41

For those who don't know, SOHC and DOHC refer to the following: SOHC - Single Over Head Cam DOHC - Double Over Head Cam A cam refers to a "cam shaft" or the thing which goes bump in the night. The cam has a "bump" or "hump" in it which actuates the valves which allows air into and exhaust out of the cylinder of the engine at the correct time so the engine ...


24

Traditionally... The major drawbacks of automatic transmissions were: parasitic losses in the torque converter, something which manual transmissions don't have. fewer gears, so a given engine was more likely to be in its sweet spot with a 5-speed manual than a 4-speed automatic during regular operation. gear selection logic which was inferior to well-...


23

There are pros and cons of each, remember you can easily spin or lock up the rear wheel, and in fact the rear wheel may be far less often at the correct speed. So the decision on this stems from physical connectivity it's much easier to connect from the front wheel to the odometer which is on the handlebars than to route from the rear wheel, up under the ...


21

A lot of new automatic transmissions (e.g. Volkswagen DSG) arent actually auto transmissions, at least not in the traditional sense. They have a normal computer-controlled dry clutch (well two actually) so they do not need to move around a lot of transmission fluid like traditional automatic transmissions do. Also they have a lot of gears (7, 8 or even 9 ...


12

Its not a rule of thumb that the Speedometer is connected to the front wheel. There are many Suzukies and hondas in my country that have the speedometer connected to the rear wheel. As Rory stated, the only reason I guess is due to the convenience factor since the front wheel is closer to the cockpit.


12

The front wheel is used in most cases with mechanical speedometers (though there are exceptions) because it's just easier (and probably cheaper) to couple the front wheel to the mechanism. Additionally, a mechanical speedometer uses a cable. The longer it is, the less reliable and accurate it becomes, thus the speedometer takes the speed from the nearest ...


10

I am assuming that by cooling you are referring as to which Engine cooling systems are better in particular scenarios... Oil-cooled: Traditional Oil-cooled engines are most commonly found in passenger commuter motorcycles which are usually anywhere between 50cc to 500cc (some sophisticated models have liquid cooled engines as well). The system uses the ...


9

I am not sure where you get the idea they haven't built larger displacement two stroke engines. Detroit Diesel built the 71 series which was very large displacement two stroke engines. From Wikipedia: The Detroit Diesel Series 71 is a two-stroke diesel engine series, available in both inline and V configurations, with the inline models including one, two, ...


9

Assuming they were the base models, the two cars you mentioned (Acura TL and Mazda6) are both Front-Wheel Drive (FWD), while the Mercedes is Rear-Wheel Drive (RWD). The FWD cars, having both their engine and transaxle mounted over the front wheels, have a front-biased weight distribution, requiring stiffer front springs to control the weight. The higher ...


8

They are being used as approach lights. When someone unlocks their car with the remote the car turns on lights around the car. I think the idea is to light up the ground around the car for you to better see where you are stepping and maybe for security. Some cars turn on the headlights, interior lights, parking lights etc. You point does make turning on the ...


8

Lobe separation angle is affects overlap between the intake and exhaust valves which can effect emissions, performance and efficiency. Example of Lobe Separation Angle Measurement of Lobe Separation Angle Measurement would be done with a degree wheel on the crank and dial indicator on the cam. The measurement occurs between the MAXIMUM lift of the intake ...


8

A sprag is a kind of clutch that will turn in one direction but not in the other. There are many designs but the common one is a set of balls on ramps. When going the wrong way the rollers run up the ramp assisted by the spring and jam rotation. When it's rotated the correct way the rollers are constantly being forced down allowing rotation. The most ...


8

This looks like your first posting with Motor Vehicle maintenance and repair site. It looks like you are an engineering student, looking at a possible school project. Is that right? Welcome to the stackexchange! You have a whole lot of decisions to make. First Choice: Type of engine? I'm going to assume you want an internal combustion engine. Choices ...


8

Oil Cooled and Water Cooled are terms used by Manufacturer's to differentiate the slight difference between the cooling systems. Note that this is specific to only motorcycles as almost all of the cars and larger automobiles have moved to Water cooling(Explained below) Oil cooling: Technically , An oil cooled engine is predominantly air cooled with ...


8

I think bubbles are less likely to have anything to do with it. The forging process makes the metal more durable by aligning the grain of the metal. After forging, there is less of a chance for stress risers to occur in the metal. This means it will stand up to a lot more abuse than you'd see a cast wheel stand up to. The forging cut from billet, can then be ...


