ESE's works engine tuner

[breezy]

Sketchy_Racer is your man for crank mods.

thanks Glen....

[ken seeber]

OK, couldn’t find an actual piston from the engines I was referring to, but this is another similar research piston we did for a company when they were investigating DI for various applications, nearly 20 years ago. It was an Ø86 * 86 size.



Funny though, it looks a lot like this one http://www.lotuscars.com/engineering...esearch-engine
This piston in the pic was just an early off tool sample and was used for refining the casting and Molykote D10 spraying process.
I reckon that if I was going down this road I’d go for an oversquare engine to reduce piston length and weight. I know it goes against all the port area/STA stuff, but my thoughts are more towards a utilitarian application, not needing to rev the tits off it as perhaps Alex is considering.

[shnaggs]

OK, couldn’t find an actual piston from the engines I was referring to, but this is another similar research piston we did for a company when they were investigating DI for various applications, nearly 20 years ago. It was an Ø86 * 86 size.



Funny though, it looks a lot like this one http://www.lotuscars.com/engineering...esearch-engine
This piston in the pic was just an early off tool sample and was used for refining the casting and Molykote D10 spraying process.
I reckon that if I was going down this road I’d go for an oversquare engine to reduce piston length and weight. I know it goes against all the port area/STA stuff, but my thoughts are more towards a utilitarian application, not needing to rev the tits off it as perhaps Alex is considering.

Funny, I was just thinking about the Lotus 2 stroke the other day and wondered if any of the guru's on this site knew anything about its life/demise.

[adegnes]

OK, couldn’t find an actual piston from the engines I was referring to, but this is another similar research piston we did for a company when they were investigating DI for various applications, nearly 20 years ago. It was an Ø86 * 86 size.



Funny though, it looks a lot like this one http://www.lotuscars.com/engineering...esearch-engine
This piston in the pic was just an early off tool sample and was used for refining the casting and Molykote D10 spraying process.
I reckon that if I was going down this road I’d go for an oversquare engine to reduce piston length and weight. I know it goes against all the port area/STA stuff, but my thoughts are more towards a utilitarian application, not needing to rev the tits off it as perhaps Alex is considering.

Nice, thanks! And, yes I like rpm more than most!

[tjbw]

Funny, I was just thinking about the Lotus 2 stroke the other day and wondered if any of the guru's on this site knew anything about its life/demise.

Interesting engine, would also be good for research work.

I also liked their rotary valve engine idea.

http://www.aqpl43.dsl.pipex.com/MUSE...veIC.htm#lotus

[shnaggs]

Interesting engine, would also be good for research work.

I also liked their rotary valve engine idea.

http://www.aqpl43.dsl.pipex.com/MUSE...veIC.htm#lotus

Never saw that ^^^ one before. Although the rotary valve head designed by McLaren for their F1 engine was a pretty neat one. I cant find pics of it, but If I remember, the FIA banned it the first time it showed up to competition.

[teriks]

Never saw that ^^^ one before. Although the rotary valve head designed by McLaren for their F1 engine was a pretty neat one. I cant find pics of it, but If I remember, the FIA banned it the first time it showed up to competition.

Here you go, Bishop rotary valve, Australian stuff:
http://home.people.net.au/~mrbdesign...utoTechBRV.pdf

[shnaggs]

Here you go, Bishop rotary valve, Australian stuff:
http://home.people.net.au/~mrbdesign...utoTechBRV.pdf

That's the one! Thanks, been a while since I've looked at that concept.

I once had a Coates rotary valve engine sitting in my shop while a legal investigation was taking place. Neat concept, but with obvious faults.

Of coarse my lack of rotary valve 2 stroke experience will shine through, but it always seemed that the rotating window of the RV would be problematic to inlet flow...causing a "sprinkler" effect, I don't know how else to describe it.

