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Discussion Starter · #1 ·
I have a 1988 formula 242ss with a 454/330hp and a bravo drive and have no idea what the best prop is for this boat i am going to be using it in lake wiinipasaukee and around boston harbor
should i have two props maybee one for power and one for speed
where should i get them and how much should i pay
also any idea on what my rpm range/top speed should be
any help would be appreciated
thanks
 

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Stokers Rule
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The Bravo1 four blade stainless steel will be the best for a strong take off and efficient mid range but not top end. If you want more top end then run a Mirage or Mirage Plus which is a three blade stainless prop.
If you want your cake and eat it too then you will need two props.

What is your current prop and performance speeds, plane time etc?
 

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Just for comparison I have a 1981 Formula 233LS with a SBC and alpha, and run two different props a 19 SS and a 21 SS.

I like the 19 better gets out of the whole better and gives the engine higher rpms at 4500, and runs 45mph.

I bet a 21 Mirage Plus would be a good fit. Just like Aquaforce said depends on what you want, high speed or whole shot. Your current set up would help us out too. :pirate:
 

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I believe the bravo 1 Is a little to large of diameter for a 330 hp 454. I had an 89 SS and did some engine work to a stock 330 Exhaust, intake, Heads. But I was running a mercury revolution 4 blade 21 pitch. Before I put the head on my rpms were about 4500. After the heads right around 4900. That prop was perfect for the boat I tried different mirage 3 blades. And with the 4 blade I only lost a couple mph's top end but everywhere else was great. I paid around $450 for it.
 

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Discussion Starter · #5 ·
i just bought the boat and am not sure what prop i have now...it is stainless has a 23 on it but the blades look as if they have been trimmed down to fit..the boat takes a long time to plane and is at 4500 rpms at wot about 45mph..is this normal speed and rpms...where should i start when looking for a new prop
 

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Bravo 1 is the prop my 242 likes the best, but with a 454/330, you'll need to look at something like 3wood suggested for a 4 blade.

I run a 22" Bravo1 which I believe is the smallest available and its just the right size for my 502.
 

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either with a 3 blade mirage, or revolution 4 you should be running about 55 mph. Top rpms should be around 4800.
 

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formula242ss said:
i just bought the boat and am not sure what prop i have now...it is stainless has a 23 on it but the blades look as if they have been trimmed down to fit..the boat takes a long time to plane and is at 4500 rpms at wot about 45mph..is this normal speed and rpms...where should i start when looking for a new prop [/QUOTE


my 454/330 liked a 21 three blade for low end, but my boat is heavy, your rpms and mostly speed don't seem to make sense. What are you trying to do, pull skiers, cruise or top speed? I'm in Maine and still have the 21 Stilletto in my boat if you would like to try it, just pay shipping. Seems as though you should be running around 4600 rpm(factory WOT) and 55mph.
 

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Oh, I do think you have a prop issue, but is your motor in tune, timing, plugs, fuel filters, etc. Overall does it run good, idle etc?
 

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Discussion Starter · #10 ·
was definatly a prop issue...tried a friend of mines 23p mirage + this weekend and it was a world of difference...boat plained much faster and did about 51 on speedo at 4300 rpms wot...i think i need to go down to a 21p to get my rpms up though...how about a four blade prop instead of the mirage+ is that something i should try or should i stick with the mirage...what are the pros and cons of a four blade
 

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If you were to go to a mercury revolution 4 21 pitch you would probably be looking at about the same rpms as the 23 pitch 3 blade, without lobbying the 4 blade. The benefits of the 4 blade are better take off out of the hole, some stern lift, less likely to blow out in a tight turn, and the nicest thing to me was if the lake got rough I could stay on plane at lower speeds about 18 -21 mph and not fall off plane. You might lose a mph at top speed.
 

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I run a merc revolution 19 4 blade. Seems to work best for what I need. I never run wide open so I don't care about top end. It gets me the best hole shot and best mid range. I tried a bravo and mirage plus, and they all had benefits in different areas. Just found the rev to work best for me.
 

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formula242ss said:
was definatly a prop issue..what are the pros and cons of a four blade

I agree with others here that the four blade will suit the hull weight of your boat best.
The pros: lower plane speed, faster plane time, more speed in the mid-range- which means better efficiency for most of your boating, and better maneuvering.

The cons: could loose 1 or 2mph off the top speed.


That is about it. The mirage plus is great for a top end prop on that hull but the Bravo1 four blade or the Rev4 will get you the best overall performance otherwise.

Have you tried a prop calculator with your current numbers?
 
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