4-blade prop?

schoolsOut · **Posted:** Thu Oct 10, 2013 2:07 pm

I get the feeling that most of you get tired of prop questions, but I will give it a go anyway. I did a search but could not find much info about 4-blade props. Any of you running them? If I understand correctly the pros are hole shot, better (more efficient) cruising speeds, low speed handling, speed control (for example when pulling skier/wake boarder). Cons: top speed.

I am not super concerned about top speed, but don't really want to lose too much. I rarely run at the top end, but like to know it is there if I want it. My 210 is not very fast to begin with, so I would like to keep mid 40's. I am running a 14.75 x 19 right now. Do I pitch it down if I move to a 4-blade? Looks like diameter is a little less with the 4's. Like 14 or 14 1/8.

Basically, do you use one or did you? Do I want one? Thanks again.

deafwish · **Posted:** Thu Oct 10, 2013 3:16 pm

What is your maximum RPM, flat out, trimmed?
I love my Amita 4 on my Horizon RS. It changed the boat's ride characteristics.

schoolsOut · **Posted:** Thu Oct 10, 2013 3:41 pm

deafwish wrote:

What is your maximum RPM, flat out, trimmed?

I would say about 4800 rpm. Definitely in the high 4000's, almost 5000 assuming the tach is accurate at those rpm's (which may be a stretch). I think, based on my reading, that I should probably pitch down to an 18" to keep the rpms in range.

deafwish · **Posted:** Thu Oct 10, 2013 11:11 pm

What is your engine's max RPM range?

boater · **Posted:** Fri Oct 11, 2013 6:29 am

I think you've got the pros and cons down.
If you ski and board I think you should get one.
I use a 19 and am very happy with it.
Looks like deafwish can help you zero in on a size.

ric · **Posted:** Fri Oct 11, 2013 6:46 am

I switched to an Alpha 4 not long ago. Better acceleration, faster plane, cruises better, easier to dock..

Pretty much it just made my boat better in every way. Zero cons.

schoolsOut · **Posted:** Fri Oct 11, 2013 10:51 am

deafwish wrote:

What is your engine's max RPM range?

Looks like 4400-4800 according to manual.

ric · **Posted:** Fri Oct 11, 2013 8:45 pm

I'm doing 4800 with an 18x14.75 Alpha 4. Coming from a 3 blade it's like owning a car with an open differential and installing a limited slip. The revolution 4 I hear is the dogs bollocks top of the line 4 blade.

deafwish · **Posted:** Sat Oct 12, 2013 2:48 am

A good read:

http://www.solas.com/newweb/propeller/tech/basic.asp

schoolsOut · **Posted:** Sun Oct 13, 2013 6:00 pm

Well, I'm convinced. Gonna make the switch in the spring to a 4 blade. The revolution appears to be a merc item only and I'm running a VP. At this point, I'm considering the solas or michigan wheel Apollo. I guess I will drop from a 19 pitch to an 18. Ideally, I would like to find a place where I can test one out before buying. I will have to see if I can find something like that in the spring. Thanks for all the feedback!

rpengr · **Posted:** Sun Oct 13, 2013 7:08 pm

If you are getting 4800 rpm with a 19 pitch, why would you drop to an 18 pitch? That would put the RPM even higher. I would stick with 19.

schoolsOut · **Posted:** Sun Oct 13, 2013 7:28 pm

rpengr wrote:

If you are getting 4800 rpm with a 19 pitch, why would you drop to an 18 pitch? That would put the RPM even higher. I would stick with 19.

Everything I am reading is that the 4-blade will drop the rpms by 100-200 and that you have to drop the pitch by 1-2" to keep the rpm's in the recommended range.

ric · **Posted:** Sun Oct 13, 2013 7:31 pm

You can run merc props on VP, it's just the hub insert. Choose the option for VP when you order the prop. Mercury props use something called a Torque Flo breakaway hub system. It's just basically a plastic insert that goes in the prop, than a metal one slips onto that to fit the shaft. One prop fits virtually everything made with a $30 hub. No tools or presses required.

Mercury in my opinion makes the best props on the market for sterndrive. Solas the worst. Michigan Wheel is in the middle. Volvo Penta doesn't really make anything specific although their 4 blade SS is quite good (not as good as a MC 4 blade SS though).

I purchased a reconditioned Alpha 4 for cheap just to test, I'm in total love with it. This spring I'll bite the bullet and get a Revolution. The Rev's run hard so like my boat I require an 18 pitch prop, I'd order a 17 pitch rev.

schoolsOut · **Posted:** Sun Oct 13, 2013 8:11 pm

Ric, I see what you are saying. The rev-4 does look like a nice option. Comes in odd pitch increments. I may have to go all the way down to a 17". Next time out, I will closely check my wot rpm's and see how close to the max I am right now. If I'm maxed out, maybe I will get another 19" and let that drop me into the middle of the range. If I'm already in the middle of the range, I guess I will have to try a 17".

kd4pbs · **Joined:** Thu Sep 05, 2013 10:34 am **Posts:** 350

My two cents:
If you're going to upgrade the prop, and you would rather have hole shot, quicker time to plane, etc. then get a 5-blade prop. I went form a 3-blade SS to a Mercruiser high-5 on my Yamaha sterndrive powered Chaparral. I only lost 2 MPH top speed but everything below that makes the boat feel like it has another 100 HP. 4 blades in the water is better than 3, but since 5 blade props are available, why not go for that?

www.iFourWinns.com

4-blade prop?

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