What engine would you put in your boat?

[Woodski]

@M-B: I assume by current carb you are referring to the Weber carb that was on the engine previously? If not, you might just do a check on the jet and needle package to make sure it has a marine calibration (richer than automotive cals). The AF ratio off the dyno certainly is not lean, but it could very well be in the mid range area if different jet / needle package.

[Michigan boarder]

@M-B: I assume by current carb you are referring to the Weber carb that was on the engine previously? If not, you might just do a check on the jet and needle package to make sure it has a marine calibration (richer than automotive cals). The AF ratio off the dyno certainly is not lean, but it could very well be in the mid range area if different jet / needle package.

Yes, the original Weber. So back when the engine started sputtering in 2013, I thought it was fuel related. I had replaced everything else in years past leading up to that. So I got a rebuilt carb from Flying Fish carbs - an exact replacement of my Weber. I bolted that on, but the problem persisted (I did not realize the head gasket was failing). Carb had about .75 hours of run time on it. Fast forward to the fall of 2014, and we bolted that carb on the engine for the first dyno runs. It was found to be running a bit lean, so Sgt and Jim (the dyno guy) tuned it to run richer, so that it was in the correct range. Dyno sheets show it was good too, so it should be right on.

[Michigan boarder]

As you know, we have a few Malibus in our quiver that we barefoot with...

3 Echelons and 1 Flightcraft

the Flightcraft is running a 260 HP carbed 350 Mag (46.5 mph) 13-13 1/2 prop

we have my old 95 Echelon XL with the 395 HP, 454 (51.5 mph) 13x14 prop

we have my new 94 Echelon Closed Bow with the 390 HP, 454 (52.5 mph) 13x14 prop

And we have a 97 Echelon Closed Bow with a 320 HP, 350 EFI Monsoon (47.5 mph) 13x13 prop

So, if you get a Monsoon EFI you will be quite impressed from what you have now...

If you are going to upgrade motors...GO EFI, not a carb!!!!! just my EXPERIENCED .02 with Echelons

By the way....ALL 3 of the Echelons are running 1:1 tranny ratios, just that the big blocks are running a taller prop to keep from over revving...

JB - based on this, I need the 13x14 prop since I am at 383hp with the stock carb, correct? What ACME number is that?

These are the engine rpm's and speed that I'm running, obtained them yesterday. 45mph is WOT. Speed was done with the GPS app that you mentioned to me. Boat load (ha ha) is me driving and wife in the spotter's seat.

Engine RPM 2290, 20 mph

Engine RPM 2650, 25 mph

Engine RPM 3130, 30 mph

Engine RPM 3750, 35 mph

Engine RPM 4450, 40 mph

Engine RPM 5330, 45 mph

I put the boat away for the season yesterday. It ran great all year, no issues at all except until the end, that oil pressure sensor developed a leak and made a mess out of my bilge. I need to use a better thread seal, teflon tape did not hold up well at all (should have know better on that one).

[JB-FOOT]

JB - based on this, I need the 13x14 prop since I am at 383hp with the stock carb, correct? What ACME number is that?

These are the engine rpm's and speed that I'm running, obtained them yesterday. 45mph is WOT. Speed was done with the GPS app that you mentioned to me. Boat load (ha ha) is me driving and wife in the spotter's seat.

Engine RPM 2290, 20 mph

Engine RPM 2650, 25 mph

Engine RPM 3130, 30 mph

Engine RPM 3750, 35 mph

Engine RPM 4450, 40 mph

Engine RPM 5330, 45 mph

I put the boat away for the season yesterday. It ran great all year, no issues at all except until the end, that oil pressure sensor developed a leak and made a mess out of my bilge. I need to use a better thread seal, teflon tape did not hold up well at all (should have know better on that one).

John

What was the EXACT prop you were running that gave you the above results?

I can send you out some ones to try in the spring!

