Right X-Dimension for 23' Nordic Viking
09-16-2007, 09:22 AM
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Right X-Dimension for 23' Nordic Viking
Hi Everybody,
I am in the midst of replacing the transom on my 1984 23' Nordic Viking. I originaly came with a Volvo 280 w/trim, I am replacing with a new Bravo 1. The drive was set up back then with the Cavitation plate even with the bottom of the V, prop shaft was 8 1/2" below the V. The boat liked to porpoise with very little trim at all if any. As the boat was running the cavitation plate was about an inch or so in the water. What is the correct height to mount in a new Bravo 1 Drive I have heard anywhere from 4-8" from the V to the center of the prop shaft. Anyone have this set up? Any Ideas. Thanks a ton.
Chad
I am in the midst of replacing the transom on my 1984 23' Nordic Viking. I originaly came with a Volvo 280 w/trim, I am replacing with a new Bravo 1. The drive was set up back then with the Cavitation plate even with the bottom of the V, prop shaft was 8 1/2" below the V. The boat liked to porpoise with very little trim at all if any. As the boat was running the cavitation plate was about an inch or so in the water. What is the correct height to mount in a new Bravo 1 Drive I have heard anywhere from 4-8" from the V to the center of the prop shaft. Anyone have this set up? Any Ideas. Thanks a ton.
Chad
Last edited by OldEliminator; 09-18-2007 at 10:57 PM.
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09-18-2007, 12:50 PM
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X dimension
Hello Chad,
There are extensive threads regarding X-dimensions on the Nordic forum. Although they are in reference to newer hulls (mostly Heats and Rages), the same general rules apply.
You are correct that you can raise the X-dimension from stock (cavitation plate flush to hull bottom/15"s) to something significantly higher. When your boat was manufactured, semi surfacing props were not available, and stock gear cases were not up the task hydrodynamically or mechanically.
A Bravo 1 drive is much more efficient and stronger than the old Volvo stuff. The props are much better too.
You should easily be able to raise your X dimension 2"s, maybe more, evidenced by how easily your boat porpoises. The more power you have, the higher you'll be able to raise your XD.
Remember, this is going to raise your entire drivetrain. You may have sunlounge clearance issues. You may have to modify your sunlounge with a hatch insert to clear your carb/flame arrestor.
You can also further fine tune your raised X setup with shorty gearcases, or spacers (to lower).
Regards,
Steve
There are extensive threads regarding X-dimensions on the Nordic forum. Although they are in reference to newer hulls (mostly Heats and Rages), the same general rules apply.
You are correct that you can raise the X-dimension from stock (cavitation plate flush to hull bottom/15"s) to something significantly higher. When your boat was manufactured, semi surfacing props were not available, and stock gear cases were not up the task hydrodynamically or mechanically.
A Bravo 1 drive is much more efficient and stronger than the old Volvo stuff. The props are much better too.
You should easily be able to raise your X dimension 2"s, maybe more, evidenced by how easily your boat porpoises. The more power you have, the higher you'll be able to raise your XD.
Remember, this is going to raise your entire drivetrain. You may have sunlounge clearance issues. You may have to modify your sunlounge with a hatch insert to clear your carb/flame arrestor.
You can also further fine tune your raised X setup with shorty gearcases, or spacers (to lower).
Regards,
Steve
Last edited by Steve Zuckerman; 09-18-2007 at 02:33 PM.
09-18-2007, 10:38 PM
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Thanks Steve,
I run around here in the rockies with the Utah Nordic boys, Jason's heat is the one in the high 90's at Havasu. I am the poor boy of the group and just love nostalgia more than anything else. The older boats just have lines that no one can recreate in my opinion. Thanks for your input, I am thinking of going up about 3" or so, that puts the actual motor 2 " taller in the bay as the Volvo has a center to center distance of 22 3/4 vs. the Bravo at 21 13/16 center to center. I just hope all this work is worth the extra effort, as I have a stroker going it at the same time.
I run around here in the rockies with the Utah Nordic boys, Jason's heat is the one in the high 90's at Havasu. I am the poor boy of the group and just love nostalgia more than anything else. The older boats just have lines that no one can recreate in my opinion. Thanks for your input, I am thinking of going up about 3" or so, that puts the actual motor 2 " taller in the bay as the Volvo has a center to center distance of 22 3/4 vs. the Bravo at 21 13/16 center to center. I just hope all this work is worth the extra effort, as I have a stroker going it at the same time.
09-19-2007, 08:28 AM
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Chad,
I like those classic west coast step deck daycruisers. I still think they look great. You should easily go 3"s. You'll realize a great deal of efficiency increase getting that drive up and surfacing your prop. Sounds like you will have the horsepower to make it work. Let us know how it turns out.
Post on the Nordic forum and stay in touch!
Regards,
Steve
I like those classic west coast step deck daycruisers. I still think they look great. You should easily go 3"s. You'll realize a great deal of efficiency increase getting that drive up and surfacing your prop. Sounds like you will have the horsepower to make it work. Let us know how it turns out.
Post on the Nordic forum and stay in touch!
Regards,
Steve
