ESE's works engine tuner

[twotempi]

Were they louder or quieter than a conventional engine?

the Crecy engine had the reputation of being the most noisy engine ever created.

But the exhausts discharged straight to atmosphere via stubs - similar to Merlin or Griffon.

Probably a bit hard to accomodate 12 expansion chambers within the frontal area of a WW2 fighter aircraft. Projected HP was 4000 + after development where the Merlin was about 1650 HP ( I think )

[TZ350]

Didn't this get dicussed in the ignitec thread?

I thought everything switched injectors and coils through earth?

Yes, that was power jet solenoids and other things that the Ignitec switches, now I have just learned that the Ecotrons EFI does it this way too with the injectors.

Like most people I am used to flicking the switch and applying power to something to make it work, like a light, fridge, stove, electric motor, motorcycle head light, or just turning the bikes ignition on etc, in fact nearly everything you can think of.

Having something permanently live and then earthing it to make it work, that took me a moment or two to get my head around.

But it is how the Igni ignition and Ecotrons EFI do it with their peripherals. Maybe its the universal automotive electronic approach to such things but it was new to me and had me fooled for a bit (fooling me, OK so thats not so hard to do).

[Frits Overmars]

the Crecy engine had the reputation of being the most noisy engine ever created.

Yes, two-strokes are unbeatable when it comes to making noise. And it's not hard to understand why: a poppet exhaust valve will open with an initial velocity of zero.
A piston-controlled exhaust port will open with the actual velocity of the piston which at that point may be about 1,5 times the average piston speed. Guess who creates the sharpest exhaust pulse.
Sleeve valves too will open the exhaust port with a larger-than-zero initial speed.
As for the four-stroke: there is one engine that can keep up with two-stroke noise: the Wankel. It too has a >0 exhaust opening speed.

[Drew]

Yes, that was power jet solenoids and other things that the Ignitec switches, now I have just learned that the Ecotrons EFI does it this way too with the injectors.

Like most people I am used to flicking the switch and applying power to something to make it work, like a light, fridge, stove, electric motor, motorcycle head light, or just turning the bikes ignition on etc, in fact nearly everything you can think of.

Having something permanently live and then earthing it to make it work, that took me a moment or two to get my head around.

But it is how the Igni ignition and Ecotrons EFI do it with their peripherals. Maybe its the universal automotive electronic approach to such things but it was new to me and had me fooled for a bit (fooling me, OK so thats not so hard to do).

Wasn't being a smart arse. Intentionally at least.

It's how everything works in modern engine management I think.

On a side note, my GL145 switches everything through earth. Lights, indicators, the lot. It's better for some reason, but I can only guess why.

[speedpro]

Ahhh! The good ol' days. I built my own CDI as well and it threw a wicked FAT blue spark. Definitely something you were careful around, even after you turned it off. Quite handy having a whole Avionics bay at your disposal with all the gear.

[koba]

Ahhh! The good ol' days. I built my own CDI as well and it threw a wicked FAT blue spark. Definitely something you were careful around, even after you turned it off. Quite handy having a whole Avionics bay at your disposal with all the gear.

Any tips on this?

I've not had much luck getting a Jaycar kit one going well.
It's OK to a point but stops working at 10,000 rpm.

I've tried up to from .47 - 3 uF in the main capacitors but it doesn't seem to make much difference.
I guess the triggering side might be a bit shit. What did you use to switch it?

[koba]

Funny where youtube surfing can lead one, this is where I ended up the Crecy vid:

http://www.youtube.com/watch?v=bKHz7wOjb9w

[TZ350]

Wasn't being a smart arse. Intentionally at least.

Didnt think you were.

It's how everything works in modern engine management I think.

Modern to me was a Morris Minor so EFI is a new experience, just taking me a bit of time to catch up.

On a side note, my GL145 switches everything through earth. Lights, indicators, the lot. It's better for some reason.

OK now I have learn t something else today .... will it ever end.

[TZ350]

Ok started to figure it out.



Spent sometime tonight trying to figure out why there was no signal at the injector. Then realized that at TPS = zero the injection map is = to zero ... ... so bumped the first line up to 100 and bingo the injectors were firing.

This will most probably have been why my solenoid and trigger coil lash up did not work.

It would not have been a problem if I had of cranked the throttle open a bit.



Put a resistor across the injector plug and connected the switched side to the Ignitecs trigger input. Now I have sparks triggered by the firing of the injector. The only issue is that the spark occurs at the start of the injection event.

Still its progress.

[koba]

Great link:
http://www.motelek.net/
There are a lot of diagrams of inside ignition units.

[speedpro]

Ok started to figure it out.



Spent sometime tonight trying to figure out why there was no signal at the injector. Then realized that at TPS = zero the injection map is = to zero ... ... Still its progress.

My TPS map is the same, but, the load weighting table points to the MAP table at very low revs so it doesn't matter.

[Drew]

Didnt think you were.



Modern to me was a Morris Minor so EFI is a new experience, just taking me a bit of time to catch up.



OK now I have learn t something else today .... will it ever end.

Oh Christ. Don't think of a Morri when working with electrics. As a lad of 10 or 12, I nearly set my mothers one on fire not realising the stupid positive earth thing!

[Flettner]

What was it, Lucus, the prince of darkness.

[Flettner]

Yes, two-strokes are unbeatable when it comes to making noise. And it's not hard to understand why: a poppet exhaust valve will open with an initial velocity of zero.
A piston-controlled exhaust port will open with the actual velocity of the piston which at that point may be about 1,5 times the average piston speed. Guess who creates the sharpest exhaust pulse.
Sleeve valves too will open the exhaust port with a larger-than-zero initial speed.
As for the four-stroke: there is one engine that can keep up with two-stroke noise: the Wankel. It too has a >0 exhaust opening speed.

I should imagine some of the Crecy's noise was due to the level of super charge.
I'll bet that FOS cylinder generates one hell of an exhaust pulse, lots of port time area. I didn't like the FOS at first but the more I think about it the better it "sounds". I do worry about the sleeve port opening time area, sleeve is slower than the piston but there is more area being opened. Sleeve drive mechanisim might be too simple Frits

[jasonu]

Yes, two-strokes are unbeatable when it comes to making music.

Fixed it for ya...