How does capacity affect BHP?
PassionFord Post Whore!!
Joined: May 2003
Posts: 8,594
Likes: 2
From: Derby
remember power is not everything dilivery is how races are won.
I have driven many a turbo for me( a crap driver ) a good v6 or a v8 N/a is much better to drive on a track than a turbo car. I find with a turbo car you are looking at the revs all the time not on the driving.
I have driven many a turbo for me( a crap driver ) a good v6 or a v8 N/a is much better to drive on a track than a turbo car. I find with a turbo car you are looking at the revs all the time not on the driving.
Advanced PassionFord User
Joined: Sep 2003
Posts: 1,529
Likes: 9
From: N Yorks
Originally Posted by JohnnyB
I find with a turbo car you are looking at the revs all the time not on the driving.
PassionFord Post Whore!!
Joined: Sep 2004
Posts: 4,773
Likes: 86
From: Nottingham
Originally Posted by Stavros
Originally Posted by focusv8
There's no replacement for displacement.
.
.
.
Professional Waffler
Joined: May 2003
Posts: 30,980
Likes: 9
From: barry-south wales
Originally Posted by focusv8
Originally Posted by Stavros
Originally Posted by focusv8
There's no replacement for displacement.
.
.
.
Advanced PassionFord User
Joined: Jan 2005
Posts: 2,053
Likes: 8
From: Glasgow/Oban
got to love the way these threads go off topic lol
to make power you need a volume of fuel air mix, and a number of them ina time period.
Either bigger bang or more bangs. For more bangs, look to bike engines, f1 engines etc etc which rev really high. For bigger bangs, FI is the way to go. cosworth commented years ago that in the new age of forced induction, it would be bottom end strength, not capacity that limited outright power.
for qa gievn capacity you have a certain amount of space for bearing surfaces, rod cross section etc etc.
so basically, there is no relationship directly, you just need more boost on the smaller engine.
If you want to keep the cylinder pressures the same, then youre back at the start
to make power you need a volume of fuel air mix, and a number of them ina time period.
Either bigger bang or more bangs. For more bangs, look to bike engines, f1 engines etc etc which rev really high. For bigger bangs, FI is the way to go. cosworth commented years ago that in the new age of forced induction, it would be bottom end strength, not capacity that limited outright power.
for qa gievn capacity you have a certain amount of space for bearing surfaces, rod cross section etc etc.
so basically, there is no relationship directly, you just need more boost on the smaller engine.
If you want to keep the cylinder pressures the same, then youre back at the start
Advanced PassionFord User
Joined: Oct 2003
Posts: 1,952
Likes: 4
From: Nth Lincolnshire
My take on this is:
On a nasp motor the engine is affectively a pump which sucks in the air.
The bigger the pump, (cc) the more air in theory it can suck in and more power it can generate which is why big V8's have big power.
On a turbo motor the air is forced fed in so the only limiting factor as stated above is the head flow.
I've destroked my engine to reduce torque low down and increase revs which will hopefully make me more power higher up the rev range which is better suited for my type of car.
On a nasp motor the engine is affectively a pump which sucks in the air.
The bigger the pump, (cc) the more air in theory it can suck in and more power it can generate which is why big V8's have big power.
On a turbo motor the air is forced fed in so the only limiting factor as stated above is the head flow.
I've destroked my engine to reduce torque low down and increase revs which will hopefully make me more power higher up the rev range which is better suited for my type of car.
Originally Posted by tabetha
The 33,000 is important and was derived at when it was found the "HORSE" could move a weight of 33,000lb 1 mile in 1 minute.
.
