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Author Topic: Southern Cross ETB diesel engine  (Read 9801 times)

ajaffa1

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Re: Southern Cross ETB diesel engine
« Reply #60 on: May 08, 2019, 11:48:20 AM »
Hey Buddy, glad to hear you like what I`ve been up to, difficult to explain the grief I have had from Narelle about doing too much to soon or getting my hand dirty.

Aluminium casting is something I have never tried, I might ask to watch Ken next time he is doing some. If you can`t find a suitable template have you thought of sculpting something out of candle wax?

I have recently been watching a couple of YouTube videos about sand casting and the current trend is to make your patterns using a 3D printer. Looks to produce very good results.

Bob

EdDee

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Re: Southern Cross ETB diesel engine
« Reply #61 on: May 09, 2019, 11:21:13 AM »
Lovely stuff indeed Bob!!

Well done!!

Try sheets of polystyrene expanded foam to make the positive for sand casting.... Works reasonably well too...

(That's if you don't have a 3d thingy to play with...)

Cheers
Ed
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
Bikes,Cars,Gunsmithing & Paintball...Oh yes, a 5Ha open air Workshop to play in!

ajaffa1

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Re: Southern Cross ETB diesel engine
« Reply #62 on: May 10, 2019, 09:24:36 AM »
Thanks Ed, I like the idea of using polystyrene to form a template for sand casting. I wonder if spray foam or fixing foam would do the same thing.

I don`t have a 3D printer but would be interested in the technology when the price comes down a bit. I read your post about moving the milling machine, I was lucky enough to spend several years operating these wonderful tools and I am hoping to buy one in the near future.

Not much achieved today but I did manage to fit the new piston to the connecting rod and fit the new gland packing, very pleased with how it all looks. Still a little too much play in the big end so I guess I will have to get the file out again.

Bob

EdDee

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Re: Southern Cross ETB diesel engine
« Reply #63 on: May 10, 2019, 09:48:52 AM »
Hi Bob,

It might indeed, but haven't tried it yet...This does present an idea... If you silicon rubber coat a master positive, then peel off carefully, use that silicon mold with spray foam to make multiple foam positives for casting....

Milling machines are the best thing since canned beer....except for my lathe of course...or beer....or rum and coke....or....

You need to build one of these things (see pic below) all the pulleys and wheels etc I cast in ali as blanks and machined them to size (beer cans for the small wheels, coffee tin for the drive wheel mold)... You will hardly touch a file after that...

Incidentally, I did exactly what you are doing a while back... The big end on a Honda 340 petrol if I remember...only thing I did differently was to squash it oval on the fly press while bolted together, then separate and sand the half shell a bit smaller and undersized, re-assemble, then bore to correct spec on the lathe using a face-plate... About 50c worth of raw material costs/electricity, 1hr of hobby time, and a more than happy friend who had his genset up and going again....

Every bit achieved is a step in the right direction!!

Cheers
Ed
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
Bikes,Cars,Gunsmithing & Paintball...Oh yes, a 5Ha open air Workshop to play in!

ajaffa1

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Re: Southern Cross ETB diesel engine
« Reply #64 on: May 11, 2019, 12:08:20 PM »
Hi Guys, now that the stitches in my hand have been removed I can do a bit more. so today I tackled the pressure bottle that is part of this old pump. It works by moderating the pulsing water pressure from the piston to produce a steady water pressure rather than a pulsing water pressure. The problem was that the base of the unit was flogged out, so I have filed out the worn parts and fitted a new center bush which was soldered in place with plumbers solder. Please see photos. The bottle was polished and sprayed with a varnish, hopefully it will look good and be functional for years to come.

Bob


ajaffa1

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Re: Southern Cross ETB diesel engine
« Reply #65 on: May 11, 2019, 12:33:09 PM »
Further to my previous post I now have a question for the forum. This old pump has two brass valves with sealing washers, one for inlet and one for outlet. When I acquired this pump it was in bits and did not have any springs behind the valves. Does anyone know if this unit originally had spring loaded valves or was it all done with gravity and water pressure? Photos attached.

I have calculated the number of piston strokes per minute at between 150 and 200, so I suspect that this pump originally had some sort of stainless steel spring above each valve, very similar to the valve springs used in a pressure washer, the travel on each valve is around 1/4", if anyone has any knowledge on this please share it.

Bob

mikenash

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Re: Southern Cross ETB diesel engine
« Reply #66 on: May 11, 2019, 07:01:28 PM »
Bob, any of those old pumps I have seen have a stainless or brass thin washer that follows the rubber or leather sealing washer and which supports a coil spring. Most I have seen have a tapered thin coil spring made from stainless wire

Traditionally you bought a "service kit" for them when they stopped working every few years

See pic?

