Help Finding Drive Shaft Centerline
 

I am trying to figure out a way to determine what my propshaft depth would be for new drives based on current engine height. My thought was if i knew the current TRS drive shaft centerline, i could then take measurements off this point for new drive. I cant find any TRS drawings with the measurements, so does anyone know what the drive shaft centerline measurement is in relation to the transom cutout? In pictures it looks like its about 4" or so from the top, or maybe in the center of the very top & bottom assembly bolts. But would like something more accurate than my eyeing of internet pics. Engines are out of boat & drives at shop. So the only reference point i have right now is the outline of the transom cutout.

I already know i will need to move the engines back, so now curious if i will need to change the engine mount height too.

TRS input shaft to prop shaft centerlines is about 24.5 inches.

What drives are you going with??

Right. But that in itself doesnt tell me where the input centerline is in relation to the drive cutout. If i knew all TRS Cafe's had propshaft at lets say 5.5" below hull, then yes i could measure up 24.5" to find input centerline, & then measure down again for the new drive length.

I just dont have any hull reference right now to know where to start my measurements. If that makes sense. lol.

Reason i am curious is i thought i was buying a pair of Konrad 540 PRS's as direct TRS replacements. What i received was a pair of ACE drives which are meant for Bravo replacements. I actually like the ACE package better since it has built in steering & extension boxes. And since i have a fresh transom without any cutouts, it wont take much more effort to use these drives. So i know i will need to move the engines back, & now just want to get an idea of the height change the engine will need.

A used pair of Konrad ACE's. They were delivered Mon & i only had time to move them into the shop. But from my initial viewing they look much more massive than my TRS- especially with those extension boxes. i will be back out at shop this weekend so thats why i wanted to try & get idea of my engine placement.

Are the new drives shorter than the TRS’s?.... with the boxes you’re going to want them higher than they were originally

I believe the regular lower is 1.7" shorter than TRS. I am pretty sure that's what is on them. Tomorrow I plan on getting the measurement to verify standard or shorty. Then the fun part of figuring out where my props should be, exhaust & transmission changes...

What you really need to find is what is the X dimension set at on the Cafe's with Bravos.
Then raise it another inch up for the ext boxes.
Then determine the difference in depth of the Konrad vs Bravo.

Does it have a notched transom ?

if not, you might try to get a hold of Carter and see if he has any info on the set up of this unit
as to where the prop shaft depth Is
https://www.offshoreonly.com/classif...35-o77771.html

https://cimg4.ibsrv.net/gimg/www.off...216265e5ea.png
https://cimg5.ibsrv.net/gimg/www.off...5443029a95.png
https://cimg6.ibsrv.net/gimg/www.off...f3d965898d.png
Originally from Full Force thread I believe.......I don't have a drawing from a TRS but the numbers seem to correlate from Image 1 to the SSM drawings as a visual aid

F.F. may have the actual drawing if you PM him