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Thread: What lower drive is this??

  1. #31
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    here is a pic of the reaction of the boat to the rotation of the prop

    the prop is spinning left torque causes the boat to roll to the right so put weight on the left side to counter act that, lh helm with the weight of the driver on the left side of the boat
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    When the sky is grey,look out to sea.
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  2. #32
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    That makes total sense.
    I am going to try the 15x19 titan and see how we do.

    My new donz is not going to be ready for a few weeks. Will this prop be OK to throw on my buddys boat to see if he should buy one too.
    He does have trim tabs. Will it react a lot different in the long run? With both of us in the boat, maybe not huh?

  3. #33
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    OK. I bought a 19RH titan
    Think I got a good deal
    $200 brand new

  4. #34
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    the solas titan for the AQ volvo is 15 and 5/8th not 15 make sure you are getting the right prop from the seller 200 bucks is a real deal if it is the right prop


    15 sounds like the saturn not the titan use this page to get the part numbers the easy way to tell you are on the right page is the titan is the only stainless that comes in a 23 pitch for the AQ the saturn and new saturn don't


    http://www.solas.com/newweb/propelle...0STERN%20DRIVE
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



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  5. #35
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    Matty, Sorry bout that.
    it is the Titan

    Solas Prop Volvo Penta 15 5/8'' 19'' Pitch Titan 3 Blade Right 8841-156-19


  6. #36
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    it is the diameter!!!

    Quote Originally Posted by Gerk View Post
    Matty, Sorry bout that.
    it is the Titan

    Solas Prop Volvo Penta 15 5/8'' 19'' Pitch Titan 3 Blade Right 8841-156-19
    Thanks to all of you and especially Matty, we will also be heading in the Titan direction when we put the boat back together with the Volvo 250. This thread is very interesting in that I knew about and heard about the late great Griz's prop design work and how effective it was. However I didn't know you could still get the props. And secondly I didn't realize until this thread that the diameter was 15 5/8". That helps pull it all together for me. All of the props we tried and experimented with (cupping etc.) when we were racing the Volvo drives were 14" diameter. And we all realized that the lower unit shape at higher speeds was literally blowing the water out and starving the props of solid water to bite into. (nose cones and speedmasters mitigated this to some degree) Using a larger diameter prop is logical and brilliant as the tips of the prop get more water bite with a given amount of blow out from the "club-like" lower unit. Those of you that are of my vintage realize that the Volvo stock lower units were superior to the Mercruiser drive lower units until the TRS and Bravo drives came along (about 1975). Anyway, Titan here we come. We will likely be under 300hp so a 19" is probably a good starting point -- does the design allow repitching to something like a 20" pitch? Ed
    1967 Triple Hatch 18' (sold)
    1969 Holman&Moody 18 2+3
    1982 454 TRS no windshield 22 2+3 (sold I'm an idiot)
    1997 454/Bravo 1 22 2+3
    + some less cool, more functional boats

  7. #37
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    Grizz said the props were pretty much perfect out of the box and any money spent trying to tweak one would be a waste the early props acted much bigger than the number the 19 acted like a 21 the 21 acted like a 23 and the 23 like a 25
    They are hooked to the water the newer production props are shaped slightly different but they are closer to the number so a 19 with 7% slip acts like a normal 20 with 10-12% slip and that is the key how much more can you tweak out of a prop that has single digit slip numbers???? You will find that the 19 on a 240-290 hp classic with 1.6 gears will be a good prop once you want more you need to figure out how to turn a 23 past 5000 rpm on 1.3 gears I think Bills work on his 16 pretty much sealed the fate of an AQ in my mind for running over 70 with 1960s tech

  8. #38
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    from the archives think these are maddad's props

    difference in size left solas right ultra
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    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  9. #39
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    Solas testing

    So I wanted to post my results with the Solas Titan 19 - Feel like this should be a start of a new thread but so much has already been written here.

    My 18 got put on the backburner slightly, so we tested on my buddy's 18.
    That is one wild prop. Still working on dialing it all in.

    It was a rougher day on the water than I would have liked to test a prop, but not awful.
    Starting out at a slower pace is terrible. Tons of cavitation. Felt like just spinning and not moving.
    Eventually we got moving and it is a smother feeling ride. Feels like its going faster, but I think we lost 1 MPH
    We were definitely airborn more than we are typically and we got a bit sideways on a few of those.

    Toward the beginning of the testing his bennett trim switch broke (great timing) so we had no trim tabs other than at the all the way up possition

    We ran 5000 RPMs at 49 MPH
    We found that giving it a lot of throttle from idle get up and goes very fast so no cavitation there. Going from cruising speed to WOT throws you in the engine compartment. Fantastic acceleration.


    The original 14 x 19 Volvo prop to use seemed like a safer and slightly faster prop although the titan was a more fun prop. We are still working on it.

