Gear ratio, what is it and what does it do?

[khc1970]

So how does one engine which has 2.0:1 compare to another with 2.5:1?

 

[Laddies]

Re: Gear ratio, what is it and what does it do?

The gear ratio does two things, it is in the upper gear hsg and permits the manufacture to build propellers with less of a pitch range, by raising the gear ratio on the on the smaller engines it helps them turn the prop (1.98 to 1) and lowering it on the V/8s making the us there hp to turn the prop faster(1.5 to 1) The other thing is a side effect it truns thye water pump faster helping to suppl the V/8s more cooling water at all RPMs---Bob

 

[jtexas]

Re: Gear ratio, what is it and what does it do?

If I interpret your question correctly:<br /><br />2.0:1 means the drive shaft rotates 2 times to rotate the propeller once.<br /><br />2.5:1 means the drive shaft rotates 2.5 times for every rotation of the propeller.<br /><br />2.5:1 means more torque (better hole shot & acceleration) but less top speed than 2.0:1<br /><br />that, plus everything laddiesservice said.

 

[jimmbo]

Re: Gear ratio, what is it and what does it do?

Originally posted by jtexas:<br /> If I interpret your question correctly:<br /><br />2.0:1 means the drive shaft rotates 2 times to rotate the propeller once.<br /><br />2.5:1 means the drive shaft rotates 2.5 times for every rotation of the propeller.<br /><br />2.5:1 means more torque (better hole shot & acceleration) but less top speed than 2.0:1<br /><br />that, plus everything laddiesservice said.

2.5:1 means prop with greater pitch turning fewer RPMs but pretty much same top speed as 2.0:1 and less pitch prop.