Righty or Lefty

So, I didn't want to threadjack on Tony's BB Mopar project, but I'm curious about Tim's comment about giving up handling using a lefty motor.

Can you guys tell me how the handling is different? I don't have much experience driving inboards, let alone Right vs Left

Don

The only thing I don't care for about my 99SN is the fact that it backs to the left when docking...

Cam, distributor gear, rear main seal and starter... anything else needed to make a GT40 turn RH? If not, thats a pretty short list.

Agree to disagree about the handling, Jody... the starboard lean is exactly what Im talking about. The narrower the boat, the more its affected- and not in a good way. Going straight is one thing, turning with that lean factored in is another.

To spend all that money on a more modern powerplant for a vintage boat, but fail to spend a little more to keep the ride/handling correct just seems like throwing good money after bad, but thats just my 2 cents! I suppose youre right that most people dont pay close attention, or just dont care. Id like to think the majority of people that come to this website would!

Not sure I understand the question. With VERY few exceptions, all direct drive CC's dating back to the 60's (and beyond) came (and still come) with RH props. 2001 included, obviously. The boats run much more close to (and in some cases perfectly) level, due to the RH prop. Depending on speed, prop, hull, weight of driver, etc. A LH prop would cause it to lean much more significantly to starboard (driver's side) under all conditions. Most obviously when just the driver is aboard.

Generally speaking, CC used reverse rotation (RH) engines in order to turn RH props prior to '89. On 89+ boats, the 1.23 reduction transmission reverses the engine's rotation, allowing conventional LH engines to turn RH props. Jody is talking about putting these newer LH engines in an older boat with a 1:1 transmission (which is incapable of reversing the engine's rotation) and thus swapping to a LH prop. The LH prop causes the boat to lean to starboard.

Interesting... all of my boats level off by skiing speeds (~30mph). Theres still a lean at slower speeds. Just imagine how much the boat would lean to stbd if the prop were exaggerating it instead of counteracting it.

TRBenj wrote: Cam, distributor gear, rear main seal and starter... anything else needed to make a GT40 turn RH? If not, thats a pretty short list. Agree to disagree about the handling, Jody... the starboard lean is exactly what Im talking about. The narrower the boat, the more its affected- and not in a good way. Going straight is one thing, turning with that lean factored in is another. To spend all that money on a more modern powerplant for a vintage boat, but fail to spend a little more to keep the ride/handling correct just seems like throwing good money after bad, but thats just my 2 cents! I suppose youre right that most people dont pay close attention, or just dont care. Id like to think the majority of people that come to this website would!

Well Tim That's what I figured you would say due to lack of experience with out side the box thinking and these boats. Not all of the boats have extra compensation built into the trailing edge of the boat, some need, some need not. Some where over compensated some not after factory water test. Some need a little rudder work, some do not!
One of the best re-powers we have done was a EX-330 in a 79 SN, Zero Off conversion and all. turns left now skis and foots better than it ever did, no adverse extra lean, needed minimum rudder work to pull the opposite direction. Boat is fast, quick and nimble.
Build three-four inboard boats a year ( and not just Correct Crafts) on top of running a full inboard service and repair facility you too will learn a thing or two out side the box!

Did I say that I hadnt driven any older CC's with (incorrect) LH props? I dont recall saying that (because it is not true). I found it to be very disconcerting!

What kind of "out of the box" things are you doing to combat the starboard lean on LH repowers? By rudder tweaks, do you mean tuning (to affect steering wheel pull)? Or are you playing with shaft/prop and rudder alignment? Adding hook to the hull (stbd side presumably?)? Glad to hear that the effects can be minimized to some extent by someone who knows which levers to tweak...

I'll maintain that any hobbyist, like myself, would still be better off sticking with a RH prop on a Correct Craft (especially an older one) if they want to maintain the proper handling of their boat. Simply dropping in a powertrain that turns a LH prop in place of one that previously spun a RH will cause handling problems, in my experience. My guess is that its easier and cheaper for most of us to simply find a way to keep a RH prop than it would be to bring our boats down to FL for you to work on. The number of people with enough knowledge to make the kinds of modifications youre describing are probably pretty few... and I tend to charge myself a cheaper hourly rate.

Yup!

You already got it:

Florida Inboards wrote: Left hand rotation inboards with the driver sitting on the right tend lean down on the drivers side.

^^I dont think anyone will argue this.^^ I also would wager a guess that we'd all agree that narrower boats (ie, older Correct Crafts) will be affected by prop rotation to a greater extent than wider boats, all things remaining equal.

What I *think* we disagree on is whether or not the extra lean to starboard causes a detrimental effect on the boat's handling. I have experienced it, no question about it. On the particular boats I've driven, I doubt that anything was done to compensate for the change in prop rotation. I *suspect* that is usually the case when an owner drops in a LH powerplant (boats converted by Florida Inboards notwithstanding?).

