(Another) Prop Question - Sorry!

[anotherrunner83]

Guys, I could use a bit of help.  I damaged my prop last weekend.  The short of it...submerged log = 3 slightly blent blades of the 4.  Prop shop says 3 weeks to repair.  A buddy of mine has a stock MC prop off of a 23' maristar that is also a  4 blade 14 x 20.  It has also had a run in, but can be repaired in a week at another shop.  The question, will the stock MC craft work on my 06 VLX?

[oldjeep]

Buy a proper spare and then get your old prop fixed.  Also consider propmd.com for your repair.  3 weeks is crazy.

 

Side note - yes the 14x20 will likely fit and the boat might go 60 mph with that prop   MC must use a lower gear ratio in the trans/v-drive than Malibu does

Edited August 8, 2017 by oldjeep

[anotherrunner83]

well, if i go down that road, wakemakers recommends either the Acme 1941 (14.5 x 15.5)  or the 1235 (14.5 x 14.25).  The current prop is the Acme 417 (14 x 20).  I know a lot of guys are running the 1235 on the surf boats, but i would still like to be able to ski behind the boat?  would the 1941 be a better all around prop?  FWIW, the topend on this boat is currently at 49mph, GPS confirmed.  

Edited August 8, 2017 by anotherrunner83

[teamerickson]

36 minutes ago, anotherrunner83 said:

Guys, I could use a bit of help.  I damaged my prop last weekend.  The short of it...submerged log = 3 slightly blent blades of the 4.  Prop shop says 3 weeks to repair.  A buddy of mine has a stock MC prop off of a 23' maristar that is also a  4 blade 14 x 20.  It has also had a run in, but can be repaired in a week at another shop.  The question, will the stock MC craft work on my 06 VLX?

Is the MC prop splined? If so, then no it won't work. 

[anotherrunner83]

no, it's from an earlier maristar, before they switched to the slined shafts.

 

[oldjeep]

14 minutes ago, anotherrunner83 said:

well, if i go down that road, wakemakers recommends either the Acme 1941 (14.5 x 15.5)  or the 1235 (14.5 x 14.25).  The current prop is the Acme 417 (14 x 20).  I know a lot of guys are running the 1235 on the surf boats, but i would still like to be able to ski behind the boat?  would the 1941 be a better all around prop?  FWIW, the topend on this boat is currently at 49mph, GPS confirmed.  

It really has a 14x20?  Then I guess the maristar prop should work.  Any idea what your transmission ratio is?  Would have thought that the stock prop should have been a 537 (13.5" x 16")

[anotherrunner83]

Just now, oldjeep said:

It really has a 14x20?  Then I guess the maristar prop should work.  Any idea what your transmission ratio is?  Would have thought that the stock prop should have been a 537 (13.5" x 16")

it's stamped as an Acme 417 and 14 x 20.  now, i can't speak to if this is the original prop or if it was replaced. i do have the monsoon 340, but i read where everything from the base motor to the hammerhead was tested/came with with the 13.5 x 16...the plot thickens 

[anotherrunner83]

owner's manual only says Acme 4 blade as the standard prop, no numbers...

[stags79]

The standard prop on an 06 vlx would be a 537, I believe that was a 13.5x16, I can't remember if the cup on that was .105 or .150.  that's what my 06 blx came with.  I'm running 1615 now and have been very happy with it.  

[ajgear]

20" of pitch is pretty insane with a 1.76:1 final drive (not sure if that's what you have, but the prop calc for 49mph on a 20" pitch would make sense with that drive ratio @4800 rpm).  The 1941 and 1235 are both popular, but consider the 1273 as well.  It will give you the low end of the 1235, but once it gets up on plane, the extra cup on the 1273 (.150 cup vs. .105 on the 1941 & 1235) will act like about an extra inch of pitch, making it effectively like the 1941.  On my 2014 VTX, the 1273 was good for 43mph (GPS verified).  It was DRAMATICALLY better than my 537 (13.5 x 16 x .105) under heavy ballast and out of the hole, and the GPS verified speed at the top end was within 0.5 mph.

[anotherrunner83]

so more information...

OJ Props recommends their 912 14 3/4" x 15 3/4"

Local prop shop says the Acme 1939 14" x 15 1/2"

Wakemakers says Acme 1235 14 1/2" x 14 1/4" or the 1941 14 1/2" x 15 1/2"

then there is AJ's post bove who is saying the 1273 14 1/2" x 14 1/4" but more cup

i really would like to keep the boat capable of mid-40 capability, just because, but I also want pretty good hole shot. this has gone from a simple will "x" work on "y" to i have the wrong prop and should replace it...  

[ajgear]

Should've asked before, but what motor do you have (what's the WOT rpm operating range)?  Do you know your final drive ratio?

Edited August 8, 2017 by ajgear

[anotherrunner83]

3 minutes ago, ajgear said:

Should've asked before, but what motor do you have?

