tbaysal2000

What type of prop is better for a 48" offshore mono with standard Zen 26cc. High lift or not?

Another question is when 3 blade is preferred to 2 blade?

Thanks
Tufan

martno1fan

Last thing you want on a mono is a high lift prop,theyre best suited to hydros and riggers,3 blade over 2 it all depends, personally i test dif props till i find the best one for the setup wether that be 2 or 3 even 4 blades.A good prop for your boat and motor would be a 7015/3 this is a very good prop for a mono,the 2 blade version is quicker to hook up but the 3 blader is a better all round prop i find.
Mart

SS RC Boats

Good posting!

martno1fan

Thanks feel free to rate it lol

tbaysal2000

Thanks Mart, I made the same conclusion by logic but then I found the below post which confused me as the owner was finally happy with X460/2, which must be a high lift prop due to "X" rating and 2 blade seemed to be a better choice for him:
http://www.rcuniverse.com/forum/m_11...m.htm#11060154

I have also have a 6717/3 but it is from dasboata with clipped ears for rough water. Owner saw not a big difference with 7015/3 and someone suggested x470/3.

Finally;
I never knew I can rate an answer, so you are the first to get the 5*

w3bby

Read the post again, X4??/? props are low lift....... Better explanation [link=http://www.rcgroups.com/forums/showpost.php?p=20791149&postcount=3]here.[/link]

martno1fan

lol you gave the 5 to ss rc boats wheres mine lol.Props can get confusing ,numbers, letters and all mean dif things from dif prop guys, have fun lol .
Mart

tbaysal2000

Yeap, I was totally confused again

And Martno, another 5s for you, I hope I'll get it right this time

martno1fan

Better late than never lol.
Did you decide which prop to go with .

tbaysal2000

If 6717/3 and 7015/3 are not big differences, I may try first X460/3.

I remember Randy aka Mistycreekboats building one and he sold it to a customer who won a race after some tune. I'll PM so maybe he can let me know what was the winning combination.
http://www.rcuniverse.com/forum/m_11130559/tm.htm

MrMikeG

Never seen a gas boat run a 60mm prop. 65 yes 60 no, (unless it is subsurface)
And I think an X460 anything will have a 3/16th shaft, not 1/4", could be wrong

tbaysal2000

It was Jackal1983's thread which he confirmed to see the improvement with X460/2:
http://www.rcuniverse.com/forum/m_11...m.htm#11060154

But suggestions based on logic were as below. So instead of X460, my alternative choice sounds better with X470/3 (by HendricX):
In a 6717 prop (metric-size) the 67 is diameter .. and the 17 is 1.7 pitch-ratio or ;

67 x 1.7 = 113,9mm total throw (moving forward) of the prop.

On the 7015 this is 70 x 1.5 = 105mm total throw.

So your engine will rev higher with the 7015.

Buy a Octura X470/3 (70 x 1.4 = 98mm total throw) and it will even reving higher.

martno1fan

60 mm is way too small for a gas boat def need 65 and up,for a stock zen id go slightly bigger so a 7015/3,470/3 would work and another would be a 7016/3 and 275/2 .
Mart

goodson

I got the best combination of speed and acceleration with a 7015/3 with my WHH M5 Zenoah. The 275 didn't stay as hooked up and the 3 blade carried the bow a little better.

Jackal1983

Since i started that thread i will add abit more of an update!

The issue was the engine!!!... It had odd Cases so it was binding up. We sorted this issue and went to the drawing board.

It could turn the x460/2 with ease... it was alot better from standing start to middle of the RPM range but It was a struggle to stop it torque roll with a 2 blader.
So i went to a X460/3 which stopped the roll but still lost the top end!!!

changed to a 6717/3 and i had lots of top end!! But cavatated low down... so we cupped the edges and my god it made a huge diffrence!!!!

I prefer the 3 bladers!

wet a wild

hi there. trust me on this one. octura x472/2, remove tongue, little back cutt, thinned blades, well b/s and you will have a very good prop for a stock application.