Blow Lamp Torch Hot Bulb - Hot-bulb engine

[Minh Thanh]

Blow Lamp Torch Hot Bulb - Hot-bulb engine
 Hi All !
I have been designing a Hot-bulb engine.
I would like to know the pressure required for a Blow lamp torch hot bulb ?
Has anyone done a Blow lamp torch small size before ?
What compression ratio is good for the engine ?
Any information, experience...on small size engine or full size engine is welcome !
Thank you!

[Alyn Foundry]

Hello.
 I have built two different scale oil engines over the years. My first attempt was a quarter scale Hornsby Akroyd around 25 years ago. The engine ran but wasn’t particularly reliable so I elected to shelve the project indefinitely.

These engines used an external lamp for starting which was then extinguished once the engine was run under a fully loaded
Condition.
I did do some testing with a pressure gauge, it showed a pressure of 60 PSI. The compression ratio is unknown as the bulbs internal surface area is finned and I didn’t have the means to accurately measure the volume.

My next oil engine was only completed last year. A third scale Robinson HA. This design employs a short tube rather than a bulb and would be considered a permanent lamp design. Again the cylinder pressure under compression is about 50 PSI

<a href="https://www.youtube.com/watch?v=eNfzFZMWXQg" target="_blank">http://www.youtube.com/watch?v=eNfzFZMWXQg</a>

<a href="https://www.youtube.com/watch?v=VoeXz7Kw5xA" target="_blank">http://www.youtube.com/watch?v=VoeXz7Kw5xA</a>


   Graham.

[Roger B]

The compression ratio for hot bulb engines is quite low, typically around 4-1 which matches Grahams 60 psi.

The fuel is injected much earlier than in a diesel so it has time to be vapourised by the hot bulb before it is compressed enough to ignite.

The injection system can be much simpler and operates at a much lower prssure than in a diesel.

[Minh Thanh]

Graham.Roger  Thank you very much !
 Roger
Maybe it would be a bit easier....mainly I want to create a collection of diesel engines