-
After doing some research on newer boats, there is no telling what size or pitch prop the manufacturer is using. The old standard of 13x13 was true when inboards were 19-21' long with a 95" beam and with a 240-285 hp motor. Now, boats are larger, with lots more hp, and more biased to wake speeds (20-22 mph). Boat builders are using different diameter and pitches to aid in wake creation/elimination and to optimize the engines peak hp for given conditions. Take a look online at waterskimag.com. They have the low-down on props for each of the new boats.
Again, you need to know what you current pitch is in order to know where to go.
-
My prop is a 13x13, according to the stamp.
I talked to the a guy at ACME and he suggested a 13x12, however he indicated that after 100 hours if I woulkd swap to all synthetic fluids I would pick up a few HP and a few RPMs and that I might be able to usea 13x12.625 prop they have. I was surprised he suggested a 3blade prop over the 4 blade.
Lastly and this really shocked me, he said if I bought it direct from Acme they had a 30 day money back guaranteee, so if one pitch did not work they would swap it for the another until we got it right. He also indicated they would do cutom cup work for $40.00 per prop if we got close and it needed a little tweaking.
Thankks for all the comments.
-
Max you are correct, I ordered an LS and waterski magazine states it has a 13 x 11. I am a little surprised but that might explain the 41mph I see often on the site, whereas the old MC will do about 47 with the 13 x 13.
As far as changin fluids goes I see no reason why you couldn't switch to Mobil One right now. I know there is often a discussion about an engine breaking in before you use the synthetics but Porsches and Corvettes leave the factory with Mobil One in them. I intend to use it!
-
A four blade prop is never faster than a 3 blade. 4 blades give you hole shot and maybe fuel economy but never speed
-
OK, I understand why the hole shot is better with the 4 blade- it's pure physics. But fuel economy? Is it just b/c the 4 blade is more efficient.
I have a 2000 Outback LS that I have not even been out on yet other than a test drive. It's got a 4 blade on it now but the original 3 blade is in a box ( I think it's a 13x13). I'm coming off a 115 hp outboard that me (215 lb.) and my two brothers (210 and 235 lb- yea, we enjoy BBQ) ski and learned to wakeboard behind.
I was wondering if we should be running the 4 blade or go back to the 3 blade. We wakeboard now about 60% of the time and ski about 10%. The other 30% is split between pulling toys like tubes and bananas for kids and running 35-40 MPH to get up the river to our ski zone.
In my estimation, coming off the outboard the hole shot is going to seem awesome to us no matter which prop we use and whether we are skiing or wakeboarding. We got great mileage with the outboard so I know our fuel cost is going to go up. So I was thinking about running the 3 blade. But, if overall fuel economy is going to be better with the 4 blade then maybe we just stick with it b/c top speed is really not a big concern. Thoughts anyone? (Thanks for all the input and assistance- you guys are the best and reaffirm every day that I made the right choice to join the Moomba family!)
-
The efficiency that you will see (or not see) between 3 and 4 blades in fuel will be difficult to detect. On order of less than 1/2 mpg, if you choose to look at it that way. I suggest that you use the boat the way it is for a while and get use to it. Especially look at your table size and shape. Then change out the prop and note the differences.
I like the 4 blades props that I have had on my last 2 boats. I still don't understand why props aren't made skewed and shrouded.
-
I don't understand why they haven't come up with a variable pitch prop yet! You could change it on the fly like our subs do! OH! Cost! Ok!
-
You know, back in the day we ran some pretty fast OB's in around the 95 - 100 mph range (and that was almost 20yrs ago). There was one guy running a variable pitch prop on his big Yammy. It was manual but variable none the less. Seemed to work fine, just wasn't available in a lot of configurations.
Kaneboats the 4 blade is what I think will fill your needs the best, especially with the split on watersports you list.
Now if some one can just help me with our clutching problem at the track I'd be golden :lol:
-
Sled,
Now I am going to have to get on the internet and look that up, that sounds great, I wonder why they stop producing it. In order to do that now we would need a hollow driveshaft and a hollow crankshaft to be able to run the mechanicals down to the prop. This is not unreasonble as there were several WWII fighters that had guns firing through the propeller hubs! I will start on this tomorrow at work!
-
Say Z, this isn't going to cost anything is it :lol:
