Lark engine torque

[bashr52]

Anyone know what the max torque a 40hp evinrude lark produces is?

 

[F_R]

Re: Lark engine torque

Nope.

 

[bashr52]

Re: Lark engine torque

FYI, if you punch the numbers, it comes in at 46.684 ft-lbs. Thats at the published 4500 RPM 40hp limit

 

[F_R]

Re: Lark engine torque

If you are able to calculate that, you are a lot smarter than I am. I wouldn't have a clue how to do it. By my short "nope", I meant that spec is not published anywhere that I know of.

OK, so while we are on the subject, any torque chart that I have ever seen (automotive) shows the torque at different RPM on a curve, higher at lower speeds and dropping off as RPM increases. How does that work out with outboards? Are you saying that "Max torque" is developed at 4500 RPM?

A subject that I've never fully understood.

 

[bashr52]

Re: Lark engine torque

I didnt see them published either but thought I'd ask if anyone had. Horsepower is a derivative of torque, and there is a simple formula for finding it.


To calculate motor full-load torque, apply this formula:

T = (HP x 5252)/RPM


T = torque (in lb-ft)
HP = horsepower
5252 = constant
rpm = revolutions per minute

May not be exact in all situations, but should be in the ballpark.

Max torque should always occur below max HP, usually 200-500 RPM lower

 

[F_R]

Re: Lark engine torque

Dang!! Where is a torque spec chart when I need one?

OK, so I had to go back a couple of years to find one. How about a 1947 Cadillac V8, 346 cubic inches? Max torque 260 ft lbs @ 1700 RPM. Max horsepower 150 @ 3400 RPM.

Your formula results in 231.7 ft lbs. But notice the difference in RPM. Did the rules change since 1947?