The Bucket Foundry

[Flettner]

Well I've spent all afternoon and can't get HCCI to work again? I had made some changes, so back to the beginning and hay presto it runs again.
Part of the problem is you need to spin the engine over faster than a hand drill on low speed but after the changes I made that's all the power I had so I needed low gear, not enough! And when it does fire up the first thing that happens, if you try to keep the drill going (and the engine going), it unscrews the flywheel nut I'm starting it on (via a socket), then the drive pully falls off. No one way drive in the system.
So it would seem I need an electric motor on a hinge with a v belt.
But it does run on HCCI (no spark plug at all) and in the short bursts It has been doing it seems to run well, free running only though.
And the fact that the engine stops when the bottom pully falls off means combustion relies on the small piston rapidly raising pressure (and heat), with out it, the engine just stops.
Interesting enough results to continue I think.

[TZ350]

Interesting enough results to continue I think.

...............

[Lightbulb]

Great news Neil.
Did you loose my phone number ?
Neil

[Flettner]

Great news Neil.
Did you loose my phone number ?
Neil

I didn't want to bother anyone untill I knew it would go.
Monday I'll set it up with an electric motor (2.2Kw) and then I'll get you out to video it if you like.
Trail ride tomorrow, Raglan, not one to be missed.

[Lightbulb]

I didn't want to bother anyone untill I knew it would go.
Monday I'll set it up with an electric motor (2.2Kw) and then I'll get you out to video it if you like.
Trail ride tomorrow, Raglan, not one to be missed.

Yeah, look forward to the call. It will be a pleasure to witness something new to me. We are having a Family day tomorrow.

[Frits Overmars]

SO, it runs!! ... Much excitment.

Neils, I don't mind telling you that reading this feels like a Christmas present. You're incredible!

you need to spin the engine over faster than a hand drill... So it would seem I need an electric motor on a hinge with a v belt.

How about screwing in a spark plug after all, and maybe a small carburetter, just as a starting aid?

[Grumph]

How about screwing in a spark plug after all, and maybe a small carburetter, just as a starting aid?

This works for me....

[Yow Ling]

wot about a glow plug just to get things underway , seems popular on diesels

[Frits Overmars]

wot about a glow plug just to get things underway , seems popular on diesels

A glow plug in an engine charged with a homogeneous fuel-air mixture is the worst thing you can have, Yow Ling. The higher the quality of the cylinder filling, the more ignition advance you will get; exactly what you do not want, because at WOT the burn will start way too early, causing a steep pressure rise before TDC, with a lot of negative work on the piston and a huge detonation risk.
I encountered this problem when working with model engines. They run way too rich because otherwise detonation would ruin the glow plug in a matter of seconds.
Using a glow plug with a shorter or thicker filament that does not glow quite so bright, would improve the power, but at the unacceptable risk that the engine might miss a combustion occurence, which would immediately stop any further chance of combustion.
Substituting the glow plug on these little engines with a spark plug would raise the power from about 5 hp to well over 6 hp, but the spark ignition would be too bulky and present too much of an interference risk with the radio control.
In a diesel it's different because the burn can only start after the first drops of fuel are injected, near TDC. And the burn will be spread over time (and over crankshaft degrees) just as the injection is spread over time.

[ken seeber]

In a diesel it's different because the burn can only start after the first drops of fuel are injected, near TDC. And the burn will be spread over time (and over crankshaft degrees) just as the injection is spread over time.

I am still a bit confused at the subtlety of difference between diesel and HCCI. I suppose with HCCI it is the seemingly capped peak values of consistent combustion pressures compared to detonation, whereas a diesel is controlled by the rate of fuelling over a discrete period of time. Still HCCI seems like a good thing when working.

I can see why that Neil likes it.....no friggin electronics, just good mechanical bits.

As to glow plugs, I always thought that diesel glow plugs were more of a pre-heater, that switched off after the engine gets up to temp. That's why that dude in the Lohmann Youtube was heating up the cylinder with a LPG torch. And glow plugs in model engines were more a necessary part of the combustion process. Either way, I agree that it would be good to have something that Neil could get it started and switch off when underway. He does have some mini plugs available and the engine has an ignition system in place. That's if he can't get a procedure to give repeatable starting/running.

Still though, what a legend he is.

[WilDun]

Perhaps it might be an idea to go back to foundry stuff now and then, so I should tell you that as I have been in hospital etc, my wife decided to "tidy up" in the garage and I had made several split patterns (ie two halves glued together using paper and PVA) - they, along with several important pieces of wood and useful ally bits and pieces, got rescued from the rubbish bag just in time! One split pattern (probably 30mm dia and about a couple of feet long was also being used for stirring weedkiller for the garden!! - pissed off? - you bet!

[Yow Ling]

A glow plug in an engine charged with a homogeneous fuel-air mixture is the worst thing you can have, Yow Ling. The higher the quality of the cylinder filling, the more ignition advance you will get; exactly what you do not want, because at WOT the burn will start way too early, causing a steep pressure rise before TDC, with a lot of negative work on the piston and a huge detonation risk.
I encountered this problem when working with model engines. They run way too rich because otherwise detonation would ruin the glow plug in a matter of seconds.
Using a glow plug with a shorter or thicker filament that does not glow quite so bright, would improve the power, but at the unacceptable risk that the engine might miss a combustion occurence, which would immediately stop any further chance of combustion.
Substituting the glow plug on these little engines with a spark plug would raise the power from about 5 hp to well over 6 hp, but the spark ignition would be too bulky and present too much of an interference risk with the radio control.
In a diesel it's different because the burn can only start after the first drops of fuel are injected, near TDC. And the burn will be spread over time (and over crankshaft degrees) just as the injection is spread over time.

Frits, my suggestion for glowplugs was to preheat the chamber before turning the engine over, just as they are used in diesels, the other old method was to use an inlet heater, my thinking was the blowtorch was a little too much Lanz Bulldog and afterall most homes have electricity we could use.
Is a semi diesel HCCI?

[speedpro]

Perhaps it might be an idea to go back to foundry stuff now and then, so I should tell you that as I have been in hospital etc, my wife decided to "tidy up" in the garage and I had made several split patterns (ie two halves glued together using paper and PVA) - they, along with several important pieces of wood and useful ally bits and pieces, got rescued from the rubbish bag just in time! One split pattern (probably 30mm dia and about a couple of feet long was also being used for stirring weedkiller for the garden!! - pissed off? - you bet!

This sort of thing is why my wife is only allowed to pass through my garage on the way to hers. After much yelling from me she has finally figured out not to touch anything in the garage, ever. The only thing that still happens is a tool might go missing only to be found much later in a kitchen drawer or cupboard. Nobody ever knows how it got there.

[Frits Overmars]

Frits, my suggestion for glowplugs was to preheat the chamber before turning the engine over, just as they are used in diesels, the other old method was to use an inlet heater, my thinking was the blowtorch was a little too much Lanz Bulldog and afterall most homes have electricity we could use.
Is a semi diesel HCCI?

A glowplug may preheat the air in the combustion chamber but I don't think it will do much good for the chamber's wall temperature.
what is a semi diesel?

[WilDun]

what is a semi diesel?

It's really just another name for a "Hot Bulb Engine" such as the German Lanz Bulldog tractor of the 'twenties' and 'thirties'.
http://www.fwi.co.uk/machinery/under...ulb-engine.htm