beat me to it
33,000lb's 1 foot in 1 minute
soemthing to do with what a watt is or horses in mines and that sort of stuff
but it's a given amount of work that can be done
if you had 2 horses you could do twice the mount of work
if you have 4 you could d 4 times the amount of work etc etc
the rate of work is all dependnat on what you want to do, but it could be that, with 4 horses you would be able to move 4 time the wieght that same foot in that one minute so thats the power side of thigns sorted (i hope )
i was always told that power is the speed at which the engine turns whilst torque is the amount of twist it will give at any given engine rpm
i think peole are also forgetting that the bigger the engine, the less revvy it is going to become as you have more and more bits to turn and slow down and friction losses and all that other technical stuff others are better at explaining than me so it's not just the "each pot is 500 cc so yu've got 200 brake from a 2.0 and 300 brake from a 3 litre" the 300 brake from the 3 litre is going to be harder to get out than the 200 brake from the 2 litre is it not as you've got more mass to rotate and different harmonics and all sorts of stuff to complicate things with
years and years ago, 100 bhp/l was almost unthinkable in n/a form but now you've got even cooking cars doing that sort of thing, bmw does it with it's m cars and honda does it with it r types, the fact that there is more mass to turn gives the m engine more torque than the little r type engine
and so on and so forth
33,000lb's 1 foot in 1 minute
soemthing to do with what a watt is or horses in mines and that sort of stuff
but it's a given amount of work that can be done
if you had 2 horses you could do twice the mount of work
if you have 4 you could d 4 times the amount of work etc etc
the rate of work is all dependnat on what you want to do, but it could be that, with 4 horses you would be able to move 4 time the wieght that same foot in that one minute so thats the power side of thigns sorted (i hope
)i was always told that power is the speed at which the engine turns whilst torque is the amount of twist it will give at any given engine rpm
i think peole are also forgetting that the bigger the engine, the less revvy it is going to become as you have more and more bits to turn and slow down and friction losses and all that other technical stuff others are better at explaining than me so it's not just the "each pot is 500 cc so yu've got 200 brake from a 2.0 and 300 brake from a 3 litre" the 300 brake from the 3 litre is going to be harder to get out than the 200 brake from the 2 litre is it not as you've got more mass to rotate and different harmonics and all sorts of stuff to complicate things with
years and years ago, 100 bhp/l was almost unthinkable in n/a form but now you've got even cooking cars doing that sort of thing, bmw does it with it's m cars and honda does it with it r types, the fact that there is more mass to turn gives the m engine more torque than the little r type engine
and so on and so forth
DEYTUKURJERBS
Joined: Apr 2004
Posts: 29,378
Likes: 1
From: North Korea
Originally Posted by JohnnyB
remember power is not everything dilivery is how races are won.
I have driven many a turbo for me( a crap driver ) a good v6 or a v8 N/a is much better to drive on a track than a turbo car. I find with a turbo car you are looking at the revs all the time not on the driving.
I have driven many a turbo for me( a crap driver ) a good v6 or a v8 N/a is much better to drive on a track than a turbo car. I find with a turbo car you are looking at the revs all the time not on the driving.
Originally Posted by JohnnyB
on a 5 speed box on a tight track its easy to drop out of the boost
Im guessing you mean a small capacity engine versus big, not turbo versus non turbo.
Non performance (well, low bhp per litre) n/a engines and big cc per car weight is of course going to make it easier to drive, but in general, a 180bhp 2litre n/a is gonna have a smaller powerband and less torque so "harder" to drive in the sense you talking about, than a 180bhp 2litre turbo.
10K+ Poster!!
Joined: May 2003
Posts: 13,146
Likes: 0
From: Newbury
it would depend on about 500 other factors Alloy...
from how physically big you wanted the block to the sorts of RPM you want to run the engine at.
Typically the higher the RPM the shorter the stroke - the reason is simply if you move the piston less distance in a given time it has a lower maximum speed. Piston speed is fairly limited or the pistons self destruct from the forces they are subjected to!
alex
from how physically big you wanted the block to the sorts of RPM you want to run the engine at.
Typically the higher the RPM the shorter the stroke - the reason is simply if you move the piston less distance in a given time it has a lower maximum speed. Piston speed is fairly limited or the pistons self destruct from the forces they are subjected to!
alex
10K+ Poster!!
Joined: May 2004
Posts: 14,907
Likes: 1
From: scotland
Originally Posted by Karl
Hello all,
I'm only on here briefly whilst checking mail, so please dont ask any other questions as I probably won't be here to reply.
Increasing capacity "can" give a power increase but usually does'nt in 95% of cases. This is because it is usually the cylinder head air flow that defines the total air flow through the engine and hence it is the cylinder head that dicates power, NOT capacity.