Jack

[Woodski]

@MB: from that data it looks like two things are going on. You are underpropped and the prop is slipping quite a bit at the upper end. As noted specific prop details are needed on that prop. From your power curve, I would certainly look at a CNC prop and a 13x14 might be a good choice. I have been successful running a lot of cup and would encourage you to also consider a prop with standard pitch (like a 515 acme) with additional pitch. You will want to spin at less than 100 rpm : 1 mph probably very similar to what JB does with a BB.

[MadMan]

Engine RPM 2290, 20 mph

Engine RPM 2650, 25 mph

Engine RPM 3130, 30 mph

Engine RPM 3750, 35 mph

Engine RPM 4450, 40 mph

Engine RPM 5330, 45 mph

These numbers are nearly identical to my 383 strokers performance. Different boat though- '00 LSV 23, 14x18 prop, 1.5:1 v-drive.

I'm not really concerned with top speed though, more of just the max pitch I can run (for cruising) and still able pull all my ballast.

[Michigan boarder]

This is with the stock 13x13 prop that came with the boat. I dinged a blade and had it tuned in 2013 right before the engine went.

I'll probably take you up on that JB! Hoping to nail it down to 1 or 2 options before swapping them around.

Can ACME or OJ add cup to a prop or is that something I have to find someone for?

[JB-FOOT]

This is with the stock 13x13 prop that came with the boat. I dinged a blade and had it tuned in 2013 right before the engine went.

I'll probably take you up on that JB! Hoping to nail it down to 1 or 2 options before swapping them around.

Can ACME or OJ add cup to a prop or is that something I have to find someone for?

I have been using Bill at Blackburns for years...

http://www.blackburnmarine.net/propeller-repair.php

but I am sure you probably have a local shop you trust too.

[Woodski]

@MB: acme or OJ can do it, a local shop can also do it. Acme has done a fair amount of testing with different cup amounts.

[Michigan boarder]

I have been using Bill at Blackburns for years...

http://www.blackburnmarine.net/propeller-repair.php

but I am sure you probably have a local shop you trust too.

I got nothin'!

@MB: acme or OJ can do it, a local shop can also do it. Acme has done a fair amount of testing with different cup amounts.

That's what I thought too.

I'm going to work on some other stuff with the boat, and will reach out to ACME or OJ later on over the winter lay-up. I like the thought of just using a standard, cookie cutter prop if possible.

[Woodski]

@MB: there are 4 Acme props past the 515 that would offer less rpm/mph that would be cookie cutter options.

[MadMan]

I'm going to work on some other stuff with the boat, and will reach out to ACME or OJ later on over the winter lay-up. I like the thought of just using a standard, cookie cutter prop if possible.

I bet you can find somebodies unused "spare" prop on ebay over the winter for less than half price. Time is on your side.

[Michigan boarder]

I bet you can find somebodies unused "spare" prop on ebay over the winter for less than half price. Time is on your side.

Good idea!

[JB-FOOT]

13x14 and 13x13 1/2 are not all that common

just sayin`

[MadMan]

I've tried 3 different props on my 383 stroker.

14x18 - 3500rpm = 33mph, able to pull my ballast.

14x16 - 3500rpm = 30mph, able to pull my ballast

14x20 - 3500rpm = 36mph, not able to pull my ballast (>10sec to get to 20mph and perfect pass struggles to maintain speed).

All had the same top speed- 44mph.

All the speeds were per gps. I believe my top speed didn't vary was because the drag of the boat is increasing faster than the speed of the boat is.

I run the 14x18, stock prop.

Edited September 12, 2015 by MadMan

[JB-FOOT]

I've tried 3 different props on my 383 stroker.

14x18 - 3500rpm = 33mph, able to pull my ballast.

14x16 - 3500rpm = 30mph, able to pull my ballast

14x20 - 3500rpm = 36mph, not able to pull my ballast (>10sec to get to 20mph and perfect pass struggles to maintain speed).

All had the same top speed- 44mph.

All the speeds were per gps. I believe my top speed didn't vary was because the drag of the boat is increasing faster than the speed of the boat is.

I run the 14x18, stock prop.

you dont mention what boat you have, but based on the props listed, I am guessing a GEAR REDUCTION V-drive, because i don't think there is any way in the world that a 1:1 ratio DD would turn those props, and the OP has a DD...