Apparently Jody is contending that the starboard lean can be compensated for in some way- presumably by tuning the rudder and/or hull. Hopefully he'll expand on those modifications in greater detail.

Starboard lean, Port lean can be adjusted with adding hook or rocker or even a bit of both. In my Brief 45 years or so of messing around, building designing, racing,skiing what have you with inboards, Not to mention Working with the designers and builders of these boats one comes to know how to manipulate running surfaces to achieve a desired effect. We went through a period from around 1994-95 where a number of tournament Ski Nautique needed either 40 pounds under the driver seat or the trailing edge of the hull re-worked because of port side lean. Turn right around in 03-05 and we have excessive starboard side lean in a few hulls. Yes some "narrow" hulls will need some sort of compensation when turning the prop opposite direction (left hand) either via hull adjustment or utilizing some weight on the port side passenger seat. some will not it is a case by case issue. Yes I have taken a re powered to left rotation boat to the lake and put it right back on the trailer and back to shop for some sanding sessions on the bottom of the hull. Not a big deal provided you have bit of back ground and some knowledge and understanding.
Propagating an ill effect is caused by an ill design, any boat that shows problems after a refit had the problem before turning from right to left.      

Now building an inboard for specific needs is another story for performance and handling. Take a flat bottom V-drive for example you can build one that turns just fine for a ski boat and run left hand rotation power train. Boat speeds in some can reach 140 mph or better in a straight line. However want to turn a one pin turn and get out of it in shape to mash the go pedal then you build right hand power train to turn left.

Tim Keep in mind it is the middle of the month of January and already I have over 30 hours of seat time in a few different boats. I doubt that you get that many hours in a year it boils down to experience so you go ahead and disagree all you want.

My advice for those that want to think out of the box is to do your homework, Seek advice from experience and don't be afraid to get a second or third opinion and measure twice. Also above all build a safe machine.
    

So the leaning issue is only a problem on Ski Nautiques?

I have a Sanger that spins LH and it does not lean.

The reasoning behind the marketing was "because most skiboats have only a driver onboard" and no one else in the boat??? I read the brochure and I'm aware of hook. Just trying to understand if it was just marketing double talk

Does hook compensate somehow? why would a boat designer design for just a driver in a skiboat? Drivers come in different weights and so do passengers/observers.

how does the hull adjust when you add an observer or passengers? (which is actually how most skiboats are used)

GlassSeeker wrote: The reasoning behind the marketing was "because most skiboats have only a driver onboard" and no one else in the boat??? I read the brochure and I'm aware of hook. Just trying to understand if it was just marketing double talk Does hook compensate somehow? why would a boat designer design for just a driver in a skiboat? Drivers come in different weights and so do passengers/observers. how does the hull adjust when you add an observer or passengers? (which is actually how most skiboats are used)

The hook is in the hull compensating for the prop torque. When prop rotation is reversed and nothing done to the hook, the hook works backwards. IE: The hull rolls from both the prop torque and the hook.

BuffaloBFN wrote: Cars usually lean to port for some reason. Cheeseburgers?

Especially mine! Winter has been rough on me!

Understanding The concept of hook and rocker is not rocket science. No worse than rudder torque and how to manipulate it.
Not always does hook need to be added to make ride changes a lot of times it is just a little sanding and polishing to increase rocker. It is not a black art like some would believe. Propellers and their dynamics are far more complicated yet is discussed nearly daily on this board.

I am off to Short line lake (Pickos site) to take two sets and spend some time in both a new 2013 TXI and put some hours on a new 2013 200. Then back to the shop to put the finishing touches on a 71 Taylor Jet boat that I just fully stringer-ed and installed a composite transom in.
Live the boating life and experience is gained!

AAM196 wrote: 74Wind wrote: AAM196 wrote: The only thing I don't care for about my 99SN is the fact that it backs to the left when docking... Old-school i guess, in a lifetime of boating never been in one that didn't back left. Backing right would sure take some getting used to. Our 83 mc s&s backs to right due to the lh rotation.... easier to dock as driver can just grab dock but leans hard to starboard w/o passenger. I find my 99 sn levels out nicely onces on plane.

My boats both deep-Vs so no leveling issues like a ski boat. Don't often boat solo, so much simpler to just let passengers worry about dock/lines on port side...

For years my bro had a small classic 70something Sutphen with a 200. Kind of a much sexier version of the Donzi Sweet 16 with a giant outboard. What a rocket!...70mph plus but hardest boat I'ver ever docked........

I was born with a hereditary inboard disease I was born with and just can't fight generations on docking on the right side of a dock.

Gotta love a Stars & Stripes...lets see some photos!