Need help choosing Prop

[Bry21317]

I am now leaning towards a Merc REV 4.

Here are all of my Specs, can anyone tell me what pitch I would need in the REV 4?

I have been trying to decide on a new SS prop for my boat. I was told to email you in some forums. I was hoping you could help me with a direction to go.

My boat is a 94 Crownline 196 Bow rider (2900lbs dry by nada). Its 19 feet long with a Mercruiser 5.0 2 bbl with thru hull exhaust. I have an alpha 1 gen 2 drive with 1.65 gears. I just purchased the boat about 4 months ago, and it came with a Michigan wheel 21 pitch prop, but my RPMS were running 5200 with this prop, when trimmed up to about 1/2 or just under, which was as high as I could get it without it blowing out. I changed this prop out for an aluminum 21 pitch Turning Point Hustler prop. I am now able to trim a little bit higher and I am only turning about 5000 RPMS, I can turn this with the boat loaded or unloaded. I get a top end speed of about 50-51 currently with this prop. The hole shot is great and throughout the range I have plenty of power. My problem is that I am trying to get the RPMS to come down, as my MAX WOT Rpms stated they should be 4200-4600. I am looking to keep it around 4600-4800 on the high side if I can.

I then tried a 23 Pitch Hustler Prop, to see if that would drop my RPMS, it did drop them down to 4200rpms, which I was surprised they fell down that much. I also lost Top end and hole shot. With this prop I could only get up to about 45.4 with 3 people on the boat.

What I am looking for is something that will give me good top end and also lower my RPMS. I was told the REV 4 is a great prop and should do this. I was also looking at the new Merc Enertia.

Any information that you can give me would be great.

Thanks,
Bryan

 

[Crownie2]

Re: Need help choosing Prop

Bryan - that you are able to turn a 21" pitch prop at 5,000 rpm's surprises me.

Are you sure the tach is correct?

Come on up to Smith Mountain Lake sometime and I will let you try my 21" Enertia!!

Bob

 

[Bry21317]

Re: Need help choosing Prop

Bob,
I can turn that 21 like its nothing, lol. And thats 2 different brand Aluminum ones. The engine runs like a scalded Dog, but I think its had some work done inside, as I purchased it from a guy that was a race freak. He told me the boat would go 64 with the 21 Pitch Michigan wheel he had on it, but theres no way. He also gave me another prop and said it would run in the 70s, but I don't see that possible either.

I do know with the prop that he had on there that was the Michigan wheel 21, when we took it for the test run he did get it up to 59 on the speedo, so about 54 on GPS, but that was a cold morning mid 40s and no other boats anywhere on the water. It was glass and my test drive before I purchased it. So the boat will run good, and even in the humid weather it will run every bit of 5000 no matter how many people I have on the boat.

It also has 4 inch straight pipes for exhaust, there are no baffles or anything. Just 2 4 inch pipes coming out the back and no Captains call or switchable exhaust.

I thought the 21 would be the right prop for it, when I switched from the MI Wheel to the Hustler, to see if the extra cupping the Hustler had would bring the Rpms down, which it did a little bit. If I could trim higher it would run more RPMS, I can only get to about 1/2 with the hustler and even with the boat full of people it will start to launch a rooster tail.

I have heard Smith mountain lake is gorgeous. I would like to try to get up there one day with the family. I like lakes with Scenery for sure. I have gone to Kerr a few times, but mostly go to Falls as it is 15 minutes away from me.

My gears are the 1.65 version, so I think this is the whole reason that I can turn that much prop no problem. Even with the 23 it was not a dog, like I had expected, it just was nothing compared to the 21.

Bryan

 

[Crownie2]

Re: Need help choosing Prop

Bryan - the straight pipes won't help much on that engine unless it has been REALLY hopped up. OK - so it's not really a 220hp 5.0.... LOL

Another thought I had - most Crownline people say that the boat really needs bow lift, not the sternlift that a 4 blade will give.

Bob

 

[Bry21317]

Re: Need help choosing Prop

All the lakes around here are drying out, it seems. So I have not been out to the lake in a few weeks and had time to mess with it. I am finishing up a punch list on my old house to get it sold this week. So, once thats done we are going to the beach for the weekend, then I will hope we have some rain, to put some water in the lake here. If not, I will be running up to Kerr Lake the following Weekend.

So does the Enertia Prop give the Bow Lift that is needed?

Just wondering. Also a little hesitant on getting the SS now, as my AL just got tore up 3 weeks ago, from the lake being so low and hitting a stump that came from nowhere. I cut the engine right away, and it still got the prop good. I even jumped out of the boat to push it out of that area.

 

[Crownie2]

Re: Need help choosing Prop

Yes, the Enertia does give good bow lift. But now that I reread my comment about bow lift re crownlines, it was directed at the newer models and I see yours is a '94 - so my comment may not apply in your case.

With what you want to accomplish maybe the Smart tabs would be worth a try - especially since you alread have them!!!

One other thought - take a look at the "tru tracker stabilizer plate" on the bobsmachine site. I had one on my last boat and was very pleased with the results, especially in the area or ride improvement, an area I know you are interested in. It would also help with the wakeboard speed issue. The bonus is that only four holes in the AV plate are needed (which could be filled if the plate is removed) and the cost is only about $45!!!!

Bob