Servicing a Marine Diesel Engine

In a traditional marine engine its power is produced by hot compressed air igniting fuel which has been sprayed into the cylinder head under very high pressure. A marine engine does not have a carburetor to mix fuel or air spark plugs to ignite the mixture. Instead, the pistons are used to compress the air to 3000 kPa, which causes it to become extremely hot and the fuel is ignited as soon as it is injected into the cylinder.

Some marine are fitted with a glow plug in the pre-combustion chamber of each cylinder or a heater plug in the inlet manifold. These can provide additional heat to the combustion air during the starting process.

Diesel marine engines are slower revving and heavier than gasoline engines but they are also more reliable because they do not have to count on external carburetion or that electrical spark for ignition.

Newer engines use an electronic fuel injection system whereby air and fuel are mixed thoroughly in the pre-combustion chamber before entering the cylinder. This system maximizes fuel and power economy and is also less polluting.

Every boater should have at least a basic understanding of so let's start by explaining the mechanical cycles.

Most reciprocating piston internal combustion engines work on one of two mechanical cyclesóeither the four-stroke cycle or the two-stroke cycle. These cycles list, in the correct order, the mechanical actions by which the fuel and air gain access to the engine cylinder, the gas pressure – due to combustion – is converted into power and, lastly, the burnt gas is expelled from the engine cylinder.

How A Basic Four-Stroke Marine Diesel Engine Works

As the name suggests it is obvious there are four strokes in one complete engine cycle. A stroke is the movement of the piston through the full length of the cylinder and, since one such movement causes the crankshaft to rotate half a turn, it follows that there are two crankshaft revolutions in one complete engine cycle.

In the order they occur the four strokes are:

1. Inlet stroke. With the inlet valve open and the exhaust valve closed, the piston moves from top dead center (TDC) to bottom dead center (BDC), which creates a low-pressure area in the cylinder. Clean, filtered air rushes through the open inlet valve to relieve this low-pressure area, and the cylinder fills with air.

2. Compression stroke. With both valves closed, the piston moves from BDC to TDC, compressing the air. During the course of this stroke the air becomes heated to a temperature high enough to ignite the fuel.

3. Power stroke. At approximately TDC, the fuel is sprayed or injected, into the hot compressed air, where it ignites, burns and expands. Both valves remain closed, and the pressure acts on the piston crown, forcing it down the cylinder from TDC to BDC.

4. Exhaust stroke. At approximately BDC the exhaust valve opens and the piston starts to move from BDC to TDC, driving the burnt gas out of the cylinder through the open exhaust valve.

Two-Stroke Diesel Engines

The two-stroke engine uses two piston strokes to complete one power stroke and, therefore, fire twice as often as a four-stroke engine. A two-stroke engine is smaller and simpler with fewer moving parts. A two-stroke engine has the potential to produce twice as much power as a four-stroke engine of the same size, however, because of the extra fitting required in a two-stroke engine, for example blowers and governors, they become more expensive to produce. There has been a move towards four stroke of late as they have become smaller and more efficient.

Protect Your Marine Diesel Engine

The engine is often idled to charge the batteries or cool  the refrigeration but if done repeatedly it will glaze the bores of the engine and cause premature engine failure. Avoid idling your marine engine for longer than ten minutes in a no-load state. If the vessel is in a berth the engine can be put in gear to create load at idle.

Every boat owner should have some knowledge of basic marine engine maintenance so grab a copy of Marine Diesel Engine Maintenance For Beginners and keep yourself and your family safe while boating.

Best Diesel Engines

Hornby Train Set

The latest competition to be announced by Sussex based model retailer Modelzone is their most recent celebration of James May's Toy Stories TV program. In one episode of this popular series Mr May and around 400 valiant volunteers pieced together enough model train track to re-establish the rail link between Barnstaple and Bideford in Devon. The volunteers and model rail enthusiasts laid a staggering 19,000 pieces of Hornby 00 gauge track over the 10 mile route which has not had a working rail link for over 40 years.

Now Modelzone are giving you the chance to win one of two fantastic Hornby model train sets. The fantastic Eurostar train set features a Eurostar locomotive along with passenger coaches and a large amount of track.

And the City Industrial train set takes us back to a time when trains like the City Industrial hauled freight and passenger coaches along branch lines throughout the British Isles. This train set includes a 7 plank wagon, a 4 wheel coach and a 12T vent van as well as track and accessories.

Constructing model railways is a whole load of fun and very educational. Children learn a lot from toys that require construction and design. Also, building and operating a model rail system provides a great way to spend some time with your children. You will find that your model railway system provides many happy hours of enjoyment for both you and your children. Children enjoy the stimulation that model railways provide to their imagination and they love the sense of achievement when the system is built and working.

So why not give yourself a chance of winning one of these fantastic train sets by visiting the Hornby competition on the Modelzone blog and submit your entry. All you need to do is answer one simple question which asks: What is the distance between Barnstaple and Bideford Stations - 8 miles, 10 miles or 15 miles? (The answer is 10 miles). Here's wishing you lots of luck.

The Way To Discover Charity Car or Truck Auctions

Charity car auction is a fantastic offer to everyone involved. The donator gets a totally free tax break while foregoing the hardships of offering and old automobile. The buyer gets a vehicle to get a very low cost; normally beneath its actual market value. As well as the charity will get a portion on the proceeds from the vehicle revenue. Charity automobile actions aren’t obtainable just about everywhere although, as there isn’t an abundance of donated autos around. Here are several pointers of wherever to glimpse for charity car auctions.

The initial place to seem for a charity car auction ought to be your very own locale. Request around town, perhaps someone appreciates of one somewhere close. Also examine your nearby newspaper for scheduled auctions in town. Public auctions often appear in classified advertisements of the local paper regardless of whether it is for charity or not. Reading the scaled-down advertisements might actually be good for you personally. Smaller ads understandably receives lesser interest, and the chance that only several persons attends these auctions also creates the cost with the vehicle dip decrease; since fewer people signifies less competition and decrease final bids.

It's also a excellent choice to speak on the charities you need to help. Some charities do conduct their personal auctions like the Salvation Army. You'll be able to verify with them about their schedule of auctions and the precise areas where they would be holding their auction. Even if the charity you like doesn’t maintain its own auctions. You possibly can still request them which companies sponsor them, and they’d be a lot more than joyful to provide you with names, areas, and contact numbers. Sometimes the charity itself will get the donated autos. And you require not look any further. You'll be able to just request them what’s the brand and make with the vehicles that are donated to them plus the rates that they're willing to market individuals at. You'll be able to then select a couple of charities to go to so that you can inspect the autos for oneself and possess a sense for its performance.