Author Topic: Side Valve IC engine (Read 20332 times)

NormanV · « **on:** February 11, 2015, 10:25:15 AM »

I am in two minds whether or not to post this project, I don't have a huge amount of confidence that I will complete it successfully.
This engine is based on a design by Edgar Westbury as a 10cc side valve water cooled engine which he named the Whippet. The cylinder and crankcase are cast in one piece and at the size he designed it I have no chance of casting it accurately enough. I decided to double up on the size, this will give me an engine that stands approximately 240mm high and have a capacity of 80cc.
Here is the pattern for the main casting.

NormanV · « **Reply #1 on:** February 11, 2015, 10:30:55 AM »

For the hollow crankcase I decided to make the core in two pieces. The mould for the crankcase core was made as a negative mould and packed with sand wetted with sodium silicate (thanks Andrew) and placed in a large plastic bag that was inflated with CO2 from a fire extinguisher. That was quite exciting as the first attempt tore the bag to shreds due to the pressure of the gas. The second attempt with a more delicate touch of the trigger did the trick. Here is the mould: I made it to separate into 5 pieces to allow removal of the core.

vtsteam · « **Reply #2 on:** February 11, 2015, 10:32:49 AM »

That's quite a project Norman!

And mahogany patterns, too....

NormanV · « **Reply #3 on:** February 11, 2015, 10:36:13 AM »

The cylinder core was more complicated. I first made a split wooden male pattern from which I cast a two piece cement mould. This was again filled with sand wetted with sodium silicate and placed in a bag of CO2 as before.
The patterns were made with Sapele which is has similar working properties to mahogany, and was free!

NormanV · « **Reply #4 on:** February 11, 2015, 10:38:07 AM »

Here are the two cores, there was a little part of the sand that broke away but it won't cause too much of a problem.

NormanV · « **Reply #5 on:** February 11, 2015, 10:39:37 AM »

I shall just use greensand for the outside of the mould, I'll have a go tomorrow if the weather holds up.

awemawson · « **Reply #6 on:** February 11, 2015, 12:35:05 PM »

Nice one Norman

If you run out of sodium silicate let me know.

I was going to ask if your Granny knew that you'd sawn up her sideboard, but Steve got in first

NormanV · « **Reply #7 on:** February 11, 2015, 02:00:08 PM »

Thank's Andrew, that's a kind offer. My granny died nearly 50 years ago so I have nothing of hers to cut up. It's just that I am a good customer of a cabinet maker! I bought a display cabinet for a ship model that I built. You can see the build log here: http://www.modelshipbuilder.com/e107_plugins/forum/forum_viewtopic.php?4006

awemawson · « **Reply #8 on:** February 11, 2015, 03:36:35 PM »

A man of many talents - that's a fine model

Was that executed when you were on the Falklands?

NormanV · « **Reply #9 on:** February 11, 2015, 04:06:09 PM »

I built in when I retired to UK. I had more time.

kayzed1 · « **Reply #10 on:** February 11, 2015, 04:22:07 PM »

Nice work Norman, if you are making casting kits i will buy one Sir, i think i could manage some thing that size

Lyn.

NormanV · « **Reply #11 on:** February 13, 2015, 12:01:20 PM »

I had a go at casting it today. Here are the cores in place in the mould ready for the top half to go on. Although I had built the patterns as accurately as possible I noticed that the wall thicknesses for the casting were not even.
Also some of the sand had broken away but that was not a problem as it would just result in bigger flashing around the edge.

NormanV · « **Reply #12 on:** February 13, 2015, 12:05:34 PM »

At first sight the casting looked ok, then as I cleared the sand I found the problems! I think that I will reduce the size of the crankcase core to make it a bit more forgiving on wall thicknesses and pour faster.

RobWilson · « **Reply #13 on:** February 13, 2015, 01:08:38 PM »

Looking good Norman

I can see this being an interesting build

Rob

vtsteam · « **Reply #14 on:** February 13, 2015, 09:29:15 PM »

Norman, nice try!! I'm sure you'll get it.

