Re-prop

Discussion in 'Gas Engines/Drives/Transmissions/Props' started by OBrother, Mar 7, 2018.

  1. OBrother

    OBrother New Member SILVER Sponsor

    12
    Apr 8, 2017
    Long Island
    340 Sundancer 2001, Garmin 5212 vhf200 gmi 10, Fox gateways, Highfield 240ul w/8hp Yamaha
    7.4 Horizons 380hp
    I have a 2001 340 with horizons 380hp v-drives. The props on it are 3 blade 17 / 16 NI L-cup. Has anyone had success with 4 blades. Would like to get on plane faster without losing too much. Anybody?
     
  2. Steve S

    Steve S Active Member GOLD Sponsor

    758
    Jun 5, 2007
    Northern IL.
    2000 400 Sedan Bridge with twin CAT 3116's

    2000 340 Sundancer - SOLD!
    210 Monaco 1987 - SOLD!
    Twin Caterpillar 3116's 350 HP straight drives
    That’s what was on my 340 also - same engines.

    Had them prop scanned and balanced. Ran smooth and got on plane quickly.
     
  3. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    Cobalt CM23
    GM SB 383" Stroker" Alpha Gen I
    Look at doing what Steve S suggested before making radical changes. Your boat was propped at the factory to achieve the recommended wide open throttle (WOT) RPMs. I'm sorry I don't know what that is for your boat. But you should find out and see if your boat is hitting that RPM range at WOT. If not, you also want to check to make sure the engines are properly tuned and the bottom is free of any growth. As a thought....how much extra crud do you keep on your boat. It is amazing how much extra weight we bring on board.

    Without finding the answers to the above and going to a 4-blade or lower pitch could cause your engines to not run within the proper range. I would find a good prop shop in your area with Prop Scan equipment and talk to them. They can help.
    Shawn
     
    Steve S likes this.
  4. mnm99

    mnm99 Well-Known Member

    Oct 2, 2015
    Long Island
    2004 340 SeaRay Sundancer
    Twin 8.1 Merc
    I agree with NorCal. Before I started playing with props changes I made sure my engines were running perfect. Changed plugs, wires , filters, oil, checked all belts, cleaned arrestor, ect... Then I also made sure the bottom was perfect. I had to sand down to the primer because of the last owner and put a fresh coat of paint. Just make sure it's clean and smooth. THEN..Do a couple WOT pulls with 3/4 tank of gas and 4 people on board. That will tell you where you stand. If your RPM are below your WOT point you can take away some pitch. That should give you some power out of the hole. If you want to go to 4 blades doing this will give your prop guy a good starting point. 4 blades will get you out of the hole better and also cruise, but may loose top end. Most of us don't worry about top end anyway as long as we can hit our WOT.
    Here are your specs
    2001 340DA TVD-7.4L MPI (310 PHP) MERCRUISER INBOARDS 1.50:1
    17 X 15 X 1.5 R3BMC NIBRAL 1524586 4600RPM
    17 X 15 X 1.5 L3BMC NIBRAL 1524602

    http://www.searay.com/boat_graphics/sea_ray_prop_charts/2001.ENGINE,DRIVE AND PROP MATRIX.pdf
     
    NorCal Boater likes this.
  5. TNT8808

    TNT8808 Active Member PLATINUM Sponsor

    262
    May 25, 2016
    West Michigan
    2008 48 Sundancer
    Cummins QSC 540's
    Avon Seasport 340
    40 HP Yamaha
    Back when I had my 340DA I reached out to ACME and their prop experts claimed to know the 340 extremely well. They talked me into a set of 4 blades, and my boat jumped out of the hole, was great around the slip, and didn't seem to lose much if anything on the top end. I couldn't have been happier.

    -Tom
     
  6. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    Cobalt CM23
    GM SB 383" Stroker" Alpha Gen I
    But you talked to a professional that told you what 4-blade prop you needed. Was your your boat already in perfect running condition? And what happened to your WOT RPMs?
     
    Last edited: Mar 9, 2018
  7. TNT8808

    TNT8808 Active Member PLATINUM Sponsor

    262
    May 25, 2016
    West Michigan
    2008 48 Sundancer
    Cummins QSC 540's
    Avon Seasport 340
    40 HP Yamaha
    Yes. ACME had prop experts on staff with a lot experience with the 340 in particular. You go online and fill out a form with all your boat specs, and then I don't remember if they called me or if I called them. I don't know if my boat was in "perfect" running condition, but it had fresh bottom paint, tune up, impellers, fluids, etc. If I lost anything on the top end it was maybe 100 RPM's or so which didn't matter to me as I didn't cruise wide open other than for a few minutes once and a while.
     
  8. OBrother

    OBrother New Member SILVER Sponsor

    12
    Apr 8, 2017
    Long Island
    340 Sundancer 2001, Garmin 5212 vhf200 gmi 10, Fox gateways, Highfield 240ul w/8hp Yamaha
    7.4 Horizons 380hp
    Thanks for the responses, bottom was cleaned and engines reached Wot without problem, we do tend to ride a bit heavy. Just looking to get on plane a bit faster.

    Now the matrix you sent me shows my Boat :
    2001 340DA TVD-7.4L MAG MPI HORIZON (380 PHP) MERC. INBDS 1.56:1
    17 X 17 X 1.5 R3BLC NIBRAL 17 X 17 X 1.5 L3BLC NIBRAL 1269174 , 1269166 4400

    Now the confusing thing is I have 17 X 16 X 1.5 on the boat now. Then when you read the owners manual they list this as another option:
    PROP, 18"X 21"X 1.5" L3BMC NIBRAL H/S
    ABOVE# OPTIONAL (MERC 7.4L MPI MAG HORIZON TVD I/B)

    Just trying to gain all the knowledge I can before the season starts and I make any decision. Thanks again
     
  9. mnm99

    mnm99 Well-Known Member

    Oct 2, 2015
    Long Island
    2004 340 SeaRay Sundancer
    Twin 8.1 Merc
    Got ya..Didn't know you had the 380HP version. What RPM range does your service manual say? When is the last time you had them scanned? You might just have to do a WOT run and bring your props in to be scanned. They can tell where you are now with the props and the RPM you are at, They can pick the correct pitch from there.
    This chard doesn't make sense also..385hp??
     

    Attached Files:

    • 7.4.jpg
      7.4.jpg
      File size:
      73.6 KB
      Views:
      63
  10. hottoddie

    hottoddie Well-Known Member

    Jan 11, 2012
    Boston/Cape Cod
    1986 Sea Ray 390 Express
    Garmin 4212 Chartplotter
    Garmin 24 HD Radar
    Garmin GSD 22 Sounder
    Garm
    454 Crusaders
    Interesting that after 9 posts about a 2001 Sundancer 340 that the owner wants to get on plane faster the discussion has only been about props and not trim tabs that is well known issue on many V Drive boats not jus Sea Ray. The 340 Sundancer will always benefit with larger tabs. Many threads about the problem on CSR.
     
    Steve S likes this.

Share This Page

Show Sidebar