Why V drives..and why remote v drives ??

[BillD]

Now that the west coast 38 WESMAC commercial build is complete and in the water, I figured you guys might want to read this new Tony Athens article.

The article sums up the benefits of a "remote v drive install".

FWIW, Bill D

Why V-Drives, and then again, Why REMOTE?

 

[delucat2]

Nonsense! Tomfoolery!

Just kidding. I have known Tony for 20 years and seeing his work "come to life" in his shop is magical for weekend warrior knuckle busters.

There are no plans to follow, no one to copy. He and his crew (Frank!) execute based on thought, imagination and practical knowledge.

Aviation succeeds because of strict adherence to rules and regulations...and what you have to realize is that that has slowed aviation and aerospace development to a snails pace...all because having people fall to their deaths is unappealing. Same with the auto industry. Boatbuilding is one of the few areas where you can make your own rules and win - depending on your market and the USCG inspectors. Unless the skipper runs one of these beauties up on a beach, the CG is not responding to a distress call from the boats that come out of Seaboard. This is awesome.

 

[[email protected]]

I don't get the part about no feeler gauge needed in the Athens article. The remote Vee needs to be aligned to the propshaft just like any conventional close coupled transmission. Most of the time this is even tougher than usual because it is on solid brackets and needs to be shimmed rather than just turning isolators up and down. From the pictures that remote looks well installed but as a former ZF field tech I saw some unbelievable mistakes. The worst was a 2500V behind a MTU 2000 that had a driveshaft angle approaching 35 degees (factory maximum allowable is 3). Yeah, 5.25 inches of drop in 13.5 inches of driveshaft length measured from the U-joint centers. I was there to put a new input shaft in the starboard gear after the spicer shaft had grenaded at 1600hrs. The other common remote mistake was insufficient brackets or mounting as all the thrust is on just 2 points instead of the 4 or 6 with a close coupled gear/engine mounting.

 

[delucat2]

You can see that Athens builds the remote v drive mountings just like engine mounts - easy to adjust to get aligned - once. No shimming. I think what he is referencing is not having to align engines. Just set in place an connect the driveshaft.

 

[BillD]

You can see that Athens builds the remote v drive mountings just like engine mounts - easy to adjust to get aligned - once. No shimming. I think what he is referencing is not having to align engines. Just set in place an connect the driveshaft.

Agreed,

And if you read the re-power articles on Tony's website you'll see that remote vdrive and shaft installation are "needle point" accurate from the beginning.

 

[[email protected]]

You can see that Athens builds the remote v drive mountings just like engine mounts - easy to adjust to get aligned - once. No shimming. I think what he is referencing is not having to align engines. Just set in place an connect the driveshaft.

I understand the engine is on isolators that are far removed from the prop shaft installation and it's alignment is absorbed by the spicer U-joints in the jackshaft, but what do you mean that there is no shimming, measuring with a feeler gauge, or aligning the transmission to the propshaft? They look like aluminum angle brackets like any crew boat repower that need to be shimmed to get somewhere around 004". I'm not saying it's undoable, I'm just saying it has to be done and checked from time to time. To say a remote Vee does away with shaft alignment is giving the installation credit it's not due. And what I am looking at in Miss Conceptions installation that looks so easy to adjust, to me it looks like angle aluminum on angle (the way I would do it on my own installation) but not easier than Barry isolators. Yeah it's easier than Chockfast Orange but not easier than standard isolators.

 

[[email protected]]

You can see that Athens builds the remote v drive mountings just like engine mounts - easy to adjust to get aligned - once. No shimming. I think what he is referencing is not having to align engines. Just set in place an connect the driveshaft.

If you scroll through them some have adjustable isolators but some are just aluminum angle on angle. I have spent considerable time on some Vee installations jacking them up and shimming.

 

[delucat2]

I think what is missing here is the understanding that in his builds he's talking about a completely new installation. The trans is mounted first, the coupling for the shaft installed with a dummy shaft - and the intermediate and strut glassed into place based on the position of the shaft. unless the trans comes out, this never changes. Replace the engine, no need to realign.

Going from one trans to another....sure, I see that you'd have to align.

I can not think of any reason that he's ever be in a position to need to shim though. When the boats he works on go from 400 to 600 hp engines, he takes the old trans out... as well as the intermediate and strut... and starts all over with the new trans. If he had a particular trans fail, he'd figure out why and reinstall the same rather than switching brands or models to solve a problem.

Get one end fixed in place (such as the rudder), mount the trans and fill in the rest of the pieces. I thing too many jobs get overly complicated and later have issues) because of trying to "make something work" instead of doing it right. Part of doing it right is understanding why something failed, not just upgrading/changing and hoping it will work out.