New prop for a 30. Worth "steping up"?

Just bought a (brand new leftover) boat with a Nissan 30 4strk, long shaft. Dealer did a test run yesterday and it's getting 30mph @ 6020rpm on a 10 pitch prop. The leg/cav plate seems to be low so I'm gueesing that raising it a notch will even improve that. ( and I will.) Anyway, I think I'll be pretty happy with that but since I want to buy a spare prop anyway.....
Wondering if I should spend some $ and splurge on a namebrand performance and/or stainless prop . Not sure how much performance ( or efficiency) I'd be buying when I'm dealing with so little hP. Wonderign if I should just hunt up any 9.9x10 or 11 (10 spline) prop and be content.
Feel free to recomend specific brands/models.
Thanks

Re: New prop for a 30. Worth "steping up"?

What are you running it on?Not just the model name what style/weight?
Is the speed by GPS?What is max recommended rpm?You should probably raise the motor before selecting the prop.Allways make one change at a time.
If it was me I would check out the Turning Point Rascal. An aluminum prop with close to stainless performance.Was about $90 here at Iboats including the hub about $60 just for the prop.If I was doing it I would get the 10" pitch
Would only be another $60 if you needed to try another.
The Rascal may allow even more height.Perhaps someone here has more info on if you need a pitch change with the Rascal.

Re: New prop for a 30. Worth "steping up"?

I agree. You should position the motor first, retest, then come back with your (potentially newer) numbers.

Re: New prop for a 30. Worth "steping up"?

Sorry for the incomplete details. For the record, speed was via GPS ( but with the tide running with the boat) . Boat is a Mirrocraft 1615-O, V hull aluminum (with some shallow V carring right through to the transom.) About 440# + another 440 for man,battery , gear and motor. http://www.mirrocraft.com/boats/simplyfishing/outfitter.php

Max recommended RPM is 6200. gear ratio is 1.92:1.


For the record, I'm not looking to go 40 mph and would not reprop JUST to get more performance. I'm happy with 30. ( This is a tiller stear.) But I figure if I want to keep a spare on the boat anyway, is it worth looking at a higher end prop to squeek more mid-high performance. ( i.e. Factory prop is $140 anyway, wondering if a stainless Solas, 4 blade or other ?? would be $ well spent.)

Will raise the height and investigate the prop sugested.

Re: New prop for a 30. Worth "steping up"?

Is the boat a bare bones utility, tiller or full dress with floor,livewell wheel etc.?
30 is a respectable speed either way.

Re: New prop for a 30. Worth "steping up"?

Hooker, what you appear to have is actually closer to an 11" pitch than a 10". When I run the calculations with 10" I come up with -1% Slip and that is not REAL, so I ran it with an 11" slip and come up with 8% slip.
You ALWAYS need to run speed trials in BOTH directions and take the average of the two to have a realistic speed over ground with GPS. So I don't really know how valid these calculations are. So I also ran it with a 10" as well for you since you were running with the tide.
Here are the Printouts:

This is for the 11" Pitch


This is for the 10" Pitch



H

Re: New prop for a 30. Worth "steping up"?

The 4 blade generally improves low end performance at a slight sacrifice of top end. Any time you buy a prop it is an oportunity to improve performance.
As I suggested check out the Turning point Rascal. prop 57.99 hub 32.99
total 90.98. any further Turning Points just prop only. From what I've read
the Rascal delivers overall performance improvement.Discounted here right now.

Re: New prop for a 30. Worth "steping up"?

From your post it reads like you have not driven this boat yet yourself.

I had a 30 4 stroke 2006 Merc and I had problems getting up on plane so I swapped it for the 2007 40 which was actually 30 lbs lighter than the 2006 30!

Maybe the 30 had issues and that was the reason for the lugging to plane. I didn't care. All I wanted was to get rid of it fast when I found how heavy it was and why they redesigned it in 2007.

Another poster had a good point. My rig has a floor and lockers which adds to the weight. Mine is even a center console which distributes my weight and my passengers weight to the center.

Even so, my 40 on the 15 foot Aluminum Lund is now sweet.
I bring this up because your tiller is going to throw all the weight to the stern. If it's electric start the battery will be there plus you and a 6 gal tank (unless it comes built in).

With a 30 on a 16 footer you might find it dragging a little to get up on plane. Raising it 1 hole to start might be too high depending on where it is mounted now. You need to see where the cavitation plate is riding now with you in it. If you raise that plate too high you could cause the boat to whip around suddenly in a fast turn and toss you right out. I raised mine two holes due to excess spray and I've run into whip around issues. I'm going down one hole before I use it this year.

Lastly, I bought a spare prop too. But I went for a one step lower pitch to get a better hole shot. True I give up a few mph top end but when another baot cuts across my bow and I have to slow down I hate waiting for the baot to get back on plane. Another benefit of the higher torgue lower pitch prop is that I swap it out when I have 3-4 people on it.

A 30 on a 16 footer . . . drive it around with a few people and your gear on board before you start raising, re-propping etc.
Unless you just troll around mostly, you may find yourself stepping up to a 40 outboard if performance is a concern. If so, do it fast so the dealer can still sell the 30 as new.

Re: New prop for a 30. Worth "steping up"?

Whip around issues I would think is more an issue of trim.Trimmed in(down) too much.If the bow catches it will push the stern.

Re: New prop for a 30. Worth "steping up"?

steelespike said:

Whip around issues I would think is more an issue of trim.Trimmed in(down) too much.If the bow catches it will push the stern.

Click to expand...

Ya, it happens to me at when I'm accelerating into a slight chop. I've duplicated it in what ever the trim position is in. I can take off from the hole with the trim all the way up (bow up) and I still can have the boat whip around under certain wave conditions.

I think it's a factor of the hull design on a small lightweight (700lbs) 15 foot boat with the max rated 40 hp on it. The weight of the heavy 4 stroke off the back helps keep the bow up too!

I don't want to hijack this thread and I've discussed my issue last year in other threads. I brought it up above because the poster could run into similar issues on a light weight aluminum rig.

But briefly, I'm going to drop the motor 1 hole as I went up two last season to eliminate the spray. Should have gone 1 hole at a time, but it was time consuming to do it all by myself with a small hydraulic floor tire jack no less.

I'm going to ad no-feedback steering as soon as I get the winter cover off to measure the cable. No-feedback will at least stop the wheel from whipping around freely when I hit a wave with the bow at a certain angle and possibly breaking my fingers. No-feedback has a dampening effect I'm told by others who have it. It was not an option when I bought it. I checked with the CS at Teleflex and they said it should get my issue under control. I'll add it myself for about $200 bucks.

Re: New prop for a 30. Worth "steping up"?

I never heard of that,been boating 60 years.I've seen all kinds of boats pushed into a flip
around,and have experienced kiting with light fast aluminum utilities.
I have a 18ft Crestliner utility,375lbs dry 50 hp tiller Evinrude been full out in storms pushed hard when skiing full bore starts in all kinds of crazy conditions
she does rear up on hole shot but really stable.
Maybe it's some sort of torque steer problem and the no feedback will help.

Re: New prop for a 30. Worth "steping up"?

Ok gents, I'll keep you posted.

ps.s. A 40 is out. I just dropped $4K on a 30 which is 75% of rated HP and planes the boat @ 1/2 throttle. It's really all I need in a tiller steer tin boat. Just tweeking at this point since I'm buying a prop anyway. Looking at the turning point rascal (11pitch is as low as they go) and a 1 hole motor raise right now.
Thanks