Ginger Nut · « **Reply #15 on:** February 14, 2015, 12:04:42 AM »

Norman thanks for the WiP

NormanV · « **Reply #16 on:** March 10, 2015, 02:23:29 PM »

I knew that this casting was going to be tricky. I have had several attempts at making the sand cores. The crankcase core fell apart on the second attempt, the CO2 didn't penetrate. On the third attempt it came out perfectly. The cylinder core was much more trouble. It just would not release from the mould and after four attempts I gave up and made a straight mould using a cardboard tube. I will have to bore out the waterspace.
I cast it today, I made sure that I vented the mould much more that usual and I used tin cans over the pouring hole and the riser to give a greater head for more pressure as I poured. It went well and when I knocked it out I found that it was almost perfect. There is one place where the metal did not flow fully, leaving a void. I think that I will be able to patch it or fill it rather than make another casting, I can claim that it is a part of the original design! I didn't remelt the original casting as I thought that it would be useful to practice on.
I will post a picture of the new casting tomorrow.

awemawson · « **Reply #17 on:** March 10, 2015, 03:00:16 PM »

Norman, put some icing sugar in the sodium silicate when making the core to improve breakdown

NormanV · « **Reply #18 on:** March 10, 2015, 03:51:26 PM »

Andrew, I wish that I had known that before. I had a heck of a job getting the core out of the first casting!

awemawson · « **Reply #19 on:** March 10, 2015, 04:03:42 PM »

Oh well .... now you do

You can buy Sodium Silicate already laced with glucose, but I've always found raiding the larder is more convenient - anyway some times you want it rock hard.

NormanV · « **Reply #20 on:** March 11, 2015, 09:35:25 AM »

When I said that my latest casting was almost perfect I meant it relative to the previous one! What I should have said was that it is usable and it shouldn't be necessary to do another.
Getting the core sand out is a problem, I've soaked it and attacked it with a kitchen fork and finally had to resort to an electric drill with a masonry bit. I still haven't got it all out but I needed a rest from it.
Well here it is, as I mentioned before it will need a cover plate made for the area where the camshaft will be,(at least I will be able to see what the cams are doing as I assemble it). It will also need some filler for the rough areas of the casting.
Some parts of the pattern had no draught built into it, I had hoped that when I rapped it I could loosen it enough to allow removal from the mould. That was not the case and as a consequence quite a lot of the edges of the sand broke away resulting in very large flashing around the joint area. Lesson learnt, time spent getting the pattern right will pay off.
My angle grinder burnt out a few months ago so I now have the choice of a lot of filing and sawing or to spend some money and buy another grinder. Roll on car boot season!

NormanV · « **Reply #21 on:** March 20, 2015, 05:32:20 PM »

It's a shame that I no longer have an angle grinder. I have had to do the fettling of this casting with a hacksaw and a file. It is now looking presentable.

appletree · « **Reply #22 on:** March 21, 2015, 08:47:05 AM »

Looking good, I admire the projects you take on and the fact you do it all yourself. I was in B and Q this morning and the had Mackalister (spelling?) angle grinder for £20 not too bad given that its brand new.

Somethings are so much cheaper than they used to be my first angle grinder was £43 in 1977. I bought a professional Makita last year on special offer for the same price.

krv3000 · « **Reply #23 on:** March 21, 2015, 05:35:45 PM »

hi well dune

RobWilson · « **Reply #24 on:** March 22, 2015, 04:24:57 AM »

Looking good Norman

Rob

NormanV · « **Reply #25 on:** April 01, 2015, 03:32:27 PM »

I've finally got back to this engine. I cleaned up the feet and drilled the mounting holes and then mounted it on the faceplate. I put a wooden bung in the top of the cylinder to aid lining it up and then faced the top.
Tomorrow I need to make the final cut to obtain a good surface.
To bore it I'm going to use a piece of 25mm Dia BMS bar as a boring bar. I've got to go in 120mm and I think that my 12mm boring bar will be too flexible with that much overhang.

vtsteam · « **Reply #26 on:** April 01, 2015, 06:40:54 PM »

You're coming along, Norman!

NormanV · « **Reply #27 on:** July 01, 2015, 10:20:22 AM »

I've finally made some progress with this engine. I have cast the cylinder head and the cover. Here are the patterns.

NormanV · « **Reply #28 on:** July 01, 2015, 10:24:50 AM »

The cover is a simple casting as it has a flat bottom.
I have often been dismayed at the time my furnace takes to melt the aluminium, I have been too embarrassed to quote my times but for this casting I only had to melt 1kg of metal and it was liquid in 20 minutes so there is obviously nothing wrong with the furnace it is just that previously I have been melting 3-4 kgs which usually takes an hour.

NormanV · « **Reply #29 on:** July 01, 2015, 10:29:11 AM »

The cylinder head was a bit more complicated as it has recesses on both sides plus the boss on the end produces an undercut. I thought that I would get around that by making a board with a cut out to cover the undercut. There was a bit of a gap between the board and the pattern, I had no putty or plasticene to plug the gap so I made a flour and water dough which did the job admirably.

