Features to Look for When Buying a Complete Car Engine

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Features to Look for When Buying a Complete Car Engine

Engines are at the heart of any vehicle. When something goes wrong with the engine, it is vital that it be repaired in order to prevent any further damage. Sometimes, the engine problem may be too extensive to warrant repair and therefore needs to be replaced. In these instances, before a person goes out and spends money on a complete car engine, it is good to know some facts about some of the features of one.

Because complete car engines differ greatly from each other, it should not be expected or assumed that the engines all have the same features. There are differences in complete engines that buyers should be aware of, ones that can affect such things as speed and fuel economy when buying a new engine. There are also other factors buyers should look out for when buying a used engine as well. Complete car engines can be located at auto part retailers and on eBay. Knowing what features are available for complete car engines and how to spot a faulty used engine can help people make a more informed decision before buying one.

Basic Parts of Engines

Sometimes, in order to know what features to look for in an engine, it takes knowing a little bit about how an engine works. Complete engines have cylinders, and depending upon the make and model of the vehicle, the amount of cylinders vary. An engine can have four, six, or eight cylinders. There are three different ways in which the cylinders can be arranged within an engine, and they are: flat, inline, or V. Understanding the different types of engines and some basic information on what makes them tick can help many individuals choose the right one for them.

There are different advantages to each type of cylinder arrangement, such as their shape, how smoothly they operate, and how much they cost. Even though the cylinder is a very important part of an engine, there are other parts that are required for it to work properly. The table below lists information about the main parts of an engine and how each part functions.

Engine Parts


Spark Plug

Ignites mix of air and fuel by giving off spark to allow combustion; timing of spark is essential in combustion process

Engine Valves

Two valves that work together; one takes in an air and fuel mixture while other expels exhaust; valves must be closed in chamber where combustion and compression take place


Piece of metal that has cylindrical shape; moves in upward and downward strokes within the cylinder

Piston Rings

Seals off area between cylinder’s inner edge and outer edge of piston; prevents leakage of fuel and air mixture from making way into sump to during compression and combustion phases; prevents oil from entering sump

Connecting Rod

Allows the crankshaft to be connected to the piston; both ends may rotate to allow proper movement of pistons


Changes upward and downward strokes of pistons into a circular pattern to allow pistons to perform their function

Oil Sump

Also known as the oil pan; surrounds the crankshaft

In order for the engine to run properly, all of these features must be working efficiently. New complete car engines are the best types to purchase on most occasions if the price is right; however, there are also many used complete engines that work just as well.

Features for Increased Power

If an engine is replaced for the purpose of adding more power to the vehicle, there is some additional information that is worth knowing. Many remanufactured complete car engines are upgraded with additional features that increase power or speed. This is beneficial to new owners because they do not have to invest time in performing the upgrades themselves. Understanding what features give an engine more power is helpful in the process of this type of upgrade.


One way to get an engine with more power is to find one that has either more cylinders or larger cylinders. The suggested limit for cylinders is 12. Having more cylinders or larger cylinders increases displacement and allows more gas to be burned in turn, giving the engine more power. Also, by increasing the amount of air and fuel within the cylinder, the power of the engine is increased. This can be accomplished by having an engine that is equipped with a turbocharger.

Compression Ratio

Increasing the pressure of the fuel and air combination can be tricky. If these elements are compressed too tightly, there is always a risk that before the spark plug can ignite it, it may spontaneously combust. Keeping a balanced ratio at the upper limits without going over them can alleviate this problem. Using fuels with higher octane content can guard against the early spontaneous combustion.


The more compressed air becomes, the hotter the temperature of the air rises. The more air that is in the cylinder, the more power an engine has because of the greater combustion process allowed. Hot air takes up a lot of room and therefore decreases the power. One solution to this problem is to have an engine that is equipped with an intercooler. An intercooler is simply a radiator that helps to cool off the air that passes through it and reaches the cylinder. Many people who have engines that are equipped with either a supercharger or a turbocharger have an intercooler for this reason.

