ShedBoys' First Engine

[ShedBoy]

I was going to build a free piston jet engine as my first but I am Having some issues finding a 125mm round piece of Ali. So I thought I would give a plumbing engine a go. It may not work, If it does it will only be for short runs because heat will be a problem. Worse case I could make a new head and run it on air. Not a great deal off planning just some basic parameters. Started with this part and a ruler to get a bore and stroke and used an engine design spreadsheet I found on the net which seems to put out some good info. This is a learning experience for me so feel free to steer me in the right direction. Sorry about some iffy photos.

The plumbing part found in bunnings 14.6mm bore

Machined down end for a cylinder deck ring, said deck ring and spark plug adapter.

Silver soldering them all together. Still need to pickle it? Can anyone tell me what to pickle it in?

Soldered cylinder. I need to practice soldering

 

[ShedBoy]

Deck squared up and then it was bored. Sparkplug thread was chased after soldering.

Drilling the head bolt holes.

Tapping. Is this an okay practice for tapping, I only use light pressure on the quill?

 

[ShedBoy]

The head was turned from some type of steel which I had in the box. Does not machine to nicely. Simple stepped turning.

I am using sunken cap screw to hold the head on. Here is how I recess them. I need some counterbores one day.

The head fit a good start. Sparkplug and head on to give an idea of layout.

 

[ShedBoy]

Righto the bit I reckon I am going to do more than once. Trying to get the valves in. I am going tp call this an unsquare engine on account of my unsquare looking head bolt. I am definately going to buy a wiggler or maybe a laser edge finder. Oh well back to the action.

Valve holes, drilling to heights, three different size drills in each hole and lots of collet changes.

More unsqareness, hate to ruin a theme. Down the bore which needs honing still.

Drilling the ports and mounting the rocker pivot should be fun. With that thought I went to bed.

 

[Chitownmachine]

Yer tapping method is in my opinion the best way to tap. Drill the hole and tap the hole with the bed in the same position. No alignment issues then, and less broken taps. Looking really sweet!

 

[maverick]

I agree, Drilling and tapping without moving the table is the way to go. More taps have been broken by misalignment or
applying a side load. With this method even 0-80s are no problem.
Good luck with your build.

Mike

 

[Steam4ian]

G'day Shedboy

Pickle, you will find citric acid works OK.
The advantage is that it doesn't eat your clothes. You can purchase the crystal from home brewing suppliers in 0.5 or 1 kg bags. I just stir it in until no more will dissolve.

Sulphuric acid is now available as drain cleaner if you want to go for something stronger, I think Bunning have that as well in a brown plastic bottle. You need a 10% solution and remember to add acid to the water not the other way around. take the usual safety precaution, like rubber gloves, face shield and plastic apron, make s citric acid seem a doddle.

Keep us posted

Regards
Ian

 

[ShedBoy]

Citric acid sounds too easy, I will go wth that. Got to go to work for another week . Back to the shed next week.

 

[T70MkIII]

I was going to build a free piston jet engine as my first but I am Having some issues finding a 125mm round piece of Ali.

Have you tried Robert Cameron Engineering in Burswood? I don't know if they have 125mm but they are sure to have something around that size or larger, and are very happy to cut off small lengths for hobbyists. I feel guilty every time I go there and ask for less than 0.5m of something, but they are great guys and just charge by dimension. Aaron or CJ in the office, and George in the workshop - great people.

 

[cfellows]

Interesting looking engine you got going there. What's the bore and stroke going to be?

Chuck

 

[ShedBoy]

15mm bore 25mm stroke. I think my valve are a bit close together so I will probably need to make a new head. Will see. Vacuum inlet maybe a governor on the exhaust valve to stop it running (if it does) too quick. I will make some proper plans while I am at work away from the shed.

 

[ShedBoy]

Robert Cameron Engineering sounds good I will give them a go. Thanx T70

 

[picclock]

Hi ShedBoy (great name)

>> engine design spreadsheet

any chance of a link ?

Looks like an interesting build, especially sealing those tiny valves. Await your next instalment with interest.

Best Regards

picclock

(shed frequenter)

 

[ShedBoy]

Hi ShedBoy (great name)

>> engine design spreadsheet

any chance of a link ?

Looks like an interesting build, especially sealing those tiny valves. Await your next instalment with interest.

Best Regards

picclock

(shed frequenter)

Send me an email and I will forward it on as I can't find the link again but have a copy of it.

 

[ShedBoy]

I am about to fly home YAY! Any idea for valves. Will the steel be okay for seat or should I put in some tiny inserts or cages? They are about 6mm round. Just found some interesting things at work while rummaging in the bin. One is about 1.5kg brass bush, should be good to melt down. Need a furnace I think. Too many thoughts I am going to pop. To the shed boy wonder.

 

[ShedBoy]

Back in the shed finally today. First up make the new quick chnge tool post fit. Just needs a trim.

Turn some valve guides from brass. I am going to cut seats in the head, see how it goes.

Two guides done so far so good.

My first attempt at turning a valve. Not a tiny turner yet me still a bit gun ho. Baby steps.
Or is that baby cuts.

 

[ShedBoy]

Second go at valves went a bit better, just need to take small cuts to match my small valves.

Don't rush it Brock is my new mantra.

I left some extra on it because I was unsure how I was going to stop the spring coming of. Need some e clips 2mm

Found some tiny E clips and made myself a cutter out of an old hacksaw blade.

Worked better than I thought it would and I was able to use it to part off the valves

Thanks for stoping in
Brock

 

[ShedBoy]

Now got two valves and a head with guides I am shocked I only broke one valve.

Need to make a valve seat cutter tomorrow that is going to be fun. Does anyone know how to identify rill rod by eye?
I have a heap of shafting from a photo copier it looks silver and very uniform size. Oooh while rummaging around in my container of Photcopier stuf I found some interesting stuff.

Ready made main bushes, phosfour (need spell check) bronze and I have the 10mm shaft that come from it.
Crankcase and crank tomorrow.

 

[ShedBoy]

Gee my photo taking is hit n miss a bit lie my spelling. I choose to blame the keyboard.
More tomorrow.
Brock

 

[ShedBoy]

My crappy scribble plans got in a picture. Please ignore them.
Brock