New versus old
Discussion
It would depend on the engine. If you were to take a cross section of modern 2 litre petrol engines you would find that they produce anywhere from about 115bhp to 240bhp in normally aspirated standard tune.
I think that on average, power outputs have increased, and emissions have also improved.
My 2 litre from 1975 produces 165ish bhp in standard tune, which is pretty good for it's time and still beats most standard tune 2 litre engines these days
(Could gas a set of badgers in under 6 secs though
)
I think that on average, power outputs have increased, and emissions have also improved.
My 2 litre from 1975 produces 165ish bhp in standard tune, which is pretty good for it's time and still beats most standard tune 2 litre engines these days
(Could gas a set of badgers in under 6 secs though
)not neccesarily... in simply terms yes... but this is not always the case
most modern engines have at least 4 valves per cylinder compared to 2 for older engines, this is generally a performance increase, but alot of them have badly set up single-point fuel injection which in pure power terms is a backwards step to a carburettor (though more efficient if you look at all the uses an engine is used for)
a 4v multipoint fuel injected car would be far superior in power, though as i've found out through running an old car not neccesarily faster as they weigh ALOT more so have a poorer power-to-weight ratio but generally are better engines on the whole and have a higher top speed
most modern engines have at least 4 valves per cylinder compared to 2 for older engines, this is generally a performance increase, but alot of them have badly set up single-point fuel injection which in pure power terms is a backwards step to a carburettor (though more efficient if you look at all the uses an engine is used for)
a 4v multipoint fuel injected car would be far superior in power, though as i've found out through running an old car not neccesarily faster as they weigh ALOT more so have a poorer power-to-weight ratio but generally are better engines on the whole and have a higher top speed
As fuel/air ratio is limited airflow is deciding factor by way of inlet valves and spin, an injector system is just sophisticated compared to a bucket of fuel and accelerator pumps on a Holley.
Agree on power weight, stick a K in Midget or V8 in B and you have a quick car or am I bias.
Paul
Agree on power weight, stick a K in Midget or V8 in B and you have a quick car or am I bias.
Paul
MGBV8 said:
As fuel/air ratio is limited airflow is deciding factor by way of inlet valves and spin, an injector system is just sophisticated compared to a bucket of fuel and accelerator pumps on a Holley.
But due to their relative crudeness, carb's can never hope to acheive the mixture consistency over temperature/pressure etc. that a decent injection system could. Also a multipoint system injects fuel very near the valve so effects of fuel puddling in the manifold are minimised. For ultimate power a fuel injection system will win over a carb IMO.
Mr2Mike said:
But due to their relative crudeness, carb's can never hope to acheive the mixture consistency over temperature/pressure etc. that a decent injection system could. Also a multipoint system injects fuel very near the valve so effects of fuel puddling in the manifold are minimised. For ultimate power a fuel injection system will win over a carb IMO.
i was always told in pure power terms the best way of fuelling a car goes (1 = best, 5 = worst):
1. throttle boddies
2. twin carbs (4 cyl)
3. multipoint fuel injection
4. single carb
5. single point fuel injection
(shit, just had a thought can't remember if 2 and 3 need to be swapped)
anyway, if you look at all scenarios for engine use then a multipoint injection system would be the best all-rounder but i believe the above list is accurate for power-only figures
littlegearl said:
i was always told in pure power terms the best way of fuelling a car goes (1 = best, 5 = worst):
1. throttle boddies
2. twin carbs (4 cyl)
3. multipoint fuel injection
4. single carb
5. single point fuel injection
(shit, just had a thought can't remember if 2 and 3 need to be swapped)
IMO Throttle bodies cannot really be a separate category as they are just a form of multi-point injection. My revised list (in order of potential power delivery) would be:
1) multipoint injection (one throttle per cylinder)
2) multipoint injection (one throttle)
3) multiple carb's with one choke per cylinder
4) one twin or quad choke carb
5) one single choke carb
6) single point injection.
If you ordered by fuel efficiency or emmsions the results would be little different, although multi-point injection pretty much wins on all counts (except cost).
my list was in its most simplistic form but have to agree with you there... though i would class throttle bodies seperately simply for the performance gains they can deliever!!!
and a mulitpoint fuel injection system would be more fuel efficient (if you cared - i only care about power!) that twin carbs or the bodies!!! imo
and a mulitpoint fuel injection system would be more fuel efficient (if you cared - i only care about power!) that twin carbs or the bodies!!! imo
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