How do car manufacturers decide on engine configurations?

[adam2007]

Ok depending lets say 2.0 engine car engine

if i put it in a straight 4 vs v6 configration would i still get same power but differnet torque all would it all be the same

5.0 v8 vs 5.0 v12

diffenet touqe levels? how do manufactur descide what to use in a normal car engine?

anything usally over 2.5 litre is then into v6 onwards why? they can make pistions big as they want to more cylinders the smoother the engine

[Jersey Tom]

Engines are not my strongpoint... but, I believe part of it is a function of what the cylinder volume and dimensions will be, and how they impact flame speed and combustion.

Engine output ultimately comes down to how much air the thing can suck in. Higher displacement, higher RPM, or forced induction.

[WhiteBlue]

Ok depending lets say 2.0 engine car engine

if i put it in a straight 4 vs v6 configration would i still get same power but differnet torque all would it all be the same

A 2L V6 would have a much smother power delivery than a 4-in-line and most likely more power.

The V6 would have more power because he would typically rev higher. That is because the inertial forces of the piston and connecting rods would be reduced due to the dimensional shrink. Each cylinder would have to have only 2/3 of the displacement of the 4-in-line. At the same L/D ratio the pistons would be smaller and have less mass, so the rod would also be having less mass for the same stress level.

The V6 would have higher manufacturing cost and more weight due to more parts being used. It would also be thirstier due to more internal friction. The torque would be pretty much the same unless you consider the different friction relevant, but the smoothness of torque over time would be better with the V6.

5.0 v8 vs 5.0 v12

diffenet touqe levels? how do manufactur descide what to use in a normal car engine?

Again the situation would be very similar. The more cylinders you add the smother the engine runs. One advantage of the V8 at that size over the V12 would be length. The V8 would be much more compact and fit in many more cars. So the 5.0 V12 is really for luxury only.

anything usally over 2.5 litre is then into v6 onwards why? they can make pistions big as they want to more cylinders the smoother the engine

2L is usually the lower limit for going to the expense of six cylinders. BMW for a long time did small six in line. They are simply bad for packaging. If you incur the cost of more than four cylinders you typically want a tight package and go the extra cost of two banks for the V6.

[JohnsonsEvilTwin]

The most powerful 2.0 liter production engine is a 4 cylinder WB.

Enter the F20C Honda 2.0 litre 4cylinder. An absolute masterpiece of engineering capable of 9250rpm and 240bhp STANDARD. play with the air filter and you get 250....thats not even touching the exhaust or engine!

[Giblet]

Sometimes car companies just throw an oddball at you for fun as well, the 1.8 liter v6 in the Mazda Mx3 Presidia for example.

This engine had only 144hp at it's best, and considering Honda at the time had a 1.6 liter DOHC 4 cylinder producing 160 hp, it makes you wonder why they went that route.

[xpensive]

The most powerful 2.0 liter production engine is a 4 cylinder WB.

Enter the F20C Honda 2.0 litre 4cylinder. An absolute masterpiece of engineering capable of 9250rpm and 240bhp STANDARD. play with the air filter and you get 250....thats not even touching the exhaust or engine!

That's all Rpm JET, to little torque for WB!

[WhiteBlue]

The most powerful 2.0 liter production engine is a 4 cylinder WB.

Enter the F20C Honda 2.0 litre 4cylinder. An absolute masterpiece of engineering capable of 9250rpm and 240bhp STANDARD. play with the air filter and you get 250....thats not even touching the exhaust or engine!

That isn't contradicting anything what I have said. This Honda engine seems to be a screamer build for extremely high revs with exotic materials that high volume engines would not use. If Honda would apply that technology to a V6 they would probably go to more than 11.000 rpm.

[Belatti]

In 1975 there was a 2.0L V8 production engine that delivered 170HP at 7,700 rpm...

[autogyro]

In 1975 there was a 2.0L V8 production engine that delivered 170HP at 7,700 rpm...

Daimler hemi, I had one in a Sunbeam Tiger.
It was a superb engine and I still recomend it for hot rods dragsters, kit cars etc. A friend and racer had one in a T bucket on methanol/nitro with a supercharger.

[JohnsonsEvilTwin]

The most powerful 2.0 liter production engine is a 4 cylinder WB.

Enter the F20C Honda 2.0 litre 4cylinder. An absolute masterpiece of engineering capable of 9250rpm and 240bhp STANDARD. play with the air filter and you get 250....thats not even touching the exhaust or engine!

That isn't contradicting anything what I have said. This Honda engine seems to be a screamer build for extremely high revs with exotic materials that high volume engines would not use. If Honda would apply that technology to a V6 they would probably go to more than 11.000 rpm.

My S2000 has 134,000 miles no problem. What Materials is in this that is not in the standard 2.o litre 4 type R engine? nothing I can tell....
And as for Honda doing a V6..they did a 3.2 litre for the NSX.....8550rpm.
That same era they had the screamer 1.6 B16(i think) that did 8800rpm.

Maybe this says more about Honda's fantastic abilities with engines than it does about fours

[JohnsonsEvilTwin]

The most powerful 2.0 liter production engine is a 4 cylinder WB.

Enter the F20C Honda 2.0 litre 4cylinder. An absolute masterpiece of engineering capable of 9250rpm and 240bhp STANDARD. play with the air filter and you get 250....thats not even touching the exhaust or engine!

That's all Rpm JET, to little torque for WB!

Torque is all very well. Im a Benz fan and they make the 1000 nm torque 6.5 litre V12 BiTurbo..... One HUGE problem with this and big torque......TRACTIONAnd as much as I love an SL65 AMG I know that its engine will be incapable of using all its power in 99% of road situations
Luckily Im a Honda fan too V-tec = Blackmagic

[WhiteBlue]

What Materials is in this that is not in the standard 2.o litre 4 type R engine?

I read that Honda heavily used metal matrix composites (MMC) in that engine. That is not a classical engine material. A much as we admire the skills of the Honda engineers I doubt that this engine was used in mid range priced family cars.

Honda made some unbelievably good bike engines starting with a 250 four stroke four cylinder racing engine in 1959! In the seventies they followed that up by the six cylinder in line production bike engine. They have set many benchmarks in history.

[adam2007]

The most powerful 2.0 liter production engine is a 4 cylinder WB.

Enter the F20C Honda 2.0 litre 4cylinder. An absolute masterpiece of engineering capable of 9250rpm and 240bhp STANDARD. play with the air filter and you get 250....thats not even touching the exhaust or engine!

What about the 2.0 Mitibushi evo engine, the car model fq400? thats very powerful

400bhp for 2.0 engine, for sure engine life has been reduced

[JohnsonsEvilTwin]

Adam

The mitsubishi engine is a turbo(booooooo!) and therefore is not compareable to the Honda which is of natural aspiration. Still a very impressive engine, granted.

WB, I have just found out via the S2000 forum that the F20C has the same innards as that of the Honda Accord Type R which has similar performance but tuned for more torque and slightly less Bhp(220).
These are high number production cars we are talking about.

Also another interesting fact about the F20 was that honda built the engine in total secrecy. The factory was akin to area 51 and staff were asked to sign industrial waivers so as not to spill any secrets in the way honda built these engines.

[xpensive]

There's also a matter of balancing, any engine can be primary balanced with counter weights, but secondary is whole different matter.

A straight-four needs balance shaft for that, which becomes a necessity above a certain size, compare the Porsche 3 liter or the Saab 2.3.

Having said that, the only thing that beats a straight-six in that respect is a V-12, there's a reason why BMW is sticking to the concept.