As a good example take a 1.6cvh fitted with a stock 32/34 weber carb. Makes around 90bhp. Bolt ALL the parts onto a 1800cvh bottom end with the same compression ratio....................guess what..............90bhp!
The difference is that the 1800 will make that same power a few hundred rpm earlier but the maximum power is actually determined by the maximum air flow through the engine. In this example it is contolled by the head flow.(and manifolds of course)
To put it another way on two otherwise identical engines except one being bigger capacity than the other, provided the smaller engine can physically rev that little harder (i.e. mechanically without failure) then the power will be the same.
These rules apply to N/A and turbo.
However what can be misunderstood is that by using a larger capacity engine with a turbo, it is possible to make use of larger turbos without excessive lag that you would encounter with a smaller engine, and hence produce more power because you have a larger turbo. (Unless you are prepared to live with the reduced response from the smaller capacity engine)
And finally for all the doubting thomas's....................
A 2.4 YB fitted with a T34 will make around 380bhp running the turbo flat out. A 2.0 fitted with the same components.....................guess what................ 380bhp.
The 2.4 will simply make it lower in the rpm band, but likewise will run out of puff earlier meaning that the power band is no wider than the 2.0, simply that it occurs at lower rpms. This scenario is only usefull in cases where the engine has reached the end of its mechanical ability to rev, yet more power is required.
I'm only on here briefly whilst checking mail, so please dont ask any other questions as I probably won't be here to reply.
Increasing capacity "can" give a power increase but usually does'nt in 95% of cases. This is because it is usually the cylinder head air flow that defines the total air flow through the engine and hence it is the cylinder head that dicates power, NOT capacity.
As a good example take a 1.6cvh fitted with a stock 32/34 weber carb. Makes around 90bhp. Bolt ALL the parts onto a 1800cvh bottom end with the same compression ratio....................guess what..............90bhp!
The difference is that the 1800 will make that same power a few hundred rpm earlier but the maximum power is actually determined by the maximum air flow through the engine. In this example it is contolled by the head flow.(and manifolds of course)
To put it another way on two otherwise identical engines except one being bigger capacity than the other, provided the smaller engine can physically rev that little harder (i.e. mechanically without failure) then the power will be the same.
These rules apply to N/A and turbo.
However what can be misunderstood is that by using a larger capacity engine with a turbo, it is possible to make use of larger turbos without excessive lag that you would encounter with a smaller engine, and hence produce more power because you have a larger turbo. (Unless you are prepared to live with the reduced response from the smaller capacity engine)
And finally for all the doubting thomas's....................
A 2.4 YB fitted with a T34 will make around 380bhp running the turbo flat out. A 2.0 fitted with the same components.....................guess what................ 380bhp.
The 2.4 will simply make it lower in the rpm band, but likewise will run out of puff earlier meaning that the power band is no wider than the 2.0, simply that it occurs at lower rpms. This scenario is only usefull in cases where the engine has reached the end of its mechanical ability to rev, yet more power is required.
If we look at the range of 6 cylinder BMW engine we see that power does in fact increase in a linear fashion as the bottom end sizes increase 1.8 thru to 2.8 etc
Another example is the sierra OHC engines, look at the 1300 thru to the 2 litre versions, the power increases in a very linear fashion.
Going back to what tabetha and Alex said about the laws of diminishing results or some nonsense? meaning that you wont get 25% more power from a 25% increase in capacity.
I have a engine data book here that proves otherwise
The OHC range again shows you actually get more power than you would expect in some cases when going up in capacity.
20K+ Super Poster.
iTrader: (1)
Joined: May 2003
Posts: 21,512
Likes: 0
From: Essex... and Birmingham!
Originally Posted by GARETH T
Originally Posted by rapidcossie
Have any of the people commenting on this thread actually done any testing on this theory, or are the just repeating what someone has told them?
I bet loads of people have told you your haircut is WANK!
Guest
Posts: n/a
Originally Posted by rapidcossie
Originally Posted by Karl
Hello all,
I'm only on here briefly whilst checking mail, so please dont ask any other questions as I probably won't be here to reply.
Increasing capacity "can" give a power increase but usually does'nt in 95% of cases. This is because it is usually the cylinder head air flow that defines the total air flow through the engine and hence it is the cylinder head that dicates power, NOT capacity.
