbon - from burning fuel & oil, - & as can be seen..
.. the 2T does not show excessive oil loss via its construction of cylinder ports being swept by piston/rings..

I hope you are now past your emotional outburst and can have a normal conversation.

From that very website:

Traditional two strokes (carburetor or EFI, but not direct injection DI) are much higher emitters of HC. This is in part because unburnt fuel and oil are pushed out the exhaust during ( which also explains the higher fuel consumption) . two stroke fuel is a mixture of petrol and oil – and this also adds to the HC load.

In addition, I think modern high ester low ash 2 stroke oils do not emit as much HC as 4 stroke oils.
This tells me that HC emissions are not a reliable way to quantify oil consumption.

"Emotional outburst"?
Mf, still with the 'projection' I see.. its a maladaptive response, & not "normal", y'know..

Anyhow, re: 'traditional' old style 2T engines - what purpose is served by stating the obvious?

Current 2T DI engines utilize discretely metered quantities of fresh, clean lubricant injected to specific points within the engine, under precise computer control - unlike the 'traditional' 2T 'wash-through' of 'premix' fuel/oil..
Never-the-less, both methods are 'total loss', with the lube burned & emitted along with the fuel residues.

The CO emissions levels tell their own story about combustion efficacy though, of course..

Current outboards whether 2T or 4T specify modern oils, with synthetic ester bases, & consumption rates are
easily checked by reference to levels, in the tank for 2Ts, & crankcase/sump for 4Ts..

So do you agree that HC emissons are not a reliable method of quantifying oil consumption ?

[J.A.W.]

So do you agree that HC emissons are not a reliable method of quantifying oil consumption ?

Mf, now you are blatantly trolling.. ..dipstick.. comes to mind..

Obviously oil consumption affects HC emissions measurements.. & 'old school' 2Ts leave a tell-tale of visible oil smoke..
But oil consumption checked against engine specifications - via volume actually consumed - is S.O.P...

& some late model cars list - fairly shocking - possible excessive oil consumption rates as 'acceptable' - in handbook blurbs..
(Such as BMW officially advising that consumption/loss - of a litre per thousand kilometres - is within book specification!)

[manolis]

Hello Henry.

You write:

“Manolis: the advantages of the increased dwell at TDC of your engine are an obviously important claim. The most significant challenge for diesel engine manufacturers today appears to be control of NOx and particulates.”


With the additional time provided, the injection strategy gets more flexible (the injection is not struggling so hard with the time) and can better focus on the reduction of the NOx and of the particulates.

Things get even better for the 2-strokes (like the PatOP and the OPRE), because the BMEP lowers (with the specific power still being significantly higher than the 4-strokes), because the temperature lowers and because there are no hot spots (like the exhaust poppet valves) wherein a big part of the NOx is more likely to be generated.




You also write:

“Do you know of any research that would suggest that the longer mix and burn you anticipate would help, or hinder, or make no difference to the pursuit of lowering these emissions?”


Not exactly.


However the following “Quasi-constant volume spark ignition combustion” (Loughborough University, UK) paper:

(Copyright 2009, SAE International):

https://dspace.lboro.ac.uk/dspace-jspui ... 5b2%5d.pdf

looks pretty relevant.


Abstract:

The Otto cycle delivers theoretical maximum thermal efficiency.
The traditional design of internal combustion engines using a simple slide-crank mechanism gives no time for a constant volume combustion which significantly reduces the cycle efficiency.
In this study, using a high torque, high bandwidth, permanent magnet electric drive system attached to the crankshaft, variable angular velocities of the engine crankshaft were implemented.
The system enabled reductions in piston velocity around the top dead centre region to a fraction of its value at constant crankshaft angular velocity typical in conventional engines.
A quasi-constant volume combustion has thus been successfully achieved, leading to improvements in engine fuel consumption and power output which are discussed in detail.”



Here is the presentation of doctor Rui Chen (Department of Aeronautical and Automotive Engineering, Loughborough University, UK) at Engine Expo 2009, Stuttgart Germany:

http://www.pesri.net/blog/wp-content/up ... 03/FPE.pdf

Look at the piston motion profile and compare to the plots given for the PatOP and OPRE engines in previous posts.



A funny story:

In the following photo, you can see at left the booth of pattakon at the Engine Expo International, Stuttgart Germany, 2009:



In front of the booth of pattakon is the Open Technology Forum (where the presentations take place, where the famous fiesta for the “Engine of the Year” takes place every year, etc); at the right side of the Forum (not shown) it was the booth of the famous Scuderi (split engine) with his “demo” (not operating) prototype.


At http://www.pattakon.com/EXPO_files/AllEXPO2009.pdf you can see the prototypes pattakon had on the desks of the pattakon booth: among others, two OPRE engines, already tested and ready to operate.


On the podium of the Open Technology Forum, Dr. Rui Chen of Loughborough University, was presenting the benefits / advantages of the long dwell of the piston at the TDC.

He was describing the “mechanism” / “arrangement” used



in order a conventional single cylinder engine to provide longer piston dwell at its TDC:



(the crankshaft of the engine is driven at variable angular speed so that the piston dwell at the TDC is substantially increased).

The same time, on the monitors of the pattakon booth the videos of the working OPRE engines were shown.
Some of the audience complained that they could not hear the professor Rui Chen.
Some others, who couldn’t believe what was happening there, came to express their surprise and support saying: “you have the engines running and he (dr. Rui Chen) describes mechanisms that will achieve what you do so simply”.


