Prop question - 340 Sport
 

Just ordered a repower for my 340 Sport center console. Going from twin 300s to twin 400s. Does anyone know what props NorTech is using on a 340CC with twin 400s? I've also sent an email to NorTech, I'm not sure who to contact there now that Terry S is gone.

Call Matt lamb, We use rev 35 xp 4
blades on triple 400

Thanks. Matt responded to the email I sent to Nor-Tech's contact address. They use the 23P Rev 4, which was what I guessed since I currently have 21s. Kudos to Matt and Nor-Tech customer service - they responded within a couple hours.:Score-101010:

Oops I’m meant 25 rev 4 s

Haha. I figured that was a missed key stroke. Found this site that shows half pitch Rev 4 offerings to 25.5. Obviously they are fine tuning the standard Merc offerings. I may call them tomorrow to find out what they are doing.

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I was going with 25.5 but Trond talk me out of them.

We need a couple nice spring days here soon to burn that fuel load off for proper prop testing.

I don't think that will be too much of a problem if Merc lead time turns out to be around 3 months. They were suppose to get the boat this week and take it to the shop to make sure they have everything ordered they need. Not sure if they still plan to do that or not. I know they need new wiring harnesses and the new Gen 5 beefier tie bar. I'm pretty sure the new external fuel water separator filters come with the engines, at least the Merc announcement of the engines from way back said it does. I'm not aware of anything else they need, but better to be safe than sorry.

So how does your boat run with the 400s? Which props did you end up with?

Still waiting on the engines. Merc has delayed them twice. The latest date they gave me on 5/29 said they would ship in 10 days, so hopefully they are in the mail and will arrive this week.

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we went with 1 size under for better mid range and acceleration and she runs 85. Ran 90.6 out of the factory with the bigger wheel. And she is for sale !

New 2019 Nor-Tech Hi Performance Boats 340 Club Sport 34ft Power Sport Center Console 34ft Power Sport Center Console

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Engines finally showed up - took about 18 weeks. Good problem for Merc to have, but a long wait. Currently being rigged. We are going to try a number of props. I'm not a huge fan of the Rev 4s, but will try those as well as some B1 combinations. I've seen a 39 quad 400 NT with modified maximus 5 blades. I don't want to mess with 5 blades, I'm afraid the torque may be too much for the lowers. Plus the NT I saw was sitting in the shop with 2 lowers removed, but I'm not sure why.

1st water test yesterday. Heading to LOTO today. Only details I got is it likes B1s better than Rev 4s, and I'm going to be happy. More after a Sunday run.

What a difference. Landed on 22 p B1s. Boat likes them way more than Rev 4s. On plane at 3k rpm vs 5k rpm with the Rev 4s. Stays on plane at 21mph vs 30. Mid-range acceleration way better. Only one hour so haven't stretched the legs completely yet, but hit 69 on a snotty Saturday afternoon, hi temps and humidity. Should end up 70+, but time will tell. This boat likes B1s way more than Rev 4s. Kudos to Big Thunder. Awesome job.

Ran over 100 miles yesterday. Added bonus, not only does the boat behave and run better, it averaged 1.8 mpg with the new set up. Use to average 1.5. Motors were set one hole higher than the factory sets them for Rev 4s. Ended up perfect for the larger diameter B1s.

I'm surprised at how little bow lift the boat has now out of the hole. Not as nose happy when running too. Waiting to see how it runs with the new wheels vs. the loaner wheels.

New props should be on sometime this week. I'm betting we end up tweaking them down a little get the last 200 rpm, but time will tell. I won't do anything until the engines have more hours on them and fall comes where some of this heat and humidity breaks.

MP- Congrats on finally getting your repower to the water.

Do you think your luck w/ Bravo props is related to the fact you own a twin engine NT.
I asked Terry & Trond both about B1's as well as the sportmaster lower case and they insisted that I stick w/ Rev4's.

Have you shared your findings w/ NT?
I'd be interested in why they believe your setup has benefited from the B1's

My first guess was right where you are suggesting about twins. Let's face it, there are not that many twin implementations out there. But with higher HP available, there might be more in the future, especially in places like LOTO where there is much less need for trips since you are not offshore. I'm guessing the trip implementations don't have the same issues I was having with the Rev 4 set up, those issues being have to spin them 5K rpm to get out of the hole, and can't keep the boat on plane at slower speeds, especially on bad wash machine weekends.