As a good example take a 1.6cvh fitted with a stock 32/34 weber carb. Makes around 90bhp. Bolt ALL the parts onto a 1800cvh bottom end with the same compression ratio....................guess what..............90bhp!
The difference is that the 1800 will make that same power a few hundred rpm earlier but the maximum power is actually determined by the maximum air flow through the engine. In this example it is contolled by the head flow.(and manifolds of course)
To put it another way on two otherwise identical engines except one being bigger capacity than the other, provided the smaller engine can physically rev that little harder (i.e. mechanically without failure) then the power will be the same.
These rules apply to N/A and turbo.
However what can be misunderstood is that by using a larger capacity engine with a turbo, it is possible to make use of larger turbos without excessive lag that you would encounter with a smaller engine, and hence produce more power because you have a larger turbo. (Unless you are prepared to live with the reduced response from the smaller capacity engine)
And finally for all the doubting thomas's....................
A 2.4 YB fitted with a T34 will make around 380bhp running the turbo flat out. A 2.0 fitted with the same components.....................guess what................ 380bhp.
The 2.4 will simply make it lower in the rpm band, but likewise will run out of puff earlier meaning that the power band is no wider than the 2.0, simply that it occurs at lower rpms. This scenario is only usefull in cases where the engine has reached the end of its mechanical ability to rev, yet more power is required.
I'm only on here briefly whilst checking mail, so please dont ask any other questions as I probably won't be here to reply.
Increasing capacity "can" give a power increase but usually does'nt in 95% of cases. This is because it is usually the cylinder head air flow that defines the total air flow through the engine and hence it is the cylinder head that dicates power, NOT capacity.
As a good example take a 1.6cvh fitted with a stock 32/34 weber carb. Makes around 90bhp. Bolt ALL the parts onto a 1800cvh bottom end with the same compression ratio....................guess what..............90bhp!
The difference is that the 1800 will make that same power a few hundred rpm earlier but the maximum power is actually determined by the maximum air flow through the engine. In this example it is contolled by the head flow.(and manifolds of course)
To put it another way on two otherwise identical engines except one being bigger capacity than the other, provided the smaller engine can physically rev that little harder (i.e. mechanically without failure) then the power will be the same.
These rules apply to N/A and turbo.
However what can be misunderstood is that by using a larger capacity engine with a turbo, it is possible to make use of larger turbos without excessive lag that you would encounter with a smaller engine, and hence produce more power because you have a larger turbo. (Unless you are prepared to live with the reduced response from the smaller capacity engine)
And finally for all the doubting thomas's....................
A 2.4 YB fitted with a T34 will make around 380bhp running the turbo flat out. A 2.0 fitted with the same components.....................guess what................ 380bhp.
The 2.4 will simply make it lower in the rpm band, but likewise will run out of puff earlier meaning that the power band is no wider than the 2.0, simply that it occurs at lower rpms. This scenario is only usefull in cases where the engine has reached the end of its mechanical ability to rev, yet more power is required.
If we look at the range of 6 cylinder BMW engine we see that power does in fact increase in a linear fashion as the bottom end sizes increase 1.8 thru to 2.8 etc
Another example is the sierra OHC engines, look at the 1300 thru to the 2 litre versions, the power increases in a very linear fashion.
Going back to what tabetha and Alex said about the laws of diminishing results or some nonsense? meaning that you wont get 25% more power from a 25% increase in capacity.
I have a engine data book here that proves otherwise
The OHC range again shows you actually get more power than you would expect in some cases when going up in capacity.
Surerly BM dont stick the same head on a 330 as a 320 without flow work?
20K+ Super Poster.
Joined: May 2003
Posts: 23,377
Likes: 0
Originally Posted by rapidcossie
Originally Posted by Karl
Hello all,
I'm only on here briefly whilst checking mail, so please dont ask any other questions as I probably won't be here to reply.
Increasing capacity "can" give a power increase but usually does'nt in 95% of cases. This is because it is usually the cylinder head air flow that defines the total air flow through the engine and hence it is the cylinder head that dicates power, NOT capacity.
As a good example take a 1.6cvh fitted with a stock 32/34 weber carb. Makes around 90bhp. Bolt ALL the parts onto a 1800cvh bottom end with the same compression ratio....................guess what..............90bhp!