Professor Rui Chen was handed a note to come in pattakon booth (10m away) and see the OPRE engines working. He never showed up.


End of the “funny” story.



The advantages of the longer piston dwell in the compression ignition engines are way more than in the spark ignition engines, because the Diesels need “absolute” time for the ignition lag – delay..


An interesting think is that with the proper injection strategy, the OPRE and PatOP engines (with the longer piston dwell at the combustion dead center) can replicate the combustion in the conventional engine (i.e. they can be “at least” as good as the conventional engines, as regards the emissions of NOx and of particulates).




You also write:

“On related point, given this slow approach to TDC is there a possibility that the specific point of combustion initiation might vary more than a more conventional design? I assume that the combustion actually starts over a range of pressure/temperature values and in your design these seem likely to occur over a wider range of crank angle. Might this have noise and vibration repercussions?”


With the piston remaining for longer near the combustion dead center, the initiation of the injection and the rate the fuel is injected can vary more than in a conventional wherein:

The early injection causes problems (the compressed air is not yet adequately hot; unburned fuel is accumulated; the combustion becomes more explosive, etc).

The late injection causes problems too (the combustion of a significant part of the fuel continues at low “expansion ratios” that reduce the torque and the fuel efficiency).

The fast injection causes problems, too.

The problem gets severe (cannot be hidden) at the “higher” revs wherein the lack of time causes the steep drop of the torque.

For instance, here is a dyno from a Subaru Boxer Diesel:



From 3,600rpm (peak power) to 4,400rpm (i.e. within only 800rpm) the torque drops by one third.



Thanks
Manolis Pattakos

[63l8qrrfy6]

So do you agree that HC emissons are not a reliable method of quantifying oil consumption ?

Mf, now you are blatantly trolling.. ..dipstick.. comes to mind..

Obviously oil consumption affects HC emissions measurements.. & 'old school' 2Ts leave a tell-tale of visible oil smoke..
But oil consumption checked against engine specifications - via volume actually consumed - is S.O.P...

& some late model cars list - fairly shocking - possible excessive oil consumption rates as 'acceptable' - in handbook blurbs..
(Such as BMW officially advising that consumption/loss - of a litre per thousand kilometres - is within book specification!)

It is a completely genuine question. I ve moved on, but if you want to carry on with the aggro thats your choice.

While I agree that oil consumption does affect HC I believe it is too small of a percentage to be used as an indicator. If you look at how much HC varies with injection pressure, EGR, scavenging, etc you will realize it can not be used to quantify oil consumption.

[Muniix]

So do you agree that HC emissons are not a reliable method of quantifying oil consumption ?

Mf, now you are blatantly trolling.. ..dipstick.. comes to mind..

So who is being abusive now!
Grow up, get over it.

If you have no technical response I suggest you refrain from any response at all.

This is a technical forum. mf is not a vendor constantly repeating false misleading claims. He has a clearly defined goal with hard parameters he is trying to achieve, no soft barely defined outcome that conviently can be associated with any favourable characteristic one finds on the interwebs. That way one can always claim success, that Gullible people swoon over.

Obviously oil consumption affects HC emissions measurements.. & 'old school' 2Ts leave a tell-tale of visible oil smoke..
But oil consumption checked against engine specifications - via volume actually consumed - is S.O.P...

& some late model cars list - fairly shocking - possible excessive oil consumption rates as 'acceptable' - in handbook blurbs..
(Such as BMW officially advising that consumption/loss - of a litre per thousand kilometres - is within book specification!)

[Muniix]

Manolis: the advantages of the increased dwell at TDC of your engine are an obviously important claim. The most significant challenge for diesel engine manufacturers today appears to be control of NOx and particulates. Do you know of any research that would suggest that the longer mix and burn you anticipate would help, or hinder, or make no difference to the pursuit of lowering these emissions?

On related point, given this slow approach to TDC is there a possibility that the specific point of combustion initiation might vary more than a more conventional design? I assume that the combustion actually starts over a range of pressure/temperature values and in your design these seem likely to occur over a wider range of crank angle. Might this have noise and vibration repercussions?

It might suit RCCI combustion, who really knows without simulation using accurate combustion models what that piston motion about tdc can be advantageous for, given the high inertial mass slower engine speeds are likely it's more efficient operation, slowing the piston velocity further seems counter intuitive. There maybe some CI combustion mode that suits this. RCCI is dual fuel mixing the characteristics of two fuels. Used to achieve better emmisions and power.

Normally one defines these issues first then designs an engine with the features to best meet goals, has all the performance metrics identified at the start so they can be used to verify design. Without you are not verify anything. Is it better? No measure of success.

There are dozens of metrics that need to be defined,
Crankcase pressure, blow-by gasses, temperature. Imep, Bmep, Bmep/Imep ratio, heat loss, thermal monitoring of hot spots and expansion, fatigue.

The list is huge, I have a huge information model schema that holds the Central point of truth for all engine revisions. It's big data on its own.

A measurement protocol is needed to verify each one or your just playing, no one can take it seriously without metrics to assess it by.

Engine control strategies to meet regulations or is it just another dieselgate. One really needs to control liner temperature for emmisions and effective combustion they are the same really
Otherwise it's an exercise in turning a large piece of metal into smaller pieces.