M500 build log

[ganuganu]

WoW day by day the engine is getting perfected and iam very very eager to watch it running..

[Chook]

You are not alone there ganuganu!!!!
It's a very impressive work of art.
Can't wait to see a video of this one running.

[Kool]

Soon we could be excepting some more seismological activity in the northern haha.
How many detonations per second are you excepting? (frequency)

Good luck with it!

[metiz]

Still deflagrations, Chook. Around 15 or so

[PyroJoe]

Any updates?

[metiz]

Looking for spraynozzles, ~3.3L/min. Suggestions?

[PyroJoe]

What is the pressure your pump can sustain at 3.3 L/min. ?

[metiz]

What is the pressure your pump can sustain at 3.3 L/min. ?

Getting a proper pump is of later concern, shouldn't be a problem as long as the injectors don't require ridiculous pressures. I think that anything under, say, 2MPa is doable at those flowrates.

[PyroJoe]

I'm thinking spray bar similar to what Keith Mcconnell did with his spray bar. I have purchased a small drill that can be used with precision. Pen Drills. They have some very small sized drill bits.

Once you have your pump you can test the flow rate in a bucket and slowly add more holes to bring it up to the rate you need.

[ace_fedde]

So, so, so to busy to do fun stuff, even to think of fun stuff....

Tried to find some materials, found them, then no clue where I left them, found them again, etc....

What I have out of high pressure water cleaners:
2 or 3 ful pumps with lot's off brass nozzles (should cool themselves with the fuel), different nozzle sizes. They pump around 2.5 to 10 kgs/h

If that's (far) to short:
High pressure water pumps with nozzles. 100 to 200 bars. 5 to 15 liters a minute. They should have less problems with fuel then with water, they are piston pumps.

Tomorrow I'm going to Croatia, back in a few weeks.

Fedde

[metiz]

I'm thinking spray bar similar to what Keith Mcconnell did with his spray bar. I have purchased a small drill that can be used with precision. Pen Drills. They have some very small sized drill bits.

Once you have your pump you can test the flow rate in a bucket and slowly add more holes to bring it up to the rate you need.

I don't know what a spraybar is, can you clarify?

[PyroJoe]

It is a simple tube drilled with holes. Attached is the one that Keith posted. Throttle is varied by changing the applied fuel pressure. Smaller holes allow it to maintain spray at lower pressures. The problem with smaller holes is they tend to clog easily. The pattern the holes are drilled can fan the spray across the intake flow to distribute the fuel evenly.

Its a low technology / low cost solution to what could be a difficult / expensive problem.

[metiz]

And those are placed inside the intake? One problem I can see happening is the the fuel exits the holes in a laminar fashion

[John Hasler]

> One problem I can see happening is the the fuel exits the holes in a laminar fashion

You need to keep the pressure high to avoid that (which in turn means smaller holes).

A method used in ag sprayers to obtain a spray of fine droplets is to arrange for the jet exiting a nozzle to immediately strike a 45 degree barrier. This produces a broad spray of very fine droplets.

[PyroJoe]

"And those are placed inside the intake? One problem I can see happening is the the fuel exits the holes in a laminar fashion"

The spray bar is probably good for fluids of low density that have viscosity properties that allow it to break up the laminar flow immediately after exiting. Alcohols appear to work well in this regard at 0.03" diameter holes.

Heavy oils appear to not break up well, and will be more likely to maintain a laminar flow. If I recall you were going to use fuel oil, that will probably require a nozzle system of some type. It would probably be a good idea to heat the oil to allow it to break up the laminar flow better.

What are your thoughts?