8

I am assuming that you don't mean to ask how the belt holds you in place. :) I'm assuming you are asking how the mechanism works. I'll break this into two parts. The simple mechanism and the pretensioner. Simple mechanism Here's the diagram: (Image source) And here's the explanation: The actual belt is attached to the a drum that is attached to the ...


7

I think it's more related to the angle of the driveshaft from the transmission to the differential. This way you could have more suspension travel without putting too much constraints on parts. In fact, to answer your question, it may be related to the geometry of the truck/driveshaft that manufacturer will select one type over another one. If the truck is ...


7

I know this thread is a bit old, but Detroit Diesel and GM EMD (Electro-Motive Division) have many 2 stroke Diesels. The crankcases! Well they aren't pressurized. How it works is different to a smaller 2 stroke engine. Instead of the underside of the piston 'pushing' an air fuel charge up a transfer port, these engines have an air gallery around the ...


7

There are two concepts to understand (which I think you might already get to an extent). As the wheel base length grows, stability is gained, but you lose maneuverability. You also risk the greater chance of the vehicle becoming high-centered (ground rubbing the center of the vehicle) when traversing bumps in the road unless you increase the ride height of ...


7

To add to the other great answers, I must point out that seat belts 'work' to reduce the impact on the passenger by stretching. In a large impact the fabric stretches quite significantly, don't quote me, but perhaps a centimetre or two. This 'extra controlled travel' in the seat belt gives the human body a few more milliseconds to decelerate (ie a little ...


6

I'm working on developing an automatic bicycle (mostly microcontroller based) and I'd presume I'd be shifting in a similar way to a car. Well, you're in for a shock: it's going to be pretty different. So my question is, what factors does the transmission take into consideration when shifting? ... So is it concerned more with speed, rpm, some ...


6

Perhaps you were thinking of 2-stroke gasoline engines when asking the question. Evinrude built a 3.6 liter gasoline 2-stroke for outboard boat motors. http://www.roadandtrack.com/car-culture/videos/a7300/video-insane-evinrude-johnson-two-stroke-v8-startup/ Interestingly the exhausts are in the V in this design, which is necessary as the carburetors ...


6

Lubrication and cooling of two-stroke engines have always been the limiting factors. The bigger the engine, the bigger the problems. A big two-stroke will have a very short service life, even with constant maintenance. Two-stroke engines burn oil in their fuel and burning oil causes pollution. The charging of the cylinders by its port arrangements mean ...


6

I was looking at this from an automobile standpoint wondering What the heck is he talking about?? The vast majority of vehicle rotors and drums are made out of grey cast iron!, then went back and reaslized you are asking about motorcycles and ATVs. To that end: Why are OEM parts made of martensitic stainless steel (AISI 4XXX series)? The main reason for ...


6

It all comes down to how the engineer designs it. The manufacturer sets how it's going to be put together. There's no real inherent design differences +/- ... It could come down to whether they want a turbocharger in front of the engine where it's easier to get to and where there might be more space. It could be that the design of a transmission limits space ...


6

All of my competition cars have had speedos, some of which didn't work at all. I have never once been in a race and had time to take my eyes off what was happening around me to look at the dials. This is why competition cars tend to equip their dashboards with bright lights which come on when attention is required. The times a speedo is useful is during ...


6

With a greater number of gears in the autobox and with a lock-up function called more frequently for the fluid flywheel. Then add a better computer based control system for moving between gears : improved algorithm and faster change control.


5

Grey cast iron possesses some traits which makes it less desirable than martensitic steel for brake disc applications: it is more brittle, which means it is easier to crack it has very low impact resistance, making it less durable under heavy braking it has less hardness (400 Brinell vs 700 Brinell), so it wears more quickly if left uncoated, it is more ...


5

A stress riser (also known as a stress concentration or stress raiser) is so called because there is more stress in one area which can cause fatigue cracks and ultimately cause part failure. This can happen in any part in the engine, but some parts are more prone to stress than others, so would suffer sooner. A stress riser can occur anywhere stress is ...


5

TLDR : Planetary center differential with viscous coupling. EDIT : This is wrt center differential transfer case and not traditional 4X4 transfer case , since the question is about torque biasing which precludes the latter. I understand that differentials are a huge topic and there are many clever solutions in the realm of torque biasing. I'l post one such ...


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