Engineering Magazines

In a conventional marine diesel engine the power is produced by hot compressed air igniting fuel sprayed under very high pressure into the cylinder head. A marine diesel engine does not use a carburetor to mix fuel and air or spark plugs to ignite the mixture. Instead it employs the pistons 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 diesel engines are fitted with a heater plug in the inlet manifold or a glow plug in the pre-combustion chamber of each cylinder to provide additional heat to the combustion air during starting.

Diesel engines are heavier and slower revving than petrol engines but they are also more reliable because they do not rely on external carburetion or an electrical spark for ignition.

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

Every boater should have an understanding of how their engine works so let’s start by explaining the mechanical cycles.

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

The Basic Four-Stroke Diesel Engine

From its name, 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.

The four strokes in the order they occur 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), creating 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 this stroke the air becomes heated to a temperature sufficiently high to ignite the fuel.

3. Power stroke. At approximately TDC, the fuel is injected, or sprayed, 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.

The Two-Stroke Diesel Engine

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 diesel engine, for example blowers and governors, they become more expensive to produce. There has been a shift towards four stroke diesel engines which have become more efficient and smaller.

Protect Your Marine Diesel Engine

Protect your engine by avoiding long periods (more than 10 minutes) of idling in a “no-load” situation. This is often done to charge batteries or cool refrigeration but if done repeatedly it will glaze the bores of the engine and cause premature engine failure. If the vessel is in a berth the engine can be put in gear to create load at idle.

All boat owners should have an understanding of basic marine diesel engine maintenance to keep themselves and their families safe on the water.

It has been 114 years since Rudolph Diesel applied for a patent for his new improved engine. It was hoped to replace the gasoline engine but as we can all see that this has not happened. The gasoline engine having just been invented in 1876 was still considered inefficient in fuel consumption and power. An evaluation of each engine’s performance tells a story that is difficult to reconcile with the way things have shaken out in the beginning of the 21st Century. The invention of the Diesel offered the world a far more efficient and effective fuel based engine. It actually provides more horsepower per gallon or liter than a gasoline. This is why diesel engines power our large earth moving equipment, trucks, marine engines, low mileage cars and now aircraft.

The diesel is a combustion injection engine. Unlike the gasoline engine, air is compressed first and then the fuel is injected into it. The compressed air is hot enough to ignite the diesel fuel without the use of a sparkplug. Diesel engines developed out of the earlier work surrounding two engines; the original diesel design and the solid injection system of Herbert Akroyd Stuart created in his hot bulb engine. This means that the upward stroke of the diesel engine compresses the air to where its’ temperature is between 1300-1650° F. When the piston has reached the top of its’ upward stroke, diesel fuel is then injected, combustion occurs, pressure increases and pushes the cylinder downwards. This motion is transmitted by means of the connecting rods to the crankshaft which itself turns thus transmitting rotating power to a drive shaft which powers ships, cars, generators, aircraft and even motorcycles.

During cold weather, diesel fuel thickens when the wax crystallizes. It becomes a gel and the fuel injection will not easily work. Technological advances have made this a problem of the past. The fuel lines and fuel filter can be pre-warmed, others use a glow plug in the combustion chamber to pre-heat its’ walls, some use resistive heaters in the intake manifold to warm air taken into the combustion chambers and engine block heaters are used in areas like Kansas or Nebraska when automobiles are left in the cold overnight.

Diesel engine speed used to be controlled by governing the rate of fuel through a gear system. Today the use of electronically controlled engines ECM (electronic control module) allows diesel engines to adjust their timing to start according to the environmental conditions of heat and cold, regulate the engine speed in terms of RPM (revolutions per minute) and maintain fuel economy.

