Recommend me an aluminum prop please

[singlesupra]

Per the sticky

1. Im not tryin to fix a performance issue, I need a new prop and hoping a different prop will give me more mph at the same rpm. The boat will plain at under/around 3000 rpms already(planes almost instantly honestly), I dont need anymore of a holeshot due to never pulling skiers. What we do most of the time is island hop or go out to eat(ie: longer trips). At around 3400rpms gps says 28-29mph. Our trip to the diner from the campground is 9 miles one way. Always me, the wife and two lil girls under 5.
2.Current prop is a 14.5X19, aluminum. Sorry I dont know the manufacturer
3.14.5X19
4.WOT RPM is around 4600, at about 43-44mph. It will however creep past that if held I think, I always back off a little
5.Engine is originanal mercruiser(gm)5.0 LX(205hp rated from the factory). alpha one drive
6. 94 Glastron 215 ssv elite

So, any prop out there that will yeild me more mph per rpm? As stated the boat planes VERY quick and I wouldnt mind giving up some planing for a higer top speed at cruisin RPM

Thanks in advance!
ps,old prop was in pretty good shape. Managed to finish it off today in a bad thunderstorm that popped up by hitting mud/sand while slowly making our way back to the dock. Was atleast 100 ft from the shore of an island dangit lol

 

[craze1cars]

Re: Recommend me an aluminum prop please

If all you want is more MPH per RPM, then you need a larger pitch. If you currently have a 19 you can run a 21 and probably accomplish your goal.

That said, if a 21 causes a lugging of the motor because it is too much prop for the boat, it will invite detonation, which increases stress substantailly on your pistons, crank, etc...causes very high combustion chamber temps, etc...

Frankly in order to prop any boat correctly, you MUST take it on a WOT run, and report your WOT rpm. I am quite certain your WOT RPM is not simply "4,600". It is far more likely a range...and it is probably "4,200 to 4,600". Might be "4,400 to 4,800." This range will most likely be written on the flame arrestor cover of your motor...there's a decal on there somewhere that gives these specs.

Depending on what that range is, for your purposes you will want to prop your boat so it runs as close to the bottom (either 4,200 or 4,400) while at WOT, but not below it. The fact that you will never drive that fast normally makes no difference....you still need to make sure you're not overloading the engine at partial throttle with a prop that is too large.

 

[singlesupra]

Re: Recommend me an aluminum prop please

Sorry, I thought I was supposed to say what MY WOT rpm is. The manual states 42-4600. MY BOAT will easily do 4200 but will eventually creep past 4600 if held WOT. So again, MY WOT IS 4600 with creep past if held for too long.
So, going by what you said and what I just wrote, I ASSume 20-21 pitch is what I should get

 

[craze1cars]

Re: Recommend me an aluminum prop please

Yes, I agree. With the knowledge that your current prop is capable of hitting 4,600, for your particular goal purposes you want to come closer to targeting 4,200 or 4,300.

Adding 2" of pitch in a propeller of similar design would accomplish this. So I'd suggest a 21 pitch prop of similar design to your current 19 pitch prop.

 

[singlesupra]

Re: Recommend me an aluminum prop please

Yes, I agree. With the knowledge that your current prop is capable of hitting 4,600, for your particular goal purposes you want to come closer to targeting 4,200 or 4,300.

Adding 2" of pitch in a propeller of similar design would accomplish this. So I'd suggest a 21 pitch prop of similar design to your current 19 pitch prop.

Ive done quite a bit of searching but I assume you mean since mine is a 3 blade aluminum, any of them will be of similar design as long as its a 3 blade aluminum? Also I keep reading about not being as stable or is that if you go down in diameter? I dont want to lose stability as the boat currently is very stable

 

[singlesupra]

Re: Recommend me an aluminum prop please

Little update, tried the prop recommended by iboat staff. Was told that as long as new prop was not marked,, scratched(ie new condition ) that I could return it for a diff one if it didn't suite my needs.
prop was same as old as far as performance now iboats is saying there was a mixup and that it can't be returned.
Your phone opperator gave me the wrong info and I have to eat the bill? That's the way iboats works? Nice...
Hope many run across my post and feedback will be left all over online as well. Also my order that was placing today for many other parts will be going to there competitor as well

Thanks iboats!

 

[Jerryh3]

Re: Recommend me an aluminum prop please

Try www.wholesalemarine.com. The prices are usually better than iboats and the shipping is very fast.

 

[srimes]

Re: Recommend me an aluminum prop please

yeah I've seen that complaint a bunch. What was the new prop and what was the problem?

 

[singlesupra]

Re: Recommend me an aluminum prop please

Old prop was 14.5x19 3 blade. New was 14.25(ish)x17 4 blade
No real problem other than still lackingthe cruising speed I was looking for. Figured that out after about a 1/8th mile. Wit range should be 42-4600, I hit4600 with ease and it will keep creeping past.
had I known I was gonna be stuck with this prop I would not have gone with a direct replacement, other than 4 blade. I woukdhave gone a little more aggressive