Hot answers tagged

35

Engine oil does much more for an engine than lubricate. It provides cooling, cleaning, and a bunch of other chores. You already know engine function is degraded when you run out of oil. Let's see if we can run it down to make more sense for you how it happens. Let's say, for lack of argument, your engine is running with very little to no oil. The engine ...


35

Stop trying to crank it and start beginning to disassemble it. Something is seriously wrong with it and forcing it will only break more stuff that might not already be broken. Especially if you have no idea what caused it to seize in the first place. The only thing more annoying than a seized engine is a seized engine with a sheared off bolt in the nose of ...


17

What is a 5 stroke engine? They tend to consist of only three cylinders rather than the more traditional 4 stroke, 4 cylinder engines that many people are using today. There are two small small high-pressure cylinders and one larger low-pressure cylinder. This video has some good information and animations. Why aren't they using them in vehicles ...


17

Lean ≠ More Air I believe the source of the misunderstanding is in how the term "lean" is being interpreted. A lean mixture doesn't indicate the presence of more air. It indicates the presence of a higher proportion of air compared to fuel (air-fuel ratio, or AFR). Quick example Mixture A has 1,000 g of air, 80 g of fuel. AFR = 1000/80 = 12.5 ...


15

Briefly: The exhaust pipes are shaped to suck gasses out of the combustion chamber over a range of RPMs. Somewhat longer: Imagine a 2 stroke engine without an exhaust*1. When the exhaust valve opens, burned gasses leave the cylinder. Leave the valve open for a long enough time and the cylinder will be at ambient air pressure. Now run the engine at a ...


14

You Asked What do these terms mean? These terms are related to the bore and stroke measurements of a pistons travel inside a bore of an internal combustion engine. Bore is the diameter of the cylinder. Stroke is the distance a piston travels within a bore. What does under-square and over-square mean? Under-square refers to a piston diameter ...


14

tl dr: Cylinder heads (commonly just called "heads") are the big piece of metal which caps and seals the end of the cylinder bore. Types of Cylinder Heads: There are three basic types of cylinder heads: Flathead Cylinder Head - These cylinder heads were used on older engines such as the flat-head Ford engines (like seen below). The oval protrusion at ...


13

You Asked What are the benefits of a dry sump? Simply put a wet sump crankcase has oil sitting in the bottom of the crankcase. It's affected by various forces as the car or motorcycle is driven. At times it is possible, during hard braking or cornering, that the oil pickup is not in oil, resulting in a low or no oil pressure condition that could ...


11

I think I know If you want citations, I have already failed you. You Asked Was there any reason someone (possibly the Volkswagen group) decided to call this configuration a W-16? Answer Maybe. Looking at this picture you can see the various designs and names of ICE platforms created by VW. If you take a V and push into another V it looks like ...


10

In most engines, when you fill the oil, it drains into a reservoir on the bottom of the engine known as the oil pan. The tube for the dipstick goes right down into this reservoir to measure the level of the oil. The other important item located in this reservoir is the pick-up tube for the oil pump. As long as the pick-up tube for the pump stays under the ...


10

It depends on a ton of things and it won't be linear in most cases. Every car has different things that wear out at different rates and those things affect horsepower differently as they age. Not everything that wears affects power. A coolant hose that wears out might cause the engine to overheat, but it won't affect power until then. But vacuum hoses can ...


10

If Sea Foam and transmission fluid did not work, I would stop trying to crank the engine. If you force the engine you will likely damage it. If I had to guess, there is rust built up on the cylinder wall around the rings. Forcing the pistons past these rust rings will likely score the cylinder wall or ruin the rings. My suggestion is not to risk it; tear ...


9

This sounds like a problem with the coolant temperature sensor. Don't worry - replacement is cheap and can be done easily by yourself or a friend who worked on cars before. Cause Cold engines need more fuel to start than warm engines. This is due to the fact that a part of the vaporized fuel condenses at the cold cylinder wall inside each cylinder. This ...


9

Depending on the car model and the technology used, not all fluids I mention here do exist. Here is list of all that I know of: fuel (some cars use two typed of fuel, e.g., petrol and gas, so they have two fuel tanks) engine oil two-stroke oil (in some systems the oil is separated and only combined in the injection) gear oil Automatic Transmission fluid ...


9

Undersquare means the stroke is bigger than the bore. Oversquare means the bore is bigger than the stroke. It doesn't necessarily mean anything in terms of RPM capability, torque curve or anything like that. Those are more dependent on things like rod ratio, head flow, camshaft profile, etc. From a purely theoretical standpoint, you would think that an ...