NormanV · « **Reply #30 on:** July 01, 2015, 10:33:50 AM »

The intention was to remove the board after doing the first ramming with sand, but like an idiot I forgot. This meant that the casting has a flange all the way around it! The inside of the casting turned out well so I will just trim it down rather than recast it. I also had some of the sand break away on the outside but that will machine off.

awemawson · « **Reply #31 on:** July 01, 2015, 11:00:53 AM »

Not too bad at all Norman - heck of a hot day to be casting !

NormanV · « **Reply #32 on:** July 01, 2015, 12:52:53 PM »

It was the warm weather that made me want to be outside, I didn't spend much time standing near to the furnace though.
The sand was lovely and warm, last time I did any casting it was near freezing!

vtsteam · « **Reply #33 on:** July 03, 2015, 12:08:12 PM »

Now that is familiar looking!!

First casting for my Tecumseh 6hp IC to steam engine conversion.

Good work, Norman!

NormanV · « **Reply #34 on:** July 03, 2015, 02:08:06 PM »

Gosh, they are very similar!
I've decided not to be so lazy and to cast another cylinder head, the metal is in the furnace as I type.
I had stupid problems moulding the sand. First attempt, I'd opened the mould and put in a screw to lift the pattern and as I removed the screwdriver from the screw it caught in the Phillips recess and dislodged the pattern. Second attempt, the sand dropped out as I opened the mould! By now I had run out of talcum powder as parting so I used some fine dry sand, that worked fine.

NormanV · « **Reply #35 on:** July 03, 2015, 02:56:00 PM »

Here is the new cylinder head. There is quite a lot of flashing on it as I made the pattern without any draught and relied on the rapping to loosen it in the sand to allow removal. The recesses on both surfaces are fine, I've a bit of cleaning up to do but the time saved in pattern making more than compensates for that.

NormanV · « **Reply #36 on:** July 03, 2015, 03:34:10 PM »

Here it is after a few minutes with a file and a hacksaw.

tom osselton · « **Reply #37 on:** July 03, 2015, 03:39:56 PM »

Turned out well!

vtsteam · « **Reply #38 on:** July 03, 2015, 03:45:19 PM »

Looks good Norman!

NormanV · « **Reply #39 on:** July 14, 2015, 09:34:22 AM »

I got back to boring out the cylinder of the engine. Firstly I had to make a more rigid boring bar. My 12mm dia one was causing chatter. I obtained a piece of 22mm square steel that was the largest size that would fit my toolholder. It made quite a beefy holder.

NormanV · « **Reply #40 on:** July 14, 2015, 09:46:40 AM »

I then cleaned up the bore and started work on the waterspace. I was about half way through and all appeared to be going well. Then I noticed a change in the sound of the cutter. I stopped the machine to check what was happening. My homebrew digital readout made from a tyre depth gauge had somehow shifted and I had cut too deep, so deep in fact that I had parted off the top of the cylinder from inside!

My immediate reaction was that was the end of this motor, but after a little thought I realized that this may not be a catast.... catastro...... problem. Having the cylinder in two halves means that I can machine the water space more accurately and then make a spacer to join the two halves back together. The cylinder is going to have a cast iron sleeve anyway so it should all go together ok.

P.S. catastrophe

awemawson · « **Reply #41 on:** July 14, 2015, 10:49:00 AM »

Oops !

Glad to see that you've found an upside - give me those positive vibs

vtsteam · « **Reply #42 on:** July 15, 2015, 12:02:07 PM »

Aha, Plan B!

NormanV · « **Reply #43 on:** August 14, 2015, 03:35:11 PM »

I've decided to give up on this engine, at least for now. There are just too many unknowns, I will keep the patterns and maybe later I will try again.

awemawson · « **Reply #44 on:** August 14, 2015, 05:45:31 PM »

Come on Norman, that's not the spirit that got you to the Falklands and back - dogged determination needed

vtsteam · « **Reply #45 on:** August 23, 2015, 08:34:56 PM »

Sometimes it's good to start over, though, and with past experience things go well and quickly. Plan B can be melting down a half finished casting and pouring a new one.

SteveT · « **Reply #46 on:** September 03, 2015, 02:30:49 PM »

Impressive work looking forward to seeing the project progressing

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Author Topic: Side Valve IC engine (Read 20332 times)

RobWilson

RobWilson