Which of the following engine configurations would generally be the most durable? Assume their displacement and basic design are the same except for the factors that are mentioned:
Engine 1: naturally aspirated, high compression
Engine 2: forced induction, low boost, medium compression
Engine 3: forced induction, high boost, low compression
rpm is what causes long term wear, not compression.
which of these has the highest rpm?
a stock ls1
Engine 1. All day every day.
N/A on high compression, and always that.
When you add Forced induction, you add more complexity beyond just the fact you're sucking more air in, not to mention moderate boosting can still exert greater forces on the engine than a n/a setup could ever achieve.
Less wear on the engine itself?
The lowest compression one. Due to cruising (although a bit gutless) it would not have any considerable boost, so technically the engine would wear less.
But all in all, maintenance is something that has to be done anyway, and adding a turbo os more maintenance parts (although not as bad as some say)
3.5l ecoboost
...
That depends on how the engine is constructed.
Boosted engines can last as long as naturaly aspirated engines, if constructed to do so.
Usually the turbocharger main bearing dies due to retards shutting the car down while the main shaft of the turbocharger is still hot.
The problem is, that the still hot shaft overheats the oil and breaks it down, leading to carbon deposits and oil starvation.
Another problem are clogged catalythic converters behind the turbocharger creating a too high backspressure, wich forces the oil ot of the main bearing.
Generaly speaking I would argue that the engine with the lowest average piston speed lives the longest since the rings in it have to travel the lowest total distance for a certain distance driven.
Diesel engine: forced induction, high boost, high compression
However you'll never see a diesel engine going over 4000 RPM, which is why they last so long.
NA Rotary with a Sohn adapter and 3 port OMP
Engine 1
The N52 for example can last forever if it isn't neglected
Depends on the driver, break-in, and the maintenance
Ignoring manufacturing tolerances, assume all 3 engines are the exact same quality/build. All 3 will live longer than most people will ever own the car. Who. The. Fuck. Cares.
/done
...
Engine 4: forced induction, high boost, high compression
Always NA
This.
>rpm is what causes long term wear, not compression.
It's a factor of both, an engine with a 5000rpm limit will last longer if it's got a lower compression than an otherwise identical unit.
5000+RMP redlines are common on most turbo diesels now.
If that where true, F20C, B16, 4AGE and many more would wear out much faster than any other engine...
But that is not the case, except for chain tensioners, F20C for example last basicly forever.
Poor maintainance and poor design are what kills a engine.
Boost doesn't kick in until you slam the pedal to the metal. If you dd a boosted car (I'm assuming not a tuned one, instead one pre-turboed from the factory) and doesn't push the engine, it'll behave just like a NAish
The fact that those engines last longer than others means nothing. Lower compression versions of those same engines will last longer than the original engines you listed.
There is no significant difference in lifespan between high and low compression engines, if both where desinged properly and get their proper fuel.
Only good post ITT
I'll add that newer turbo engines have water cooled bearings to avoid the issue you pointed out
>All 3 will live longer than most people will ever own the car. Who. The. Fuck. Cares.
I must admit that i agree, but i'mstill not used to this thought.
> newer turbo engines have water cooled bearings to avoid the issue
Not only that, electronic oil pumps are a coming thing in new cars as well.
They keep the oil circulating untill the main shaft is adequately cooled down.
They also help a lot with lubrication when the engine is getting started.
N/A petrol engines are the most durable engines out of all configurations.
Too bad that you can only get 110-150 bhp out of 2 litre N/A petrol engines, same as an 1 litre turbocharged engine.
VW used to have a 2.0L N/A which developed a massive 116 bhp and it had 170 Nm torque starting from 2400 rpm. On a fucking petrol.
Slow, lazy, somewhat thirsty but downright indestructible and silent. And people bought it just for its ridiculous reliability.
>Too bad that you can only get 110-150 bhp out of 2 litre N/A petrol engines, same as an 1 litre turbocharged engine
Try 250bhp
>can only get 110-150 bhp out of 2 litre N/A petrol engine
That is wrong, you can get up to 250 ps out of a N/A gas engine.
Stop living in boiracer worlds fags, all the major manufacturers got 110-150 bhp out of their 2 litre N/A petrol engines.
VW - 136 bhp from 2.0 16v
BMW - 143 bhp from the 2.0
Ford - 145 bhp from the 2.0 Duratec
Toyota - 147 bhp from their 2.0
>Diesel engines
are the most maintenance intensive
Actualy VW was getting 150 hp out of its 2.0 FSi engines in ´04
That engine was used in the Golf, not a boiracer/sports car.
BMW is known for its 6-cylinder engines and their high specific output of about 100 hp/L
Toyota made 165 hp with a 1,6l
Mazda can only just manage 150 out of a 2L in the new Miata sports car.
>benchracer world
K20s made like 200hp easily and have no problems hitting 400k+ kms from the Acuras I've seen
Tuned for lower end torque, incredible fuel mileage and very low emissions
Skyactiv-X is going to be supercharged and will make something like 190bhp and 210lb-ft of torque from a 2L while getting even better fuel economy and much lower emissions (virtually no nox emissions)
A 2.5L Skyactive-X should easily make like 230bhp and plenty more torque
They could do more, but they did focus more on price, fuel economy and emissions.
this question is pretty broad
there's potential that all 3 engines could be equally durable, if the quality of parts remains the same
but "generally" the n/a engine would win 9 times out of 10
fucking bench racers
>b-bench racers!
