how much power do you think the fan uses on my 1500 Midget
Discussion
I use to have a Mk2 Escort grasstracker and I didn`t remove the fan but removed the alternator and belt. I use to have two 12v batteries instead.
They reckon the alternator drains about 8 BHP. Not sure if thats true.
I don`t know how long your races are and whether you can last long enough without an alternator. Take into account possible restarts, warm up lap and time waiting to line up on the grid, etc....
They reckon the alternator drains about 8 BHP. Not sure if thats true.
I don`t know how long your races are and whether you can last long enough without an alternator. Take into account possible restarts, warm up lap and time waiting to line up on the grid, etc....
I use to have a Mk2 Escort grasstracker and I didn`t remove the fan but removed the alternator and belt. I use to have two 12v batteries instead.
They reckon the alternator drains about 8 BHP. Not sure if thats true.
I don`t know how long your races are and whether you can last long enough without an alternator. Take into account possible restarts, warm up lap and time waiting to line up on the grid, etc....
They reckon the alternator drains about 8 BHP. Not sure if thats true.
I don`t know how long your races are and whether you can last long enough without an alternator. Take into account possible restarts, warm up lap and time waiting to line up on the grid, etc....
the fan will cause a drag. Can you have a viscous coupling attached, so it wont turn at engine speed?
A seperate electric fan will help, of coruse. but put more strain on the electrics.
One fianl thought: if you imagine the fan, then its the friction of the blades turning the air which causes drag. If you have to keep the fan, does it have to have all the baldes? if the blades..ahem...snapped off, then you still have the fan installed, but without the bhp loss??
A seperate electric fan will help, of coruse. but put more strain on the electrics.
One fianl thought: if you imagine the fan, then its the friction of the blades turning the air which causes drag. If you have to keep the fan, does it have to have all the baldes? if the blades..ahem...snapped off, then you still have the fan installed, but without the bhp loss??
williamp said:
the fan will cause a drag.
Don't know if one of these would be too big.http://www.moroso.com/catalog/categorydisplay.asp?...
Motown Junk said:
williamp said:
the fan will cause a drag.
Don't know if one of these would be too big.http://www.moroso.com/catalog/categorydisplay.asp?...
Don't want to remove blades as 1) Car has to be driven to and from events and might need the cooling power. 2) could cause vibration problems. 3) don't think it is allowed to be modified - only replaced.
TBH the I suspect the rule is more to do with allowing people to compete in the "standard class" with the sort of modification an every day (ie nearly standard) car might have, than allowing a performance gain. I'm also allowed electronic ignition, I guess for the same reason.
Edit:In fact, rule says "electric fan may be fitted" so ignore non electric replacement ideas, thanks.
Edited by BMWChris on Tuesday 9th February 12:03
coetzeeh said:
I understand the fan consumes approx 4hp on my 1300 alfa romeo ('69 model).
It is a common upgrade to fit an electric fan + thermostat from a later AR. Much less noise too.
4bhp! That's about 5%! It is a common upgrade to fit an electric fan + thermostat from a later AR. Much less noise too.
How much would a small dent in the down pipe cost (tubular 4-1 system)? Dent is as it passes the sump.
BMWChris said:
coetzeeh said:
I understand the fan consumes approx 4hp on my 1300 alfa romeo ('69 model).
It is a common upgrade to fit an electric fan + thermostat from a later AR. Much less noise too.
4bhp! That's about 5%! It is a common upgrade to fit an electric fan + thermostat from a later AR. Much less noise too.
How much would a small dent in the down pipe cost (tubular 4-1 system)? Dent is as it passes the sump.
kenlowe (makers of fan kits) reckon 8.5% of total engine power is typical but most of their litterature seems to be about 4x4s which need lots of cooling for going very slowly in the Sahara and therefore have huge fans.
Even if they are exaggerating and it is really 5% it seems worth having.
Even if they are exaggerating and it is really 5% it seems worth having.
On the MGE BBS it is said that the fan costs(is worth?) around 4 BHP
I fitted an MGB electric one to my 1293 and for track days it does seem slightly better
Maniflow could probably give you an idea of the power loss from pinched down pipes, it would probably be like fitting a tube exaust into a small diameter system
I fitted an MGB electric one to my 1293 and for track days it does seem slightly better
Maniflow could probably give you an idea of the power loss from pinched down pipes, it would probably be like fitting a tube exaust into a small diameter system
The pitch angle of the fan blades makes a difference. If you have a metal fan and bend the blades so as they don’t do any work then they will consume less power.
Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
Uncle Fester said:
The pitch angle of the fan blades makes a difference. If you have a metal fan and bend the blades so as they don’t do any work then they will consume less power.
Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
I know exactly what you mean. However, I can't alter the fan, only replace it with an electric one. Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
If it gains me 4bhp then that's fine. Money well spent!
BMWChris said:
Uncle Fester said:
The pitch angle of the fan blades makes a difference. If you have a metal fan and bend the blades so as they don’t do any work then they will consume less power.
Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
I know exactly what you mean. However, I can't alter the fan, only replace it with an electric one. Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
If it gains me 4bhp then that's fine. Money well spent!
All engine driven fans, with the exception of a viscous type, are flawed by the very nature of their design. The only time you actually need a fan to cool the radiator is when you are stationary or travelling at very slow speed,i.e when there is no natural airflow through the core of your radiator.
The problem with an engine driven fan is that the amount of power it absorbs is proportional to engine RPM. In other words the faster your engine is turning, the more power it absorbs, and of course this is when you don't need it!
That is why an electric fan is so efficient; it only switches on when the engine temperature requires, usually only at idle. Removing your mechanical fan will release that drag from the drive belt, and the higher your engine revs, the more benefit you will get. On a track car, you will be driving the engine hard, so the benefits are greater than they would be on an ordinary road car.
DO NOT remove your fan belt or alternator; the same belt drives the water pump!
Hope this explains things for you.
J
You could argue that at speed the air flow through the rediator is driving the fan, so there will be a loss of power by removing it.
I really don't think it matters that much.
If it gains me 4bhp then that's fine. Money well spent!Chris,
All engine driven fans, with the exception of a viscous type, are flawed by the very nature of their design. The only time you actually need a fan to cool the radiator is when you are stationary or travelling at very slow speed,i.e when there is no natural airflow through the core of your radiator.
The problem with an engine driven fan is that the amount of power it absorbs is proportional to engine RPM. In other words the faster your engine is turning, the more power it absorbs, and of course this is when you don't need it!
That is why an electric fan is so efficient; it only switches on when the engine temperature requires, usually only at idle. Removing your mechanical fan will release that drag from the drive belt, and the higher your engine revs, the more benefit you will get. On a track car, you will be driving the engine hard, so the benefits are greater than they would be on an ordinary road car.
DO NOT remove your fan belt or alternator; the same belt drives the water pump!
Hope this explains things for you.
J
I really don't think it matters that much.
jith said:
BMWChris said:
Uncle Fester said:
The pitch angle of the fan blades makes a difference. If you have a metal fan and bend the blades so as they don’t do any work then they will consume less power.
Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
I know exactly what you mean. However, I can't alter the fan, only replace it with an electric one. Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
If it gains me 4bhp then that's fine. Money well spent!
All engine driven fans, with the exception of a viscous type, are flawed by the very nature of their design. The only time you actually need a fan to cool the radiator is when you are stationary or travelling at very slow speed,i.e when there is no natural airflow through the core of your radiator.
The problem with an engine driven fan is that the amount of power it absorbs is proportional to engine RPM. In other words the faster your engine is turning, the more power it absorbs, and of course this is when you don't need it!
That is why an electric fan is so efficient; it only switches on when the engine temperature requires, usually only at idle. Removing your mechanical fan will release that drag from the drive belt, and the higher your engine revs, the more benefit you will get. On a track car, you will be driving the engine hard, so the benefits are greater than they would be on an ordinary road car.
DO NOT remove your fan belt or alternator; the same belt drives the water pump!
Hope this explains things for you.
J
AJAX50 said:
You could argue that at speed the air flow through the rediator is driving the fan, so there will be a loss of power by removing it.
I really don't think it matters that much.
If it gains me 4bhp then that's fine. Money well spent!Chris,
All engine driven fans, with the exception of a viscous type, are flawed by the very nature of their design. The only time you actually need a fan to cool the radiator is when you are stationary or travelling at very slow speed,i.e when there is no natural airflow through the core of your radiator.
The problem with an engine driven fan is that the amount of power it absorbs is proportional to engine RPM. In other words the faster your engine is turning, the more power it absorbs, and of course this is when you don't need it!
