Semi diesels, anyone?

[Cornelius]

In response to some posts in another thread:

My brother had an old fishing boat with a 1cyl 50hp semi-diesel (hot-bulb engine), and if memory serves right, he had a crude-oil tank wrapped around part of the exhaust pipe...
It started on diesel by pre-heating the top with a blow-torch and turn the engine once with compressed air pushing the piston down. When the engine got warm, and the crude-oil got hot and liquid enough to be used as fuel, one switched over to crude-oil... Once started in the spring, it was seldom stopped before fall... It was important to remember to switch over to diesel before stopping the engine, else you'll end up with cleaning the whole fuel line assembly...

Screw all this!  I want to hear about the 50 HP semi-diesel!     Sure would like to hear one run!  Stand on the deck and feel the thump (pause) thump (pause) thump.

The sound of a 1cyl 50hp++ semidiesel are something everyone should experience, if not feel...

Here is a video of a 1932 freightship with a 1cyl Wickman 60hp; weight: 6500kg, max rpm: 170: http://www.fiskeri.no/Video/Snutter9d.htm
No snapshot of the engine itself though...

This is a startup of a similar engine, a 1cyl Brunvoll 50hp: http://www.semidiesel.no/engines/brunvoll/video/brunvoll_50hk_redigert_oppstart_bakking_hoy%20oppl.WMV (a bit low quality...)

The fun part is, that these beast can run on anything available;  natural gas, kerosene, paraffin, crude oil, vegetable oil, creosote; even used motor-oil...

[Cornelius]

Here is a feisty one with a bit too much oil in the crankcase: http://www.youtube.com/watch?v=AG1MnXkHhlM

Remember, this engine are two-stroke...

[Cornelius]

These engines uses a combination of vaporiser- and compression-ignition; Since one have the hot-bulb at the top, almost any fuel will ignite when it's vapourized and injected at the beginning of the intake stroke and then compressed up toward the hot hot-bulb. Compression ratio are rather low; about 3:1...

These engines was made both as four-stroke and two-stroke; the latter one had no lubricating oil in the crankcase, so a bit lubricating oil was brought in together with the air intake to lubricate the piston, and the bearings was fed from a lubricating apparatus. Our friend in the last video above had a bit excess lubricating oil in the crankcase, so when the engine started, it sucked that oil into the cylinder; creating a runaway situation...

[Henry W]

Here is a feisty one with a bit too much oil in the crankcase: http://www.youtube.com/watch?v=AG1MnXkHhlM

Remember, this engine are two-stroke...

What were they thinking of. Not safe at all.

Henry

[SHIPCHIEF]

You have to consider the relative efficiency of the Hot Bulb engine to the small marine steam plants of the day.
Also, you won't need a stoker and a fireman to tend the boiler, Heck, you don't need the boiler either. Now there is more room in the boat for a larger cargo hold, and two less berths in the cabin.
The oil (crude as it may have been) is more expensive than coal, but so much less is used, and it is stored in tanks, some below the floors of the holds. Now the bunkers are gone. More room for cargo.
Hot bulb engines are inefficient, dirty, difficult to start, and heavy polluters. Still, a remarkable advancement over steam reciprocating engines of the day. Also the evolutionary step to diesel engines.
I love 'em.

[Cornelius]

Yes, fascinating creatures; aren't they?

[Wizard]

Thanks for better treatise on the semi-diesel using hot bulb.  3:1 compression ratio!!  That's way low than even model T engine gasser (estimated at 4:1 to 5:1).  I didn't realize the big "muffler" box riddled with bolts to keep it sealed is filled with warmed fuel!!

But I do agree that was big step from steam motive technology to IC tech.

Cheers, Wizard

[Cornelius]

I'm not sure, but i do not think that the Muffler box are anything else than just that... If memory serves me right, my brothers crude-oil tank was wrapped around the exhaust line right above that muffler...

I'm no expert on these engines; i've only experienced one or two myself; fascinated by a single cylinder, measured in the 3-5 gallons range manages to move at all...

[Halfcrazy]

That you tube video is wild they did good to stay with it and try to shut it down.