    Does this review sound right or should we have gotten a 21? We just can't seem to break that 50 MPH mark (without going Bravo) He was thinking maybe his engine runs between 300-350 HP


    Thanks all

  10. #40
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    Thanks

    Quote Originally Posted by Gerk View Post
    So I wanted to post my results with the Solas Titan 19 - Feel like this should be a start of a new thread but so much has already been written here.

    My 18 got put on the backburner slightly, so we tested on my buddy's 18.
    That is one wild prop. Still working on dialing it all in.

    It was a rougher day on the water than I would have liked to test a prop, but not awful.
    Starting out at a slower pace is terrible. Tons of cavitation. Felt like just spinning and not moving.
    Eventually we got moving and it is a smother feeling ride. Feels like its going faster, but I think we lost 1 MPH
    We were definitely airborn more than we are typically and we got a bit sideways on a few of those.

    Toward the beginning of the testing his bennett trim switch broke (great timing) so we had no trim tabs other than at the all the way up possition

    We ran 5000 RPMs at 49 MPH
    We found that giving it a lot of throttle from idle get up and goes very fast so no cavitation there. Going from cruising speed to WOT throws you in the engine compartment. Fantastic acceleration.


    The original 14 x 19 Volvo prop to use seemed like a safer and slightly faster prop although the titan was a more fun prop. We are still working on it.

    Does this review sound right or should we have gotten a 21? We just can't seem to break that 50 MPH mark (without going Bravo) He was thinking maybe his engine runs between 300-350 HP


    Thanks all
    Thank you for keeping us in the loop. We are on a similar path. Although our 18 is not together yet we are making good progress. I just ordered a Titan (21"LH) as I need the prop to figure out how to mount it on the 250 drive. The 19 vs 21 decision was difficult and time will tell if we made the right choice. The data Matty provided indicated that the Titan seems to fit into the formulas as if it had about an additional inch of pitch so the 21 could be too much for us. There are so many variables. Coincidently with our 302 H&M engine (which was probably somewhere between 200-235 hp, I think closer to 200 based on lots of data) and with a 1.61 Volvo 250 drive using a Johnson 14x19 bronze prop (slightly modified Volvo design prop) we were running close to 5000 rpm and 49 gps. We did a lot of things to the engine (GT40 heads, stroker crank, hyd roller cam) and on the dyno we are seeing about 285 hp with a very flat torque curve between about 3000 and 5000.
    We thought we would be over 300 hp but the dyno is calibrated and more like gps speed compared to our optimistic hp guesses. We are several months away from splashing the boat but the water testing will tell the story. Your comments on the boats handling with the Titan did not seem too good to me. We do not use tabs and use the middle adjustment for drive trim and this boat has always been a pleasure at all speeds with a good hole shot for skiing etc. Hopefully the Titan does not screw all of that up or we will be using it as a spare. Thks for the data, Ed
    1967 Triple Hatch 18' (sold)
    1969 Holman&Moody 18 2+3
    1982 454 TRS no windshield 22 2+3 (sold I'm an idiot)
    1997 454/Bravo 1 22 2+3
    + some less cool, more functional boats

  11. #41
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    Cavitation is one thing I have never seen on a Solas Titan they are usually hooked up to the water and love rough water no ventilation or cavitation
    Are you sure you have the right prop and. Not another version for the AQ
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  12. #42
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    Here is the formula to see what your 1.6 looks like on paper at 19p and 21p at rpm.
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    Sean Conroy,
    1964 Formula Jr. (hull #2) project

    1972 Greavette Sunflash III
    1981 Kavalk Mistral project

    "A man can accomplish anything... as long as he doesn't care who gets the credit."

  13. #43
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    something else to think about if he is making 300-350 he should be spinning a 19 way past 5000 rpm

    going from a solas 19 to a 21 is going to be more than a 200 rpm drop it will be north of 400 rpm


    using http://www.rbbi.com/folders/prop/propcalc.htm


    plug in your numbers the more accurate the better use 7-8% slip for the solas using 4600 1.6 21 and 7% i have you at around 52-53 mph
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  14. #44
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    The prop I ordered is Solas Titan #8842-156-19

    I have to remember that high altitude plays a huge role up here. Boats that can do 50 up here can easily do 60 down at sea level. I was expecting however to get more than the stock prop.

    Are you guys saying to move to a 21? I'm not sure how many more props I can buy haha. Guess I should buy more Donzis to put these props on.

  15. #45
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    You might want to look around and see if there is a prop specialist near your location.

    We have a company near here that when you bring him your boat you can spend all day testing props with their "experts" to narrow down to just the right one. Then you buy it.... you're kinda committed to at that point. But, you get the right prop!
    Sean Conroy,
    1964 Formula Jr. (hull #2) project

    1972 Greavette Sunflash III
    1981 Kavalk Mistral project

    "A man can accomplish anything... as long as he doesn't care who gets the credit."

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