Solid Engine Mounts

[zerubb]

I have recently purchased a heavy displacement Laurent Giles Vertue fitted with a Bukh DV 18ME twin cylinder (1990 vintage). The engine has very low hours and appears to be in excellent condition, however it has been fitted on solid timber engine mounts, through bolted directly to the longitudinal hull bearers. The engine is quite noisy; I believe the engine mounts to be the cause as the entire hull seems to act like an amplifier. On the delivery trip we were forced to motor for nine hours, due to lack of wind. The engine performed faultlessly, except for the noise levels, although at the end of that trip I noticed a few hoses had worked loose. Once tightened, no further problems have been experienced.
The solid mounts were professionally fitted a few months ago, no doubt to save cost. I could probably get used to the noise levels but I am concerned that this set up is not ideal and could potentially cause problems down the track. Bukh recommend flexible mounts for this engine, but these cost around A$750 plus the cost and hassle of fitting. Could anyone advise if solid mounts are acceptable on this type of engine?

[PBzeer]

An engine is going to vibrate, and if not isolated by flexible mounts, will transfer that vibration, and though I'm by no means an engineer, logic says that vibration will have a negative effect. This seems like a "pay me now, or pay me later" situation, that would best be done now.

Regards,

[GordMay]

Marine Engine Mounts:

Bushings,Inc.
1967 Rochester Industrial Drive  Rochester Hills, MI 48309-3340
Tel: (248) 650-0603
Fax: (248) 650-0606
Web: http://www.bushingsinc.com/marine.htm

R & D Drivetrain Solutions
12532 Beverly Park Rd.,Lynnwood, WA 98087-1524
Toll Free: 800-523-7558
Fax: 425-355-3661
Email: Info@Flexible-Coupling.com
Web: http://www.flexible-coupling.com/r-a...ne-mounts.html

[sailingdog]

I'd agree that the solid engine mounts are probably not such a good idea. They will transmit all the vibration to the rest of the boat, and that's probably not too good for the rest of the boat.

Also, the excess noise and vibration caused by the solid engine mounts are going to be a stressor on anyone working/living on the boat while the engine is being run... and that can cause mental fatigue and other problems, which can probably be avoided or reduced by using vibration isolating engine mounts.

[redcorvette1995]

Vibration breaks things.
I would get the flexable mounts ASAP.
Money spent now will save you lots later IMHO.

Todd

[Sasha_V]

The only advantage to solid mounts aside form cost is that they are less likely to break in a knockdown or rollover situation. There are numerous accounts of boats being "kerwacked" by big seas only to come upright without a mast...and the engine knocked off its mounts and unable to drive the boat.

If you are not planning on playing in the Southern Ocean, then you want to investigate getting the anti-vibration mounts.

Sasha

[haffiman37]

If not mistakem that engine is rather heavy with a huge flywheel in the front. The original Bukh mounts does not make that big difference in vibration as the forward mounts are rather 'solid'. What I have seen on that type and even other on similar types is to mount the engine on a frame and the frame on mounts. This way it is possible to get the rubber mounts furter apart and a possibility of using softer mounts.

[zerubb]

Thanks for all the advice. It seems I will have to draw on the cruising funds and install flexible mounts. According to the Bukh owners manual the engine is "light weight 118kg". The Vertue is just under 26' LOA with a beam of only 8' so the engine bay is a bit cramped, certainly not enough room for a meaningful frame.
Regards Joe