The Alyn Foundry IF Allman engine.

[Alyn Foundry]

Okay....

Back home and suitably fed by " takeaway ".

The journey was horrendous, particularly the roadworks on the M 5 but the welcome Mathew and I received at both the foundry and Andy's made up for it.

I'm hoping to post a picture of the casting on the Strictly thread.

Andy was reluctant to " board " the Allman so he took many photos instead.

Cheers Graham.

[Jasonb]

Thanks for all the Photo's Andy they have all been downloaded now.

[Chipmaster]

Some pictures of the details on Graham's Allman,

P1080295 by Andy, on Flickr
P1080297 by Andy, on Flickr
P1080299 by Andy, on Flickr
P1080300 by Andy, on Flickr
P1080302 by Andy, on Flickr
P1080303 by Andy, on Flickr
P1080305 by Andy, on Flickr
P1080308 by Andy, on Flickr
P1080309 by Andy, on Flickr
P1080310 by Andy, on Flickr
P1080318 by Andy, on Flickr
P1080320 by Andy, on Flickr
P1080321 by Andy, on Flickr
P1080323 by Andy, on Flickr
P1080330 by Andy, on Flickr
P1080331 by Andy, on Flickr
P1080332 by Andy, on Flickr
P1080334 by P1080336 by Andy, on Flickr
P1080337 by Andy, on Flickr

Andy

[Jasonb]

The postie dropped these onto the mat this morning.



As the clever ones will be able to work out from the numbers they are a pair of 1.5MOD gears with 14 & 28T, this should leave enough meat in teh smaller gear for a keyway to drive it and keeps the PCD to a size where the pivot for the larger gear will fit withing teh A frame's web. At just under £20 the pair delivered from Beltingomline it was not really worth thinking about buying cutters and making them especially as being 16mm wide plus a boss there will be enough for two engines even allowing for a wonky saw cut

In the week I managed to get the exhaust block machined, first the hole and counter bores for the valve, I Like to do it in the lathe as turning the 45deg seat always seems better than a CSK bit in the mill.



Then the cross hole tapped M12 x 1 for the exhaust stack, a 1/2" thread was getting a bit close to the waist just below the flange so went down to 12mm. Other builders can do as they wish if not keen on mixing thread forms.



Then knocled up a valve from 303



Finally a collet for the top of the spring and turned down the casting where the valve pokes out to locate the other end of the spring



J

PS Andy by any chance did you measure the angle that the hot tube chimney is leaning at? I'm sure this is a critical factor in getting the engine to run well and Graham has spent many an hour getting the lean just right

[Chipmaster]

That may be awkward Jason  I think it was carefully tied on with a length of steel wire wrapped around  another adjacent part to achieve that jaunty tilt, it was probably susceptible to accidental adjustments as well.
Whatever the chimney angle, Graham had the engine running within a two or three minutes.
Andy

[Jasonb]

The cylinder liner was the one casting I had my doubts about being able to use as it was not upto the old Alyn standards, the two halves had moved at least 1/16" out of line and the core was off to one side which left very little to clean up externally. However I felt it was worth taking a few cuts to see if a usable part could be squeezed out of it.



The cored hole was quite straight if a bit lumpy in one or two places so I decided to use this as my reference to set things up, an aluminium plug was pressed into the flanged end first and supported with the tailstock to clean up the OD of teh flange so it was round and concentric to the cored hole. I then held the flange edge and used the bung in the other end to turn the liner to fit the outer cylinder, it only just cleaned up, luckily the casting is overlength and the bit beyond the red line is not required. Also thinned the flange and left a 1/16 x 1/16" step at the flange end



It was then out with the fixed steady to support the liner while it was bored and the end cut off though still a littel overlength for now.



A bit of careful pre-planning meant the liner just cleared the hole in the 4-jaw chuck so it was easy to hold and remove the unwanted large dia flange to leave the step at the end.

[Jasonb]

With the liner done I could use that to size the cylinder head, it was a bit chilled around the rim of the "hemi Head but a CCMT had the cast iron swarf comming off like ribbons of steel.





Stainless stubbie exhaust stack



Cut the smaller gear in two and broached a keyway



Eccentric strap, bit hard so needed 10mins at red heat before the spigot could be worked on.



Also poked a couple of extra holes in the cylinder jacket



Just as well I'm not retired otherwise this engine would be finished in no time

[Jo]

Just as well I'm not retired otherwise this engine would be finished in no time

Just be thankful you don't have an Elephant with another two sets of castings that he needed help fondling  and he has just reminded me that someone still has one of his Allman castings 

Jo   

[Jasonb]

I think he is teaching you bad ways, you seem to be spending your retirement fondling as there have been very few sightings of swarf since you gave up pretending to work full time

[Jo]

You have no idea 

Best you keep on working you wouldn't enjoy what I have been doing  and someone needs to keep paying the taxes

Jo   

[Alyn Foundry]

Hi Jason.

So what's your plan for the " tank " cooling?

Are you going to form some bosses to look like they were as cast?

I was also wondering why you didn't use a BSP thread for the exhaust outlet? I did mine at 3/8 BSP. BSP fittings are readily available and dirt cheap!!

Cheers Graham.

[Jasonb]

I'm not sure I will have a tank, I usually don't run my engines for extended periods so they only get run "dry" maybe hook up the compressor to blow a bit of cold air through the waterspace.

Yes I will JBWeld some stubs of 1/2" steel into the holes so that they look like cast in bosses, they will take 1/8" BSP OK or could be done 5/16 x 32 for PMResearch elbows.

Your original castings must be a lot larger, as I said the narrower waist just below where the exhaust goes is only 0.573" on mine so with 1/4" BSP being 0.518" OD would have only left 1/32" all round assuming flange and waist are concentric. Don't know how you got 3/8" BSP in there as that is just over 5/8" OD The main front exhaust is 1/4" BSP and if I wanted to plumb the secondary exhaust it would be easy enough to make a M12-1/4BSP nipple or rethread a 1/4" BSP street elbow down to M12 x 1

[Tennessee Whiskey]

Coming along very well, even with far eastern machines  . This is one I’m really looking forward to hear running.

Eric

[Alyn Foundry]

Hi Jason.

Oops, my mistake, yes 1/4" BSP.

I had to remake the inlet and exhaust valve chest patterns so I might have been a little tighter on the flange than previously.

I seem to remember using 1/2" BSP for the inlet valve chest top and used an off the shelf Brass " flange plug " to close and fit the ignition tube into. A word of caution, I managed to crack a casting with the 1/2" BSP tap. I had cleaned up the outside diameter beforehand. I'd suggest tapping the hole before reducing/neatening the outside of the casting.

Cheers Graham.

[Jasonb]

I thought that may be the case as using your existing casting for the master and then I assume an aluminium one cast from that to go to the Foundry would have had a bit of shrinkage.

Have not got to the workings of the inlet valve yet but do have a nice M18 x 1 tap should 1/2" BSP be a bit tight. At the moment I'm thinking of having a small 1/32" hole coming from the gas connection drilled through from the 45degree valve seat so that when the valve is opened on the intake stroke you will get the usual flow of air and the valve will also open up the gas hole, much like a Lunkenheimer carb uncovers the fuel passage from the needle valve.