Diesel engines may not have beaten its’ chief contender, the gasoline engine, but it has kept ahead in terms of heavy machine and naval engines. It has recently performed outstandingly in the area of remotely piloted vehicle engines, set amazing land speed records for racecars and motorcycles. The diesel engine has improved amazingly in the past 114 years. The use of electronics has given all engines abilities of fuel conservation unheard of in past years. This makes the diesel engine a real budget-winning contender. This year the new 2006, Volkswagen diesel won fourth place in the best mileage evaluation according to http://www.fueleconomy.gov. Diesels may prove to be the green vehicle engine of choice in the future since they have very little carbon monoxide emissions. Catalytic converters and diesel particulate air filters have made diesel engines free from particulate, nitrogen and sulfur oxides. Diesel engines may prove to be the easiest solution to greenhouse gases.

Looking for the engine replacement? Do you own a Honda car? Yes! But finding quite expensive, if yes then you must be now thinking to change your car with a new one. Wait, if you are planning change your car due to the expensive engine then read on this article.

Nowadays, you will find everything from car to furniture, PCs to mobile phone and many more things used, which means all these things at cheaper cost. Used things doesn’t means inferior. Sometimes, they are resold by users due to shifting to one place to another or sometime they are resold due to some other reason, but these things are good to use. Similar in the case of engines, these days you will find used engines of various brands at cheaper cost. After reading this, plenty of questions must be arising in your mind like is used engine suitable for my car? Can it be able to give same speed and average like the new engine? Yes, it is true that used engines are capable to thousands of more miles like new engine and it is easy to install as well. There are various reasons why you should use engines; some of them are as follow:

· Cost Advantage – Used engines has cost advantage over new engine. You will get used engine at much cheaper cost than the new one. With used engine, you can save more than 50% of your precious money and speed up your car again on the road.

· Simple to install – As compare to new engines, used engines are easy to install. All you need to do is to bring the used engine to a reputed mechanic in order to get it install properly.

· Properly tested – Used engines are properly tested for leakdown, compression, oil content, no sign of spark plug, etc. in order to give you more satisfaction.

If you have set your mind to buy a used engine for your Honda car, then you are going on the right track as you will lots of your money and gear up your Honda car again on the road. If you are looking for a reputed engine dealer from where you can buy used engine then the Internet is the best resource to find a suitable engine dealer. You will find plenty of dealers which are dealing in used Honda engines, Lexus engines, Acura engines, Suzuki engines, and many other used engines as per your needs.

Engine World USA, a leading used engines dealer, providing a wide range of used engines to meet your budgetary requirements. Whether you are looking for Honda engines, Suzuki engines, or any other used engines, Engine World USA is the one stop solution for you.

There are many people who own Honda car. But they are not using their car due to its engine failure and they also think that it will take lots of money to swap the old engine with new one. May be they are not familiar with “used engines” or they might think that they are reliable to buy. But it is absolutely wrong that used engines are unsafe to use. Used engines are safe, convenient, durable, and cost effective. Used engine is best way to speed up your car again on the road. Used engines have certain advantages; some of them are listed below:



It has cost advantage. Used engines with few miles are often available at reasonable cost and are extensively below the high retail costs of new units. By purchasing used engine, it is possible to save half or more than half of your money rather than buying new engine. Used engines also don’t have any extra cost for decorating and packaging.

Properly checked – Used engines should be compression tested, oil content tested, horsepower tested, smooth crankshaft tested, tested for no sign of spark plug fouling, etc. So, there are very less chances of any problem in used Honda engines.

Simple to install – It is another major advantage of purchasing used Honda engines that it is very simple to install. You can buy them from any where and bring it to the experienced and reputed engine automobile mechanic.



There are lots of companies those are dealing in used engines and having adequate and trained staff to properly remanufacture the used engines. It is a fact that most of used engines are exported from Japan, because to own a car in Japan is a costly matter. As per the studies, it is said that gasoline, parking, labor, highway toll and repairing cost is 400 percent higher than US. Car with small scratches or minimum damage considered as the unsafe car. Cars in Japan recycled early. You will find hardly any car which is more than 6 or 7 year old. This is due to lack of auto parts. Due to this engines are recycled and exported for the purpose of reselling.

So, if you are thinking to replace your engine with used Honda engine then you are on the right track. EngineWorld USA is dedicated to provide used engines of various brands like Honda engines, Lexus engines, Acura engines, Mitsubishi engines, and many other engines. Buy durable and cost effective used engines from EngineWorld USA.

