Hot Bulb Engine, here we go...

[Niels Abildgaard]

The real beauty of the scheme is that You can make a new cylinder with a single piston controlled hole or port and demonstrate something that has never been done before.I wish You swift progress and cannot wait.

 

[Chaffe]

Hello, i have just registered after reading this thread. I find this topic very interesting and am currently in the process of building a model engine myself, i was going to go the conventional spark plug ignition route but always fancied compression/diesel ignition. Are you still going ahead with this build? I will be keeping an eye on this. James

 

[compspecial]

Hi chuck, another wonderful and interesting project, I'm sure your mapp torch will have absolutely no trouble heating the part to a mere 230 degrees.
cheers Stew.

 

[Dave G]

Hi Chuck, very interesting build you have going on there. I'm anxious to see your hot bulb being built. It looks like it will be alot of fun. Nice to see others build their own designs. we can all benefit from it. Thank you for sharing and good luck with the build. Dave

 

[kanvelchoudhary]

hi chuck. your new work seems just awesome as usual. you have always inspired me. after reading about your new project i noticed something is odd about your inlet and exhaust port. i am not sure whether placing the port on side is a nice idea since it is too close to both injector and hot tube and it might cause some heating problems. now as you mentioned only a single port will be serving the purpose of both inlet and exhaust ports so timing is a great issue. and even a slight change in dimensions due to over heating might disturb it all. what i suggest is that placing the port just beneath the injector. i beg your pardon if i have misunderstand your design and come up with some wrong issues. but i wanted to share my opinion with you.
anyway all the best and i wish you will soon have that engine running.
kanvel

 

[cfellows]

This project has been put on the back burner for a while. I want to get back to it at some point, but don't know when that will be.

Chuck

 

[Edward Perera]

Hi, Chuck,
I joined the forum a couple of days ago. I am really interested in building a model hot bulb engine.
May I know how far you have progressed in designing and building your project?
Even though I have quite a good experience in building items according to plans, I believe that I do not have enough knowledge to design some thing new.
I would be grateful to you if you could kindly let me know whether you could advice me on this project.

Cheers, Edward.

 

[Cogsy]

Hi Edward,
I'm not sure if Chuck ever finished this design or not, but unfortunately Chuck has since passed away.

 

[Edward Perera]

Hi, Thanks very much for letting me know. So sorry to hear that...

Edward

 

[Jennifer Edwards]

Is that anything like “Hot Tube” ignition?

I once restored an old farm engine that had a kerosene burner under a copper tube that was sealed on one end, the other was open to the cylinder.

You lit the burner, waited for the tube to get real hot, then primed and cranked the engine.

If you were lucky it started without breaking your arm.

 

[mortimer]

http://findsminimodelhotbulbengines.dk/twostrokehot-bulbengine.html

here's a 2 stroke hot bulb

 

[Mechanicboy]

Jennifer Edwards - "If you were lucky it started without breaking your arm."

I had the old Sabb semidiesel (hotbulb engine), to crank the engine was easy.
Tilt the flywheel in both directions and turn the flywheel backwards fast before you get rid of. Then the engine starts in the right direction after the bounched start was performed.

Here is the Sabb who are easy to start up..

 

[Edward Perera]

Is that anything like “Hot Tube” ignition?

I once restored an old farm engine that had a kerosene burner under a copper tube that was sealed on one end, the other was open to the cylinder.

You lit the burner, waited for the tube to get real hot, then primed and cranked the engine.

If you were lucky it started without breaking your arm.

The hot bulb engine is fitted with an external chamber (bulb) attached to the top of the cylinder and the fuel is injected into it.

 

[Edward Perera]

http://findsminimodelhotbulbengines.dk/twostrokehot-bulbengine.html

here's a 2 stroke hot bulb

Visited the site. It is a marvellous piece of engineering!!!

 

[Mechanicboy]

The hot bulb engine is fitted with an external chamber (bulb) attached to the top of the cylinder and the fuel is injected into it.

Not only direct into hot bulb.. The fuel is injected into hot bulb under idling and under full load, then the fuel is injected direct into the cylinder. You can see there is injection control handle so you can change between directly on hot bulb or directly in cylinder as i showed the movie of Sabb engine (top of cylinder where injector with handle are there, not where the man is fiddling with air starter valve on the front of cylinder). It's to preventing knocking and overheated hot bulb under load.

 

[Edward Perera]

Not only direct into hot bulb.. The fuel is injected into hot bulb under idling and under full load, then the fuel is injected direct into the cylinder. You can see there is injection control handle so you can change between directly on hot bulb or directly in cylinder as i showed the movie of Sabb engine (top of cylinder where injector with handle are there, not where the man is fiddling with air starter valve on the front of cylinder). It's to preventing knocking and overheated hot bulb under load.

Thank you very much for your kind explanation. I wasn't aware of this arrangement until now.

 

[Racemybuick]

This is my father's hot bulb engine called a "charter."

It was an experimental prototype with very heavy flywheels, dual injector for multi fuel (runs on kerosene now) and has a heat exchanger in the exhaust.

Cool stuff

John

 

[Mechanicboy]

Racemybuick (John)
The "Charter" engine is near same as Mietz and Weiss engine.

 

[Racemybuick]

Racemybuick (John)
The "Charter" engine is near same as Mietz and Weiss engine.

It's funny you mentioned that... The charter was a product of Mietz and Weiss post bankruptcy it "buyout". After Weiss closed, Charter continued several models until collapsing in the 60's. This was a later model that was used in a college, or so the back story goes.

John

 

[Mechanicboy]

John, exactly,.. i saw the engine was more same as Mietz and Weiss. I did no know the Charter engine was a continued product of the Mietz and Weiss.

I loaned the book "Hot bulb engines" printed in 1919, there was a picture of the large 3 cylinder hot bulb marine engine Mietz and Weiss, it has one pump only to distribute to all 3 cylinder, it has 3 cam lobe and one disc with 1 hole with other disc with 3 hole to distribute the fuel for each 3 cylinder. Also it's a distributor fuel pump.