The Bucket Foundry

[Flettner]

The trouble with prototyping is you need to build the item just good enough to get sensible results but not waste too much time or money getting there.So how much do you cobble together existing parts off other engines (and suffer some compromise) and how much do you build specific for the development. Comes down to cost and time I guess (and how much you realy want it). It could be said once again that's where I'm let down, because I can build parts I do, when another existing part would do the job, although sometimes trying to fit / modify an existing part can be just as much trouble. It can be a real dilemma.
You need to be a little bit "hard ball" on the development sometimes and know when to just walk away. Unfortunatly I'm too soft and just can't help myself and just keep hammering away

I'm trying to work out wether to just shove another engine on to of my AG100 or just build components specific, real work starts again tomorrow and time for play will run short again. I think I saw the rest of another AG100 engine in Blackwoods bin.

Lets get real, my HCCI engine uses Diesel type compressions so It needs to be more robust than an AG100! BUT if those combustion pressures happen after TDC will ordinary components do the job, lets see?? Just thinking out loud.

I managed to smuge the small pistons ring and lose compression, won't start again.

[Flettner]

Apart from the exhaust pipe that you're going to need anyway and that would prevent the engine from inhaling oxygen through the biggest port?
A decent pipe can markedly raise the cylinder pressure at exhaust closure and that will change everything that happens further in the cycle.
Like how much compression you need, and when you need it.

PS: after seeing the pictures of your HCCI head I understand why the 30,5 mm bore and 8 mm stroke. I knew there would be a good reason for it .

After thinking about your comment I'll fit an exhaust, clean up the small piston / ring and give it one more try before I start on the mark two.

[Flettner]

I wonder how this system might work with Hydrogen fuel? Am I right in thinking Hydrogen a problem for normal engines due to it's low octane number? With this setup low octane number doesn't matter.

[tjbw]

I wonder how this system might work with Hydrogen fuel? Am I right in thinking Hydrogen a problem for normal engines due to it's low octane number? With this setup low octane number doesn't matter.

There are quite a few hydrogen powered vehicles on the road, some use compressed liquid hydrogen. There are guides for conversion, and kits available. Also need to be aware of risks:

http://hydrogenunits.com/disadvantag...drogen-car.php

[WilDun]

Also need to be aware of risks:

Petrol vapour is highly inflammible but we just drive on and pretend that the danger isn't there! - just a matter of being aware and doing our best to prevent these things happening I guess.

Neil, will you be having your first flight with the new engine this week?

[husaberg]

I wonder how this system might work with Hydrogen fuel? Am I right in thinking Hydrogen a problem for normal engines due to it's low octane number? With this setup low octane number doesn't matter.

hydogen has a very fast combustion (like too fast, basically an explosion) it works well on a rotary engine though.
http://www2.mazda.com/en/csr/environ...006_01_03.html

[eldog]

Perhaps the nicest reaction 2H2 + O2 -> 2H2O + energy out

Can spontaneously combust with the right concentrations

anyone remember the Hindenburg?

[WilDun]

Perhaps the nicest reaction 2H2 + O2 -> 2H2O + energy out

Can spontaneously combust with the right concentrations

anyone remember the Hindenburg?

Wasn't the Hindenburg accident was caused by static electricity? ie when it was being connected the anchor tower - then it was made worse by the aluminium paint which reacted and spread the flame to the other hydrogen bags?

[eldog]

Wasn't the Hindenburg accident was caused by static electricity? ie when it was being connected the anchor tower - then it was made worse by the aluminium paint which reacted and spread the flame to the other hydrogen bags?

Yes, just show you how simple events can have devastating outcomes.

I know of some people who were playing around with a hydrogen generator when it went boom boom.
I don't think it was a flame, but the amount of H2(leaked) and air in the room most likely caused it.

Just be careful.

[Flettner]

perhaps a knock sensor connected to my old battery CDI connected to a timing light will give an accurate ignition time? What does a knock sensor put out? 4V pulse?

[Flettner]

Petrol vapour is highly inflammible but we just drive on and pretend that the danger isn't there! - just a matter of being aware and doing our best to prevent these things happening I guess.

Neil, will you be having your first flight with the new engine this week?

Will, next weekend, national gyro fly in.

[Frits Overmars]

I wonder how this system might work with Hydrogen fuel? Am I right in thinking Hydrogen a problem for normal engines due to it's low octane number? With this setup low octane number doesn't matter.

Hydrogen has an octane number > 130 so it may not want to play ball in your HCCI engine.
What it does have is an extremely wide flammability window. That's fine, but it is not required with HCCI.

Here's some more hydro-reading:http://www1.eere.energy.gov/hydrogen...fs/fcm01r0.pdf

Perhaps the nicest reaction 2H2 + O2 -> 2H2O + energy out

That looks too good to be true. And you know what they say...
It'll work if you carry not only the hydrogen but also bring your own oxygen. Yes, there's oxygen in the air, but it's polluted by an overdose of nitrogen.
And if you put that in a combustion engine, you will have H2O + energy + NOx out.
Enter the fuel cell: no high temperatures, so no NOx.

[seattle smitty]

It being that what's drawn into the carburetor is only about 21% oxygen, how would HCCI engines work with "oxidizer" fuels (particularly methanol, nitromethane, and other common fuels and fuel fractions traditionally used in many kinds of racing)??

Flettner's engine, on gasoline, tried to "run away" on him; would nitro, which has a tendency to auto-ignite already, be utterly uncontrollable in an HCCI engine? (There are some co-solvents for nitromethane that are less prone to detonation than methanol/nitromethane, but probably they are unaffordable).

[WilDun]

Will, next weekend, national gyro fly in.

Neil, where exactly is it to be held? I might like to see it.
I don't usually go to airshows etc. anymore because I have a frozen neck and I can't look up or sideways which makes it difficult to say the least! - could take a swivel recliner with me though, too good to miss I reckon.

[Flettner]

Neil, where exactly is it to be held? I might like to see it.
I don't usually go to airshows etc. anymore because I have a frozen neck and I can't look up or sideways which makes it difficult to say the least! - could take a swivel recliner with me though, too good to miss I reckon.

Bit of a drive, Dannevirke.