9

An addition to the previous answers: A limiting factor in car construction is the engine height. Using a dry sump setup the engine gets smaller in height and can be located lower. This lowers the car's center of gravity resulting in a better track performance.


9

Background You asked Why is the effect of a bad fuel pump more noticeable at higher speeds? I assume that by 'higher speeds' you mean engine speeds or RPM's. During high RPM operation an ICE consumes more fuel so the flow rate into the fuel injection system or carburetor increases at higher RPM's. This taxes the fuel system and puts more load on the ...


9

An engine is a very large thermal mass. When the engine is cold it takes time to warm up. If you only run the engine for 15 to 30 seconds from cold there should be no problem. Running the engine any longer than that may cause the engine to overheat.


9

Intake manifold runner length is the linear distance from the inlet port (the face of the head) to a common point shared by all cylinders. Depending on the throttle position this could be the open atmosphere (if each cylinder has its own throttle butterfly) or a plenum (if they share a throttle body). The intake runner volume is the volume of that section ...


8

tl;dr: We do. It's just expensive. One of the differences between electric and chemical energy motors is that the electric systems make it much more convenient to capture and retain energy (e.g., a battery). All you need to do is use induction to create an electric current right there at the wheel while braking. Point that current at that battery and you've ...


8

Royal Enfields are poor man's Harley they both have a thing in common , a relatively high displacement engine for less amount of horsepower. Example : Royal Enfield Continental GT 535CC engine produces 29hp from 87mm x 90mm It has a Big bore long stroke design , it gives out excellent low end Torque , I have driven this motorcycle and you get almost all of ...


8

First of all, I don't really know much about motorcycles, so don't beat me... For a good comparison, one needs torque/hp diagrams. However, they are not easily to find on the web for certain models. In most cases, you will find plots showing curves before/after tuning. I tried a little and found these two bikes, which hopefully are comparable in this ...


8

Dry sump oiling systems are primarily used in racing situations. The main purpose is it will provide oil pressure under any type of hi-G maneuvers, to include cornering, braking, and acceleration. A dry sump oiling system is made up of several parts. The reason why it is called a "dry sump" is because the sump, where in a normal engine is the reservoir for ...


8

I'm by no means an expert, but found an interesting article on Wikipedia about the W engine that indicates the W being a relatively recent addition to the automotive world, but not the aircraft/motorcycle worlds: https://en.wikipedia.org/wiki/W_engine Three different configurations have been called W engines: Three banks of cylinders sharing a ...


8

It's not that the catalytic converter can't handle more air per se, it's that running lean increases the temperature of combustion (I actually don't know why, but now I'm curious) and the catalytic converter needs to run inside it's chemical operating range. Something to do with the chemistry that I also don't know. As for advantages for turbo boost and ...


7

In general, a clutch is a part which allows to connect / disconnect two shafts also while they are rotating. The most simple clutch consists of to discs, each firmly attached to one shaft. Press them together, and the friction between them allows to transfer torque from the one shaft to the other. Pull them apart, and the shafts aren't connected any more, ...


7

There is this nice animation of a 2-stroke engine with an expansion chamber Source It works like this: While moving downwards after ignition, the piston exposes the exhaust opening, and the burned gas streams into the exhaust pipe like a (high pressure) shock wave. Due to the inertia, this gas will create a slight vacuum wave behind it, which helps to ...


7

NOTE: Wankel engines are still Otto cycle engines (re: intake, compression, ignition, exhaust), they just perform the strokes differently than a valve controlled reciprocating engine. Lower Compression Ratio - It is known that a higher compression ratio provides more power without any other modification. This difference in compression ratio is said to be ...


7

It can absolutely be started without a radiator. You will not cause any damage as long as the engine does not overheat. If you don't run it long enough for the engine to get too hot, it's not an issue. To give you an example of how it could be beneficial: I used to own a 94 Camaro Z28. The engine in it was a Gen-II LT1 350. This engine has what's called an ...


7

This particular bottle is knows as a degas bottle. The reason it has a strange shape is two fold. First, the bottle needs to fit somewhere and the shape helps that. Second and more important is that these degas bottles hold pressure. The shape reinforces the bottle so that it does not explode. In cooling systems with degas bottles the coolant does not ...



Only top voted, non community-wiki answers of a minimum length are eligible