That is why an electric fan is so efficient; it only switches on when the engine temperature requires, usually only at idle. Removing your mechanical fan will release that drag from the drive belt, and the higher your engine revs, the more benefit you will get. On a track car, you will be driving the engine hard, so the benefits are greater than they would be on an ordinary road car.
DO NOT remove your fan belt or alternator; the same belt drives the water pump!
Hope this explains things for you.
J
Sorry, but it matters quite significantly.I really don't think it matters that much.
jith said:
BMWChris said:
Uncle Fester said:
The pitch angle of the fan blades makes a difference. If you have a metal fan and bend the blades so as they don’t do any work then they will consume less power.
Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
I know exactly what you mean. However, I can't alter the fan, only replace it with an electric one. Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
If it gains me 4bhp then that's fine. Money well spent!
All engine driven fans, with the exception of a viscous type, are flawed by the very nature of their design. The only time you actually need a fan to cool the radiator is when you are stationary or travelling at very slow speed,i.e when there is no natural airflow through the core of your radiator.
The problem with an engine driven fan is that the amount of power it absorbs is proportional to engine RPM. In other words the faster your engine is turning, the more power it absorbs, and of course this is when you don't need it!
That is why an electric fan is so efficient; it only switches on when the engine temperature requires, usually only at idle. Removing your mechanical fan will release that drag from the drive belt, and the higher your engine revs, the more benefit you will get. On a track car, you will be driving the engine hard, so the benefits are greater than they would be on an ordinary road car.
DO NOT remove your fan belt or alternator; the same belt drives the water pump!
Hope this explains things for you.
J
You can get the figures for power/MPG improvements from Kenlowe. Generally speaking, the smaller the engine, the better the gain.
I'm sure Kenlow will produce some good figures based on static testing. The best way is to test in the real world, time your car between two point with then without the fan, then make up your mind. There are too many variables at work to have a simple theoretical answer.
You can get the figures for power/MPG improvements from Kenlowe. Generally speaking, the smaller the engine, the better the gain.
jith said:
AJAX50 said:
You could argue that at speed the air flow through the rediator is driving the fan, so there will be a loss of power by removing it.
I really don't think it matters that much.
If it gains me 4bhp then that's fine. Money well spent!Chris,
All engine driven fans, with the exception of a viscous type, are flawed by the very nature of their design. The only time you actually need a fan to cool the radiator is when you are stationary or travelling at very slow speed,i.e when there is no natural airflow through the core of your radiator.
The problem with an engine driven fan is that the amount of power it absorbs is proportional to engine RPM. In other words the faster your engine is turning, the more power it absorbs, and of course this is when you don't need it!
That is why an electric fan is so efficient; it only switches on when the engine temperature requires, usually only at idle. Removing your mechanical fan will release that drag from the drive belt, and the higher your engine revs, the more benefit you will get. On a track car, you will be driving the engine hard, so the benefits are greater than they would be on an ordinary road car.
DO NOT remove your fan belt or alternator; the same belt drives the water pump!
Hope this explains things for you.
J
Sorry, but it matters quite significantly.I really don't think it matters that much.
jith said:
BMWChris said:
Uncle Fester said:
The pitch angle of the fan blades makes a difference. If you have a metal fan and bend the blades so as they don’t do any work then they will consume less power.
Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
I know exactly what you mean. However, I can't alter the fan, only replace it with an electric one. Take a look at the theory of propeller selection for powerboats; or information for variable pitch aircraft propeller control and you will see what I mean.
If it gains me 4bhp then that's fine. Money well spent!
All engine driven fans, with the exception of a viscous type, are flawed by the very nature of their design. The only time you actually need a fan to cool the radiator is when you are stationary or travelling at very slow speed,i.e when there is no natural airflow through the core of your radiator.
The problem with an engine driven fan is that the amount of power it absorbs is proportional to engine RPM. In other words the faster your engine is turning, the more power it absorbs, and of course this is when you don't need it!
That is why an electric fan is so efficient; it only switches on when the engine temperature requires, usually only at idle. Removing your mechanical fan will release that drag from the drive belt, and the higher your engine revs, the more benefit you will get. On a track car, you will be driving the engine hard, so the benefits are greater than they would be on an ordinary road car.
DO NOT remove your fan belt or alternator; the same belt drives the water pump!
Hope this explains things for you.
J
You can get the figures for power/MPG improvements from Kenlowe. Generally speaking, the smaller the engine, the better the gain.
Gassing Station | Classic Cars and Yesterday's Heroes | Top of Page | What's New | My Stuff