What Propeller to run???

[stace911]

Was looking for a little direction from you guys out there please :D

Upgrading engines and will need "HOW MUCH" more PROP??

**Specifics**

Old engine - Very tired 2.4 Carb 200HP Black Max
1.87 gear with Bob's lower Big nose cone
Top speed - 72 GPS @ 6K RPM with RE3 Mazco 26P (Round blade)
1988 - 18' CP Race Hull (Racing Tunnel Hull)
10" Offset fixed transom bracket
1.5" above pad
Approx. Loaded weight with one person is 1,200lbs

New engine

1998 - 225 Pro Max 20" (All Stock) with fresh powerhead rebuilt by (TUX974)

I was thinking 30P?? Any suggestions? Using the boat for recreation not racing.

Thanks for any input :thumbsup:

[Eagle One]

Most of the Pro Max engines had RPM limiters at around 6300. They made a lot of torque and would pull a big prop. We had a customer with a 20 Bullet bass boat and he ran a Mazco 30 RE 4. Boat ran right at 90 with a load and was right at the limiter. Not saying this is exactly what you need but it's a good reference point. I'd try any and everything I could before I bought anything if you can. We sell a clone of an ET in a 30 pitch 3 and 4 blade that might do the trick. Just not real familiar with your boat.

[Dave Strong]

Pro Max limiters are 6750rpm.

Dave

[tux974]

Stacey,
Post the boat brand, a picture so if some one has a similar boat they can best provide you helpful info.
6750 is correct!
Was the 26 on the limiter/out of prop?
If you go to a 4 blade you need to drop pitch, just something to keep in mind if you think you need a 28 or 30.
I have a 26 Trophy Plus I can send you to try if someone thinks it may work.

[rkmirage]

Soft limited at 6750, mine with stock limiter will run 7200. The Promax puts out 248 at the prop and a fresh 200 2.4 is about 190. You will have another 1000 rpm, about 60 more h.p. and a lot more torque. I bet it would turn a 32p, but I'm not familure with your boat.

[stace911]

I am still learning how to post pics on this forum. In a nut shell, California Performance hulls were built for Jet Drives only. Their popular one was called the "Gull Wing". The hull builder, Bill Scotten just told me he made 3 of these hulls I have. The reason only 3 is they did not work very well with a Jet drive V-8 application unless under WOT. They would porpous at lower speeds not making it a recreation friendly boat. He made only one with an outboard per the request of the customer back in 88 and I have this boat now. With the 10" offset engine jack plate the boat does not porpous. has baker style sharp 90 degree angles that allow it to turn on a dime at hi speeds. Let's see if I can post these pics!

290659
290660
290661
290662
290663

[David]

Assuming speed proportional to square root of HP, 248 vs 190, and putting 85 mph into a prop calculator, I get a 28

You could start with the 26 you have. It should accelerate a lot better and still be good for 80

[stace911]

290665

[rkmirage]

A 30 ET would be a good all around prop. Go to a S&F gathering in your area and try as many different props as you can. No one can really give you a specific prop, all boats react differently to different props. It's all about finding that right one then dial it in.

[Little Jon]

i would sat try a ET for sure.

[stace911]

290669
290670
290671
290672

[stace911]

What pitch are you using on your 17'?
ET is 3 blade correct?

[timmc6]

2.4 @190 lol!!!!

[stace911]

I will have to post who is in my area since I don't know anyone on here that is in my area as of yet. Thanks!

[stace911]

Is an ET that much different than a Mazco?

[stace911]

Did you mean a 4 Blace Pro E.T. or a 3 Blade Lightning E.T.?

[rkmirage]

3 blade.

[stace911]

Ok, thanks! Have you tried a Cleaver? I hear the bow lift is minimal but don't know if that will make a big difference in speed?

[rkmirage]

I've got a nice 30 cleaver collecting dust, my Mirage doesn't like it at all. But they run well on other boats.

[stace911]

I am curious what a cleaver would do on my boat. I have a tunnel hull to and need some bow lift. What don't you like about it?

[rkmirage]

Mine likes bowlift too and I don't get enough with the cleaver, feels too light in the stern.

[stace911]

Tony, I bumped up from a Mazco RE3 24 that came with the bought when I bought it. It was at the limiter so I bumped up to a RE3 26 and the RPM's went down 100 and the speed went from 68 to 72 on gps. I think I will need more pitch than any 26.

[stace911]

I think that will be my problem too. I replaced my transom from the original 4 months ago to fiber board. I reinforced the transom inside with some 1/2" thick angle aluminum. With no more flex in the transom the bow lift is so much better and the boat feels tight and very stable at 70. The 225 Promax should be a great adrenaline addition!! I will prop out with a 26 for sure!

[stace911]

I cannot pre-judge until I try one :)
Which Cleaver do you have? Would you sell it?

[tux974]

Stacey,
send a PM to stokernick on here he has a similar boat and has a good handle on setup which will probably best help you.
With props is a bolt up and try them. I would start with your 26 and see what it does after breakin. 3 blade ET's are a great prop and the newer ones are not slinging blades like the early ones, I would get a non labbed one.
Also do not rule out the newer 4 blade props especially if you are not looking for the high top #. Great hole shot, better on lower units with a great mid range.
If it does turn out you need a 28 or bigger 3 blade I can send you the 26 4 blade Trophy Plus to try.

[stace911]

Ok, thank you!

[stace911]

What is the price on the 3 & 4 blade?

[tux974]

What is the price on the 3 & 4 blade?

3 & 4 what kind of prop?
Check with Jaco Marine or Diamond Marine. Lighting ET is a 3 blade and Pro ET is a 4 blade. Trophy Plus are 4 blade only, Mercury Choppers are 3 blade, Mazco R4 is 4 blade etc.
I suggest to not buy anything until you try what you have, you need a base line or you might be wasting money. JMPO!!!!!!

[stace911]

LoL! I thought I was asking the question to Diamond Marine for the second post at the beginning of this thread :)
You said 4 blade is easier on your lower unit. What did you mean?

[dnelson964]

If you come across a Spinelli DR4 30 I would grab it. It should you run smooth, fast, and have strong weight carry ability.JMO

[That's Right]

If you come across a Spinelli DR4 30 I would grab it. It should you run smooth, fast, and have strong weight carry ability.JMO

Ditto --- I owned one for 2 days and lost it in the Suwannee in November. I had the boat loaded down full tank of fuel, my wife and all her shet she takes with us LOL. It carried the weight great and ran great up top. Damn I miss that prop and they are hard to find.

[stace911]

Cool thanks! Nice rooster tail!!

[tux974]

LoL! I thought I was asking the question to Diamond Marine for the second post at the beginning of this thread :)
You said 4 blade is easier on your lower unit. What did you mean?

OK, over my head......but DITTO this with some add on's about the 4 blade.
It should run smoother, maybe even faster, and have a stronger weight carrying ability. Not that this rule will pretend or work the same on your boat though, nothing is guarantied with props!!
BTW, Jaco or Diamond for pricing if you do not find a used one!!!!!!!