30hp etec prop opinions

[johnyrude200]

Maverick: I feel the need
Goose: Surmising
Maverick: I feel the need, for speed.

My 14 foot 2001 starcraft goes about 28mph on GPS with the stock prop.

I have to trim it about 10° to prevent ventilation plate spray at any speed above 1/4 throttle, but a 1" trim up at WOT gives me 2-3MPH more (with no spray).

I’m ready to go SST, change pitch, and add a hydrofoil (which I know is just for quicker planing @ lower speeds).

To all my mentors and those who have already gone through this process, please, I’m all ears.

I see 15" pitch SST props out there…but what I want to put my money on is…WHAT WORKS. There’s also the component of safety. I mean, going 28MPH as it is on the open seas keeps my eyes wide open for anything along with the kill lanyard securely attached, but what can I say, having my eyes tear up without sunglasses and making the snooty people turn their heads with vessels which cost 20k more than mine always brings a grin to my face.

Thanks guys.

[willg]

Joel,

Your 30 hp ETEC should be turning 5500 to 6000 rpm at full throttle, so before changing the prop, I’d like to know what it’s turning with the stock prop. The best way to see what your max RPM is is to have a dealer hook up Evinrude Diagnostics to the engine and view the RPM profile stored in the EMM. The stock pitch supplied with the engine is a 13 inch pitch, however I haven’t really played with props on the small ETECS yet. I’d stay with an aluminum wheel unless you really need a stainless as that 15 pitch sst wheel is just about 300 bucks, whereas the aluminum wheels run about 120 bucks. I have also seen many gearcases just destroyed inside that came off bass boats with sst props when the guy hit something. Not trying to scare you, but just telling you what I have seen.

[kerry]

X2 on checking RPM at full throttle. Very important to know when prop tuning. A major no from me regarding the fin. There are other ways to improve holeshot. Will, I agree with the cost factor of SST’s, but they have benefits regarding speed- which is what those bass boats are about. Destroying gearcases because the guy hit something (probably at high speed) is not usually the fault of the prop, but the operator running too fast in unfamiliar areas. A prop can’t fix stupid.

If you have too many, AND not enough, you're a collector.

[johnyrude200]

Does the EMM prevent the motor from running away with itself? I mean, the CDI systems have 5800-6000RPM limiters on them, I’m sure the EMM does the same. So does this eliminate the worry of having too high of a RPM at WOT?

I’m not worried about price on a SST prop, it is my present to myself. I’ve seen some Solas SST props at a very affordable cost below $200.00. Just figured I’d like to buy 1 SST prop and get it right, than buy one and waste that money when I could have made a better investment with a different purchase.

I’ll have to look at my prop but I believe it’s a 10.2 x 12 prop, but it could be 13.

Also is there much of a speed improvement with a 4 blade vs a 3 blade on one of these motors?

[johnyrude200]

If I hook up a tach onto the motor and run it live, what should I be looking for in terms of indicators for prop selection. I have a tach (the type that wraps around 1 plug wire), and I can easily get the max RPM under load.

Kerry – what is your opposition to hydrofoils? I had a veteran mechanic say to avoid the hydrofoils which are two fins, each one on a side of the ventilation plate because they are prone to breaking that plate off when in waves. He said to use the ones like ‘stingray’ brand, which are all one piece with the horizontal connector between fins to avoid breaking the ventilation plate. I"m all ears because I want to do the best I can to care for my motor so I get as much life as I can out of it. I will say I recently saw an ad on CL for a pair of big Etecs from the ocean from (I believe) 2006, which had around 2,000 hours on both. That is encouraging to see them still chugging along, I put on about 100-150 hours on my motor each year.

I like the idea of staying on plane at lower RPM. My boat is a small 14′ deep V aluminum, so many times I spend my time at 12-15MPH when the waters start to get choppy, and staying just above the chop but not slow enough where I’m plowing and getting knocked all over the water is very helpful on my back.

And sometimes I just downright need to get the hell out of where I am due to inclement weather or giant wakes from cruise ships and tour vessels (I’ve been out on the coast, and around NYC [hudson], that can be very rough).

[kerry]

Reading your original post, you led me to believe you wanted top speed from your rig- period. No mention of slow planing. Yes, the ‘foils will let you do this, but at a price. Look at your rig on the trailer, where your cav plate runs in relation to the bottom of the boat. If yours is normal, your cav plate is a bit below, which means its running submerged on plane. Adding a fin, irregardless of its design, creates drag, which kills speed. That drag is also stressing the cav plates, where holes were drilled to mount them. These cav plates are Castings, which means they are brittle- no warning before they break. It may not happen, but s**t happens to good people all the time. If trim tabs weren’t so expensive, they would be my only suggestion. I would say you need to decide if you want speed OR slow planing with a foil- unless you know metalwork and can fab a set of tabs for the transom.

If you have too many, AND not enough, you're a collector.

[johnyrude200]

I hadn’t even thought of that, good point with planing vs top speed. I have my motor set with the ventilation plate about 1" above the bottom of the boat. I’ve set most my motors up this way and it seems to give an extra 2-3 MPH once up on plane. You think this would help avoid the extra drag off a hydrofoil that you are talking about?

I also checked my prop – it is a 10.3 x 12. So switching over to a SST 14 or 15 pitch, I would think, will make a pretty noticeable difference in speed? I top out at 27-28MPH, going 31-33 would be a pretty big difference!

[fleetwin]

Well, I realize I am die hard old school, not to mention close minded and stubborn. But, I hate those stupid fins and would never have one on my engine. The only possible benefit of one of those things is to help the boat plane off easier, so it isn’t needed at all if your rig planes relatively easily.
And, I’m with Will, I would skip the SST propeller. You really need a performance oriented hull to get much benefit from the SST props, along with power trim. And, like Will says, damage is usually transferred inside the gearcase if you hit something with an SST prop, they tend to be tougher on clutch dogs also.

[johnyrude200]

The motor does have built in PT/T, but I am all ears in terms of heading everyone’s advice. With SST props — I have heard you gain another 1-2 mph out of them (even with the same pitch as an aluminum). Is this because they just flex less than aluminum? Or is this just urban legend?

[fleetwin]

Again, there is no such guarantee as the one you have heard. Everything must be right with the hull, and the RPM must be right as well. I have seen cases where performance has actually descreased with the same size SST prop installed because of an RPM drop, your power trim will certainly help take advantage of the SST because you can usually trim the SST props out farther without ventilation.
And yes, one of the performance benefits of the SST is that its blades are thinner and flex less than the aluminum props.

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