Here are some of the standard foreign and domestic automotive maintenance procedures that you should be sure to have done periodically:

Oil Changes: This is one of the most obvious, yet it is also one of the most frequently overlooked. Changing your oil and oil filter every three thousand miles keeps your engine running smoothly. Not changing your oil and oil filter often enough, on the other hand, can be disastrous: Over time, the additives in your engine oil break down, and the oil becomes thick and sludge-like. When this happens, the oil creates resistance on the engine, causing buildup and premature wear. Old engine oil can also cause the rubber seals in your engine to prematurely dry out and crack, creating leaks that can be quite expensive to fix.

There are a lot of quick-lube places that will change your oil quickly and cheaply, which may make you question the need to take your car to a good foreign or domestic automotive maintenance shop. However, it is definitely worth the extra money to make sure an experienced professional services your car. It is not uncommon for quick-lube shops to employ inexperienced teenagers at minimum wage, and horror stories (driving off without oil in the engine, finding months later that the oil plug won’t come out because it was stripped) abound.

Air Filter Replacement: Replacing the air filter is another important precaution that many people forget about. The silly thing is that this is also the easiest thing you’ll have to do on your car. Just as easy, if not easier, as filling the washer fluid on some cars. In fact, this one is so easy that you may not even have to get a foreign or domestic automotive maintenance shop to do it for you. Just make sure you get a high quality replacement filter. If you are not sure where it goes, ask. There will be a couple of clips you’ll have to undo to open the air filter box, but that’s about it.

Your air filter should be replaced once or twice a year. Every six months, you should at least check it. If it looks dirty, replace it. The better airflow your engine gets, the better it will perform, which to you means higher gas mileage and lower maintenance costs over time.

Basic Tune-Up: A tune-up basically involves replacing a bunch of inexpensive, quick-to-wear-out parts, and checking out a bunch of more expensive, slower-to-wear-out parts. This should be done once a year, but again, many people aren’t very good at making sure it gets done regularly.

A basic tune-up involves replacing (or cleaning and re-gapping) your spark plugs, replacing your distributor cap and rotor, and checking and/or replacing your spark plug wires. Other parts that might need to be replaced during a tune-up are your PCV (positive crankcase ventilation valve) and your oxygen sensor. All of these can affect the way your car runs, causing your gas mileage to go down and the carbon monoxide in your exhaust to go up.

Radiator Flush and Coolant Replacement: Your cooling system is a vital system. It prevents your engine from overheating, which can ruin an entire engine in mere minutes. Your cooling system therefore ought to be treated with respect, which means flushing your radiator and replacing the coolant every year or so, preferably at the end of summer or fall, before the cold weather hits.

The reason for flushing your radiator and replacing the coolant is that the Ph balance in antifreeze breaks down after a while, destroying many of its protective properties. Not only will it not cool to as low a temperature, but it will also begin to allow rust to form in your cooling system, which may lead to premature leaks in your radiator.

Be sure your replacement coolant is half water and half antifreeze. The 50/50 mixture has the lowest possible freezing temperature, the highest possible boiling point (meaning your coolant won’t boil on hot days), and will protect against corrosion inside the system.

Automatic Transmission Fluid and Filter Replacement: Many people don’t realize that their automatic transmission contains fluid and a filter that need to be replaced periodically, just like an engine. Unfortunately, neglecting this maintenance repair can result in parts in the transmission going out more quickly than they should, requiring you to overhaul or replace your transmission, which is a costly venture, to say the least.

The fluid and filter in your automatic transmission should typically be replaced about every 25,000 miles, which is less than a year’s worth of driving for most cars. The oil in a standard transmission doesn’t need to be replaced as frequently. Replacement about once every couple of years, unless you happen to do a lot of hard driving, such as towing.

Keeping up on these five preventative maintenance repairs will ensure that you maximize the life of your car. A good foreign or domestic automotive maintenance shop can help you keep track of the required maintenance, making sure that you don’t miss anything important.