E29 Atomic-4 Engine mounts

J

jkenan

Member III
I am concerned that the Engine mounts in my E29 for the A4 do not hold the engine captive to the hull. The design of each mount is basically a shoe that is bolted to the engine compartment that receives a rubber foot which has the integral bolt used to secure the A4, and assumes gravity will keep the engine in place. I could envision the engine 'jumping out' in a knockdown, being held only by the shaft, and am afraid of the damage that scenario could do to the shaft, engine, and more importantly, the shaft log.

Anyone else tackled this?
 
footrope

footrope

Contributing Partner
Blogs Author
the rubber is used for vibration and noise reduction. the mounts i have appear to be able to keep the engine in place even if the rubber is deteriorated and useless. are you planning to chain the engine down as a safety measure or are your mounts designed so as not to keep the engine roughly in place even if they're shot? could you post a picture or one of them?
 
J

jkenan

Member III
The rubber seems to be in decent condition - no crumbling, cracks, etc - so alignment is not the concern (Engine seems to have stayed in good alignment since I bought the boat in '95). The rubber footings will pull out of the mounts (bolted to engine pan) without too much effort, so there is nothing keeping them in their mounts except for gravity, which is the basis of my concern, and I don't think I want to chain the engine down.

I am planning on cutting out the bottom part of the engine pan so I can do two projects:
1) Replace the wood blocks on either side which are glassed underneath the mounts - this is because some of the bolts which secure the mounts have stripped the threads in those blocks, and I suspect rot.
2) I want to fill in the sump, and glass over the fill material with roving - also install a couple of recessed bilge pumps (Rule 2500's) into that area. Removing the lower part of the engine pan will give me excellent access for this, and provide a more direct route for the bilge pump lines to the stern.

I would re-install the cut-out part of the engine pan after completing those projects.

Replacing the mounts seems like an obvious upgrade if I move forward with these projects, and I'd like to use mounts that dampen noise and vibration as well as hold the engine securely in a knockdown and not just 'float' the engine on it's mounts as my current mounts do.

Any ideas on which mounts to use?
 
footrope

footrope

Contributing Partner
Blogs Author
I misunderstood what you were concerned about. There are threads that deal with the situation that you have and a search would find the posts.

The isolators (probably the proper term) that I use are cast and circular with the rubber pieces that must be donut shaped. The casting includes two ears for bolts or lag screws to attach to the beds. The rubber donuts are captured inside the casting. As long as the rubber is in good shape, that will keep the engine from falling over in a knockdown.

The rails or beds that the isolators mount onto are another matter and that area in my boat is ok. Loren's link is probably a good place to start. Have fun.
 
You must log in or register to reply here.
Top