Author Topic: Alyn Foundry Sphinx  (Read 7706 times)

Online Jasonb

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Re: Alyn Foundry Sphinx
« Reply #45 on: May 01, 2019, 08:40:47 PM »
Ray, did you put the inlet stud holes in at the drawn 13/32" or at 21/32" (13/32 + Recess depth) ? ditto the inlet hole at 1/2" or 3/4"

Offline RayW

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Re: Alyn Foundry Sphinx
« Reply #46 on: May 01, 2019, 09:37:23 PM »
Hi Jason,
I stuck to the dimensions as per the drawing and it looks ok. The cylinder flange just shows in the inlet port, so I may just round off that part with a Dremel to provide a smooth gas flow in and out.
Have you noticed, by the way, that there are no dimensions for the central cylinder head bore? Also, the holes for the manifold studs intersect two of the four vertical holes





Ray

Online Jasonb

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Re: Alyn Foundry Sphinx
« Reply #47 on: May 02, 2019, 07:18:46 AM »
Hi Jason,
I stuck to the dimensions as per the drawing and it looks ok. The cylinder flange just shows in the inlet port, so I may just round off that part with a Dremel to provide a smooth gas flow in and out.
Have you noticed, by the way, that there are no dimensions for the central cylinder head bore? Also, the holes for the manifold studs intersect two of the four vertical holes

I expect it will run fine with those dimensions but you may need to shorten something in the exhaust valve/eccentric as the valve block will be closer to the crankshaft by 1/4"

Yes even at 2BA they still clash so could be drilled shallower as the studs won't go in past the head bolts. The shallower depth won't be such an issue with the smaller diameter as you will get more than one diameter depth thread engagement.

I took the recess as 5/8"




Offline RayW

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Re: Alyn Foundry Sphinx
« Reply #48 on: May 02, 2019, 10:06:45 AM »
Yes, I had already thought of that. Shouldn't be a problem to shorten the pushrod to compensate. I made the central bore 9/16".
« Last Edit: May 03, 2019, 04:22:10 PM by RayW »
Ray

Offline RayW

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Re: Alyn Foundry Sphinx
« Reply #49 on: May 02, 2019, 10:40:26 AM »
This is my cylinder head on Fusion 360, with dimensions as per drawing, ie. no adjustment to compensate for the 1/4" recess.


Ray

Offline RayW

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Re: Alyn Foundry Sphinx
« Reply #50 on: May 07, 2019, 04:53:34 PM »
Finished honing the cylinder. After I had bored out the casting, there were about 8 or 10 blow holes, ranging from pinprick size up to about 2 or 3mm. Fortunately, none of the larger ones were at what I would call the business end of the cylinder. Filled them all with JB Weld before final honing, and have ended up with a really nice finish to the bore. With the cylinder held vertically against a flat surface, a heavy brass plug slides down quite slowly, and, if pushed down, there is quite good compression.
Ray

Offline RayW

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Re: Alyn Foundry Sphinx
« Reply #51 on: June 10, 2019, 03:16:13 PM »
 After an enjoyable 3 week break in Scotland, I am back in the workshop and making swarf (or cast iron dust) again. After several abortive attempts using different methods to bore the large hole in the front face of the main casting, I finally came up with a solution - a hole saw, as seen in the attached photo. Definitely not the quickest way, but it did the job in the end. Bearing in mind that this does not need to be a precision fit hole, I am satisfied with the result.

 
Ray

Offline Roger B

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Re: Alyn Foundry Sphinx
« Reply #52 on: June 10, 2019, 05:08:38 PM »
Hole saws are good  :ThumbsUp: I have used them to start cylinder bores, they are slow but probably quicker than boring and you end up with a usable blank rather than swarf.

This was a 22mm hole in a 50mm diameter 80mm long piece of cast iron cut from both ends.
Best regards

Roger

Offline RayW

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Re: Alyn Foundry Sphinx
« Reply #53 on: June 13, 2019, 08:58:42 PM »
Hi Roger,
Unfortunately, before using the hole saw, I had already drilled a central hole, so the plug I have left will only be useful for making washers!

Drilled and tapped the holes for the bearing cap studs today, and the holes for the cylinder head studs. The brass rings at both ends of the water jacket have now been Loctited in position. Once they are fully set, there is just a small amount to skim off the one at the cylinder head end. I have ordered some stainless rod for making the various studs and a selection of stainless BSW nuts (from China!).
As shown in the attached photo, I roughly assembled the main body, cylinder and water Jacket, and cylinder head to ensure that everything lined up. 
Ray

Offline Alyn Foundry

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Re: Alyn Foundry Sphinx
« Reply #54 on: June 13, 2019, 09:12:42 PM »
Hi Ray.

You're over the hardest part now, with the cylinder liner hole made and faced.

I hope from your photograph, that with a little imagination, you can see where the engine got its name from?

Cheers Graham.

Online Jasonb

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Re: Alyn Foundry Sphinx
« Reply #55 on: June 14, 2019, 07:08:15 AM »
I think that Sphinx has got it's head stuck in a tin of cat food :LittleDevil:

Looking good Ray, on the subject of nuts for those that like a nice looking BSF or Whit nut that is single chamfer and fully machined rather than the presses out offerings these people have some nice ones though at a price.

https://historicthreads.co.uk/

Offline RayW

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Re: Alyn Foundry Sphinx
« Reply #56 on: June 14, 2019, 08:00:30 AM »
Hi Graham and Jason.
I can definitely  see what you mean about the Egyptian look (and the cat food tin!). The nuts from Historic Threads look good, but, as you say, pretty expensive. I will see what my Chinese cheapies are like when they arrive before I decide if they look OK.
« Last Edit: June 14, 2019, 09:58:16 AM by RayW »
Ray

Online Jo

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Re: Alyn Foundry Sphinx
« Reply #57 on: June 14, 2019, 09:15:30 AM »
Well done Ray  :)

You're over the hardest part now, with the cylinder liner hole made and faced.

Does that mean I will have no problem getting mine to run? Jason will be so disappointed  ::)

Jo
Enjoyment is more important than achievement.

Online Jasonb

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Re: Alyn Foundry Sphinx
« Reply #58 on: June 14, 2019, 10:32:47 AM »
Well it would probably be your first 4-stroke that runs if it did, though you have got to finish it first :LittleDevil:

Offline Alyn Foundry

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Re: Alyn Foundry Sphinx
« Reply #59 on: June 14, 2019, 11:38:10 AM »
Cat food tin??

Where?

I'm a champion for the cause of recycling/repurposing items you know!   :)

In answer to Jo, of the few kits sold there are many videos showing a successful running engine on YouTube. She's a simple design with no fiddlely gears, get the air/gas ratio correct, voila!!

Cheers Graham.
« Last Edit: June 14, 2019, 11:44:41 AM by Alyn Foundry »