Hoglet (first IC engine)

[Nick_G]

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Time for another engine build.  This will be my 3rd project and have decided to try my hand at an IC engine.

With the assistance of another member I have chosen this the be a Hoglet V twin. This is very loosely based upon the Harley engine and has an open crank.

I had a nosey at the plans for a couple of days and then proceed to start to butcher metal and increase the weight of my scarp bin. 

So I had some 1/4" plate delivered so into attack mode.

I made the crankcase halves as a pair and tacked together with super glue so that I could be sure they matched and separated later. This of course means that if you drop a clanger you butcher twice as much metal for the bin. - This was my second try.!  Fortunately I had ordered more metal than I needed.



The crankcase tops were also made as a pair.



I aided the superglue bond with threads to make sure they did not separate in the lathe 4 jaw while I bored out the hole that the cylinder liner will sit into.





Golly.!!!! ...... They all fit.







The studs are just temp until the cap head screws arrive. Having said that I think I prefer the look of studs (if they are all the correct length) and nuts over cap head screws. - Opinions please.?

All seems true with it on the surface table. I was also surprised how rigid it was when fixed together. However I think that sooner rather than later I will make a temp base to support the bottom and stop it getting twisted during construction stages. ............. Me being ham fisted un-all. 

Nick

[Nick_G]

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Took a trip today to Mac Models in Macclesfield to buy some steel, aluminium and cast iron.



While I was out that way I took a blast on my motorbike up the 'Cat & Fiddle' road for an adrenaline rush. 

Anyway. Those materials should keep me busy for a while on this Hoglet thing.

Nick

[Nick_G]

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Thought I better do something useful with that metal. So had a stab at one of the cylinders.

The drawing calls for the cylinder to be made in one piece from cast iron. Many others though have opted to make them from aluminium and then sleeve with a cast iron liner. - I went for an all cast iron one as per the drawing.

Macc models did not have the close size for the cylinder dia. So I went a size larger and will part off the excess length I bought to make the cylinder head. (which is a larger dia) This meant I had to spend a bit more time carving down to the cylinder dia.



Then cut in the cooling fins.



Then ready to part off. - I think CI is really nice to machine if it's good quality stuff. Pity it makes such a damned mess though.



Fliiped it round into the collet chuck and a boring session we did go.! At this stage I also added the 5 degree taper to some of the fins. - The bore is quite a nice finish with it being nice CI. But left a 1/2 thou for a tad of honing.



Hey presto. 

There is a wide groove to be made yet below the bottom fin that makes a step in the lower section to form a flange. I will do this later when I have both cylinders done and made a mandrel to hold them.





Now I have to make another cylinder that 'looks'  exactly the same.!

 

Nick

[vcutajar]

Got the plans for this one but did the Corliss instead and now I am hooked on steam engines.  They seem more forgiving to get them running as opposed to IC engines.  Will be following along and picking up pointers for the day that I actually decide to do the Hoglet.

Vince

[zeeprogrammer]

Beautiful cylinder.  Very nicely done.

 

[Kim]

Very nice start!  The crankcase and cylinder both look great!
Kim

[Nick_G]

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Cheers for the replies. 

Moving on. I made the second cylinder OK.

Over to the mill and used the DRO to drill the holes through the cooling fins.



Made the 8 studs. Threaded them at just one end for now and will get the final length when I have the heads done.



So far it seems to be going to plan. 







Nick

[Dave Otto]

Hi Nick

Wow you are making great progress on your new project and the parts are looking very nice!

Dave

[Don1966]

Man your making some impressive headway Nick. Those are some impressive looking parts. I will be following along........

 
Don

[b.lindsey]

Impressive is an understatement Nick!!  This is such an interesting engine too, and I am looking  forward to following your continued Hoglet adventures!!

Bill

[Jo]

  Doing very well Nick.

Maybe you will shame Jason in to finishing his 

Jo

[Jasonb]

I'm keeping mine as it is incase it needs taking apart to show Nick any parts as I did not take many photos when I made it.

Well thats my excuse anyway

[Roger B]

That's a good start    The joys of cast iron, black bogey time 

[fumopuc]

Hi Nick, a very good start. The valve springs and gears are under my bench already and most metric conversion for shafts and bearings is in my head also. Roy has sent me the ignition system some months ago.It will be definitive my next progress. I will follow along.

[Nick_G]

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Thanks for the remarks folks.

Cylinder heads next I think.

The drawings give details of a jig to hold the head while the machining of inlet and exhaust ports, spark plug holes and cooling fins take place. The valve guide holes and head securing holes have to be made into the cast iron blank first to enable it to be fixed. - These are then a ref point for everything else.

So this eve I made the jig from a length of 2"x2" square bar as suggested.



I am wondering ............. And thus asking the members here if they think I should machine the ports and spark plug hole first then the cooling fins. Or fins first then the holes.?

Here is a section of the drawing detailing the head.



Also not sure of the best way to secure the valve guides when the time comes.?

I gather that one of the main issues and problem areas with a small 'home made' IC 4 strokes is getting the valves to seal properly with the head.

Thanks, Nick