[JanBros]

I reckon that if I was going down this road I’d go for an oversquare engine to reduce piston length and weight. I know it goes against all the port area/STA stuff, but my thoughts are more towards a utilitarian application, not needing to rev the tits off it as perhaps Alex is considering.

but all that "port area/STA stuff" is for normaly aspirated 2-strokes.
so for supercharged engines surely the STA-stuff is way less important or maybe totaly different numbers will be the optimum. my (not so educated) guess

[chrisc]

I don't run a det counter and I really want to understand my 98 RS125 better so I got an EGT. It's a standard engine, ignition, pipe, carb, etc. Only changes are a VHM head with a standard profile 10.4cc insert, and a reed block stuffer (stock reeds).

How far down the header should I be putting this probe? and how far into the header should it be?

I've searched the ESE thread and saw some comment on jetting to certain Fahrenheit temps at wide open throttle. Are these temps pretty universal across race 2 strokes? Any other advice on how I should get my own base line and at what point this stock 125 of mine might lunch itself is greatly appreciated.

One of these:


Other discussion in the thread:

In any badly tuned 2T you can easily get readings over 1300*F and survive,ONLY if the setup is not optimal.
If the com is too low for the fuel, or if the timing is overly retarded, then the excess heat produced late in the combustion cycle is dumped into the pipe
and thus alot less is soaked into the piston.

If a correctly setup engine cannot be held under 1200*F by the jetting, then it should be richened immediately so that it can be.
THEN, go down one size at a time and approx 50* rise should occur for each change, shooting for a max on AvGas of 1250*F.
If the change produces less than 50* delta in egt then that indicates that you are approaching deto rather than making more power from the extra heat of combustion.
The opposite is true as well, if more than 50* is seen with 1 jet leaner, then you can be sure the setup is not correct for the fuel and a heap of unused heat is being dumped into the pipe.
But, using excess fuel to cool the combustion process will not make anywhere near the actual power available ,if the ignition and com was optimised.
This means as a general rule for a fast watercooled 125 cylinder on AvGas that the com is close to 16:1 and the peak power timing is close to 15* - any numbers alot less than that
then you dont need AvGas,and or you do need to rethink the tuning.

[breezy]

Sorry https://youtu.be/OnLMIMiXoR8

Katinas, did the engine feel tight when you first started the engine... feeling like high compression? have you any breather system for the crankcase now that its sealed? have you had to increase the pilot circuit in the carb for it to start ? thanks , breezy

[F5 Dave]

Chris. Had wondered if you had disappeared. Guage instructions usually say 5-6" down header (note bung on your 50). But I've read Wob quote much shorter. Don't shorten sensor lead but that made for intolerable length on my kit as car based. Your kit looks much shorter.
Just mounted it on the 500 but not reading stable when engine running. Been suggested that I run an earth from the sensor to the gauge earth. I should know that shit.
Slip joint. Rubber mounts. Yeah can see that being a ground issue.

Probe needs to be exposed type. Mine claimed to be superb but I doubt it.
Run it up on the dyno with bung fitted and then with probe to see that it isn't influencing. Played havoc on the 50. The 500 doesn't seem to care.

I see a clamp type of wire splice in that kit. Quickly stamp on it and throw it in the bin. Preferably on fire.

[emess]

How far down the header should I be putting this probe? and how far into the header should it be?

From Wobbly on page 562 he suggests 150mm

That was in 2012 . . .

https://www.kiwibiker.co.nz/forums/s...post1130362060

[DoldGuy]

Have a Digatron Gauge, instructions say 5-6 inches from the face of the piston, mounted mine at 6. Just remember it's your temp readings, they can be higher or lower readings based on placement. It's a great tool gathering data & can save you from a melt down.

My gauge has the RPM pickup from the spark plug coil & instructed to keep the EGT/Temp leads away from the RPM lead as there can be interference if too close, giving erratic readings on other data.

[adegnes]

Run it up on the dyno with bung fitted and then with probe to see that it isn't influencing. Played havoc on the 50. The 500 doesn't seem to care.

Great you mentioned this, I had forgoten that you talked about it earlier. Have only run my Spx with the probe, will test without it.