The difference is that the 1800 will make that same power a few hundred rpm earlier but the maximum power is actually determined by the maximum air flow through the engine. In this example it is contolled by the head flow.(and manifolds of course)
To put it another way on two otherwise identical engines except one being bigger capacity than the other, provided the smaller engine can physically rev that little harder (i.e. mechanically without failure) then the power will be the same.
These rules apply to N/A and turbo.
However what can be misunderstood is that by using a larger capacity engine with a turbo, it is possible to make use of larger turbos without excessive lag that you would encounter with a smaller engine, and hence produce more power because you have a larger turbo. (Unless you are prepared to live with the reduced response from the smaller capacity engine)
And finally for all the doubting thomas's....................
A 2.4 YB fitted with a T34 will make around 380bhp running the turbo flat out. A 2.0 fitted with the same components.....................guess what................ 380bhp.
The 2.4 will simply make it lower in the rpm band, but likewise will run out of puff earlier meaning that the power band is no wider than the 2.0, simply that it occurs at lower rpms. This scenario is only usefull in cases where the engine has reached the end of its mechanical ability to rev, yet more power is required.
I'm only on here briefly whilst checking mail, so please dont ask any other questions as I probably won't be here to reply.
Increasing capacity "can" give a power increase but usually does'nt in 95% of cases. This is because it is usually the cylinder head air flow that defines the total air flow through the engine and hence it is the cylinder head that dicates power, NOT capacity.
As a good example take a 1.6cvh fitted with a stock 32/34 weber carb. Makes around 90bhp. Bolt ALL the parts onto a 1800cvh bottom end with the same compression ratio....................guess what..............90bhp!
The difference is that the 1800 will make that same power a few hundred rpm earlier but the maximum power is actually determined by the maximum air flow through the engine. In this example it is contolled by the head flow.(and manifolds of course)
To put it another way on two otherwise identical engines except one being bigger capacity than the other, provided the smaller engine can physically rev that little harder (i.e. mechanically without failure) then the power will be the same.
These rules apply to N/A and turbo.
However what can be misunderstood is that by using a larger capacity engine with a turbo, it is possible to make use of larger turbos without excessive lag that you would encounter with a smaller engine, and hence produce more power because you have a larger turbo. (Unless you are prepared to live with the reduced response from the smaller capacity engine)
And finally for all the doubting thomas's....................
A 2.4 YB fitted with a T34 will make around 380bhp running the turbo flat out. A 2.0 fitted with the same components.....................guess what................ 380bhp.
The 2.4 will simply make it lower in the rpm band, but likewise will run out of puff earlier meaning that the power band is no wider than the 2.0, simply that it occurs at lower rpms. This scenario is only usefull in cases where the engine has reached the end of its mechanical ability to rev, yet more power is required.
If we look at the range of 6 cylinder BMW engine we see that power does in fact increase in a linear fashion as the bottom end sizes increase 1.8 thru to 2.8 etc
Testing the future
Joined: Jul 2003
Posts: 17,597
Likes: 24
From: W. Sussex
Originally Posted by AlexF
Typically the higher the RPM the shorter the stroke - the reason is simply if you move the piston less distance in a given time it has a lower maximum speed. Piston speed is fairly limited or the pistons self destruct from the forces they are subjected to!
alex
alex
Too many posts.. I need a life!!
Joined: Oct 2005
Posts: 779
Likes: 0
From: naam TOTNAAM
Originally Posted by rapidcossie
If capcity makes no differance in max HP produced, why are all the big power N/A cars of a very large capacity?
saw a 7.2 litre today , it makes 550 bhp.
No chance you can get that from a 2 litre is there.
saw a 7.2 litre today , it makes 550 bhp.
No chance you can get that from a 2 litre is there.
Proving only it's an easier way to flow a large amount of air.
PassionFords Creator
iTrader: (12)
Joined: May 2003
Posts: 28,824
Likes: 95
From: Blackpool, UK Destination: Rev limiter
Originally Posted by rapidcossie
Going back to what tabetha and Alex said about the laws of diminishing results or some nonsense? meaning that you wont get 25% more power from a 25% increase in capacity.
