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11

For most practical purposes, it's done for cosmetic reasons. One might prefer to use black over silver for better heat dissipation but the motivation is almost always going to be to enhance appearance. In cast iron blocks, the paint can act as a means of rust prevention.


9

Stopping a naturally aspirated engine will cool it down, regardless of the fan running and etc. The idea behind "turbo timers" on turbocharged cars is not at all engine cooling related, rather it is to allow the delicate and extremely hot turbocharger components to cool down via keeping the oil feed circulating through it for additional 15-30 seconds or a ...


9

It's true that modern engines produce more power The stats tell it all, but here's a quick example in numbers: 1976 BMW M17 1990 cc 113 hp 2011 BMW N20 1997 cc 340 hp But some things will never change Air + Fuel = Bang + Emissions The chemical equation governing internal combustion hasn't changed. This means that the optimum air-to-fuel ratio (AFR) ...


7

It is mainly for aesthetics. Something else it can do for you is to allow you to see when you have a leak. I've seen blocks painted white for this reason. Something you didn't mention was whether you are talking about painting the outside or the inside of the engine. If done right, painting the inside of the engine can result in oil returning faster to ...


7

If you really want an intake that will likely survive deep water, you're going to need something more like: However... Is the height of the bottom of the chassis the maximum height I can drive through without hydrolocking? (This question is bordering on offtopic, sorry!) Would I hydrolock, even though the intake is really high? You might ...


6

If the height of the new piston above the rod connection centerline is greater than for the old piston, that will increase the compression ratio quickly. For the assumption made by Zaid on the stroke, a height change of 3.2 mm will produce that new compression. If that is the case (taller piston) you would also need to wonder about valve clearance.


6

The simple answer to your question is: They rotate all the time. This happens during the open/close cycling and not while closed. This is the reason why we have to lap the valves so the entire face of the valve will seal with the seat and not just one little part.


6

I think the overheating episode did a permanent damage to your car. A gasket could have cracked or the head could have warped or even cracked, thus allowing water into the engine itself. Too much heat in an engine can cause serious problems because heat causes metal to expand. The hotter the engine gets, the tighter clearances become until there are ...


6

It's not a good idea to run the engine dry like that because the bearings on the crankshaft need oil pressure for lubrication. Having said that, some engines can run without oil for a short amount of time thanks to whatever residual oil is trapped between the bearing surfaces. I don't think you would spin a bearing with a limited amount of cranking, but you ...


6

The oil cooler is one possible place where oil and coolant could mix, but there are other culprits: a compromised head gasket can allow oil to mix into the cylinder head's cooling jacket a warped cylinder head can do the same.


4

I'm told that the bulk of the break-in is done in the first few minutes of running and that no synthetic of any kind should be used. You're in "test pilot" land now, all bets are off... If it was me (a person not afraid of blowing up an engine), I'd switch to conventional and do a lot of WOT/decel runs to try to beat in the last of the break-in that I could ...


4

Yes, the valves do rotate under normal operation albeit slowly. Some valves have rotate mechanisms to ensure they rotate at a predictable rate. http://www.cdxetextbook.com/engines/comp/vlves/valverotation.html http://courses.washington.edu/engr100/Section_Wei/engine/UofWindsorManual/Valve%20Train.htm The rotation action helps keep the valve and seat ...


4

Liquid cannot compress. The volume of the cylinder is smallest when the cylinder is at TDC. IF you know things like piston dish volume, head combustion chamber volume, head gasket thickness, you can calculate this volume. I am assume you do not know these values... Here is what I do. Set the engine to TDC on #1. Pull the plug. Fill up the cylinder. ...


4

There is no way that a 1 mm increase in bore diameter will change compression ratio that drastically unless the stroke is changed as well. My rough calculations indicate that the change in bore will result in a new compression ratio of 8.66:1ยน. Even though you're not after power per se, the higher CR should translate to more torque. A rebored piston will ...


4

Your final sentence is the one that is subjective here. You find the V8 best. V8's are good, but so are V12's - they have different characteristics and tend to be chosen for those characteristics. A V8 is a lot smaller, so can fit in a smaller space - where space is at a premium that may be the key criterion. With less space limitations, however, going for ...


