ESE's works engine tuner

[seattle smitty]

The temperature of the washed-through mixture will always be below the temperature of the spigot, hence heat will always be transferred from the spigot to the mixture.

Frits, I'm just a dumb liberal arts major, and I don't get how that could be. The interior surface of the spigot (not a term we use here, but I gather that it refers to the extension of the exhaust port, to which the header section of the pipe is bolted) didn't get hot on its own, but from the exhaust gases passing through. How can it get hotter than those gasses?

[Frits Overmars]

Do you have a picture of the 24/7 setup?

Yep, posted several of 'm here. Look for "Modena 24-7".

The interior surface of the spigot... didn't get hot on its own, but from the exhaust gases passing through. How can it get hotter than those gasses?

I never said that it does, Smitty. The interior surface of the spigot gets hotter than the washed-through unburned mixture.

[Haufen]

The temperature of the washed-through mixture will always be below the temperature of the spigot, hence heat will always be transferred from the spigot to the mixture. The hotter the spigot, the more it will heat up the mixture. I don't think that's what we want.

Nope, I don't think so. I am with the simulation software on this one, have a look:

[wobbly]

Here is how you cool the spigot,this made more power and also enabled leaner jetting with no deto.
I am just about to get a cylinder Exhaust duct coated with ceramic to see who is right or wrong about the trapped charge overheating
and causing deto, or more heat energy being transferred to the pipe,thus making more power.

[katinas]

Hi Can anyone recomend the best aluminium for a weld on packer to extend my cylinder ?
Thanks Neil

Best 2219 (Weldural) very good weldability and high strength under heat stress, but its hard to find.

All 6000 series have very good welding properties, but 6026 highest strength, when treat gone after welding,

[katinas]

Running it: yes. Starting it: no.
That is why my 24/7 inlet system has a hinged reed that can be shut for starting the engine in the conventional reed-mode, and that can be swung out of the way, once the engine is running in the power band and the exhaust pipe suction is taking care of things.

Once testing engine with trimmed reed petals ( open area 40x6mm ). Starting engine just after "high speed run" with the bike. From 0 to 6000 rpm no power at all ( very similar to my rygerised engine, maybe too soft reed petals ) just terrible sound from carb. When pipe is on, more power than with normal reeds, but not much ( maybe with fully open area would be more ).
But it was very unstable carburation. Between lean and rich very thin line and maybe with adjustable reed block would be better open at last 1000-2000 revs.

[TZ350]

Got the chance to try my new pressure sensor tonight.



Bottom line is the ignition pickup, top line is the in cylinder pressure sensor. There was not much of a signal from the sensor, nothing usable anyway.

The hole in the wall of the cylinder is exposed before exhaust port opening for about the same number of crank shaft degrees as the positive side of the ignition triggers wave form.

I suspect the new pressure sensor is too slow reacting, I was hoping for a signal that looked like the positive side of the ignition triggers pulse but I guess the cylinder pressure sensor is electronically damped to cut out noise. Mechanical pressure sensors are often damped with fluid so I guess its logical that an electronic one could be damped too.

Its very hard to get a good photo, so here is a video clip of the oscilloscope screen:- https://youtu.be/Hnqeh5jNtfE

[diesel62]

How come you don't have a continuous flat line on the pressure sensor?. Are you only measuring it over x degrees?

Sent from my SM-P555 using Tapatalk

[Muhr]

Got the chance to try my new pressure sensor tonight.




I suspect the new pressure sensor is too slow reacting,

[/URL]

I suppose pipe length to the sensor is devastating for reaction time!?
something more that came to mind was Bernoulli's principle

[seattle smitty]

Dang! Sorry Frits, it was clear enough.

[peewee]

We want the heat & energy from the exhaust pulse to go out into the chamber. The spigot & duct should absorb, hold and re-transfer as little heat to the charge as possible.
Make your reducer from stainless steel, pull the air out the cavities before sealing them, if you can. Polish the surfaces. Just like a Vacuum flask.

and a Happy New Year to All. Cheers, Daryl.

hey mate i never thought of stainless steel. would 304 be suitable ? if so then ill just get a small chunk and machine the whole spigot as one piece and forget about them hollow voids and forget about any welding

[TZ350]

Made myself a little pressure sensor from a cheep piezo disk. Gave a reasonable signal at least 2-3 Volts at idle.

https://youtu.be/bHCxhSV_6hw

I still have to work out if the collapse in the signal when I blip the throttle is on over run or actually during acceleration at which time I would have expected the signal to be stronger??? ... maybe need to get it on the dyno so as to hold the acceleration load/pressure for longer.

Piezo sensor is the top trace, the ignition trigger pulse is the bottom. The gaps in the traces are due to the difference in sweep speed as apposed to engine rpm.

[Pursang]

hey mate i never thought of stainless steel. would 304 be suitable ? if so then ill just get a small chunk and machine the whole spigot as one piece and forget about them hollow voids and forget about any welding

A chunk of SS in the port might be a good thing.....or a disaster.
SS has thermal conductivity around half of steel and perhaps a 10th of cast alum.

Maybe it will absorb less heat during the exhaust flow and transfer less to the 'flow through' charge. (Win/Win)

Or....It might just heat up and up and transfer huge quantities of heat to the new charge (Lose/Deto/Lose)
Far too many factors to consider just at the moment.

The reference to the vacuum flask is for a purpose.
There are 3 factors to be combined for a Thermos to work, miss out on any one and all you have is a bottle.

Shiny surface to reflect heat transfer by radiation. (Like Wobbly's piston crowns).
Vacuum (or air) gaps to prevent transfer by convection. (or bubbles in foam or some ceramics)
Long, thin, pathways and materials to reduce conduction, (SS better than steel and alum. not as good as glass & some ceramics)

Do some experiments and report what happens. Might be the next 'Big Thing' in 2T technology.

Cheers, Daryl.

[Muhr]

A chunk of SS in the port might be a good thing.....or a disaster.
SS has thermal conductivity around half of steel and perhaps a 10th of cast alum.

Maybe it will absorb less heat during the exhaust flow and transfer less to the 'flow through' charge. (Win/Win)

Or....It might just heat up and up and transfer huge quantities of heat to the new charge (Lose/Deto/Lose)
Far too many factors to consider just at the moment.

The reference to the vacuum flask is for a purpose.
There are 3 factors to be combined for a Thermos to work, miss out on any one and all you have is a bottle.

Shiny surface to reflect heat transfer by radiation. (Like Wobbly's piston crowns).
Vacuum (or air) gaps to prevent transfer by convection. (or bubbles in foam or some ceramics)
Long, thin, pathways and materials to reduce conduction, (SS better than steel and alum. not as good as glass & some ceramics)

Do some experiments and report what happens. Might be the next 'Big Thing' in 2T technology.

Cheers, Daryl.

if you go that way why not Invar

[lodgernz]

What if you water-cooled the SS?