# Estimated power of a motor needed for a ford focus

1. Oct 13, 2008

### education1983

How do I calculate the estimated power of a motor needed for a ford focus, engine size:1788cc, 4 cylinders??

2. Oct 13, 2008

### brewnog

Re: Cars...

You need to provide some more information. Are you asking how much power a typical Ford 1.8L engine can produce? Or how much a 1.8L engine could theoretically produce? Or how much it actually produces? What information have you been given when you were asked this question?

3. Oct 13, 2008

### education1983

Re: Cars...

I was told to choose a car, a petrol car, and using the engine size of the car(1798cc), work out the power of the starter motor the car would require. The cars specs are:

1798cc, 4 cylinders.

4. Oct 13, 2008

### education1983

Re: Cars...

info given were:
2 cylinders= 125N.m
4 '' =80N.m
6 '' = 65N.m

5. Oct 13, 2008

### Mech_Engineer

Re: Cars...

Your question was obviously poorly posed from the start since you mentioned nothing about the fact that you are sizing the starter motor and not the engine itself. It seems that this is a homework assignment and so we will have to ask you first, what have you done to try and solve the problem thus far?

By the way, the displacement of the engine alone is not enough to determine the required torque of the starter motor. You will probably need to know things like the diameter of the flywheel (pitch diameter), diameter of the starter's pinion gear (pitch diameter), the engine's compression ratio, and probably the engine's bore and stroke. This may give you a very rough estimate, assuming you're ignoring friction in the cylinder.

6. Oct 14, 2008

### brewnog

Re: Cars...

A good response from Mech Engineer.

Also, I'm sure you won't just have been told that "2 cylinders = 125Nm"; this itself is meaningless.

If indeed this is a homework question, I suggest you read the rules for posting such questions and then have a go at following them. Then you'll get all the help you could possibly need.

7. Oct 15, 2008

### ashishbhagwat

Re: Cars...

A vehicle's engine rotates at 5640 rpm and produces 62 hp. If the final drive ratio is 4.00 and the transmission gear ratio is 3.00, calculate the vehicle speed, in mph. The tire radius is 10.1 inches. Vehicle is at constant speed.

8. Oct 15, 2008

### brewnog

Re: Cars...

Why don't you have a read of the rules we have here about homework questions? Remember, the ones you agreed to when signing up?