Mechanical Engineering
• 0

# 2 stroke power output

## Question

Hi

I am currently sitting my HND in computer aided draughting and design at new college lanarkshire and for my graded unit i am planning to do a trailer with an adjustable (in height) trailer bed, my question is that with a 2 stroke engine what equations can i use to calculate what power output i need from the engine to lift certain weights (i have a limited knowledge of maths and physics so bare with me)

thanks

Andrew

## Recommended Posts

• 0

This depends entirely on the size of the weights and the rate at which you want to lift them. If you will settle for super slow, a very low power level will suffice; if you want it done quickly, it will require more power.

Power = work/time

DrD

##### Share on other sites
• 0

As DrD has stated above, a great deal will depend on the weight you intend to lift in your design. As far as measuring the power output of your notional two stroke engine goes, there is only one accurate way in which you can do this and that is with a dynamometer. This equipment is able to accurately determine the brake horse power (BHP) and torque at the output shaft. Having raced and tuned both two-stroke and four-stroke racing engines in competition for many years, I can tell you that the power produced will depend on port timing, carburettor jetting and ignition timing. The exhaust expansion chamber is also critical on a two-stroke engine in terms of its shape, length, volumetric efficiency and the back-pressure it provides within a given rev-band. As you will appreciate with all naturally-aspirated engines, altitude will greatly affect power output also due to the density of the air. As far as your design goes, can I suggest that you consider using your slave motor to power a hydraulic pump to lift your weight. In this way your objective will more easily be attainable.

##### Share on other sites
• 0

Roger, this is all no doubt true, but I suspect is is far more information than the original poster can digest. I think his question is back at the level of "what is the relation between force, displacement, and power?" But who knows? It really is not clear where he is.

DrD

##### Share on other sites
• 0

Yes, DrD, I think I'm inclined to agree with you

##### Share on other sites
• 0

Andrew, you first need to know what mass (weight) you will be lifting and over what distance?                   Consider in your calculations that you will require 1 horse power (745.7 watts) to raise 75kg against the force of gravity over a distance of 1 metre in 1 second. Of course this calculation does not take into account any losses due to friction.

## Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

×   Pasted as rich text.   Paste as plain text instead

Only 75 emoji are allowed.

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×

×
×
• Create New...