4

I wanted to get my comments compiled into a full answer, to make sure we are thorough. Draining oil through the filter connection by running the starting motor to pump the oil brings a few concerns to mind: There is the possibility that fuel will flood the cylinders as you turn the engine over without a spark to burn the fuel. As you said, the ATV started ...


3

With BMW's it used to be that the last two numbers represented the engine size. Sadly on newer cars this seems to have been abandoned so it is no longer a valid way to tell. You'll have to do some research based not only on the model but also the year the car was manufactured. This information is generally available in publications such as Parkers or ...


3

tl;dr In general, short block = block + rotating assembly long block = short block + heads When talking short or long block, you are suggesting the completeness of the engine. Basically, a short block will consist of the following: Engine block Main caps Rotating assembly Crankshaft Connecting Rods Pistons Rings Bearings (both rod and main) ...


3

In general: carbon build-up (CBU) impairs the ability of the valves to properly seat, resulting in lack of compression, which leads to loss of engine torque. if the vehicle is equipped with AIR (secondary-air pump), CBU in secondary air tracts prevents the emissions-control from functioning properly during cold starts. If bad enough, this can lead to the ...


3

Your post raises several possible issues that you could eliminate to start with. Firstly if it is still on an incline I suggest you push or tow it to flat ground. It will help rule out fuel starvation and make it easier and safer to work on. Second i would drain the fuel tank and put fresh fuel in it. From there you can try starting it a few times. ...


3

In fuel-injected systems, hot-start problems indicate that the fuel line is unable to maintain pressure. This could be due to a few things related to the fuel supply line, including: a leaky fuel injector minute cracks in the fuel line which leak fuel when under pressure The reason why this happens only for hot starts is because the fuel is more likely ...


3

You seem to have several concerns here, so let me try to address them one at a time. You are worried about the car starting up properly. Since the engine would not turn over when you tried to start it, then it started right away with a jump start, it sounds like it was only the battery you need to worry about. Either you left a light on or something else ...


3

It depends on the vehicle, why it is being left, and how it is prepared before being left. If it's a vehicle that's in reasonably regular use, then I'd recommend making sure it's used at least once every week or so, and is driven far enough for the engine to get up to full operating temperature. Just starting it and letting it run is better than nothing ...


3

According to me there are 3 major events or advancements which have contributed for most of the efficiency and improvement of the modern engines. 1. Electronic Fuel Injection The elimination of the carburettor meant that the Air Fuel Mixture ratio can now be adjusted to a higher degree and an optimum and combustion environment is possible for the engine ...


3

No. Stalling the car will not damage your car , your car is designed to absorb the impact at least a hundred times.(Most of my family members learnt driving in my car and it has stalled half of its life and its working perfectly) Stalling the car extremely frequently especially with load(passengers) can put additional stress on the transmission components ...


2

I'm betting your Corsa is Drive-By-Wire (DBW), meaning, there isn't a direct connection between you and the throttle. If so, the gas pedal rheostat is probably telling the computer you are pressing it, causing the throttle to go up and in some cases not respond at all. You could possibly test the gas pedal by unplugging it and checking for even/smooth ...


2

I agree with Gary's assessment about the Manifold gaskets. The Olds 3800 is a "workhorse" engine as is the 3.3, only you don't see much of the 3.3's on the shelf or in the shop. As this is an older piece of iron it stands to reason that the gaskets may need replacing. If you have a tuned ear you can hear a leak or at least hear the approximate location of ...


2

They are non-reusable in the sense that if you take them out, you have to replace them. Valve guides are reusable until they are worn out; you don't replace them unless they are worn beyond usefulness. When they wear out, you can usually do one of three things: knurl; valve guide sleeve; new valve guide. You check the valve guide by the amount of side play ...


2

Before you go thinking the belt is out of time, when your mechanic told you about the wires, what he may have been suggesting is that you have the wires on the wrong plugs. This will create the imbalance you are talking about, yet most of the time will not show a trouble code (because they are all still firing, just not at the right time). Double check to ...


2

The source of the pffft sound is the AC system's expansion valve. It is normal to hear it when the AC engages/disengages; it doesn't indicate that the expansion valve has an issue per se. However, what is not normal is that the AC is cycling on and off so frequently. 6-7 seconds tells me that something is disengaging the compressor clutch. This could be ...



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