Now that I've got my engine out, and getting it reconditioned, I'm looking at my bearings and beds. The beds have been extended by a previous owner by joining additional timber to the forward end, but the forward bolt-holes align with the joint, creating the cracks in the photos.

I have three options;

1 Do nothing and re-fit the old bearings into the old screw-holes in the old beds. Pros - least work. Cons - I should probably replace the bearings, Murphy will guarantee the new bearings will not fit the old holes, the problems with the beds are still there.

2 New bearings and partial rebuild of beds by replacing the lower "step". Pros - new bearings, fixes the forward bolt holes that align with the joint, retains rear bolt-holes that I might be able to re-use to re-align the engine

3 New bearings and total rebuild of beds. Pros - new beds, bearings, everything anchored and secured nicely. Cons - plenty of work and fiddly re-alignment of engine.

Consequential question - what kinds of new bearings should I get? Will "generic" (meaning, designed for the size of the engine) bearings be OK? Or, do I need specialist Bukh bearings for my Bukh motor?

Assume when you say "bearings" you are talking about the engine mounts. The timber work extension is bad - should have been spliced in. Albeit a decent epoxy glue joint should have held it. The black gunk doesn't look line epoxy though - is it a polyurethane adhesive / sealant?

Would not do 1 or 3, rather 2. Would not replace all the timber in the lower step rather remove all the old added on timber and splice in a suitably shaped oregon piece which replaces this timber but splices in gradually to the rest of the original timber, with the new timber piece ending just forward of the step down but faired in nicely so that this corner at the step down doesn't become a stress concentration hotspot and lead to the timber beds cracking there. Good epoxy joints, no voids, the joint assisted by suitable gauge and length csunk monel wood screws. Good bond to the timber of the beds as well as the grp of the hull floor. Epoxy resin add suitable cloth over the whole lot of new timber - round timber edges so the cloth has no voids.

How old are the engine mounts and what is their condition? Probably new mounts are suggested - check Bukh prices as well as equivalents from Polyflex which are excellent - assuming they are true equivalents as regards load rating and stiffness.

Don't forget to replace your polyflex bearing as well.
They do work harden.

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r13 said..
How old are the engine mounts and what is their condition? Probably new mounts are suggested - check Bukh prices as well as equivalents from Polyflex which are excellent - assuming they are true equivalents as regards load rating and stiffness.

I would definitely go with new engine mounts as well as your flexible disc coupling.

Have a look at the Poly Flex Australia website www.polyflex.com.au/products

I recently replaced my engine mounts & coupling and found them very helpful - send them an email or give them a ring with your engine specs - great product!!

Considering the expense and effort your putting in I would replace engine mounts, flex drive and fix the engine bed extension while you can get at it all

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Achernar,
have a look at Blackwoods, I got my Bukh engine mounts from them a lot cheaper than Bukh Aust, exactly the same product, been in service for about 7 years with no issues
Mackay M135219 Flange Isolator Sdd


Mike

Thanks for your replies.

An update. Today, I took off the extensions to see what lurks beneath. All it took was a half-inch socket and a few taps with an old chisel. As expected, the extensions were held by coach bolts and epoxy. The epoxy is the brown stuff in the photos and is hard-bonded to the original finish on the bed towards the rear, but not well bonded to the timber extensions. The timber extensions were surprisingly wet, but felt like sound timber. Could they be teak or western red cedar? Maybe the natural oil in the timber prevented the epoxy from bonding better. The port bolt-hole passes down the join between the extension and the bed. My current thinking is to scarf in some new timber on the lower step, per Option 2, above.

I might be getting into ship-wright territory to get the beds sorted and aligned.

PS The photo with the wires is the starboard bed. The chip at the top left corner exposes the light finish on the original bed, beneath the dark brown epoxy for the extension.

IF that is epoxy it was used to seal the timber not as a glue, typically with epoxy the wood fails before the glue if tested to destruction. If the mount bolt goes through the joint, how about cutting the bed back a bit and bolting in a stainless or gal or painted steel bracket to take the engine mount mounting bolt ?