ESE's works engine tuner

[TZ350]

Managed to get some dyno time today.

Blue:- RG50 Piston-Port/Reed setup

Green:- RG50 Piston-Port/Reed cylinder and head swapped onto the Rotary Valve bottom end.
No other changes to the cylinder carb or ignition timing. Just plugged the inlet and swapped it all over.

Red:- The Rotary Valve setup after some carb and ignition tuning.

Very nearly there, more fiddling next week.....

[Francisco Erjavec]

Dear all,
I would like to share my RSA tech datasheet made with information shared by Jan and Frits.

[jonny quest]

TZ350, nice work!

Francisco... great data! Maybe include ex sta

[F5 Dave]

Hey Rob. Great increase. Now you need a decent pipe and that will start to look really impressive.

[TZ350]

Now you need a decent pipe and that will start to look really impressive.

Yes, most definitely need a proper purpose designed pipe. The current one is a Wobbly design for a 65cc engine peeking at 12,000 rpm.

I have plans developed using EngMod2T for a new RG50 cylinder with different port timing and a pipe designed to suit. And a crankshaft that can handle higher rpm.

[Vannik]

I know this is 4T stuff but too much info in there not to ignore. This was posted by a friend of mine on a 4T forum.

Pat Symonds presentation on current F1 engines: https://www.youtube.com/watch?v=mUq-K9jcaB8

Takeaways:

* Thermal Efficiency of 52%
* BSFC 167gms/kw-hr (0.27lbs/hp-hr), occurs at peak power
* 800bhp from 1.6L (then another ~200hp or so from the hybrid unit)
* Lambda 1.3-1.4. Compare that to the DI / spark plug Audi DTM engine which runs at Lambda 1.15-1.38
* Rules limited 18:1 geometric compression ratio. All are at max
* Spark assisted HCCI, which Honda pretty much showed (earlier in the thread)
* They are Miller Cycle engines, with IVC before BDC
* Separate oil circuit for piston oil jets that runs cooler than the other circuits
* Miller Cycle requires very aggressive intake valve opening / closing designs and a lot of boost
* Valve angles low (5-7*), obviously done for squish geometry
* "Omega" piston bowls. Illustration in video helps visualize that
* Modeling from the FIA shows around 5.5bar boost (~80psi or so) and 50% mass fraction burn by 8* ATDC. Lose 1-2% of MFB in the prechamber. Quick combustion from 2-80% MFB and a slowing combustion beyond that. This final 20% with slowing combustion speed is where knock can occur.

[Peter1962]

This requires precision engineering, and is out of range for DIY projects...

The mechanical 2 stroke geniusses from the past, like Helmuth Fath, avoided those problems by using a simple toothet belt.

And it worked.

[Muhr]

Then we have something to test forget carbon fiber on. The reason I am interested in testing is that I also thought of trying to make connecting rods like Lamborghini does tests on.

[Frits Overmars]

I know this is 4T stuff but too much info in there not to ignore. This was posted by a friend of mine on a 4T forum.
Pat Symonds presentation on current F1 engines: https://www.youtube.com/watch?v=mUq-K9jcaB8

Great stuff! Thank you Neels.

[41juergen]

I know this is 4T stuff but too much info in there not to ignore. This was posted by a friend of mine on a 4T forum.

Pat Symonds presentation on current F1 engines: https://www.youtube.com/watch?v=mUq-K9jcaB8

Takeaways:

* Thermal Efficiency of 52%
* BSFC 167gms/kw-hr (0.27lbs/hp-hr), occurs at peak power
* 800bhp from 1.6L (then another ~200hp or so from the hybrid unit)
* Lambda 1.3-1.4. Compare that to the DI / spark plug Audi DTM engine which runs at Lambda 1.15-1.38
* Rules limited 18:1 geometric compression ratio. All are at max
* Spark assisted HCCI, which Honda pretty much showed (earlier in the thread)
* They are Miller Cycle engines, with IVC before BDC
* Separate oil circuit for piston oil jets that runs cooler than the other circuits
* Miller Cycle requires very aggressive intake valve opening / closing designs and a lot of boost
* Valve angles low (5-7*), obviously done for squish geometry
* "Omega" piston bowls. Illustration in video helps visualize that
* Modeling from the FIA shows around 5.5bar boost (~80psi or so) and 50% mass fraction burn by 8* ATDC. Lose 1-2% of MFB in the prechamber. Quick combustion from 2-80% MFB and a slowing combustion beyond that. This final 20% with slowing combustion speed is where knock can occur.

Thank's alot Neels! Some of that that stuff is now used by BMW for their new 6 cyl. engine....

[husaberg]

https://24htech.asia/throwback-thurs...r-s135555.html

[ken seeber]

[QUOTE=Vannik;1131200593]I know this is 4T stuff but too much info in there not to ignore. This was posted by a friend of mine on a 4T forum.

Pat Symonds presentation on current F1 engines:

* BSFC 167gms/kw-hr (0.27lbs/hp-hr), occurs at peak power

167 gms/kWhr....AMAZING.. Wonder what that'd relate to in an emission drive cycle....1-2 lit/100k ??

[Francisco Erjavec]

Combustion PRE-chamber concept is used in internal combustion engines for a long time and the JET ignition is the top evolution of this concept. See the JET ignition concept description in the link below:


https://www.youtube.com/watch?v=n6Eutw0WU3U

[sniemisto]

Hello gentlemen. I’m back on Derbi endurance moped build. Started preparing new Athena power valve for base line testing. I knew that there was small chip of plating missing on side of aux ex port, but I unluckily didn’t try it on warranty 3y back as I tough that its on area to be ported away.

It now appears that plating is re-chipping on and on as I proceed with stone bit on the port window, so I assume there has been something wrong in plating process. It’s same grade stone bit I’ve used on previous plated cylinders without any chipping. Now as I need to send it to re-plating, it’s tempting to get it near 55cc class limit.

That would mean max bore of 41.84mm. Only suitable piston I found was from IAME X30 water swift kart. I don’t really like it as ring ends are not centered in back and it has L-ring. Thinking of is it better to stay with 50cc than go extra 5cc with over square, limited B transfer width and more friction..?

Is there other 12mm pin piston someone can suggest?

If I go to 55cc, I would like to bore it by myself to be able port and check timings with piston before plating. Idea is to bolt thick plate on cylinder base, round the plate in lathe with cylinder attached on mandrel. Then attach cylinder to lathe from base plate and bore with boring bar.

Is it ok to bore cylinder until “before plating” dimension with this method and what is the spec for extra clearance before plating i.e. plating thickness with work allowance?

I have bottom end ready matched to this Athena and for Malossi MHR Team cylinder, plan was to have both stock baselined on dyno before trying to get best out off them. Shame that it’s not now possible with this “flaky” one.


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[Muhr]

Then we have something to test forget carbon fiber on. The reason I am interested in testing is that I also thought of trying to make connecting rods like Lamborghini does tests on.

Here is the result of the first attempt! I'm pretty happy with how it looks straight from the mold. Have just scraped off flashing with a knife