Thats a bit of an arrogant stance to take, especially for someone who is wrong and missunderstanding what people are talking about.
10K+ Poster!!
Joined: May 2004
Posts: 14,907
Likes: 1
From: scotland
Originally Posted by RichardPON
Originally Posted by rapidcossie
Originally Posted by Karl
Hello all,
I'm only on here briefly whilst checking mail, so please dont ask any other questions as I probably won't be here to reply.
Increasing capacity "can" give a power increase but usually does'nt in 95% of cases. This is because it is usually the cylinder head air flow that defines the total air flow through the engine and hence it is the cylinder head that dicates power, NOT capacity.
As a good example take a 1.6cvh fitted with a stock 32/34 weber carb. Makes around 90bhp. Bolt ALL the parts onto a 1800cvh bottom end with the same compression ratio....................guess what..............90bhp!
The difference is that the 1800 will make that same power a few hundred rpm earlier but the maximum power is actually determined by the maximum air flow through the engine. In this example it is contolled by the head flow.(and manifolds of course)
To put it another way on two otherwise identical engines except one being bigger capacity than the other, provided the smaller engine can physically rev that little harder (i.e. mechanically without failure) then the power will be the same.
These rules apply to N/A and turbo.
However what can be misunderstood is that by using a larger capacity engine with a turbo, it is possible to make use of larger turbos without excessive lag that you would encounter with a smaller engine, and hence produce more power because you have a larger turbo. (Unless you are prepared to live with the reduced response from the smaller capacity engine)
And finally for all the doubting thomas's....................
A 2.4 YB fitted with a T34 will make around 380bhp running the turbo flat out. A 2.0 fitted with the same components.....................guess what................ 380bhp.
The 2.4 will simply make it lower in the rpm band, but likewise will run out of puff earlier meaning that the power band is no wider than the 2.0, simply that it occurs at lower rpms. This scenario is only usefull in cases where the engine has reached the end of its mechanical ability to rev, yet more power is required.
I'm only on here briefly whilst checking mail, so please dont ask any other questions as I probably won't be here to reply.
Increasing capacity "can" give a power increase but usually does'nt in 95% of cases. This is because it is usually the cylinder head air flow that defines the total air flow through the engine and hence it is the cylinder head that dicates power, NOT capacity.
As a good example take a 1.6cvh fitted with a stock 32/34 weber carb. Makes around 90bhp. Bolt ALL the parts onto a 1800cvh bottom end with the same compression ratio....................guess what..............90bhp!
The difference is that the 1800 will make that same power a few hundred rpm earlier but the maximum power is actually determined by the maximum air flow through the engine. In this example it is contolled by the head flow.(and manifolds of course)
To put it another way on two otherwise identical engines except one being bigger capacity than the other, provided the smaller engine can physically rev that little harder (i.e. mechanically without failure) then the power will be the same.
These rules apply to N/A and turbo.
However what can be misunderstood is that by using a larger capacity engine with a turbo, it is possible to make use of larger turbos without excessive lag that you would encounter with a smaller engine, and hence produce more power because you have a larger turbo. (Unless you are prepared to live with the reduced response from the smaller capacity engine)
And finally for all the doubting thomas's....................
A 2.4 YB fitted with a T34 will make around 380bhp running the turbo flat out. A 2.0 fitted with the same components.....................guess what................ 380bhp.
The 2.4 will simply make it lower in the rpm band, but likewise will run out of puff earlier meaning that the power band is no wider than the 2.0, simply that it occurs at lower rpms. This scenario is only usefull in cases where the engine has reached the end of its mechanical ability to rev, yet more power is required.
If we look at the range of 6 cylinder BMW engine we see that power does in fact increase in a linear fashion as the bottom end sizes increase 1.8 thru to 2.8 etc
10K+ Poster!!
Joined: May 2004
Posts: 14,907
Likes: 1
From: scotland
Originally Posted by Stu @ M Developments
Originally Posted by rapidcossie
Going back to what tabetha and Alex said about the laws of diminishing results or some nonsense? meaning that you wont get 25% more power from a 25% increase in capacity.
Thats a bit of an arrogant stance to take, especially for someone who is wrong and missunderstanding what people are talking about.
