Author Topic: Plenty & Son marine engine restoration  (Read 11658 times)

Offline steamer

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Re: Plenty & Son marine engine restoration
« Reply #30 on: September 03, 2014, 03:01:31 PM »
4 holes for the 4 bearing surfaces
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Rivergypsy

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Re: Plenty & Son marine engine restoration
« Reply #31 on: September 03, 2014, 04:28:38 PM »
DOH! :facepalm: Thanks for that!

What do you think about the white metal lining, Steamer?

Offline steamer

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Re: Plenty & Son marine engine restoration
« Reply #32 on: September 03, 2014, 04:42:43 PM »
Babbit is the way to go with these bearings...   It's old, but it works!...

These engines were designed to be worked hard all day, you can count on it.   It's finding someone who can do it is the challenge.  Those are poured bearings...not machined.    You may be able to use the crank as the core.  Keep the shims, you will need them for the pour, and to take up wear later.

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Maryak

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Re: Plenty & Son marine engine restoration
« Reply #33 on: September 04, 2014, 03:43:56 AM »
Hi Guys,

Babbit............. now there's some good old fashioned technology......love it. OK not trying to teach you to suck eggs but there are quite a range of babbit metals and a lot of the formulae used in the good old days are no longer made today and the cost of making a batch for such a small one off is absolutely prohibitive. Maybe you can find the  formula but without the drawings, almost impossible.

Probably the cheapest option would be to buy a bar, (ingot), of say ASTM No.5 Babbit and pour with that. I would recommend that you make up dummy cores etc. because for a successful pour the elements involved need to be preheated so that the Babbit does not contract too rapidly and lose its properties and integrity. Lastly cleanliness is next to godliness where the Babbit meets the backing material and tinning the backing material with plumbers solder is very helpful in getting good integration.

HTH

Best Regards
Bob

Edit: I've been thinking, (always dangerous), but where to go to get help? Looks to me like you are in UK so I would suggest your nearest, (not that anywhere is that far away!), vintage car club,your local crane maintenance depot or your local underground mining location. Why the last 2? Because the ends of the wireropes are normally fitted into a knuckle which is in turn held to the wire by whitemetal poured into the knuckle amongst the evenly spread out strands of the wirerope. Lastly there may still be some expertise around from those involved with aircraft carrier arrester gear or working steam engine museums.
« Last Edit: September 04, 2014, 05:54:38 AM by Maryak »
Если вы у Тетушки были яйца, она была бы Дядюшкой

Offline Jasonb

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Re: Plenty & Son marine engine restoration
« Reply #34 on: September 04, 2014, 07:54:08 AM »
I wonder if the two holes in teh bearing cap were to pour the white metal as it would be a job to try and stand the engine on end or dam it up so you could pour from the side. Once cooled the cap could be lifted and the while metal drilled out to take two more wick tubes. As it is now if you filled it with oil it would all want to flow down the two lower holes leaving little for the wicks to draw down the tubes.

Alec Tiranti do bars of white metal, also ask around teh stationary engine (hit & miss type ) guys as quite a few of those are white metalled.


http://www.tiranti.co.uk/EdgeImpactShop/subcatdivision.php?Division=524&Content=Bearing+Metal+
J

Offline Rivergypsy

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Re: Plenty & Son marine engine restoration
« Reply #35 on: September 04, 2014, 08:03:25 AM »
Dave, Bob - many thanks on the advice. I've never poured bearings before, so I'll have to have a good bit of research and some practise runs before I go for the main job.

Jason - many thanks for the advice and link too. I did a double check of those holes last night, and they are both larger than the tube/wick holes, and also burred inside the oil cup as if they've been drilled from the underside, so perhaps they were added for pouring the bearing.

Offline Rivergypsy

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Re: Plenty & Son marine engine restoration
« Reply #36 on: September 12, 2014, 01:18:22 PM »
Well whilst I still haven't obtained lifting gear, I have been busy with the tape measure, verniers and SW on the cylinder block and valve gear, so here's where I'm at so far. There's still a hell of a lot to add to the block, including ports, lagging lugs, etc, but the basics are taking shape. According to SW we've got around 135kg here so far...what have i started??  :facepalm:



Offline doubletop

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Re: Plenty & Son marine engine restoration
« Reply #37 on: September 21, 2014, 10:39:12 AM »
For what it's worth: there was always a great competition in Newbury to get an apprenticeship with Plenty. One of my school-chums was lucky enough to get a place.  At the end of it he received his First Class Machinist papers and his cards,  The manager told him to go away and get some experience with other companies after which Plenty & Son would welcome him back.  He always said that after Plenty, the other companies tolerances seemed wide-open and sloppy - he being used to tenths of thous.

When I used to cycle past, their yard was full of rusting casting.  Duncan later told me they would rough-machine each piece, then set the castings outside to "weather" (stress-relief the natural way) for two to three years before performing the finish machining.

Geoff
Old Newburian
Thailand

When I saw the thread header it got my interest as Plenty's were on the list of apprenticeships to go for when leaving school. In the end I joined the RAF and electronics engineering. 'O' level metalwork 'failed' wouldn't have helped my chances with Plenty's.

Now following progress on this restoration

Pete
Old Newburian
New Zealand
?To achieve anything in this game, you must be prepared to dabble on the boundary of disaster.? - Stirling Moss

Online b.lindsey

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Re: Plenty & Son marine engine restoration
« Reply #38 on: September 21, 2014, 01:20:49 PM »
Still following along Dave ...what a nice project too. Can't help with the babbit but interested to see how that goes.

Bill

Offline Myrickman

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Re: Plenty & Son marine engine restoration
« Reply #39 on: February 10, 2016, 12:08:17 AM »
Just saw this topic...neat piece. If the fit between the shims and the crank is very close, then the shims could be aids for pouring the bearings. The hole in the center could be a pour hole. Of course side dams would be needed with damming compound. After pouring and trimming, a simple shim keeps the bearing halves separate and provides a bit of additional shim clearance. When you pull the crank out there should be a rough surface or divots in the casting to anchor the Babbitt to it. You'll spend several hours prepping the pour and minute pouring them . My preference is for no. 2 or 3 high tin alloy. I show some model bearing pour setups in my posts. On this one I, if you use the crank as a mandrel, final fit should be a snap.