Man vs. Diesel Starter Motor

[Pete7]

If you can get her going sailing well then dropping it in gear with a fixed prop may well bump start the diesel and we found out with a Nic 55. Quite infurating as the skipper wanted the prop locked in forward. So everytime we surfed down a wave the prop turned and the old Perkins roared into life pushing us even faster down the wave. After about the sixth mad dive for the engine stop lever he relented and we left it in neutral.

Pete

[ErikFinn]

Back in the 1980's we had a 7m wooden fishing boat with a twin cylinder 18hp Olympia diesel from 1950's with no startermotor, just a leg crank. You would release compression, pour it some petrol choke in to its special brass choke cups and then carefully find the correct compression spot with the crank, followed by an all you got jump and pray to God you don't lose a leg. Worked most of the times but almost broke my brothers leg once. Kickstarting a HD was nothing compared to that one.

[double u]

Originally Posted by Pete7

If you can get her going sailing well then dropping it in gear with a fixed prop may well bump start the diesel and we found out with a Nic 55. Quite infurating as the skipper wanted the prop locked in forward. So everytime we surfed down a wave the prop turned and the old Perkins roared into life pushing us even faster down the wave. After about the sixth mad dive for the engine stop lever he relented and we left it in neutral.

Pete

wow! I always thought Rosie Swales story that their inboards started in reverse when surfing a tall tale...
cone or plate cluches would slip in forward though...
regarding crankstart:
saw some yanmar 3gm30 (the direct cooled variety) with a crankstart-claw on their front. had decompression-levers though (we never tried the crankstarting
the one engine I successfully crankstarted was a singlecylinder aircooled 20hp ducati diesel with decop. lever. that was still on it's pallett & I was 23 (those were the days...'78) then & with an absolute all-out effort it was just possible...next thing I did was order the optional dynastart for it

[UNCIVILIZED]

In addition to hand cranks, spring starters, & compressed air, you'll occassionally see them being started via a rope around a flywheel (or purpose built starter sheave). Usually either by the motive force of a huge sail, or something heavy hoisted up the rig. There was a thread on here about a month ago which had a video featuring sail starting a diesel. It was done by a singlehander on a huge mono, & took quite a bit of ingenuity.

[Blue Stocking]

Originally Posted by Bill Seal

starting boeing vintage - Bing video

Or, if you're lazy, a Coffman cartridge starter.

someone has been hanging around English Electric Canberras or Martin B-57s.

[Sailmonkey]

Originally Posted by double u

if a starter motor has 1,5kW - how are 400 or 500 watts or even the 800 of a champion going to be sufficient? the 1600 are BS

Even though most starters are approx 1500 watts on a small engine, you don't need all of that power unless the engine is exceptionally cold. It takes far less power to spin over in the tropics than it does in the arctic.

[rwidman]

My one question is: Why would you want to?

[donradcliffe]

Originally Posted by double u

if that is meant as "power at the crank" (not total energyrelease by the body including heat) then is total BS! champion mountainbiker can produce peaks of just over 800watts & 400 steady. everybody just climb on their ergometers (as I did yesterday...)
https://en.wikipedia.org/wiki/Bicycle_performance

Evidently you have a reading comprehension problem.

From the wiki you referenced--


Active humans can produce between 1.5 W/kg (untrained women for longer periods) and 24 W/kg (top-class male athletes during 5 s).

So do still you think a 70 kg elite cyclist x 24 W/kg = 1680 watts is total BS??

Of course, I'm not sure these guys qualify as human.

[fryewe]

If failure to start is due to lack of electrical power, a workaround for the fuel shutoff solenoid would be needed in addition to an alternate motive force for spinning the engine...if equipped with such a solenoid valve.

[donradcliffe]

The fuel shutoff solenoid does not need power unless you want to shut the engine off.

[donradcliffe]

I talked to someone today who had a starter fail on the Transpac. They wrapped a line around a spare pulley on the front of the engine and rigged it to the coffee grinder winch. Worked a treat.

[undercutter]

Wasn't there a story about a guy, with a wood boat and a 4 cylinder Perkins engine. After having had the wrong components installed during a starter rebuild in NZ (The same starter body fit a tractor version of the engine but was wound differently resulting in lower RPM's during cranking) and someone suggested covering the air intake as this would eliminate combustion allowing the engine to turn freely. I assume that this would significantly reduce the power required to get her up to speed and the momentum of the engine would help to get her started when the air blockage was removed.

That guy sailed around the world in the early 80's and was still navigating by sextant and overcame many difficulties during the voyage. Not quite a Slocum but he was certainly humour-us in his storytelling.

[Pete7]

No sure that is going to work as it just creates a vacuum. A can of easy start might help if you are using a cranking handle and don't have decompression levers.

[undercutter]

Originally Posted by Pete7

No sure that is going to work as it just creates a vacuum. A can of easy start might help if you are using a cranking handle and don't have decompression levers.

Don't know for sure but worked in the book. True story. Blown Home Again or some such.

However made sense to me, similar to choking a petrol engine for air restriction and it is the air which creates combustion to unite the fuel in a diesel as opposed to a spark. The injectors are still pumping fuel so there is no vacuum by any means.

[double u]

what you save in compression you loose in sucktion...