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Post by lollygagger on May 17, 2017 19:20:45 GMT
OK, I still love my boat. It's mine for all it's sins and it has ... some good points. This is wrong isn't it? Not the water/diesel mix, the wood blocks. Why have they been jammed under the engine? Hit me with it, I can take it!   |
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Post by lollygagger on May 17, 2017 19:27:24 GMT
Just noticed from the pictures that the bottom two look opposite wedge shaped. Height adjusters. Grrr. Not much point mounting an engine on vibration absorbing mounts then ramming firkin timer wedges under it is there? Grr. I feel a block and tackle purchase washing over me, I've always wanted one.
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Post by Delta9 on May 17, 2017 21:41:26 GMT
Hard to understand whats going on there from the pictures. Are the blocks taking the weight of the engine? Where are the engine mounts and what do they look like?
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Post by lollygagger on May 17, 2017 22:03:58 GMT
Hard to understand whats going on there from the pictures. Are the blocks taking the weight of the engine? Where are the engine mounts and what do they look like? it looks like they take the/some weight of the engine, under the sump. I'm going to have a guess. The/an engine mount(s) is knackered, engine shook, all eeky eeky with prop shaft, jam in wood for temp fix, never got any further. Now it's my job, I can't be content with that going on. |
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Post by lollygagger on May 17, 2017 22:06:50 GMT
Actually looking again, not under sump, under (I don't know what you'd call it - bell housing?) The bit encasing the flywheel.
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Post by Delta9 on May 17, 2017 22:13:46 GMT
Do the mounts look fucked? Take the wood out and start it it up while watching it to see if there is any noticeable difference.
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Deleted Member
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Post by Deleted on May 17, 2017 22:25:20 GMT
Could be engine mount(s) bottoming out on the steel rail underneath. I had this with some rubber mounts on a Lister LPW2 and it made the engine very noisy. There was a loud hammering noise. If I levered the engine up a bit it would quieten it down. I obtained new rubbers for the mounts which solved it properly. The wood blocks might be doing a similar job or as you say just maintaining alignment on shagged mounts.
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Post by lollygagger on May 18, 2017 7:01:59 GMT
Do the mounts look fucked? Take the wood out and start it it up while watching it to see if there is any noticeable difference. I won't be taking them out until I'm tooled and parted up to fix it. Lord knows how they got them there, I can just about get a hand to them. I'll check out the mounts later, I was clearing out the bilge when the camera spotted the wood blocks. |
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Post by lollygagger on May 18, 2017 7:03:37 GMT
Could be engine mount(s) bottoming out on the steel rail underneath. I had this with some rubber mounts on a Lister LPW2 and it made the engine very noisy. There was a loud hammering noise. If I levered the engine up a bit it would quieten it down. I obtained new rubbers for the mounts which solved it properly. The wood blocks might be doing a similar job or as you say just maintaining alignment on shagged mounts. Good call, I'll report back later. |
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Post by lollygagger on May 18, 2017 8:42:07 GMT
Shock absorbing engine mounts are for sissies? Real men just bolt it to a couple of bits of 2"x3" timber. :thumbup: Stern at top of pics. Front...  Rear...  |
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Post by lollygagger on May 18, 2017 8:53:30 GMT
... and 29 years ago...Photos of photos...   |
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Post by lollygagger on May 18, 2017 9:16:13 GMT
The timber under the mounts is on steel bearers and more or less packing. Maybe it shrunk enough over nearly 30 years to cause a problem. If that were the case, tightening the bolts to take up the shrinkage would have made it worse. But I'd have thought it would have been easier and more sensible to shim the mounts so maybe there's another reason for the blocks under the flywheel casing.
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Post by lollygagger on May 18, 2017 11:08:22 GMT
The coupling to the prop shaft is also solid.
Would I be right in thinking that if I replace the timber bearers with rubber mounts the same thickness using the same bolt holes and fit a flexible coupling to the prop shaft I should be still lined up a a whole lot less boat vibration?
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Post by TonyDunkley on May 18, 2017 13:26:25 GMT
Would I be right in thinking that if I replace the timber bearers with rubber mounts the same thickness using the same bolt holes and fit a flexible coupling to the prop shaft I should be still lined up a a whole lot less boat vibration? Yes, broadly speaking, but there are a good few qualifying "ifs" to be thrown into the reckoning to achieve that result. Solid couplings and engines bolted down solidly to the bearers with a hardwood strip under the engine feet is a perfectly acceptable way of doing things, but is a method that has now fallen into disuse owing to the reduction in both (relatively) high frequency noise and vibration that can be eliminated by using resilient engine mountings and gearbox to tailshaft couplings. A correctly lined up installation with solid couplings and solidly bolted down engine will give many years of reliable and minimal wear service, but it will transmit a lot of mechanical noise and combustion induced vibration direct through the hull structure while it's doing it. From what can be seen in the photo's, I would think that those shallow angle, folding wedges to the side of the flywheel housing and under the engine were probably used to lift the engine and slew or move it sideways whilst it was being lined up with the tailshaft, . . . and that whoever did the job either forgot to remove them afterwards, or just couldn't be bothered. If you do need to lift the engine, don't go blowing a load of cash on lifting gear, . . . I've got a good selection of Pul-Lifts and chain blocks, and you are more than welcome to borrow whatever you need. That engine looks like a marinised D3.152. The flywheel alone is around 2 cwt. on those engines, and with the gearbox and cooling equipment etc., the all up weight will be in the order of around 8 cwt. |
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Post by lollygagger on May 18, 2017 15:15:30 GMT
Would I be right in thinking that if I replace the timber bearers with rubber mounts the same thickness using the same bolt holes and fit a flexible coupling to the prop shaft I should be still lined up a a whole lot less boat vibration? Yes, broadly speaking, but there are a good few qualifying "ifs" to be thrown into the reckoning to achieve that result. Solid couplings and engines bolted down solidly to the bearers with a hardwood strip under the engine feet is a perfectly acceptable way of doing things, but is a method that has now fallen into disuse owing to the reduction in both (relatively) high frequency noise and vibration that can be eliminated by using resilient engine mountings and gearbox to tailshaft couplings. A correctly lined up installation with solid couplings and solidly bolted down engine will give many years of reliable and minimal wear service, but it will transmit a lot of mechanical noise and combustion induced vibration direct through the hull structure while it's doing it. From what can be seen in the photo's, I would think that those shallow angle, folding wedges to the side of the flywheel housing and under the engine were probably used to lift the engine and slew or move it sideways whilst it was being lined up with the tailshaft, . . . and that whoever did the job either forgot to remove them afterwards, or just couldn't be bothered. If you do need to lift the engine, don't go blowing a load of cash on lifting gear, . . . I've got a good selection of Pul-Lifts and chain blocks, and you are more than welcome to borrow whatever you need. That engine looks like a marinised D3.152. The flywheel alone is around 2 cwt. on those engines, and with the gearbox and cooling equipment etc., the all up weight will be in the order of around 8 cwt. Happy Birthday.  Thank you for taking the trouble to answer so fully and for the kind offer of lifting gear. There's just one set of blocks under the flywheel housing, the photos are deceptive. You knew you had the engine ID right so I won't confirm that.  It can't really do much good for the general structure of the fit-out to be so vibrated, but it's been well used for almost 30 years so I guess it's more a matter of whether it bugs me, which it didn't before my camera spotted the chunks under the engine. If they've been there all that time, it would probably be asking for trouble to remove them. I think I'll leave it, the vibration can be quite restful and a touch hypnotic. |
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