New Engine vs Old Engine

[bax]

i know the title can be misleading but what i meant was not old Engine technology vs New engine technology ..

its simple really an Engine with 1000km Mileage (Probably not the best word since im suing Kilometers ) and another with 150000km ..

Is the new Engine better in all aspects than the older one ?
i guess we need a scenario to compare so lets say a Drag race 0 to max speed how would it go ? , assuming both car are in identical condition when it comes to tires and suspension , only difference is the age of the Engine/Tranny/Turbo .. for the sake of Discussion lets assume all the previously mentioned components are regularly maintained and with proper fluids and such .

is there truth to the statement that an older engine that has been pushed to its limits can show more power and speed than one that is still fresh or ist the other way around due to worn parts and such ?

heres a Case for example which we can use to shed some light on the matter .. 2 cars Same engine one with 250000km the other with 1500km , the older one is 1 second slower than the new one in accelerating from 0-160kmh which so far makes sense but then we checked for higher numbers 0-190Kmh (which is somewhat close to the top speed on that Vehicle ) the Results varied as the New engine was 11 seconds faster even though it was only 1 second faster up till 160Kmh ..

this case is actually the reason why im bringing this up , it made no sense to me that both will get similar times up to 160kmh and then something happens that grants the new engine a 10 second lead ..

what are your thoughts on this ?

oh and for those wondering the engines in the case are Turbo diesel ones

 

[obi_waynne]

Engines do need to bed in so perhaps this accounts for the difference. As long as compression is good and there is minimal carbon build up there is nothing wrong with an older engine.

I think your question is really why would an new engine be better at accelerating from 160km than an older identical one.

Perhaps the peak power is much higher. Worn valves, piston rings etc will all contribute to a lower top end power.

 

[bax]

Oo thanks for the swift reply , indeed that would be cutting straight to the point as it is the main reason for my confusion ..
so worn out engine components is the main suspect eh ? lets take this question one step forward , would an Engine overhaul aid in solving this issue or whats done is done and its time to move on ?

 

[HDi fun]

The question that's more interesting is what contributes to accelerated engine wear. The example you cite is obviously accurate but I think we'd need to take a far bigger data sample than 2 in order to come up with any kind of cohesive theory.

Brand new engines often don't off their full power potential until run in properly. Without digressing too far, there's a lot written regarding the correct and optimal way to 'run-in' an engine. It's starting to appear that the old method of low load and low revs is probably not the best in terms of assuring longevity of an engine.

I would also add that engines might well take 20,000 - 30,000 miles to give of their best in terms of power. However, this does not necessarily mean that degradation starts immediately from that point.

I've driven cars with less than a dozen miles on the clock that feel fine, if a little 'tight'. I've driven 40,000 mile cars that feel tired. I've driven 250,000 mile cars (which have not been subject to engine work or rebuild) that feel lively and pleasant as you would expect of that particular car with that particular engine option.

I think it's down to maintenance and driving style. Driving style during the run-in period seems to be a key factor - the idea is to burnish the rings to the bores so that good contact, oil control and compression are maintained. This is often attributed to a fairly rigorous running in process and not to the Little Miss Daisy style running in methodology.

As is subsequent maintenance. If we ignore problems with fuel injection systems, poor fuel etc and concentrate on the heavy stuff: crank and con rod bearings, piston (small end) bearings, bore, ring and piston wear, camshaft bearing and follower wear then I think that we can reduce that to negligible if proper maintenance is followed.

During normal usage I believe that cold starts are not the greatest cause of engine wear - modern synthetic oils circulate extremely well from cold. Allow it to idle 30 seconds or so before driving though, get the fluids moving. Drive gently whilst the engine is in it's warm up phase. Don't pile on the revs, nor lug the engine at low revs. The bigger problem is short journey usage where the engine never reaches full operating temperature. Shutting down a lukewarm engine leaves a nasty mixture of moisture and acidic gases which literally etch away at the internals.

Once warmed up there's no reason not to use full power and the full rev range. The red line generally denotes the top end of the usable power band. It's not instant engine destruction by any means. Of course, you don't have to visit the red line in every gear, but you are achieving nothing by driving the car with a self imposed artificial and arbitrary, let's say 3000rpm limit. My BMW was quite happy at 180,000 miles and lapped up revs with consummate ease. It had no issues with oil usage and had ridiculously low CO and HC figures. The cause of this car's demise was a 17 year old who put a Polo into the back of it at 45mph (I was stationary) and bent the floorpan.

I've run cars to higher mileage than this and have not had engine problems. Nor experienced a falloff in performance.

And shutting down - let it idle for 30 seconds or so. More so with turbocharged engines. Latent heat kills turbochargers.

 

[TCJBOLDIE]

An engine rebuild with honed bores and new rings and bearings along with a recoed head plus cleaned and flow tested injectors should see a return to new car performance IMO.

You have to do the sums and decide as to whether you keep the old girl or not

 

[bax]

No matter how i look at it , its just not worth it the gain is huge yes but only past 160kmh .. for a car which has a top speed of 200Kmh thats really not an issue .. it will still bug me but for those 10 seconds i could buy a faster car at the cost needed for an engine rebuild ..

so its solved then , older engine with worn components will have lower top end power yet somehow maintains optimal performance up to a certain speed in my case it was 160Kmh .. so newer is better atleast in this case ..

I recall the old Mazda 323 lantis with the 1.6 engine could barely get to 160kmh in new condition but after you start pushing the engine to its limits and breaking its chains or so to speak it manages 180Kmh ... guess this holds true for non turbo Petrol engines ?

 

[obi_waynne]

The original golf gti 8v engines made more power as they get older and felt more lively.

 

[HDi fun]

The 1997/1998 Golf GTi 2.0 8 valve was a very likeable and drivable car. It was one of these which I drove with just 3 miles on the odometer. It felt fine, a little reluctant to respond to my right foot torque demands but that's all.