I am still confused so I hope this will clear it up for me. Looking at my terrible drawing, my props spin out as shown. Currently I have my drives slightly "Toe Out". Measuring at the front of the drive torpedo it measures 36-5/8" and at the end of the prop shaft it measures 36-7/16". Did I go the wrong way for props turning out?

PQ290,

This is a very simple way of looking at it. The prop nuts are going to want to deflect in the direction the top tops of the props are moving while spinning, so you want to pre-set them in the opposite direction of parallel. When the drives absorb the lateral load of the prop torque, the drives will deflect toward parallel. By your diagram, you want them to have "toe out" while not under load.

Thanks. Brad.

your boat have tabs? run them down until they just touch the water. when the boat leans one way the tab will push against the lean. kind of like training wheels on a bike

Thanks Brad. It looks like by accident I got it right. Saber, I do have tabs but was just wondering if there was any relationship between drive alignment and chine walk. Just looking at options that come to mind as I reassemble the boat and get ready for the upcoming season.

PQ290,

Just thinking theoretically in my head, considering the physics that I think are in play.... I would think your alignment should be somewhere between dead parallel and some slight toe out while under load. How much preload misalignment that is going to mean, I have no idea. My thinking is that, as the boat lists to one side during chine walk, that prop and outdrive skeg would gain traction over the other, and work to counter the lean. With this in mind, I would think that props spinning out, as you have in your diagram, would be far preferable to spinning in. For the life of me, no matter how I try and rationalize otherwise, I can't think of a good reason to have props spinning in, and this thread just further entrenches that belief in my mind.

Thanks. Brad.
(937)545-8991

Your right cheech....i must have been hanging out with Chong a bit too much and a few brain cells dont work any more! LOL
For some reason i was thinking the vertical shaft inside the drive would have been the pivot point...stupid me should of known better
But i still stand by my posting "the prop shafts at the tips are farther away from the centerline of the drive then the nose cones are" I guess i should have said it better instead of "centerline"....should have used "Pivot point".... Thanks for setting me straight
either way the jist is the same...adjusting the distance at the prop shaft tips will net small changes at the nose cones....

how balanced is your boat ? in perfectly calm water is the transom level? the boat being heavier on one side could cause problems.

now i'm no expert but on cars or anything with wheels you always set the front wheels to toe in. i can always tell a car that has bent a tie rod in a car that has the rack behind the wheels because it makes the car toe out.

they drive skittish and hunt back and forth.

i dont really buy stories about deflection in the drive or transom assembly. maybe some super small amount like .020 but the tie bar isnt stretching or compressing. and i dont see how the transom assembly is moving so that would leave the drive to twist?

mine has a fat 1/16 toe in measured off the leading edge of the lower unit to the prop shaft centerline

Funny you should ask. I don't know how it looked just sitting in the water however, when I put the stereo in I thought it would be a great idea to have 2 larger (physically) batteries running it so there was absolutely a chance that the boat was not as balanced as it could have been. This year I only have one battery on each side and they match of course. I was thinking about getting the AGM batteries and locating them between the stringers to keep the weight centered and low as possible. I have also reduced the weight in the transom by swapping out a bunch of cast iron parts for aluminum. New heads, intakes, and exhaust. After studying a little further, I have come to the conclusion that weight itself is probably not the chine walk problem with my boat because they produced my boat with LS engines and also made a couple with just a single BBC and they too at speeds in the 70's had some chine walk. I have my drives now about the same distance of "toe" but in reverse from yours. At this point, I'm just going to run it and see what happens. I have no idea how my boat will handle the new power and speed plus I changed out so many things that I really won't know what may have had the biggest impact. This drive alignment question was just something I thought about as I was getting ready to install them and I know that some guys don't set them up exactly parallel and I was wondering why and which way to go. I too don't know what is moving underway. I guess the case is flexing in one direction based on prop rotation? I've read other threads about other manufactured boats and they too have some walk in the 70's so I'm not alone. I really like this boat and will live with whatever comes my way. With a total of 1,000 hp I'm sure it's going to be a riot!