Props terminology

icamposo · Newbie Joined: 21 May 2003 Posts: 2

Could somebody explain me what’s the difference between a 13X13 and a 13X14 props, and what’s the first and second number stand for?

Thanks for your help

boehnkew · Outlaw Joined: 26 Mar 2003 Posts: 112 City: Kennewick, WA

The first number is the diameter and the second number is the pitch (both in inches). The pitch is the theoretical distance that the prop would travel in a single revolution with no slippage. Generally speaking, changing to a higher pitch and keeping the same diameter would give you a higher top speed at the cost of less hole shot power. Of course this depends on other things. The wrong size/pitch prop could allow your engine to over-rev at Wide Open Throttle. The goal of original equipment props is usually to get close but slightly under redline at WOT.

bluefish86 · Posted: May 22, 2003 3:41 pm Post subject:

Also, props with even number of blades will have an even number pitch, and a prop with an odd number pitch will have an odd number of blades, so a 13x13 wold have 3 or 5 bades, and a 13x14 would have 4 blades (possibly 2).

boehnkew · Outlaw Joined: 26 Mar 2003 Posts: 112 City: Kennewick, WA

My 14X18 (original) is a 3 blade.

jrichard · Posted: May 22, 2003 8:01 pm Post subject:

Why would the pitch have anything to do with the number of blades?

Phaeton · Addict Joined: 12 Jan 2003 Posts: 572 City: Redding

bluefish86, Put the crack pipe down!

Cary K. · Outlaw Joined: 13 Jan 2003 Posts: 225 City: Wilson, NC

I've never heard of that either. I have a 14x12.5 3blade, and a 13x13 4blade. Pass the dutchie to the left hand side, lol !!!