Prop for 500 Caddy

[mickey5978]

I have been asking about props for moy motor. I know several people with stock Caddy 500 running a 72X38 paddle. I have a stepped up caddy and am wondering if a 72X44 would still work with the stepped up motor. It is the same lenght with a little more pitch. This will move more air, right? How much would the extra 6 degrees drag on the motor?

 

[a1mudpuppy]

A LOT, what are you calling a step up motor?
I've got a 14' GTO , 500 caddy with 120cc heads, .030 flat top pistons ,Comp Cam, EDELBROCK INTAKE WITH 750CFM CARBURETOR, headers and after market HEI.
I've got a 72" Power Shift set @ 38deg runs fine may need to set it to 40deg because I still can get 3200rpm out of the motor.

I think it would run like a slug but you never know until you try it.

 

[BigBoom]

Get a Sensenich 3 blade 72" carbon fiber. It's the best single thing you can do to improve performance. I don't know how much they are now, I think around $2200.00.

 

[mickey5978]

motor is putting out 430 HP at 3000 and about 580-590 lbs torque at the same. you think I could spin the prop at 2900 or 3000?

 

[a1mudpuppy]

Maybe ....spend the money and get a composite prop so you can adjust it.

 

[mickey5978]

I think that is the best thing to do too, just don't have the money after the motor. what kind of #'s is your motor putting out?

 

[a1mudpuppy]

Don't Know how would I tell???

 

[cntry141iq]

You would have to pull your motor off and take it to an shop with a dyno and have them run it for you. It can cost between 200 and 500 bucks or maybe more and you couls lose your motor if it blows up.

 

[nebraskaairboater]

The best advice if you are going to use a wood prop would be to call a manufacturer of wood props and get their advice. We got ours from Florida Airboat Propellers http://www.floridaairboatpropellers.com/

Sensenich also makes a good wood prop

http://www.sensenichprop.com/sen_html/airboat.html

If you know someone who has a prop the same size you want to use see if you can borrow it... then you will know how it works. You might think of going to a 76 x 38 I have heard that it is better to swing a longer prop with less pitch if you can. Most of the push comes from the middle of the blades and I guess the longer the blade the more pushing surface you have.

Just my opinion. BTW... If you get a new wood prop it is probably going to be around $ 700.00 I think we paid $1,600 for our composite prop new and you can get them as factory seconds from Whirl Wind for $1,100.00 with the standard warranty. (Just an example)