Catto 3 Blade Questions

[Mel]

Originally Posted by DanLandry

66" diameter is standard for the 3-blade, 68 for 2-blade.
Solo climb is typical for me to see 2200-2300 fpm once I pull at 120mph.

Actually my latest 3-blade prop from Craig is 68" diameter.

[roadrunner20]

Originally Posted by Mel

Actually my latest 3-blade prop from Craig is 68" diameter.

I didn't know that. Was that a recent change?
I should have read the previous post as they indicated a 68" 3-blade prop.

[rvn817j]

My new 3 blade is 68" diameter by 74" pitch. Design rpm is 2750 with a red line of 3400. You should torque your bolts to 42 lbs. using a 7 inch crush plate. I addition to length changes, Craig has also changed the blade shape over the past several years.

[flyenforfun]

Originally Posted by rvn817j

My new 3 blade is 68" diameter by 74" pitch. Design rpm is 2750 with a red line of 3400. You should torque your bolts to 42 lbs. using a 7 inch crush plate. I addition to length changes, Craig has also changed the blade shape over the past several years.

My email from Craig said most RVers are using the 68x74 now, with alot of people going 75 on the -8 since its a bit faster. What would suffer if going from 74 to 75? Climb performance?

Are you talking prop redline or engine redline??

[rvn817j]

Originally Posted by flyenforfun

What would suffer if going from 74 to 75? Climb performance?

Are you talking prop redline or engine redline??

I do not know the speed vs. climb issue of going to a prop with more pitch, but I assume it is more climb. My request to Craig was for more cruise speed and I am pleased with what I have gotten.

Your engine manufacturers rpm red line remains the same. (I believe Craig deals with many racers and they are always pushing their engines, so he puts a "prop" redline on the label. I rarely go over 2700 rpm on my engine.)

[CODon]

I have a 3 blade On my RV7 and am very satisfied as the other posts. 194 mph top and cruise at 180 on just a bit less than 8 gph. Light weight does move the CG aft, and I went with a 14 lb spacer to get it forward. Want to get the leading edge protection when I get rich and famous. As you know, it is a bit tough to get the lower cowl off and on, but the looks and smoothness make it worth it.

[flyenforfun]

Originally Posted by CODon

I have a 3 blade On my RV7 and am very satisfied as the other posts. 194 mph top and cruise at 180 on just a bit less than 8 gph. Light weight does move the CG aft, and I went with a 14 lb spacer to get it forward. Want to get the leading edge protection when I get rich and famous. As you know, it is a bit tough to get the lower cowl off and on, but the looks and smoothness make it worth it.

What spacer do you use?