I DONT think I am.
I staed that a 25% increase in capacity will see you a 25 % increase in power...
I got shot down in flames for stating this even tho i know it to be true.
10K+ Poster!!
Joined: May 2003
Posts: 13,146
Likes: 0
From: Newbury
OK lets take a range of BMW engine...
Which ones would you like to talk about?
You can't compare many of them though... as soon as you go from say a 330 (N52 soon N53 engine) to a 335 (N54 engine) you are now compairing TOTALLY difference engines, not just a change in capacity.
Alex
Which ones would you like to talk about?
You can't compare many of them though... as soon as you go from say a 330 (N52 soon N53 engine) to a 335 (N54 engine) you are now compairing TOTALLY difference engines, not just a change in capacity.
Alex
10K+ Poster!!
Joined: May 2004
Posts: 14,907
Likes: 1
From: scotland
1.3 OHC
The smallest member of the family was the 1.3 L (1294 cc) "1.3 HC JCT". With a 79.0 mm (3.11 in) bore and 66.0 mm (2.60 in) stroke, it produced 44 kW (59 hp) and 98 Nˇm (72 ftˇlbf) in the Ford Sierra
1.6 OHC
A later version also displaced 1.6 L but measured 1597 cc with an 81.3 mm (3.20 in) bore and 76.9 mm (3.03 in) stroke. This "HC E LSD", used in the Ford Sierra, produced 55 kW (73.8 hp) and 123 Nˇm (90 ftˇlbf).
1.8 OHC
A 1.8 L (1796 cc) version was used in the Ford Sierra. This engine, the "HC E REB", had an 86.2 mm (3.39 in) bore and 76.9 mm (3.03 in) stroke. Output was 66 kW (88.5 hp) and 140 Nˇm (103 ftˇlbf).
Looks good to me
The smallest member of the family was the 1.3 L (1294 cc) "1.3 HC JCT". With a 79.0 mm (3.11 in) bore and 66.0 mm (2.60 in) stroke, it produced 44 kW (59 hp) and 98 Nˇm (72 ftˇlbf) in the Ford Sierra
1.6 OHC
A later version also displaced 1.6 L but measured 1597 cc with an 81.3 mm (3.20 in) bore and 76.9 mm (3.03 in) stroke. This "HC E LSD", used in the Ford Sierra, produced 55 kW (73.8 hp) and 123 Nˇm (90 ftˇlbf).
1.8 OHC
A 1.8 L (1796 cc) version was used in the Ford Sierra. This engine, the "HC E REB", had an 86.2 mm (3.39 in) bore and 76.9 mm (3.03 in) stroke. Output was 66 kW (88.5 hp) and 140 Nˇm (103 ftˇlbf).
Looks good to me
10K+ Poster!!
Joined: May 2004
Posts: 14,907
Likes: 1
From: scotland
Originally Posted by AlexF
OK lets take a range of BMW engine...
Which ones would you like to talk about?
You can't compare many of them though... as soon as you go from say a 330 (N52 soon N53 engine) to a 335 (N54 engine) you are now compairing TOTALLY difference engines, not just a change in capacity.
Alex
Which ones would you like to talk about?
You can't compare many of them though... as soon as you go from say a 330 (N52 soon N53 engine) to a 335 (N54 engine) you are now compairing TOTALLY difference engines, not just a change in capacity.
Alex
DEYTUKURJERBS
Joined: Apr 2004
Posts: 29,378
Likes: 1
From: North Korea
Originally Posted by rapidcossie
Originally Posted by Stu @ M Developments
Originally Posted by rapidcossie
Going back to what tabetha and Alex said about the laws of diminishing results or some nonsense? meaning that you wont get 25% more power from a 25% increase in capacity.
Thats a bit of an arrogant stance to take, especially for someone who is wrong and missunderstanding what people are talking about.
I DONT think I am.
I staed that a 25% increase in capacity will see you a 25 % increase in power...
I got shot down in flames for stating thiseven tho i know it to be true.
just becuase some production engines go up in power along with capacity, that means nothing, thats just becuase if theydidnt people wouldnt see the point of the bigger engines...
10K+ Poster!!
Joined: May 2004
Posts: 14,907
Likes: 1
From: scotland
Im not talking about maximum power Stavros....
