Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Martin_1962]

How about this for complex - from wikipedia

[nixoro]

Its missing its cambelt/chain, must be massive though

[Martin_1962]

Its missing its cambelt/chain, must be massive though

It is a section of a D18 two stroke supercharged, about 6 foot high and about 10 foot long

Found in naval vessels and railway locos.

http://en.wikipedia.org/wiki/Napier_Deltic

[Pitchfork]

So why do we not use 2 stokes in cars/ trucks?
Are they not more efficient than 4 strokes?

[Chopsdad]

Are the tiny people a Vx stock item or do you have to order them in?

[Andy B]

So why do we not use 2 stokes in cars/ trucks?
Are they not more efficient than 4 strokes?

You never smelt a 2 stroke scooter as it screamed past you then.  

[Markjay]

' The Oompa-Loompas were busy at at Vauxhall Ellesmere Port V6 Plant '

[Martin_1962]

Also smokey - I'll post a video still soon and demonstrate a D18 on full power, (can't use both engines on a preserved railway too much power)

[Martin_1962]

Still from a 19 year old video tape

[hotel21]

So why do we not use 2 stokes in cars/ trucks?
Are they not more efficient than 4 strokes?

These are two strokes for various reasons, main one being power output versus engine movement and low revolutions.

Dead slow ahead is generally 35 revs.  Not 350, but 35.  Flat out, full sea speed is generally 110 revs or so, not 11000 as some cars.

Also, propeller most times on really big beasties like this is fixed blade so for the ship to go astern, the engine runs in reverse.  The valve timing gear (if it has an exhaust valve, depends on make) and the fuel pump timing is altered to take account of change of rotation.  It develops the same power irrespective of engine rotation direction.

Oil sump is continually purified via a set of centrifuges, topped up when required.

Additional oil is injected into the cylinder bores below the top piston ring to ensure cylinder is lubricated and to improve sealing capability.

Smaller, 6 cylinder versions used to burn circa 35 tonnes fuel oil per day (35 000 litres) to get the ship around 250 to 300 nautical miles along the way, if laden.

Fuel oil is consistancy of Fowlers Black treacle which needed heating to a very high temperature to allow injection through a fuel valve which, incidentally, could be a two man lift.  The fuel valve, that is.....

I used to work on these things years ago as a plooky yoof.  Good fun, if a bit noisy and dirty!

B