Engines under forced induction

[Shteifen]

Ive been getting alot of mixed responses when i ask different people about this. People being teachers at tafe, and other qualified technicians.

Is an engine under forced induction going to last very long? and how long?

i would assume its not going to last as long, just based on physics.

i suppose it also depends on many thing like what oil you use, how much boost its running, whether its turbo or supercharged, what parts it was made with and how long ago it was made with them ( by parts i mean pistons, rings, rods, bearings, valves etc.)

i ask this because its going to affect how i build my engine. or rebuild i should say. whether i do it for FI with relatively stock, or maybe a little lower compression, or NA with higher compression, either way i dont see why it shouldnt be a 3.0 litre.

from what i gather NA will last longer and i suppose its going to have a higher resale value (MUCH later down the track) and FI might die a bit quicker and anyone who knows anything will know its been thrashed.

by the way, if i do chose FI itll be a super charger as rediculous power on a front wheel drive is pretty useless.

what are anyones opinions on the longevity of FI verses NA engines?

-steve

[Bubu]

i suppose it also depends on many thing like what oil you use, how much boost its running, whether its turbo or supercharged, what parts it was made with and how long ago it was made with them ( by parts i mean pistons, rings, rods, bearings, valves etc.)

You said it!

It also depends how well you maintain it and how hard you drive it.

When people tell you turbo engines dont last, just think of all the trucks out there that have done 1 million kms, and those trucks run high boost too. Its probably not the best comparison, seeing that trucks run on diesel and are built to go the distance, but it does show that a FI engine can go the distance.

Also another thing to keep in mind, is if the set up and tune is done right you dont have to rev a FI engine really high to get good power, unlike a N/A engine. Revving your engine high will cause extra wear on the engine over time.

[Mrk_Mickey]

This is just my opinion..

To be honest, I think that if you maintain the engine well and build it PROPERLY for the outcome that you want, you will have an engine that, if continued to be taken care of, will outlast most if not all the other engines of the same type.

[Jarred]

Nelson racing engines make streetable big block TT engines that put out with in the region of 1500-2000HP. now they do that with lots of boost and lots of cubes, but they're still turn key reliable.

how? all got to do with building the right set up with the right bits, and maintaining it properly.

[KI11Z]

I believe that a tuned n/a engine will not last as long as a tuned fi engine, n/a would be under a lot more stress with its high compression and high revs. if you want reliable cheap power, go a low boost sc or turbs setup. my2c

[Spyda]

I believe that a tuned n/a engine will not last as long as a tuned fi engine, n/a would be under a lot more stress with its high compression and high revs. if you want reliable cheap power, go a low boost sc or turbs setup. my2c

I agree. A FI engine on low boost should out last a NA engine making the same power. But i guess it all depends on the motor.

[Mrk_Mickey]

i guess it all depends on the motor.

Not to mention the parts used too. You know how it goes... ''you get what you pay for'' yada yada, i would just say that going skimp on something internal would be a bad idea, unless its been proven that's it's still good.

[KI11Z]

yes, without a doubt, remember, THE MOST EXPENSIVE WAY IS THE CHEAPEST WAY!

[mr gee]

Would be interesting to hear what those TAFE teachers and technicians have to say.

If both NA and FI engines are designed from the onset to do as advertised, they will last as long as their designers deemed them to last.

Obviously, speccing the right materials, bearing loads, lubrications etc as you said will go meet those ends.

If you treat an NA engine to an aftermarket turbo, then you will be imposing additional stresses not intended of it by the designer. However, engines are built with a certain amount of tolerance and therefore if this is not exceeded, there's no reason that engine will not last. There is also something in that an NA engine needs loads of revs to get power whereas a FI engine revs less and produces more torque imposing less 'G' loads on the con rods as a result.

I've played with some aftermarket turbos as well as boosting turbo cars usually by only about 50% and had no reliability issues with the engines though clutches are another matter. lol

[DubSteve]

There are guys with chargers on vortex that have lasted them with 100 000 miles, so I think your ok with it.