Edited September 13, 2015 by JB-FOOT

[MadMan]

These numbers are nearly identical to my 383 strokers performance. Different boat though- '00 LSV 23, 14x18 prop, 1.5:1 v-drive.

I'm not really concerned with top speed though, more of just the max pitch I can run (for cruising) and still able pull all my ballast.

you dont mention what boat you have, but based on the props listed, I am guessing a GEAR REDUCTION V-drive, because i don't think there is any way in the world that a 1:1 ratio DD would turn those props, and the OP has a DD...

I should have mentioned it again. '00 lsv 23.

[JB-FOOT]

I should have mentioned it again. '00 lsv 23.

Guess I should.could read the entire post, sorry

[MadMan]

I'm going to answer the original question of this thread. 3 years ago I replaced the damaged 350 Monsoon in my boat with a 383. If I was doing it now, I'd go with a 454, solely on the price of gas now.

[Michigan boarder]

I'm going to answer the original question of this thread. 3 years ago I replaced the damaged 350 Monsoon in my boat with a 383. If I was doing it now, I'd go with a 454, solely on the price of gas now.

We considered that, but the engine cover needs to be bigger, so I opted against that.

I do think we ended up with the perfect engine for this boat - a 388 stroker that puts out what a 454 does (minus some weight). Wouldn't want it any other way.

[Michigan boarder]

I'm going to see the prop guys at the boat show this weekend.

JB and Woodski - is there anything I should be asking them or leaning towards? I'm bringing my dyno sheets and the RPM/MPH readings that I logged too.

Edit: read back on this thread a bit, I'll talk to them about the 13x14 Acme 1257. LH rotation, correct? This looks like a good price:

http://www.nettleprops.com/store/p/281-Acme-1257-Propeller-3-Blade-13-x-14-LH-1-1/8-135-Cup.aspx

I want this to get this dialed in as soon as the ice is off the lake - spring is coming fellas!!

Edited February 18, 2016 by Michigan boarder

[Woodski]

@MB: I would ask about the 1257 but IMO that is probably a bit too much pitch and would result in probably too slow an engine speed at the surf/boarding speeds (lower speeds & ballasted), but just a guess on my part, it would be fine for slalom and barefooting but still spin slower than typical. What I would ask, is whether they have / make a 449 or 515 with .135 cup. I customized my prop with added cup and really like it, ended up with just under 1:100 speed/RPM and the added cup improved the holeshot. You have plenty of power under the curve to spin a big prop, the extra pitch probably would dampen the response of changing throttle position. I would ask them if they have any test or feedback on that when discussing the 1257.

[JB-FOOT]

I'm going to see the prop guys at the boat show this weekend.

JB and Woodski - is there anything I should be asking them or leaning towards? I'm bringing my dyno sheets and the RPM/MPH readings that I logged too.

Edit: read back on this thread a bit, I'll talk to them about the 13x14 Acme 1257. LH rotation, correct? This looks like a good price:

http://www.nettleprops.com/store/p/281-Acme-1257-Propeller-3-Blade-13-x-14-LH-1-1/8-135-Cup.aspx

I want this to get this dialed in as soon as the ice is off the lake - spring is coming fellas!!

The 1257 was an absolute winner on my boat

[MadMan]

We considered that, but the engine cover needs to be bigger, so I opted against that.

I do think we ended up with the perfect engine for this boat - a 388 stroker that puts out what a 454 does (minus some weight). Wouldn't want it any other way.

Yep, I'm happy with my stoker too, but it's also pretty easy to build a 1 horsepower per cubic inch big block. And, with that 4" stroke, it would have a healthy amount of torque.

[Woodski]

@JB-Foot: Awesome to hear the 1257 is a winner. Could you provide some RPM v Speed data for John (and us) to digest so the best decision can be made on what prop will suit him as you are running the same hull so Speed v RPM should be very close. My curiosity would be RPM @ 34 / 36 / 41 mph. Thanks.