the drivetrain dynos were made by AVL. They are the end all manufacturer of dynos. All F1 teams use AVL . The Axiline Might work , with a few adaptations.

If your wanting to physically stand next to the drive at full steam and monitor things ,prob going to be the the stern drive hydrolic dyno , i think they will absorb somewhere in the neighborhood of 350 hp. If you probe and gopro a wet test with 2 boats tied together ,old axial pump test style do please share destruction videos . If destruction happens

I hope this test involves strain gauges and data logging. I'd love to see what those cases do under load.

We have an OLD K&O Dyno like you mention Airjunky , but its hard to keep the oil cool enough to do any durability . I would like to see the drives tested to destruction also! I think land & Sea also has a propshaft dyno . But then your beating on your engines too.

Are you looking to connect the drive, and then apply load to BOTH ends to determine how much torque / rpms before the drive grenades? Might be something that a hydraulic lab like the one at Eaton Transmission in Marshall Michigan might be able to work with.

Need a hydraulic torque stand that would somehow let the prop shaft spin at a specified level to reproduce slip. If you could measure torque and let the shaft slip 10% that would be pretty cool.

We test hydraulic tubing and casing tongs that way. The fixtures would be expensive for the drive setup!

Imco also made a drive dyno to test their outdrives before they were tested on the water and out on the market place. It was just for the outdrive only not needing any sort of engine to run it.

The outdrive could be rotated at low rpm and loaded to various resistance pressure levels like it was pushing a boat thru the water. Imco drive dyno had a electric motor, a hydraulic pump, a control box to shift the outdrive.

Also the drive dyno had a reservoir tank that had adjustment valves to regulate the pressure against the drive if I recall correctly ran a line then compled to the propshaft.

The reservoir tank also had a mechanical pressure gauge that could be monitored for the different pressure levels.

The unit also had a blower type belt to electric motor that tide in (spun) the hydraulic pump in which had a coupler & shafted into to the upper of the outdrive to run it. .Again no engine needed.

BUP ..... Sounds like I need to talk to Imco. Thx.

My buddy works on the elec motor turbines that cool the nuke power plants basically 2 berkeley jet boat pumps with bronze "b" impellers daisy chained .run easy . The electric motor that runs those things is massive. I would think to duplicate the 500ftlbs of a big block for at the limit testing , your may need a big block with 500ft lbs
what you wont need is 3 phase 480 at least lol . But yea whatever your into here sure does sound interesting

maybe another source to talk to or see if anyone has a drive dyno would be Craig Colabella he is in the Sanford area or possible close to Orlando area. he use to work at Merc Racing and did a lot of their drive work and for the race teams. He worked at Lake X back in the day to.

Someone up here would have his number if not Velocity Powerboats has his address and number. Or just google it.

Also another possible source for info could be Mel Riggs in WI.