340 monsoon

[anotherrunner83]

4 hours ago, stags79 said:

The standard prop on an 06 vlx would be a 537, I believe that was a 13.5x16, I can't remember if the cup on that was .105 or .150.  that's what my 06 blx came with.  I'm running 1615 now and have been very happy with it.  

what's this doing for you on the top end?  i'm starting to wonder if i'm just splitting hairs at this point...

[ajgear]

The 1939 should give you very similar performance to the 1273, but by different means.  The smaller diameter of the 1939 will give you more slip under ballast and in the hole shot, and the slip will diminish as the boat planes off and comes up to cruise/ski speed.  There's a fair bit of discussion around the thread below as well.  Toward the end, you can see similar results to what I had on the 1273.

 

[oldjeep]

56 minutes ago, anotherrunner83 said:

so more information...

OJ Props recommends their 912 14 3/4" x 15 3/4"

Local prop shop says the Acme 1939 14" x 15 1/2"

Wakemakers says Acme 1235 14 1/2" x 14 1/4" or the 1941 14 1/2" x 15 1/2"

then there is AJ's post bove who is saying the 1273 14 1/2" x 14 1/4" but more cup

i really would like to keep the boat capable of mid-40 capability, just because, but I also want pretty good hole shot. this has gone from a simple will "x" work on "y" to i have the wrong prop and should replace it...  

1939 is what I run on my VTX, works great for slalom and boarding.  Don't surf so no idea how it chugs along at 8 MPH with the boat half sunk

 

[ajgear]

1 minute ago, oldjeep said:

1939 is what I run on my VTX, works great for slalom and boarding.  Don't surf so no idea how it chugs along at 8 MPH with the boat half sunk

 

Come on man...we surf at 10.5 - 11, and it's WAY more than half sunk...

What do you get for top speed with the 1939?

[oldjeep]

3 minutes ago, ajgear said:

Come on man...we surf at 10.5 - 11, and it's WAY more than half sunk...

What do you get for top speed with the 1939?

Somewhere around 45MPH 

[anotherrunner83]

so, just spoke to Acme directly.  they recommend 1847 14 x 14.25 to carry the weight and still have a ski-able wake

[ajgear]

That makes perfect sense.  It's essentially the 1273 (same pitch and cup) but 1/2 inch smaller diameter.  It should end up performing like the 1939 on the top end, but if you surf, you'll be much happier with the shallower pitch and the low end performance that it brings.  Speaking with ACME directly is what got me into the 1273 in the first place.  Funny that the people that actually design and make the props have better advice than us... 

[anotherrunner83]

50 minutes ago, ajgear said:

The 1939 should give you very similar performance to the 1273, but by different means.  The smaller diameter of the 1939 will give you more slip under ballast and in the hole shot, and the slip will diminish as the boat planes off and comes up to cruise/ski speed.  There's a fair bit of discussion around the thread below as well.  Toward the end, you can see similar results to what I had on the 1273.

 

how much weight were you carrying with your 1273.  i am currently only running full ballast and 900 extra...

[stags79]

51 minutes ago, anotherrunner83 said:

what's this doing for you on the top end?  i'm starting to wonder if i'm just splitting hairs at this point...

I haven't verified with gps, but I think my top end dropped a couple mph.  I was able to get 45 or 46 with the 537, I'm still able to get 43-44 with the 1615.  

[anotherrunner83]

1 minute ago, stags79 said:

I haven't verified with gps, but I think my top end dropped a couple mph.  I was able to get 45 or 46 with the 537, I'm still able to get 43-44 with the 1615.  

are you surfing? extra ballast? skiing? sorry for drawing this out.  i prefer to know as much as possible before sinking $500 into something and not be happy with it. i'm asking for the boat to do a lot, i get that, but there has to be something that is "a jack of all trades but master of none".  

[ajgear]

10 minutes ago, anotherrunner83 said:

how much weight were you carrying with your 1273.  i am currently only running full ballast and 900 extra...

I was rolling with about 2600 lbs total plus the wedge.  200 in each factory rear, 350 in the factory midship, +/- 180 in a plumbed-in bow bag under the front seats, PnP 650s in the rear (usually not completely full), and a 475 Sumo bag in the front walk way.  We typically had a smaller crew of 3 or 4.  When we got more than that on the boat, I'd drain some ballast or pull the wedge up.  Not because the prop wouldn't push it, but because the wave actually started to deteriorate.  There is such a thing as too much weight (based on hull shape and size) when surfing.  The biggest issue in ballasting the boat properly is weight distribution.  Rule of thumb is to add 1.5:1 to 2:1 (rear to front).  So if you put 900 in back, add 450 to 600 up front (I found 2:1 to be just fine).

Edited August 8, 2017 by ajgear

[minnmarker]

Same hull. 42 with 1235 and 44 with 537. Gps speeds and Monsoon 340.

 Surfs MUCH better with the 1235.