[dado]

high revs kills the FI engine not high commpresion,so it is right balance really and properly run FI should outlast NA engine in my opinion.

[Shteifen]

this is good discussion, i like it!

i would think with an FI engine with a turbo would require a little more maintenance than a supercharged one, just because of the heat generated by the turbo getting so hot would make the oil turn acidic quicker causing the engine to wear. so i suppose a turbo engine would require oil changes more frequently, would that be right?
supercharger wouldnt get as hot i'd imagine.

i think i heard somewhere when i was younger that it puts components under less stress to make power at higher RPMs. like for example a stock 1.8t motor, makes its highest torque at around 1750 rpm. now wouldnt having the piston forced down with an explosion at such low rpm make give more stress to bearings in the crank and rods and such for a longer time, than making the same power higher up, at say 4000rpm? maybe thats not a good comparison.
i suppose making the power higher up might be putting less stress on the bottom end from torque, but more stress on other components, like rings, because they are doing that same movement with a force for a shorter period of time be much more often...


and just to clarify either NA or FI, i wouldnt be looking for massive power, just a fair bit more than i have now and a nice sound.
i wouldnt be skimping on any parts either, pretty much everything would be replaced, bringing km's back to zero, on the engine and maybe the gear box too.
if FI i was thinking a supercharger at around 6-8 pounds would do it, with some cams, in a three litre would do it nicely.
if NA i was thinking, still the three litre, cams, good p&p job, and maybe 10.5-11:1 compression, so not crazy compression but a bit of a bump.
either way i go, FI is going to be more expensive because i'd have to fork out for the parts of rebuild, and on top of that the FI parts.

-steve

[Bug_racer]

I'll make this a simple post as I could be here all day :

Turbo it . low boost with a fresh engine . If your worried about longevity and engine bay temps lower compression ratio and add a thermostatically controlled oil cooler . A turbo running low boost will have the most volumetric efficiency vs cost of any engine in the long term .

Keeping it naturally aspirated to gain more power your going to need to rev it harder , boring and stroking does little on a VR6 , its the head that cant flow . Once youve opened to the head up and it revs , you'll find your gonna need to cool the engine down cause of the extra heat generated & your gonna need to run high octane fuel all the time . You'll find you'll be getting more oil / coolant leaks as well , as well as the pulleys / p/s pump , water pump etc needing to be changed more often .

Supercharging is inefficient . To make the power you have to use the power , and on a small engine like the VR6 it robs it off too much in order to work efficiently . superchargers work better with larger displacement .

[Jarred]

I'll make this a simple post as I could be here all day :

Turbo it . low boost with a fresh engine . If your worried about longevity and engine bay temps lower compression ratio and add a thermostatically controlled oil cooler . A turbo running low boost will have the most volumetric efficiency vs cost of any engine in the long term .

Keeping it naturally aspirated to gain more power your going to need to rev it harder , boring and stroking does little on a VR6 , its the head that cant flow . Once youve opened to the head up and it revs , you'll find your gonna need to cool the engine down cause of the extra heat generated & your gonna need to run high octane fuel all the time . You'll find you'll be getting more oil / coolant leaks as well , as well as the pulleys / p/s pump , water pump etc needing to be changed more often .

Supercharging is inefficient . To make the power you have to use the power , and on a small engine like the VR6 it robs it off too much in order to work efficiently . superchargers work better with larger displacement .

/end thread imo

[gareth_oau]

more and more manufacturers are running forced induction these days, and they cant afford to do this unless it comes with a reasonable level of reliability or theyd bankrupt themselves with warranty repairs.

you can also expect that they will build a decent safe working margin into them so if you choose to go higher that standard then it wouldnt be overly risky.

I worked and turboed a 2L ford engine many years ago, and was getting over 250KW from an engine originally built for 70KW. Was superb fun until one of the conrods headed west instead of north/south. but in this instance i well and truly overdid it, and I suspect a lot of bad stories are from people who have overdone it, or not done it properly