i/o to o/b conversions?

[low277]

Re: i/o to o/b conversions?

Thanks, maybe I will be better off to let this one go.

 

[jrs151]

Re: i/o to o/b conversions? 25 or 20

Re: i/o to o/b conversions? 25 or 20

Force OB's?? Yeah, stay away ! It?s strictly a parts "un"-availability issue.

I agree that given the choice I?d go 25? OB on an offshore bracket any day, just for the added height insurance. But it doesn?t mean 20?s are totally off the table given you plan and prioritize your bracket design and boat configuration.

Given the a-typical offshore bracket setup the OB will run a tad deeper, thus the added 5 inches on an XL are indeed welcome. Couple reasons for that :

At rest: an OB on a bracket essentially leverages the OB?s weight rearward, effectively the boat will ?act? like it?s got a much Heavier OB hung on it, the stern tends to dip lower and the bow out the water as the fulcrum moves rear. It gets progressively worse the further the setback and/or heavier the OB. But this is where added buoyancy really counts in an effort to nullify this phenomenon. While bracket buoyancy won?t do anything for cruising on-plane, it will and can reduce this fulcrum shift rearward at anchor and no-wake operation.

On plane: in both traditional OB and IO setups, the prop is not that far setback from the stern, thus the wake-rise is nearly a non-factor. You simply set your prop preferred height accordingly with keel reference and this depth is ?good? for the entire craft?s speed range. HOWEVER, the offshore bracket introduces a wake-rise characteristic that is variable based on draft and speed, thus your prop depth changes based on your speed. So to prevent possible ventilation/cooling issues the ideal/minimum prop depth is set to compliment max-speed when the wake is virtually flat. So therein is the ?rub? with offshore brackets. It means that your prop depth (engine height) will run deeper for cruise and trawling speeds - aka where ironically much of your time will be. So the so-called solution is run with a 25? OB as to compensate for this ?deeper? natured configuration.

Well ... that all said, I suggest yet another solution to this dilemma --> minimizing bracket offset. Granted, full tilt may not be possible, but a shorter bracket will proportionately reduce this wake rise issue and thus allow one to get away with a 20?. I?ll be repowering my OB with an offshore bracket. But I aslo want to remove the splashwell, going for full transom. So I plan to measure my OB and determin the the minimum setback when the prop is tilted just above the keel.

 

[jbcurt00]

Re: i/o to o/b conversions?

It's been since April JC, I doubt Low's still looking at that hull or a conversion to it......

There should have been a large red banner across the bottom of the screen that indicated this thread is inactive (more then 90days since the original poster [OP] has commented) and to avoid posting in inactive threads.............

Once inactive, it's best to treat threads as closed until the OP posts up again. But like I said, I really don't think Low is still looking at this hull......


Might post those bracket thoughts in a thread about your resto, if you're thinking about adding a bracket or pod to your's...............

Any movement on that front? Purchased the Kay-Cel yet?

 

[barato2]

Re: i/o to o/b conversions?

seconded. i'm always interested in learning more about pod setups. you've given me food for thought already and ejjicated me on sevl issues i didn't know existed.

 

[low277]

Re: i/o to o/b conversions?

I actually did buy the boat and hope to get t back on the water. My timeline was put on hold due to family concerns but I think that we are good to start this spring. I have been checking on stevesmiths? progress and it is looking good!

 

[barato2]

Re: i/o to o/b conversions?

hey, is your boat married? i notice from your sig that it's "powerless" too....

no worries. all too many of us have found our 3 month resto plan turning into 3 years. i thought the Starchief i bought in 2010 was near water ready.....

 

[Gibbles]

Re: i/o to o/b conversions?

^ yeah I thought I would have my chief in the water early last spring... :facepalm:

Deadlines... don't set them, it stressed me the heck out.

 

[bob johnson]

Re: i/o to o/b conversions?

I have PODs on my Lowe ukltra roughneck MOD V... and I love them.... they lift the stern when at rest and when going slow... this is usefull in shallows...once at speed they are effectively out of the equation.


I build an offshore bracket that has pods built in.. this also will raise the stern at rest....or going slow, at speed they will probably be barely in the water if at all... thus lessening the drag on the boat....

bob

 

[jrs151]

Re: i/o to o/b conversions?

LOL, yeah, I know it's been since April - I posted just to offer a bit more value to this thread for future surfers.

.......
Might post those bracket thoughts in a thread about your resto, if you're thinking about adding a bracket or pod to your's...............

Any movement on that front? Purchased the Kay-Cel yet?

Thanks for asking. Unfortunately I'm still stuck in rivet-land. Hull still flipped nude and awaiting me to donate more time which has been very limited lately. I starting seeing the reinforcement-chat and it’s got me thinking I need to pause and get my plan figured out.
Yes, I need to update my resto thread, was able to find a 1998 rude 90 HP looper, so most of my time lately has been cleaning and going through every inch of that OB. It's a 20", so yes, when I get to the bracket build I will most likely heed my own advice here & post results.

 

[Bamaman1]

Re: i/o to o/b conversions?

This is an 8 month old posting. But let me say a couple of things about I/O to outboard conversions.
1. The transom for an I/O is not built to handle weight and stress of an outboard . That means a diagonal support needs to go from the lengthwise stringers in the hull to where the motor mount is mounted to the transom. I would be putting in another layer of marine plywood or two with both screws and epoxy for additional support.
2. This is a good compromise if the hull is in exceptional condition, or if it's a fantastic old boat. Otherwise, it can be a waste of money.
3. The owner must be willing to invest in a modern outboard motor that's appropriate to the weight and style of the boat--preferably 4 stroke. Don't go an put an old junk engine on the boat that drinks gas.

Modern outboards are light, quiet and efficient. After having two I/O's, I'll never have another. They're good the first few years, but nothing but problems after that.

 

[Bwana Don]

Re: i/o to o/b conversions?

^ yeah I thought I would have my chief in the water early last spring... :facepalm:

Deadlines... don't set them, it stressed me the heck out.

Deadlines are anti productive if you ask me. I have one heart stressing deadline after another at work. I don't need that in my hobby. Fishing and boating are supposed to relax us. Enjoy.

 

[low277]

Re: i/o to o/b conversions?

As much as I would like to convert to a outboard it would probably be a whole lot easier to switch from the old omc to a mercruiser.

If I buy a donor boat with say a 3.0 mercruiser is there any thing special that I should look for? or avoid?

 

[barato2]

Re: i/o to o/b conversions?

easier or not, it will be a WHOLE WHOLE lot cheaper. and yeah, i think it might be easier too.

which leads to your next Q: yeah, cracked block. rusted out exh manifolds. signs of blown freeze plugs. later model with the 3.0 liters, 140 hp, and alpha 1 drive (as opposed to the old MR-1) will be better and easier to find stuff for. oh yeah, and one thing you REALLY want to avoid when you drag home a donor boat is the frying pan or rolling pin....common hazard when you arrive with a derelict whatever.