Cheers

ajaffa1

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Re: Southern Cross ETB diesel engine
« Reply #67 on: May 11, 2019, 11:56:30 PM »
Hi Mike, not much chance of getting a service kit for a pump that was made in the 1940`s. I guess I will have to adapt whatever I can find on fleabay. I`m also going to have to rework the original valves, I was thinking to replace the worn shafts with stainless steel.

Any idea what sort of pressure I should expect to get out of this contraption? It would originally have had a pressure gauge which I would like to replace.

Bob

mikenash

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Re: Southern Cross ETB diesel engine
« Reply #68 on: May 12, 2019, 12:25:31 AM »
Y'know, most rural service towns have a pump shop with some old fart who knows all about these old units - there's still a place here that works on ones similar to your cos people continue to use them because they are positive displacement units.  So if you can find a pump shop and just ask them about springs you might get lucky with a close match

That said, if you look at what's happening when the piston goes back and forth - there's pressure on one side and suction on the other, probably?  If that's the case, the spring isn't withstanding pressure, it's just holding the rubber "valve" in place maybe?

See the springs in the pic?  They're light - maybe anything like that you can find will do?

If it was in good shape maybe it would do six or eight bar?  Maybe 100PSI or a bit better?  Just a guess - no way of knowing really.  Gauges are cheap anyway - put a cheap one on and look around for a good one once you understand the pressure range?

If you have a look on google for some pumps with a similar physical structure, find a pic with a name/ID plate visible, then google the "pump curve"  - that will give you an idea

I will watch with interest.  Cheers

ajaffa1

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Re: Southern Cross ETB diesel engine
« Reply #69 on: May 12, 2019, 01:23:06 AM »
Hi mike, went to my local pump shop last week looking for gland packing. Asked the guy about springs and seals to fit old piston pumps, sadly the owner cleared out all his old stock recently. He only deals in centrifugal pumps now.

Bought myself some 40mm nylon round bar that I am going to Sikaflex to the face of the valves, I will then face them off in the lathe to give me a decent seal.

Bob

mikenash

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Re: Southern Cross ETB diesel engine
« Reply #70 on: May 12, 2019, 01:50:29 AM »
Interesting

Somewhere there will be a stash of that old shit - and the know-how.  In a small town I bet

Wouldn't surprise me if the seating "valves" want something softer than UMWHE type stuff?  But I don't really know why I think that.  My memory is of rubber valves around 40mm diameter with a full-width washer behind them - kinda like a penny washer - so ghey may have been designed to be both soft and rigid?

You'll figure it out

Cheers

ajaffa1

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Re: Southern Cross ETB diesel engine
« Reply #71 on: May 12, 2019, 10:36:44 AM »
Hi Mike, I have one of the original washers, it`s past it`s useful life but appears to be a composite with two nylon faces with a softer fabric or rubber layer in between, presumably these were reversible. The original is around 3mm thick, my plan was to use 2mm of Sikaflex and 1mm of MDPE, hopefully the rubberized adhesive will provide enough of a cushion to stop any hammering. I guess I will just have to try it and see what happens.

Bob

Cockie

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Re: Southern Cross ETB diesel engine
« Reply #72 on: November 07, 2019, 02:28:16 AM »
Bob,
Good to see you version of the cart, that's different having the front wheels inside the frame, I like the concept. I expect to take delivery of an ETB in the next week or so, it's coming over from Magnetic Island, where it was pumping water for domestic use. Do you have a photo of the completed project? I would love to see them as I intend to couple my ETB up to a IBC piston pump.
Dave

ajaffa1

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Re: Southern Cross ETB diesel engine
« Reply #73 on: November 07, 2019, 09:35:05 AM »
Hi Cockie, sadly I do not have photos of the completed engine as I have had a devil of a job finding any engineering company willing to fit a sleeve to the cylinder. I now have three cylinders and a cylinder head, for various engines, awaiting machine work in Alstonville NSW. They will cost me around $2,000! I would have done the job myself if I could find a milling machine at a sensible price.

If you need any advice with your rebuild please contact me. I have a few contacts for parts and etc. Once you receive your engine you should register it with the southern cross registry, they will email you a whole lot of information and a service manual. It`s a free service. Good luck

Bob


Cockie

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Re: Southern Cross ETB diesel engine
« Reply #74 on: November 08, 2019, 03:03:40 AM »
Thanks Bob, Ian the SC register guy, is a fellow member of North Queensland Machinery Preservationists, yes he has a lot of information, on anything Southern Cross.