Re: New to inboards
V Drive transmissions are available from a few manufacturers. The most popular are Paragon and Borg Warners' Velvet Drive. Their primary benefit is to allow the engine to be placed near the stern of the boat, allowing the builder to maximize interior living volume. Often the V Drive's shaft packing can be extremely difficult to service because if it's location directly beneath the engine.
Here's some info cut and pasted from various sources:
Paragon:
Velvet Drive:
VELVET DRIVE 71 - 72 V-DRIVE
Borg-Warner's integral V-Drive marine transmission is a compact, self-contained unit that helps create extra cargo and cabin space by allowing you to move your engines further aft. Because the V-Drive requires no universal joints, a potentially costly maintenance item is completely eliminated. The deeper offset of the Velvet Drive? V-Drive marine gear allows easy propeller shaft alignment for quick, simple installation. A series of reduction ratios is available. For twin-screw applications, opposite propeller rotation can be provided for two engines of like rotation through the use of gear and chain drive transmissions.
Cutaway:
Random thoughts about inboard power:
Shifting will be smoother with inboards.
Less maintenance compared to I/O's
From my experience, inboards are typically more responsive (than equivelent I/O's) during low speed manuevering due to their propellers being located closer to the boats' pivot point. OTOH, inboard rudders are usually NOT very effective at low speeds because they require waterflow over their surface to work. Most competent captains will not turn the wheel, but use the transmissions and/or throttles to control the boat around the docks.
The packings (shaft and rudder) are typicallly flax, sometimes impregnated with teflon. These should be adjusted to minimize water entry, but properly adjusted flax packings SHOULD allow a miniscule amount of seepage to lubricate the shaft (roughly 1 drop per minute). The newer GFO packing is completely self-lubricating, so they should be adjusted to the point where NO water enters the hull.
The strut bearings (supporting the shaft below the hull) are lubricated by water and not adjustable. If they are holding the shaft without allowing lateral movement, they are OK.
Obviously, inboards are not trimmable or tiltable so extra care must be taken operating in shallow water.