Need advice regarding prop.(SC19, 190HP)
 

Hello!

I own a 2005 SC19 with the V6, 4.3L, 190HP. I want to change the original prop. to a Michigan Ballistic steel prop. My problem is that I don`t know witch to choose. The boat does 39,40 GPS knobs with one or 6 persons, and the engine always engage the safetysystem regarding the rpm of the engine(lack of a better word). The instrument shows 5000rpm when this occurs.

I guess the prop. is standard. What pitch, diameter and number of blades should I choose?(I use the boat for cruising, and a little bit of wakeboarding. I want a boat that uses a little less gas(less rpm?) and posibility of tilting the Alpha One more than 90 degrees without a spin.(curved blades?)

Thanks in advance, guys!

Kyn

hi Kyn

I'm not sure what prop you already have installed on the boat but the fact that you are hitting 5000 rpms at WOT indicates that you do not want to lower the pitch any or your rpms will increase. I'm pretty sure the recommended rpm range for your engine is 4400 to 4800 so you are already above the limits.

I'm going to assume you have a 19 pitch 3 blade aluminum prop? You could go to a 4 blade, 20 pitch prop, preferably S.S., which would drop your rpm very slightly but give you more "bite" out of the hole and a little more mid-range 'oomph' which will help with wakeboards / tubers / skiiers etc. It shouldn't affect your top end either as the increase in pitch will offset going from 3 blades to 4 blades.

Let us know what prop you have installed on the boat now.

I checked the size of prop. today. It says 14.5 X 19P, it`s a black alu Mercury(Black Max?)

Do I need RH or LH prop.?

Ok. So the 4 blade, 20 pitch prop is a good option. You could also go with a 21 pitch 3 blade. The advantages will be a higher top speed (2 mph or so) and a lower rpm (around 4600 - 4700 at WOT). The disadvantages will be that it is slower coming out of the hole & it will have a little less mid range kick. I believe all single prop drives are RH.

As said earlier, a SS prop will outperform an equivalent aluminum prop. If you can find a prop vendor that will let you test run a prop then you have everything you need to sort her out quickly.

I have searched for Ballistic 4-blade, but no luck:-(
I see that the Ballistic 3-blade comes in these sizes: 14 3/8 x 21, 14 1/2 x 19 and 14 1/4 x 23. Witch one?

I have no possibility for trying these out as our(Norwegian) distributor/stores sell them for 1100-1300$/pice!!! So I buy from US:-) So: No chance to try!

Go with the 21 pitch prop then if you cant find a 4 blade - 20 pitch. I bought a Michigan Wheel "Apollo XHS" SS 14.25 x 20" pitch 4 blade thru IBoats.com for mine and it performs very well.

Thanks! I did a search on IBoats.com, but all they had in Michigan 4-blade was 14 1/8 x 20, so I think I buy the Ballistic 3-blade, 14 3/8 x 21P from http://www.deepblueyachtsupply.com/ (338$) Do you know of a better deal?(they have to ship to Norway)

Do you know if it is true that the Ballistic do not need a hub-kit?

All props need a hub kit. Michigan Wheel may supply hub kits with the prop, which is why they say you don't need one. This is very confusing, so make certain it has the hub kit!

From your explanation of everything, I think the 14 3/8 x 21p will be a great match. As Mikeyt stated - you'll lose a little response out of the hole, but should be a good compromise between hole shot and top speed. Let us know how you like it!

oops. The Apollo prop i bought was a 14 1/8" diameter not 14.25

Either the Apollo prop or the Ballistic will improve matters for you. The Apollo may split the difference between the 19" you have now and the 21" Ballistic. The Apollo comes with the proper hub kit.

Ok, then I found it at the deepblue-site for a little over 200 $. Do I have 4-3/4" Gearcase? It was not listed for Mercruiser/mercury engines, just as a standard dimention. (didn`t include hub-kit, costs 33 $ extra:-)

Will the 4-blade make my boat use less fuel? Or is it just for the akseleration-matters? What about those curved blades on the Ballistic vs Apollo? Any advantages/disadvantages? I really want to tilt my boat higher up at WOT/or near without getting spin.

Just for the confusion:-) This is cut from their site: Ballistic propellers have a pressed in hub, so you do not need the XHS Hub Kit with this propeller.

hi Kyn

I dont know much about the Ballistic line of props. They do seem like more of a 'performance' prop than the Apollo with the highly cupped blades but then i read this at the Deep Blue site also:

Michigan Match and Ballistic propellers do not use the XHS™ Hub Kit. However, Deep Blue Yacht Supply always recommends an Apollo or Vortex propeller where appropriate, as the hub kit system will save you money in the long run, as well as being an equal to or higher performance propeller.

One of the main disadvantages of 'pressed in' hubs is that if you spin the hub, its not something you're going to be able to repair yourself. You will have to send/take the prop into a prop shop for repairs. Another disadvantage of the agressive rakes on this prop is that it will reduce your hole shot at the expense of higher top end performance. It's not designed to be a 'load' prop. Where it does shine though is cruising at the higher rpms although i understand it has a habit of venting in high speed turns which means you will have to tuck your drive in when doing this.

Looks like model 345134 is the correct Ballistic prop if thats what you want to go with. Model 993205 is the correct Apollo prop along with hub #102 if you go that direction.

I agree! The same numbers I have looked up:-), hmmmmm.. this is not an easy desision doing over seas.

Anyone tried Mercurys "new" Enertia stanless steel propeller? I talked to some guys here in Norway, and they said that this superthin bladed prop. is really something compared to Michigan Ballistic and others. Mayby it`s just a hype? They cost over 500$:(

And now you're throwing a 3rd prop (@ $500++) into the mix? If you keep adding prop choices here, it will be winter in Norway before your new prop shows up. :)

Basically, what characteristic are you willing to give up? Your choices are 1) Performance, 2) Cruiseability, and 3) Economy. Compromise means you go for performance and accept the resulting economy, or you go for cruisability and MPG and give up performance. Sharp rakes & thin blades are performance props.

From what i see the Enertia is designed to be a top end (rpm) performance / cruising prop and not a low rpm 'get you out of the hole' or 'pull a skiier' prop.

For what its worth, have a look at the Stiletto Bay Pro II also. It's a very good compromise prop. I have a friend with a 19' Regal and the 4.3 He runs a 20" pitch Stiletto and is very happy with its performance. The Apollo would be another good compromise prop worth looking at as they are very reasonably priced.

He he! I get it! I guess I will choose the Apollo 4-blade.

You might want to also consider a set of Smart Tabs. They will help get you on plane quickly, reduce or eliminate that 'low speed wander' and help keep you on plane at lower speeds. They will be around $175-200 shipped to Norway and you can install them yourself in about 45 mins. I wont go into the full details here because we've discussed this numerous times elsewhere. Do a site search for "Smart Tabs" if you want to read more or visit the mfr site at www.nauticusinc.com

Just ordered:wink_thumbup:

I have read a little about them, but didn`t notice the-low-speed-wandering argument. This is a serious problem with my Sc19:(

You ordered them with the 60 lb actuators i hope? The 80# arms will be too strong for your boat.

****! Are you sure? Just ordered the 80 cause in the web this look like the match for my boat considering the lenght of boat and enginesize.

Absolutely. The 80# actuators will be too strong. Nauticus will exchange them for you though so send then an email ([email protected])

There! I got to the seller before he sent the Smart Tabs, so now I`m waiting for a couple of 60`s:)

Thanks!