Need for Speed!

[On The Rocks]

By the looks of the other posts, this one should be easy for you.

I am looking to increase my top-end speed and wanted to know how far up I can increase my prop pitch without loosing too much of my hole-shot. I have a '97 Crownline 266 BR with a 454 Bravo 3. NADA listed a 4400 lbs dry weight. Currently I have a 26 pitch prop. I can usually go 50-55 depending on how much gas is in it, but I am striving for 60-65+ with a full tank! What are your suggestions?

[Christian]

50-55 at what RPM, that would be the first question

[Caincando1]

It takes more HP to turn a larger pitch prop. It won't be as simple as just swapping props unless for some reason the boat is under proped to begin with.

Like christian said you need to know your WOT RPM's and current speed. Preferable with a GPS, speedo's can be inaccurate.

[Christian]

I also just saw that he is running a B3 drive so that will affect it some as well

[GVL]

If I had to guess I'll bet your already running around 4400-4500 rpm. Without adding some serious $$$ your not going to see much in top speed with the stock setup.

[dunnit]

10+ MPH??? That's gonna hurt....$$$$ :shock:

[h2oboy]

Faster tow vehicle...

Honestly, you may be able to remap the computer, change props, take out the interior..... sounds like new boat time..

[Shallow Minded]

Faster tow vehicle...

Honestly, you may be able to remap the computer, change props, take out the interior..... sounds like new boat time..

That's funny, but about right. Short of spending some serious $, not much you can do to get you there. If it's any consolation, my bro has the same boat with the 496HO / B3 combo and I think he's only seeing 60 or so.

[GVL]

I've got a better idea, trade it for a 33AVS we have.:mrgreen:

[Hell Ya!]

I've got a better idea, trade it for a 33AVS we have.:mrgreen:

Glen, What year and power?

[Average Joe]

http://www.glencovemarine.com/newpreowned/3369.htm

looks nice[smilie=042.gif]

[Hell Ya!]

Thanks Joe!

She will run 75 with ease on GPS and It will run a true 80 gps with a little tweeking.

Nice Boat!

[coolcarwrench]

Sounds like the guys are right on here. Mercruiser has done most of the work to give you a good all round prop, that being said if you go up on pitch it will hurt your performance out of the hole. Look at your prop like a transmission, going bigger will be like taking off in 2nd gear or so, it will take more power to get up to where the motor will be in its power band. Like I have said before, there is no free lunch here. I have had luck getting 2-3 mph with having a prop shop adding a little cup to the trailing edge, and not effecting the hole shot.

[GVL]

It's a 98 with 502 mags. Very clean boat with around 215 Hrs. Its sitting at our Highway store.

[On The Rocks]

WOT is 4600, HP 310.

Just got the ride this year, so most likely a no go on trading it or major upgrades to the motor (this year anyway).

What kind of speed increases can I expect from a 28P or 30P? I've got what I believe to be a pretty good hole shot right now. I think I can sacrafice a little.
(thanks for the suggestions)

[Bootypirate]

I'm not that good with math but I'll give it shot, it would take more HP to turn a 30P in that boat. If you could turn it at 4600 RPM you would be at about 63 MPH. Assuming 5200# wet ready to go, you would need at an additional 100 HP to accomplish this. So roughly 30% more power and a lot more $$$$.

[dunnit]

WOT is 4600, HP 310.

Just got the ride this year, so most likely a no go on trading it or major upgrades to the motor (this year anyway).

What kind of speed increases can I expect from a 28P or 30P? I've got what I believe to be a pretty good hole shot right now. I think I can sacrafice a little.
(thanks for the suggestions)

I don't think you can turn those kinda props...w/o losing speed! I think your cheapest route, if you have to have that kind of speed, is a huffer which is gonna cost anywhere's from 5 to 8K and your setup doesn't support those kind of upgrades kindly.

My question is this....are you sure you want to push that hull that fast? Now before I say this...I want to make it clear that I am not bashing any particular brand of boat (including C/L!) But is that hull made for that speed? What will its handling characteristics be? Are you sure you want to sacrifice its designed performance for something that you prolly can only use at (at best) perfect conditions? I know a guy that is trying to get 80+ outta a 225. He's gone thru 2 motors and frankly, scares the hell outta me trying to reach his goals...I mean chit, we are talking about a run-about!

My advice is to get your ride dialed in, squeeze the couple of MPH you can outta her and have fun! For the kind of speeds your asking for, you would be cheaper in the long run to trade her in and get the HP your looking for in a hull that supports speed. In any event....wish you luck in accomplishing your goals!! [smilie=trink39] [smilie=042.gif]

[On The Rocks]

Thanks for the advise. I didn't realize how complicated it can be. I had a 20' caravelle w/ a V6 that had a 17 P on it and would go about 38 mph. I bought a 21P and could do 50 mph. I thought this would be the same concept. I am ok w/ the speed now, I just thought that uping the pitch would get me more speed cheap. And you're right, I almost have to have glass conditions now to get the 55 mph out of it.

I guess I just have to hang out in the back of the pack for now![smilie=106.gif] Until the better half is ready to go fast!

Thanks for keeping me from wasting $$$ on new props so I can save it for a faster ride![smilie=042.gif]

[cabin fever]

I' ve got a 225 CCR with the same motor, and out drive. I also turn 26 props. Best i've seen to date is 61 MPH. The 7.4L isn't a good motor to sink money into. Cast internals. I've been told you can change the front prop to a 28, while keeping the rear at 26, and that should net you 1-2 mph at most. I've never tried it, so I don't know first hand if its worth it or not. The C/L's are just not fast boats. You'd have to throw a lot of money at it to pick up just 5 mph. IMO, its just not worth it. I plan to keep mine for a few more years, and then pick up a faster hull to play with.

[Pat Bates]

My question is this....are you sure you want to push that hull that fast? Now before I say this...I want to make it clear that I am not bashing any particular brand of boat (including C/L!) But is that hull made for that speed? What will its handling characteristics be? Are you sure you want to sacrifice its designed performance for something that you prolly can only use at (at best) perfect conditions? I know a guy that is trying to get 80+ outta a 225. He's gone thru 2 motors and frankly, scares the hell outta me trying to reach his goals...I mean chit, we are talking about a run-about!



Ya gotta love Brett. He's just sick about that last motor.

[dunnit]

Ya gotta love Brett. He's just sick about that last motor.

Yea...sounds like a real chitty deal. We hope the best for him and Lori!!

[bbladesprops]

There is one other option to pick up another 1-3 mph. We have been doing more and more Labbing of B3 propellers. You would need to go up to 28's, 30's are out of the question. Ultimately the rpm's would drop about 200 leaving you in the range of 4400 which these engines can handle (if I understand you correctly). The benefits are better cruise speed and maybe a couple on the top.

I believe the better option would be to rework the existing propellers to make them cleaner through the water. We use a specific thickness curve to increase the rpm, then adjust the pitch and TE cup height to bring the R's back down. This also increase throttle response and trim response. All in all, you will only see a few mph in all throttle settings 91-3 0. It is a fine tune to get the most out of your set up. Your earlier desires were pretty much explained by everyone else, 10 mph is going to take more than just props.

There are also some new XR series propellers for B3's. They are better suited for mid range and cavitation burn problems.

Call us if we can help!

Brett

[eallis]

What should WOT be on a C/L 266 with a 300hp 350 mpi

[bbladesprops]

4600-5000 operating range. You should prop in the 4800 -5000 range.