12
votes
Who came up with "suck, squeeze, bang, blow"?
This phrase has been around very long and has been used in the aviation industry as well as automobile. This is a very good, and more importantly, very easy for anyone to understand way of describing ...
- 13.3k
10
votes
Accepted
What makes two-stroke engines less fuel-efficient than four-strokes?
Just so we're on the same page as to how two strokes work, here's a pic. I had to look it up because I had the wrong picture in my head.
In looking at how the cycle actually works, the power stroke ...
- 9,326
9
votes
Accepted
Two-stroke vs four-stroke design
Depends.
A key point of 2-cycle engines is that a thing called scavenging happens with the piston at the bottom: at the end of the power cycle/ beginning of the compression cycle. During ...
8
votes
What makes two-stroke engines less fuel-efficient than four-strokes?
The efficiency of any internal combustion engine is directly related to its Carnot efficiency, where efficiency equals the inlet air temperature minus the exhaust temperature divided by the inlet ...
- 81
7
votes
Accepted
What is the efficiency delta between rotary and modern four-stroke engines
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 ...
- 153k
7
votes
Accepted
Do 3 and 5 cylinder engines have uneven power delivery?
You are thinking too linearly. A V8 engine has two connecting rods attached at each crank journal with a crank spacing of 90° between each crank journal. The I5 (like the GM LLR) has a single ...
- 153k
6
votes
Brake Specific Fuel Consumption of 2-stroke vs 4-stroke
BSFC is just engineer-speak for how much fuel is consumed by the engine per unit of energy output¹.
This webpage provides a very concise comparison for several different engines:
+-------------------...
- 39.1k
6
votes
Two-stroke vs four-stroke design
For Two Stroke engine:
One working stroke in each cylinder per revolution of crankshaft.
Light in weight.
Moving parts are few.
Mechanical efficiency is more.
Thermal efficiency is less because a ...
- 169
6
votes
Accepted
What is meant by bore and stroke?
Bore is the diameter of each cylinder and stroke is the length that it travels when moving from bottom position to the top position. Thus if the engine has 1 cylinder with bore x stroke of 78 x 52.3 ...
- 1,739
5
votes
Accepted
Two-Stroke vs. Four-Stroke Diesel Engines - What is most commonly used in heavy vehicles?
Most small(ish) diesel engines in cars, diggers, generators etc are 4-stroke.
The main reason being efficiency - Although a 2-stroke engine is technically capable of more power output, a 4-...
4
votes
What makes two-stroke engines less fuel-efficient than four-strokes?
I have to both agree and disagree with your statements in the question and the article.
The higher fuel consumption of a two stroke engine is mostly due to the fact that it has a power stroke per ...
- 8,956
4
votes
Accepted
Ignition timing of 4 stroke two wheeler
As Steve Matthews says, get your flywheel in a proper position, it shouldn't be able to fit it wrong way. Unless you have lost a part number 6 "keyway". To me looks like
coil 3 is a high voltage coil ...
- 1,448
4
votes
Ignition timing of 4 stroke two wheeler
I would say that, almost certainly, the orientation of the flywheel relative to the position of the engine will be important. Looking at the diagram, I'd guess you physically removed part number 7 to ...
- 23.5k
4
votes
Two-stroke vs four-stroke design
Not sure if you count that under “besides the apparent”... but IMO the single most striking peculiarity of a two-stroke is that it uses both sides of the pistons to work on gas volumes†. That's what ...
- 435
4
votes
Accepted
Which engine type gives more HP- two or four cycle?
Theoretically, with all other factors being equal, the 2 stroke engine should produce 2 times the power of the 4 stroke engine. The reason being that the 2 stroke engine has twice as many power ...
- 12.1k
3
votes
Accepted
What are the dangers of too high TBN?
You might want to read the article here:
TBN Discussion
But the key point on too high a TBN number is:
So should we all use a High TBN oil? There are advantages, but there
are also ...
- 12.1k
3
votes
Accepted
Starting fluid, does it require a spark or autoignite?
If the engine is cold, there is no way the combustion chamber is going to get up to 160 degrees C. even when the air is compressed. So your problem is with the fuel system; either the fuel pump, or ...
- 364
3
votes
Two-stroke vs four-stroke design
Yes, number of power strokes per revolution, less complicated : fewer moving parts, emissions or pollution levels. Have a look here : http://mechstuff.com/differences-advantages-disadvantages-of-4-...
- 34.6k
2
votes
What makes two-stroke engines less fuel-efficient than four-strokes?
Very much depends on the particular 2 stroke and 4 stroke engines. But a major advantage of a 2 stroke is that they can be produced incredibly simply and so cheaply. An engine with 3 moving components ...
- 561
2
votes
What is difference between stock CDI and racing CDI in a 4 stroke motorcycle?
A CDI ignition system uses capacitors to charge up the energy for the spark plug discharge. Generally speaking, capacitors do this more quickly than electrical coils, allowing the ignition system to ...
- 12.2k
2
votes
Oil sump for 2 stroke vehicles
Because in a two-stroke, the air-fuel charge gets taken into the crankcase. If there were a sump of oil there, it would get sucked into the engine. There are many two-strokes where the oil is stored ...
- 1,708
2
votes
In a petrol engine, how does the first stroke happen when the gas pedal is first pressed?
Judging from your question, you are indeed new to mechanics. The pressing of the gas pedal does not start the engine. The engine is already running, disconnected from the wheels by a slipping torque ...
- 14.5k
2
votes
Oil sump for 2 stroke vehicles
So there are quite a few two stroke engines. For gassers like chain saws, the oil and fuel (gasoline) are mixed and introduced into the crankcase by the carburetor. The oil lubes the engine, and is ...
- 2,115
1
vote
Accepted
Motor oil requirements on exhaust system
Oils have various additives. Some of the oils in 4 cycle oil form ash if they are burned in combustion; elements like zinc and barium . Because all the 2 cycle oil will be burned it is formulated with ...
- 3,708
1
vote
Oil sump for 2 stroke vehicles
There are in fact two stroke engines that get lubricated by an oil sump / pump system and do not receive the lubricating oil through the air-fuel mix.
Those are two stroke diesel engines used in ...
- 8,448
1
vote
Accepted
More difficult to start the MotorCycle
20 kicks is a lot, I'd expect 2 or 3 kicks should be enough to start a motorcycle. Looking at the slingshot specs it says it's a carbureted engine, not fuel injected, I suspect what's happening is ...
- 16.2k
1
vote
More In Cylinder Pressure Testing Questions
I did some searching on IATN and found known good pressure waveforms that are identical to my after repair captures. Unfortunately I can't post them here. It turns out that hump is completely normal.
...
- 10.7k
1
vote
What is the efficiency delta between rotary and modern four-stroke engines
I couldnt help but notice,the much bigger rotary "piston" surface/per amount of fuel, was being somewhat overlooked in these other answers considerations. It might be a compensating factor in ...
- 11
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