I have sent these pics to Tom  (jetboat performance) but wanted to get some feedback from you guys on my current mock setup for my new engine, pump, and drive line setup.  I have the engine (built by Barry) as low as it will go unless I take out the leveler bolts which will drop it another inch or so.  I just want to be sure i'm not stressing the drive line out to much.  Please take a look at the pics and tell me what you think. I know the drive line is to deep into the splines, but I'm just trying to get the motor and drive line in the right angle. Thanks in advance for your opinions / help.

Bill

Dan,
 
thanks for your feedback.. I was afraid of the pan depth being an issue..    I need to figure out what pan to get for this Merlin 632 block. 

I believe on my BBC, the pan measured out at 7 3/4", and clears the pump intake less than 1/4 ". I had 3 other pans that were 8.25 to 9", a huge breadbox pan,(8.625") bbc truck pan (9.0") and a dooley pan (8.25") were too deep.
It may also be to wide for the Vee of the boat.
Nice lookin mill, btw

Daniel
Mash on it

What engine/pan was in the hull before?... or is this a new build that you don't have any history.

Hey Bill, how does the angle of the engine compare to the angle of the intake? 

taking out/cutting off the leveling bolts (what you did) would have been my suggestion.

0.5 degrees is good. its all in personal preference.

some like it at 0 - their argument is there's an equation that X amount of HP is lost per degree. I dont recall what the speculated HP loss per degree it is.

some like it 1 degree off - their argument is that the driveline needs a little tension to avoid vibration.

I've run a setup as extreme as 3 degrees with no issues.

I learned a little about driveline angles and u joints when I put the Gear Vendors on the Ford and went from two piece shaft to one piece.

This is just the same as a one piece shaft, just shorter. Two u joints and one shaft need to work together on two angles,using a bubble protractor, find the angle on the back of the motor and the angle of the face of that first bearing on the jet need to be opposites in order to get u joints to cancel each other. U joints don't lubricate themselves if they don't have to flex..

I'm not pulling this out my ass, I went through months of trial and error with driveline angles and vibrations at different speeds. Engine to jet is simpler because the jet doesn't torque upward under load when you mash on it so the static angles you wind up at don't change under load.

Lemme find the picture that was worth a thousand words and I will post back.

Sent from my ADR6400L using Tapatalk

Your example shows one way a driveline can be configured.  The other way is with the tailshaft of the engine/transmission pointed at a down angle, like your diagram shows, and the pinion end of the differential also pointing down, so that the angles are equal (but opposite, relative to the centerline of the driveshaft).  I "think" that this is the way that many drivelines in jet boats typically end up looking like, if you rotate the whole boat (in your mind) so that the h-bar is parallel to the horizon: The input end of the pump shaft is pointed down, and the flywheel end of the engine also pointing down.

To understand why a driveshaft has to be configured in either one of these configurations, you have to remember (or realize) that a u-joints (and the attached driveshaft) are not a constant-velocity devices unless everything is operating along the centerline of the driveshaft (no angle at either end).   This is rarely the case, and not recommended (for bearing lubrication and wear issues).  The cross ends of the joints are accelerating and decelerating throughout one revolution of the joint, as is the driveline.  You need to have each end of the driveshaft accelerating and decelerating in-phase to minimize vibration and destructive harmonics.

Good comments re; angles between H bar and engine crank and the H bar and the pump shaft needing to be the same.   It does not matter if the angle is up or down as long as it is the same.  For high speed 3 degrees is pretty high but will work.  You will see decreased life of the u-joint.  1-1 1/2 degrees is good rule of thumb.  You need some angle as it results in the needle bearings rotating in the caps and causes lube to be pulled into area between the components.  Very small angles or no angle and the bearings will brinnell due to load being exerted on same area with no lube.  Good Luck with your build.

Working on new photo's..   Stand by...

Bill