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-   -   Z278 Prop Change Thoughts (http://www.mariahownersclub.com/forum/prop-talk/5253-z278-prop-change-thoughts.html)

shabah 1 03-20-2011 01:22 PM

Z278 Prop Change Thoughts
 
I have a 2001 Z278 Cuddy Cabin and love it. It has a 7.4L MPI with a Bravo III outdrive and was delivered with a 22P prop, it was a dealer leftover that I bought new in 2004. The boat has an excellent hole shot and can pull up 3 slalom skiers easy, although the wake made by the boat is tough to ski behind. The kids are older and now have their own boats and not much skiing is done behind the Mariah these days. I should also mention the boat has always hit the Rev Limiter at 4600 RPMs with 1/2 tank of fuel, 4 people and a tank of fresh water. I'm considering purchasing a set of Bravo III 24P propellers but have been cautioned by the dealer that lugging the engine can cause serious damage. He did not not infer the 24P props would lug the engine but wanted me to be aware so as not to damage the engine. Does anyone have a Z278/Z272/Z275 with a 7.4L MPI, Bravo III with 24P props? I realize the weights of these boats are different, but I have been told the hull is the same. If so how well does the combination work and does the boat still plane out well, also what is your max RPM achieved? Any help or guidance is very much appreciated.

mikeyt 03-20-2011 04:54 PM

Re: Z278 Prop Change Thoughts
 
I'm really not overly knowledgeable about Bravo 3 prop set ups but....from everything i've read, the 22" is the most efficient prop for your size boat with the 7.4L and that seems to bear out with you noting that your boat hits 4600rpm at WOT. In your case, increasing the pitch to 24" will drop your rpms to around 4200-4300 & i suspect you will also lose 1-2mph off your top end as well as being a little sluggish out of the hole.

z275st 03-21-2011 01:19 AM

Re: Z278 Prop Change Thoughts
 
A friend of mine mine had a 1998 272 Bravo3 with a 454-MAG I think. He had 28" props and I always thought it was sluggish. He bought a 2000 302 with a 502 that had 26" props and switched props between boats. With the 26" props the 272 was much quicker and did not drop on the top end because they could turn faster. If at all possible try 24" and 26" props. Until you max out before you hit the rev-limiter it is a tough guess. If you easily hit the limiter I think you are under propped!

mikeyt 03-21-2011 04:21 PM

Re: Z278 Prop Change Thoughts
 
I just re-read the original post. Did you mean that you are hitting the rev limiter before WOT? If so, then yes, you could probably go up 2" in pitch & see a bit of improvement. You "should" be hitting somewhere around 54mph at WOT ideally at 4600rpm. The Z275 & Z278 weigh about the same so performance should be similar but the Z272 is about 500lbs lighter so it might handle the additional prop pitch a little better.

darkcalling 06-30-2011 03:20 PM

Re: Z278 Prop Change Thoughts
 
I know this is a week old I have a Z 278 with 26" pitch Bravo 3 during water trial I hit 4500 rpm no prob with 3 people 3/4 tawnk of fuel, if that helps.

shabah 1 07-11-2011 08:54 PM

Re: Z278 Prop Change Thoughts
 
Quote:

Originally Posted by darkcalling (Post 30483)
I know this is a week old I have a Z 278 with 26" pitch Bravo 3 during water trial I hit 4500 rpm no prob with 3 people 3/4 tawnk of fuel, if that helps.

It's been awhile since I looked at this thread, but rev limiter kicks in at 4600 rpms as it supposed too. The dealer told me not to let it hit the rev limiter as it is very hard on the engine. I would like to try 24' props but can't seem to find anyone that will loan or rent Bravo III props. I guess I'll keep looking. I would be happy to hit 4500 rpms with a 24' prop. :)


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