How To Read Engine Specifications?


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Oh what is this calculation?? Can you explain in detail?? This is new to me!!


Why some of the manufacturers mention PS and some of them BHP??
 
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These are from my older savings taken from net long back


BRAKE Horsepower is the horsepower delivered at the wheels as opposed to the CRANK Horsepower being the power delivered at the flywheel attached to the crankshaft.

Both a measured with Dynometers, but of different types.
Brake is measured on a full car dynometer and crank is on a static dynometer where the engine is not even in a vehicle.

Obviously BRAKE is the one that matters to enthusiasts since we can go to specialty shops and have that measured for tuning purposes.


In simple terms it is used to measure the power your engine will apply to your wheels to make them turn. BUT, that is only 1 aspect of performance. For example, 150 BHP is fantastic in a motorcycle but utterly useless in a truck. And vice versa, a truck engine may produce 100's of BHP but it won't break any speed records.

PS stands for Pferdestärke (literally, 'horse strength').

PS is a slightly higher figure than the bhp that we quote

to get a bhp figure from ps multiply the PS figure by 0.9864 to reach the bhp total, or bhp by 1.0139This is what i have mentioned as 1.05, read this in a book to get back to PS.

BHP is "Brake Horse Power" - the standard used in the US under the Society of Automotive Engineers (SAE). It is measured by applying resistance (a "brake") on a dynamometer and measuring the heat produced while maintaining rpms as the load is gradually increased.

PS is the European equivalent, sometimes called DIN (Deutesche Institut fur Normung, for 'German Institute for Standardization'). DIN horsepower numbers are approximately 1.38% higher than SAE numbers.
 
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Brake horsepower (bhp) is the measure of an engine's horsepower without the loss in power caused by the gearbox, alternator, differential, water pump, and other auxiliary components such as power steering pump, muffled exhaust system, etc. Brake refers to a device which was used to load an engine and hold it at a desired RPM. During testing, the output torque and rotational speed were measured to determine the brake horsepower.


The above part is taken from Wikipedia

The engine develops some power , but due to resistance from various friction , 100% engine power is not got at the wheels . This is bhp and ps in German calculation.

Literally power is calculated in watt.

The method of calculation which you asked - i too don't know .

Simple they measure with a device. The procedure , i don't know
 
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bhp and ps

hp (mechanical) =746 watts
hp (metric) =736 watts
Germans are using the second one called ps.
Thats why the ps value is always higher than bhp.
Another thing is that the bhp is only a calculated value, only torque and rpm are measured from the dynamometer.
Torque in pound feet multiplied by the rpm and divided by 5252 gets the bhp at that rpm.
 

Arun

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In a layman's world, engine displacement is directly proportional to power!!

Greater the displacement of a engine (cc), greater the power output!
 
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In a layman's world, engine displacement is directly proportional to power!!

Greater the displacement of a engine (cc), greater the power output!
In other words ,
greater the power , the maximum power can be extracted by good mechanical part.

Depends upon gear ratio , its design like that!
 
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what is meant by cc (1250cc,100cc,150cc).how it will calculate..?
CC - Its a mesurement of Engine displacement - which is the volume swept by all the pistons inside the cylinders of an internal combustion engine in a single movement from top dead centre (TDC) to bottom dead centre (BDC).

Displacement.gif
One complete cycle of a four cylinder, four stroke engine. The volume displaced is marked in orange.
 
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3 questions for the xperts:

1) Max. power [PS (kW) @ rpm] 122 (90) @ 5000 . This is Jetta 1.4 TSI petrol specification

What does the number 90 in brackets indicate? I know that 122 is the max power at 5000 rpm

2) Max. torque (Nm @ rpm) 200 @ 1500-4000 This is Jetta 1.4 TSI petrol specification

is the torque 200@1500 rpm or 200@4000 rpm. How do I read this?


3) "Higher engine displacement means more power" . I read this in one of the posts above. How do you explain this:

Vento 1.6L cc petrol, Max. Power (PS (kW) @ rpm) 105 (77) @ 5250
Jetta 1.4L cc TSI petrol- Max. power [PS (kW) @ rpm] 122 (90) @ 5000

Vento has higher displacement but lower horse power than Jetta petrol.
Torque of Jetta is also higher than Vento.
How do I compare?
 
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3 questions for the xperts:

1) Max. power [PS (kW) @ rpm] 122 (90) @ 5000 . This is Jetta 1.4 TSI petrol specification

What does the number 90 in brackets indicate? I know that 122 is the max power at 5000 rpm

2) Max. torque (Nm @ rpm) 200 @ 1500-4000 This is Jetta 1.4 TSI petrol specification

is the torque 200@1500 rpm or 200@4000 rpm. How do I read this?

3) "Higher engine displacement means more power" . I read this in one of the posts above. How do you explain this:

Vento 1.6L cc petrol, Max. Power (PS (kW) @ rpm) 105 (77) @ 5250
Jetta 1.4L cc TSI petrol- Max. power [PS (kW) @ rpm] 122 (90) @ 5000

Vento has higher displacement but lower horse power than Jetta petrol.
Torque of Jetta is also higher than Vento.
How do I compare?
Ans 1::it indicates the power in KiloWatts

Ans 2:max torque of 200Nm btwn 1500rpm and 4000rpm

Ans 3:Jetta with TSI (Turbo Stratified injection) engine uses turbocharger and supercharger for increasing the power and torque as well.. so only that 1.4L engine got more power.
 
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The TSI is said to make more power because it uses higher compression ratio and it is also more efficient.

A lot of manufacturers are turning to smaller displacement turbo charged engines that have more power than the normally aspirated engines like the 1.6lt engine in the Vento whilst still being fuel efficient.

The only problem here is that turbos are very finicky and you need to make sure that the turbo receives oil and coolant to keep it running properly.Also need to keep an eye on the intercooler to make sure it doesn't get clogged.
 

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