PHILLYDOGS
New member
I own a 2005 33ss with 396 mags I have a 4 post lift.. I would like to know the proper spacing of the bunks, does anyone have the same setup? Thanks Phil
Bunk spacing on 4 post lift
- Thread starter PHILLYDOGS
- Start date
rclementtx
Member
Hey PhillyDogs ... how about the guidance in the following post?
http://formulaboatsforum.com/VBFORUM/showthread.php?8716-2005-33-ss-center-of-gravity
http://formulaboatsforum.com/VBFORUM/showthread.php?8716-2005-33-ss-center-of-gravity
PHILLYDOGS
New member
They are floating lifts different setup...I live in Cape Coral lots of 28 33 35ss on 4 post lifts I will inspect closer as I head to the gulf thru the canals hopefully ill see owner first ......Thanks
rclementtx
Member
Indeed - different. But I still think 75% of the guidance for a floating lift applies.
If I had my druthers, I'd locate my bunks under or just inboard of the lifting strake that's about 18" in from the chine on the outer edge of the boat. That's my primary lift point on my hydrohoist as well and we arrived at that location via trial and error. Its also just inboard (towards the boat's center line) from where my trim tabs are mounted, giving me some assurance that I won't wrack the tabs if they fail to retract when I power down or if I lift the boat just a bit before powering down. (Tab retraction was an early problem I had before replacing both hydraulic cylinders.). I find that when I lift my boat, nothing's perfect and I might be off by 4-6" from my preferred location. As long as I don't wrack my tabs, I'm fine.
In making your decision, make sure that you have vertical supports (holding up your bunks) under your transom since that's where most of the weight is and you don't want to induce a deflection in your hull by having no support under that location.
Lastly, make sure that your bunks are high enough that the boat's bottom doesn't hit the cross braces on the lift. I think this comes down to tradeoffs that work for you - wider spaced bunks that are high enough to avoid hitting the cross members give you some flexibility in locating your boat as long as you don't hit your tabs. Closer spaced bunks aligned with the lifting strake just off the boat's centerline let you have lower hight bunks but are likely less forgiving in terms of getting the bunks and strakes lined up.
If I had my druthers, I'd locate my bunks under or just inboard of the lifting strake that's about 18" in from the chine on the outer edge of the boat. That's my primary lift point on my hydrohoist as well and we arrived at that location via trial and error. Its also just inboard (towards the boat's center line) from where my trim tabs are mounted, giving me some assurance that I won't wrack the tabs if they fail to retract when I power down or if I lift the boat just a bit before powering down. (Tab retraction was an early problem I had before replacing both hydraulic cylinders.). I find that when I lift my boat, nothing's perfect and I might be off by 4-6" from my preferred location. As long as I don't wrack my tabs, I'm fine.
In making your decision, make sure that you have vertical supports (holding up your bunks) under your transom since that's where most of the weight is and you don't want to induce a deflection in your hull by having no support under that location.
Lastly, make sure that your bunks are high enough that the boat's bottom doesn't hit the cross braces on the lift. I think this comes down to tradeoffs that work for you - wider spaced bunks that are high enough to avoid hitting the cross members give you some flexibility in locating your boat as long as you don't hit your tabs. Closer spaced bunks aligned with the lifting strake just off the boat's centerline let you have lower hight bunks but are likely less forgiving in terms of getting the bunks and strakes lined up.
Last edited:
PHILLYDOGS
New member
Thanks for all your advice, I have it sitting nice on 12x3 inch bunks spaced 42" inside measurement which places them about 6" from the second chine......The only concern I have is the bunk is about 16" in from the trim tab, some say no problem I'll look further into that the bunks I have are 14 feet long...
rclementtx
Member
Congratulations on your progress.
Here's a shot of my 310SS placement on my bunks. As I've said before, it was a day of trial and error to get it sitting level and far enough up that I didn't hit the supporting steel or the air chambers. If you are happy with how things sit and the deflection of the bunks is minimal under load, I'd say you're there.
I don't think there's anything sacred about how far from the trim tabs the bunks are, as long as they don't hit the tabs and the boat sits high enough not to hit the steelwork. As long as you are stable and you can accommodate any lateral misalignment when you lift, you should be pleased.
Note that my bunks extend slightly beyond the end of the boat, but that the vertical steel support for the bunk is very closely aligned with the transom. I found that my bunks (2x10 or 2x12) tended to flex under the weight of the boat, and if the transom was meaningfully misaligned with the aft steel support I got very imperfect contact with the lifting strake / v on the boat.
Attachments
Last edited:
PHILLYDOGS
New member
Thanks for the picture, I think I will extend the rear of the bunks to sit about 6-12 inches from the trim tab it will just make me feel better thanks again.......Phil