All i said was that an increase in capcity should see you with an increase in power of the same amount.
Various people posted saying I was wrong and that you very rarely see any increase in power.
Karl even stated that he has bolted a 1.8 bottom end on instaed of a 1.6 and got no extra power.
he must have missed something as power should have jumped over 10 bhp just by changing the bottom end.
All i said was that an increase in capcity should see you with an increase in power of the same amount.
Various people posted saying I was wrong and that you very rarely see any increase in power.
Karl even stated that he has bolted a 1.8 bottom end on instaed of a 1.6 and got no extra power.
he must have missed something as power should have jumped over 10 bhp just by changing the bottom end.
10K+ Poster!!
Joined: May 2003
Posts: 13,146
Likes: 0
From: Newbury
Karl missed something?
Are you sure about that statement?
There are some VERY clever people on here - I know Karl worked in R&D for more a very major manufacturer in the same way I have!
When we (When I was at Ford - Not Karl and I LOL) created the 2,2 diesel for the Jag X-type by bolting the 2.4 crank into the 2 liter block the power did not go up! It needed head redesigns and FIE changes to make the difference you feel and can see in the figures
Alex
Are you sure about that statement?
There are some VERY clever people on here - I know Karl worked in R&D for more a very major manufacturer in the same way I have!
When we (When I was at Ford - Not Karl and I LOL) created the 2,2 diesel for the Jag X-type by bolting the 2.4 crank into the 2 liter block the power did not go up! It needed head redesigns and FIE changes to make the difference you feel and can see in the figures
Alex
10K+ Poster!!
Joined: May 2004
Posts: 14,907
Likes: 1
From: scotland
Im not talking about engines that are restricted by some factor Im talking about a normal engine.
Look at the engines before the restriction IE at 3k....the bigger capacity engine will have more power.
Look at the engines before the restriction IE at 3k....the bigger capacity engine will have more power.
20K+ Super Poster.
Joined: May 2003
Posts: 20,599
Likes: 0
From: Ramsgate, Kent Drives: E39 530D Touring
rapidcossie, the problem you have, is that you're looking at 1 changing factor in an engine's design, and it's overall peak bhp, to compare 2 different engine, and makinjg an assumption based on that one factor.
it's likecomparing a bog standard ford focus, and a ford focus WRC car, and saying that the reason the WRC car is faster on a rally course is because it had bigger brakes. you're just missing the other fundemental changes which has caused the car to change
it's likecomparing a bog standard ford focus, and a ford focus WRC car, and saying that the reason the WRC car is faster on a rally course is because it had bigger brakes. you're just missing the other fundemental changes which has caused the car to change
PassionFords Creator
iTrader: (12)
Joined: May 2003
Posts: 28,824
Likes: 95
From: Blackpool, UK Destination: Rev limiter
I think everyone is arguing for different scenarios now.
Maybe someone should do a summary... Hows this.
IF you design an engine that achieve a given volumetric efficiency (say 85%) at a given RPM it will make X power.
If you then change its capacity, but redesign the engine itself to allow it to still meet the same VE and RPM statistics as the first engine, you WILL make more power.
Maybe someone should do a summary... Hows this.
IF you design an engine that achieve a given volumetric efficiency (say 85%) at a given RPM it will make X power.
If you then change its capacity, but redesign the engine itself to allow it to still meet the same VE and RPM statistics as the first engine, you WILL make more power.
10K+ Poster!!
Joined: May 2004
Posts: 14,907
Likes: 1
From: scotland
Originally Posted by Jim Galbally
rapidcossie, the problem you have, is that you're looking at 1 changing factor in an engine's design, and it's overall peak bhp, to compare 2 different engine, and makinjg an assumption based on that one factor.
it's likecomparing a bog standard ford focus, and a ford focus WRC car, and saying that the reason the WRC car is faster on a rally course is because it had bigger brakes. you're just missing the other fundemental changes which has caused the car to change
it's likecomparing a bog standard ford focus, and a ford focus WRC car, and saying that the reason the WRC car is faster on a rally course is because it had bigger brakes. you're just missing the other fundemental changes which has caused the car to change
Im not making assumptions either, cos its plain fact