He should have mentioned something other than power, like emissions and fuel economy
Because they are the most important things in a sports car. If you are stupid. It doesn't even get good milage given the small car it's in. Mazda just can't make a decent engine. The 1.5L 150bhp Golf Petrol averages 55MPG in a heavier less aerodynamically efficient body, 17 more than the 42mph Mazda claim from the MX5, then if yol look at the GT86 that averages 40mpg and gets 50bhp more from a 2L in a larger, heavier body. Skyactiv is lets be 100% honest total shit.
(All MPGs from the official EU testing)
That is not benchracing, even old fucking corollas, old Golfs and Civics exceed your claimed specific output of about 60 hp/L.
good one shit stain
>Because they are the most important things in a sports car. If you are stupid.
Or if you are a goverment mandating shit like that...
>newfag
get out
British gallons are smaller than American gallons dumbass
this55mpg in Britain is like 45mpg in the US
>RWD sports car with a rag top and literally no over (6th gear is 1:1) drive only gets 3mpg worse mileage than an economy car
>GT86 that averages 40mpg
That's like barely 30 in the US. A Corvette with a massive V8 could do that
>A Corvette with a massive V8 could do that
You forget the corvette has a really really low drag coefficient. The v8 has little to do with it.
>55mpg in Britain is like 45mpg in the US
>(All MPGs from the official EU testing)
So they are both the same size gallon.
Lol no, otherwise it would have bad lift like the earlier ones did. Aero package drag coefficient is like 0.34, so pretty bad
The new LT1 has cylinder deactivation and the car uses a taller 7th gear. They even have a lean burn function that's disabled because lol US emissions, but it could easily get 35mpg with that, maybe even more
Please tell me why the EU would use US customary units instead of litres per 100kms?
The difference is the realy fucking long overdrive, wich gets the engine from a verry low load and high rpm to a higher load and low rpm, where it is more efficient.
(pic related)
Which makes Mazda's engine in the Miata even more impressive since it has no over drive and can still get over 40mpg
>Lol no, otherwise it would have bad lift like the earlier ones did. Aero package drag coefficient is like 0.34, so pretty bad
LOL yeah it does. You find that same ls1 engine in another car and you wonder why it doesn't get as good mileage. That much less drag means that much less force and energy required to maintain speed against any and all friction
Notice how no other gm car gets that kind of gas mileage
OH so gm just cheeses it like Ford does with the mustangs 6th gear being so fuckin long
Because other GM cars that use those engines are usually brick shaped Camaros and trucks
The Corvette may be sleeker than those things, but they're not super low drag like a Tesla
Porsche does the same thing too, it's not like you're using top gear for anything other than cruising
Comparatively the corvette is a fucking pencil
Couple that with the corvettes stupid long overdrive it's pretty much cheering it. 40mpg isn't indicative of normal use
Highway fuel economy is basicly:
>running engine efficient at about 10-20 kW
>having a aerodynamic body
>low rolling resistance
1 They aren't using US units
2 Not all of the EU use L/100km, maybe once the UK leaves the EU they will stop quoting in both metrics but at the moment they quote in both L/100km and miles per imperial (not US) gallon).
Wow the homosexuals or shills are out in force.
The drag coefficient alone says nonthing, it is about drag coefficient*frontal area
And the corvette does not have much frontal area.
So Skyactiv gets 25% less power from 5% less fuel? A hahahahaha the FA20 sucks
>mazda MX-5 ND
Average fuel consumption: 6,77L/100km
Best: 5,43L/100km
spritmonitor.de
>toyota GT-86
Average fuel consumtion 8,71/100km
Best: 6,66L/100km
spritmonitor.de
The MX-5 needs significantly less fuel in real life situations.
Meanwhile the Miata's engine revs high because no over drive and doesn't have an aerodynamic body because rag top
Exactly. Imperial gallons are smaller than US gallon, which is why the numbers for MPG in Europe are higher
Indeed, but it still gets a decent fuel economy in real life since its engine is incerdible efficient.
And people still call Skyactiv a meme
63 posts 23 posters, all Skyactiv are not shit posts more than 60 seconds apart, one samefagging shill.
>less than 3 posts per IP
As a rule of thumb, the higher the Piston speed, the shorter the life span
The amount of side load created by a high piston speed setup won't last anywhere near as long as a high revving, short-stroke motor with high compression
I've ridden a CBR250RR with like 200k kms and it's engine was fine for a 25 year old motorbike that revs to nearly 20k rpm
>170 g/kwh brake specific fuel consumption
>shit
That is a awesome performance, even most diesel engines can´t do anything close.
The first generation Insight for example only got 215 g/kwh.
Most cars get only 240 g/kwh
High revving ≠ high piston speed
Are you telling me that an engine with a 33mm stroke at 19k rpm has a low piston speed?
Compared to an engine with 37mm stroke at 19k rpm, yes
And which engine would that be?
n/a i6 or f/i i6
i6 is gods engine
21m/s isn't exactly stellar, even an LS7 can manage that. 24 is the common limit for performance production cars.
Assuming
>Identical levels of engineering
>Identical displacement
>Identical output
Then the net power placed on the rotating assembly should be somwhat similar (although maybe a bit less for the turbo's, since they have more efficient compression). This means that their lifespan should all be similar.
That said, the n/a engine has less parts, so I think that be most durable.
>Too bad that you can only get 110-150 bhp out of 2 litre N/A petrol engine.
There have been cars that exceed that, and a lot of motorcycles regularly exceed 150hp despite being 1L n/a.
That's because they rev much higher and don't make enough torque to move something as heavy as a car