Big Thunder did talk to Terry regarding the setup. I've texted Terry to let him know how well the B1s responded to the boat. 22P B1s is the smallest pitch they offer. Honestly, I'm not sure, (well maybe I am) the 300s would have a chance of turning those props. Most likely not. Since 300s were the highest HP offered when I got the boat, B1s probably couldn't be considered. I have not reported any findings to NT. But I have sent Randy Kent a note on how well the boat responded to the B1s. I invited him to go out for a few hours to test it, he responded he would like to. Makes sense for him since he is the market for twin 34s. I may contact Matt Lamb with the info. I'm not totally into top speed, although I don't seem to be giving any of it up. I'm getting better stern lift with the B1s. The boat seems to rise level onto plane versus go nose high and wait for the props to bite. It keeps the level attitude at slow speeds, and when running in the slop. Plus there is the surprising benefit of 20% better MPG. I did not expect that.

If the trip implementations don't have any of the issues I had with twins, not sure what benefits B1s would have. Although, it would be really interesting to take a triple 350 implementation, raise the engines an inch, and hang some B1s on it. The B1s bite, and carry the attitude on the twin implementation way better than the Revs do. Just as fyi, my neighbor just picked up a new 32 Sunsation CC with twin 350s....turning B1s! So it may be just a twin benefit. Does spark your curiosity though.

Well keep us posted on your continued analysis & findings.
Triple 350's can get a NT 340 on plane fairly easily & there is bow rise but it typically rolls over on plane rather quickly.

When you say say raise the engines an inch were your twin's mounted UP 1" on purpose knowing you planed to run B1's?
I ask b/c I tried to get them to mount mine a bit higher on the last boat and they claimed no gain and all that would occur was the engines barking much more in choppy conditions. NT may have simply been taking the more conservative approach or not wanted to fix what wasn't broke. Sometimes it takes someone like you or I to venture out and experiment. I'm pretty tight w/ boat building & racing veteran Ben Robertson and he swears the B1's would be better BUT his knowledge and experience generally surrounds perform,ance improvements found and made to Fountains. A Nor-Tech isn't a Fountain and Vise Versa.

Yes, raising the engines 1 hole was done deliberately for trying the B1s. My rigger, also a race set up guy, agrees completely with Ben on the B1s being a better choice. He took the boat through some tests with the old engines and Rev 4s before the swap. Needless to say, he wasn't enthusiastic regarding the boats behavior getting or staying on plane. The factory rigs the twin 400s, maybe trips too, in holes 2 and 3. He moved them up to holes 1 and 2 (highest two holes) thinking the larger diameter B1s would not need to run as deep. It worked. I ran all day Sunday with a significant portion of the run in the usual weekend wash machine water common at LOTO. I was careful throttling, being ready to pull back slightly if I freed the props, but it was not a problem. I get very little bow rise coming on plane now. And the attitude of the boat running hard through the sloppy conditions is much better. The other major difference I noticed is I can trim the engines much higher at higher RPMs, get increased speed response, and not get prop blowout. At a certain point trimming the REV 4s at high RPMs, the props would wash out and just sit on the rev limiter. So far I'm leaving a few hundred RPM on the table, but I was running a set of borrowed B1s. One in pretty good condition, the other has seen some debris in the water over its life. New props should be on any day now.

I will continue to test as the engines break in. If needed this fall or winter I may get the props tweaked to pick up any remaining RPM. We were told FJ propeller is opening a shop by LOTO. That will be a nice convenience.

Amazing the difference the setup/props made. It doesn't feel like the same boat only with more power that now runs 8 MPH faster. It feels like a totally different hull. Jim Watson and crew at Big Thunder Marine did a great job on the re-power/setup. There is definitely more speed to be had once the mills are broken in and props are tweaked to get that last couple hundred RPM out of her.