Features for Improved Air Flow

Improved air flow is one way of getting more power out of an engine. There are a few ways that this can be accomplished. Adding larger air filters makes a big difference when it comes to allowing more air get where it needs to go. Having two air intake valves in each cylinder helps to replace the air that is lost when the pistons perform their intake stroke. When a piston moves in that downward motion, it can create air resistance, thus robbing power from the engine. Polished intake manifolds are popular on engines for newer car models because this type of manifold is also useful in decreasing air resistance as well.

Exhaust Valves

The addition of an extra exhaust valve is one more way that an engine can realise more power. When exhaust is able to escape more easily, the power is increased because of the decreased air resistance. Engines that have a second exhaust valve added to the cylinder, also known as dual exhaust engines, are ones to look for if this issue is a problem with a previous engine. Headers, free flowing mufflers, and larger tail pipes are also engine features that decrease back pressure that is often created by air resistance.

Used Complete Engines

Used complete car engines can offer a lot of value to a vehicle if the proper one is chosen. One dilemma that many people face is not knowing the history of possible engine problems. If a person wants to buy a used engine and cannot locate an adequate history, there are some things that can be helpful in aiding a person see possible problems before committing to purchase it.

Engine Inspection

Being able to physically inspect an engine offers many advantages to an interested person. There are many things that should be taken into consideration and inspected before making a final decision.

Outer Engine Inspection

While inspecting an engine, there are many things to look for in order to prevent purchasing an engine that may come with possible problems down the road. When performing a physical inspection of a complete engine, it is important to look for signs of wear and tear. Check to see if there are any cracks in the exterior engine housing or if any of the engine parts are cracked as well. In addition to checking for cracks, also make sure that there are no leaks of any kind and that any bolts are securely fastened.

Inspect Inner Components

A common problem for used motors to have experienced is overheating. Overheating is very hard on an engine and can ruin it entirely. There are some telltale signs to watch out for that may point to the engine having experienced this problem in the past. Checking the oil dipstick for any signs of rust, discoloured oil, and oil foam can signal the fact that water or coolant may have entered the oil chamber. While checking the oil, it is also a good idea to inspect the rockers located on the underside of the oil cap for contaminants. Make sure that the spark plugs are clean, and there is no rust build-up on the thermostat housing. The motor should spin freely when the crank pulley is spun as well.

When Physical Inspection Is Not Possible

In cases where a direct physical inspection cannot be done by the prospective buyer, the seller should be contacted and be asked about any possible problems the used engine may have had while in service. It is also important to know if there have been any parts that recently have been replaced as well as how many miles the engine was driven prior to being sold. It is also not a bad idea to have the seller put the terms of the sale and any possible defects in writing before a buyer commits to such a purchase if there is any doubt to the legitimacy of the seller’s claim.

How to Buy a Complete Engine on eBay

Purchasing a complete engine with all the bells and whistles on eBay is super easy. Start by going to the eBay home page and enter a search for the item that is desired at the top of the page in the search query box that is provided. You can enter as few or as many relevant keywords for the type of engine that you are looking for as you want.

For example, if you want a complete motor but do not want to limit yourself to any particular brand or feature, enter a broad keyword search by using the keywords "complete engine". Afterwards, all of the items that have been categorised with those keywords are displayed. At this point you may browse through the selected items or refine your search results by adding additional words. There is also an advance search feature option that allows other categorical filters to be applied such as price, brand, make, and model in addition to other choices.


Purchasing a complete car engine is a great way to put life back into a dormant vehicle. Buying the right car engine is easier when it is understood what type of features an engine is equipped with. Knowing how the features like the spark plugs, valves, pistons, and other common parts all work together ensures that buyers are able to distinguish what features they want from a new car engine.

Also, having knowledge about other vital features of an engine, such as cylinders, intercoolers, and exhaust valves, and how they play a part in adding to or detracting from an engine’s power supply is useful when choosing an engine desired for increased speed and power. Purchasing a used car engine can also save money if the engine is able to be inspected physically or the buyer knows what questions to ask the seller about the engine’s history. All of these aspects can alleviate stress when choosing a car engine for its available features.

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