Since it is finally warming up around these parts, I finally took the Bravo 1 props in to FJ propeller in Osage Beach. I must say, it's nice to have that reputable of a prop shop within a 10 minute drive. After talking through our experience last summer with the new 22P B1s, we decided to make some changes. The most obvious work that needs to be done is true up each blade and balance them. It was obvious looking at the props that one prop had more cup in it than the other, one prop had no cup in any blade. And the other didn't have consistent cup across all 4 blades. Pitch will checked and balanced between all blades, and we are going to thin the blades slightly to make sure they are all the same, and balanced. In order to carry the nose a little better at speed, we are going to cut off half the diffuser ring. I hesitated on that choice the most because I like the transom lift I get, especially at low speeds and getting on plane. But that comes with lack of carrying the bow properly at higher speeds. Casey at FJ felt by getting the cup right and getting more prop bite (I'm currently at 16% slip across the rpm range), losing half the diffuser ring would have minimal impact on the hole shot, and improve efficiency across the entire rpm range. But we will keep the 3/4 inch we cut off just in case we need it back!

Props should be done and back on in a week or so. Then I need to burn off about 150 gallons of fuel to see how they perform, as I filled the tank before winter:eek: More to report after I get some hours on the re-worked props.

Nascat, the guys at FJ here are really big on the MAX 5s Merc came out with for OBs. Makes me wonder if NorTech has tried them at all yet. Maybe you should experiment! They are pricey enough that I decided to work the B1s as step 1, and depending on how this goes I may or may not get motivated to try a set of Max 5s.

MP-
I'm definitely interested in your prop testing. Ben Robertson tried to get me to go w/ Bravo's on my 34's b/c he's had great success w/ them on the Fountain's back in the day BUT Terry & Trond insist that the NT hull does NOT like them.
I've inquired about SportMaster lowers & it was a No Go too.

My new boat and another were tested w/ the Max 5's, all I was told was that they didn't work & the Rev4's performed better. I'm not gonna lie that when I here NO to so many different tuning options that I begin to wonder if they just rather stick w/ what they know or stick w/ the proven but I really don't think thats the case. Nor-tech tends to constantly seek improvement w/ their products, whether that be design, options, fit & finish or performance.

Keep us posted!

It would have to have noticeable improvement to go from the Rev 4s to the Max 5s given the price difference. I will respectfully disagree with the guys at NorTech regarding the use of B1s on my particular set up. But that's neither here nor there, as most 34 builds are with triples. If we can in fact tweak the B1s to carry the nose better above 5k rpm, there will be no downside of the B1s over the Rev 4s.

Understood and yes your application is different as would be the case w/ a Merc 400's or 7 Marine powered boat.
Shouldn't be 1 size fits all but typically up to the boat owner to experiment as you are.

I can't believe how much Merc props blow straight out of the box. Redunkuless!!!

Haha. Yep, it was way off from spec. The ears on the 2 weren't even finished the same, but they were finished by 2 different people. One had the points from the casting still at the end of the ear. The other had the points rounded off. I'm wondering if we will find each ear is a slightly different pitch too. I will find out when I get them back. I'll know way more then. Then again, B1s are cheap compared to a lot of props out there.

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FJ work done. Unfortunately due to Easter and a family obligation I won't be down to give these a spin until early May. But they look great!

I'll be in Fort Myers Fri & Sat & can run your L & R prop on my outer engines w/ my R prop in the center :party-smiley-004:

They look fast just sitting there.

That would be a fun test.:D

Good thought. I didn't experience any ill handling with the limited time on the change last season, but it certainly might be a concern. With this work I had FJ cut off 3/4 inch of the diffuser ring and tweak the blades to carry the nose better. Should result in a bit less stern lift and better carry the nose at higher rpms. I guess time will tell.

I may be down this weekend. I know where the keys are!

What top speed did you end up achieving?

70 at LOTO. Lake is 660 elevation.

Out of curiosity, what speeds does a 34 with twin 300's run?

62 top at LOTO with maybe 100 gallons of fuel and perfect conditions. Otherwise count on 60. Sobo showed 65.5 on the recall on their test run in Florida, likely with the 20 some gallons of fuel in it when it got delivered and at sea level. 400s upped top speed about 9mph given all other factors consistent. Interesting enough my over all fuel burn improved over 25% with the 400s.

Anyone have experience with raising one hole on twin 350’s? New to me 2017 340 currently running rev 4 19p and just felt like the motors had more to give but props just maxed out. The conversation above leads me to believe that this is a good starting point. Any advice not to or go ahead and start this? I know I need some baseline data first just looking for ideals and advice.