45CC Wall Wizard

[Jo]

Did you notice that on the old drawings there are two different drawings for the caps and the valve guides and the valves


Having made up a go/no go gauge I could bore the big ends. Because of that slither in the gap I had to first use a four flute over end cutter to give me a flat surface where the hole was to go then could drill the centre bring the bore slowly up and finish with a boring head. The finish being proven with the gauge 

The rods can then be mounted up on a mandrel and the faces of the big end turned.

I still have the little end to round but as you can see one side is nice and central but the other side is a bit off due to the casting being slightly out of line. 

Jo

[Jasonb]

Did you notice that on the old drawings there are two different drawings for the caps and the valve guides and the valves

Yes and BOTH show a counterbore so that when the spring pushes against the retainer it is held centrally by the counterbore on the upper full diameter of the valve stem. One drawing mentions the counterbore the other just shows it. The later Coles drawings have missed it off.

[Jo]

A few weeks ago the tops of the cylinder heads were machined and made so that they could be mounted on a jig - now comes time to make use of that jig  to hold the head in the four jaw chuck. The part of the head that needs machining is the inside face not the outside and we use the outside curve of the head to centre with - to do this I am working by eye using the edge of a tool and moving the head in the four jaw until the tip of the tool follows the outside of the head as I rotate it.

The first step is to bore the diameter to fit the barrel liner, then using a round nosed tool the inside corner of the head can be machined.

The result is the heads can now be fitted with the cylinders on one side of the crank case and everything begins to look more engine like 

Jo

[Jasonb]

Is that a flaw in the casting shown in the round nose tool pic? if so lucky it fell between where the two valve seats will be

Is the radius to reduce the risk of a stress fracture or better firing?

[Mike Bondarczuk]

Jo,

Inspiring work you are performing in this new posting.

Looking forward to challenging you with some off the Clarkson castings at the show.

Mike
.

[Roger B]

Looking good  What's the boring tool you are using before the profiling tool? The valve area seems quite small for the bore, but I guess that's the way things were 

[Jo]

The top of the plug mounting was taken down to 1.6mm above the theoretical diameter of the bottom fin of the head and a 9mm hole drilled where the plug is going. Then using a M10 * 1.0 tap the plug thread tapped.

The plug looks about the right size but it does not have sufficient reach so I need to buy some more longer ones 

Jo

[Jo]

I hummed and hared but decided to finish turning up the valve guides and to push them in to place before drilling the exhaust and inlet ports on the head. This means I can now see how deep the valve guides are in the head and can plan the position of the ports breaking through such that they leave space for the valve seats.

I have chosen to make the valves in two pieces and silver solder them together. This has the advantage of not wasting lots of material and the 3.18mm diameter stainless already is the correct diameter and has a nice finish all the way down, the chances are if you try turning such a long spindly stem it will bend away from the tool somewhere along the length if held between centres and you will get a thick bit which will not fit in the valve guides or with a travelling steady the metal can ride up if a bit  of swarf gets caught and you will get a groove 

Tomorrow I hope to finish turning up the valves 

Jo

[Jasonb]

I thought you may have cut them from solid and collected up the swarf to save having to splash the cash on a couple of scouring pads for the Robinson

[Dave Otto]

I thought you may have cut them from solid and collected up the swarf to save having to splash the cash on a couple of scouring pads for the Robinson

She must be, as my friend Max says, giving the Robinson the silent treatment. 

That is an interesting little press Jo, I have never seen one like it?


Dave

[Jo]

She must be, as my friend Max says, giving the Robinson the silent treatment. 

How long did the Pacific Vapor Engine take Dave? And if his posted progress is to be believed JB hasn't been in his workshop for weeks I accept that those of you who still have to work can use that as an excuse as you don't get much workshop time  But at least you can look forward to retiring at some point in your future (maybe)

Which reminds me I have some heavy thinking to do... what shall I do today  difficult, difficult  hang on it is the weekend  I don't notice those sneaking up any more  , everyday is just one long weekend/holiday once you are RETIRED     Saturday is gardening with my Dad day 

Jo

P.S. That is a Elliot size 0 press Dave, they were used for pressing pins into PCB boards on production lines. That one was sat unloved when I helped clear some old Clarkson Sanderson beam engine castings at a deceased estate sale I mentioned it looked "cute" so they threw it in my box with the rest of the bits for me 

[Jasonb]

Did not think people would be that interested in photos of paint drying Jo so have not been posting the progress on the final touches of the R&V Vertical, but your engines never get to that stage anyway

You must have also missed the bit of machining from last night posted elsewhere today.

Oh and I did turn the inlet valve for the Allman, luckily my equipment allows valves to be turned from solid and I can fine tune the fit rather than use probably undersize stock in an oversize H7 or H8 reamed hole. Does that finish on the barstock not get lost when you clean them up after soldering?

Then there was the video of boring a 100mm dia hole on a Sieg mill that all the old school with their outdated old iron said can't be done and I managed it with ease

[Jo]

It seems to be taking a long time to paint but then I suppose it does if you want to achieve a good job, I'm not a lover of painting. Positive thinking at least you won't have to give the R&V back to its owner 

Yes missed that I rarely go to the Model Engineer Magazine site as they don't make model engines and when they do they seem to be Choochoos   

Getting technical on fits doesn't help all the members understand what you are on about and these standards are different around the world: The valves will be a good working fit in the valve guides. The stainless is 1/8th and the guides have been reamed with a 1/8th reamer, pressing them in the hole may have reduced the centre hole size in the guides but as I have a choice of only standard tolerance reamers and not a full every known tolerance set so that will have to do 

So which model engine was the 100mm hole for? I don't think we have seen that one    I've just taken delivery of a new side and face cutter, its not quite 100cm and I don't think it is going to give a very good finish so there will have to be a bit of tidying up after 

Jo

[Jasonb]

Well if its worth doing , you may as well do it right and there are a lot of bits to paint. Especially when you have to etch prine, High Build prime, colour prime (2 colours). paint (2 colours) clear fuel proof. Oh and heat resistant black for the exhaust.

Wrong forum it was on here I posted

Does not matter what size reamer you have when the valve is turned to fit. When you say running fit do you mean to say that this one will run

I only bored a bit of scrap to show it can be done. The guy managed it on his SX2P without a problem, its for his traction engine, this is his finished hole



And me doing it on a couple of scraps of finger plate using the SX2.7

<a href="https://www.youtube.com/watch?v=ENBbPieW3ss" target="_blank">http://www.youtube.com/watch?v=ENBbPieW3ss</a>

Not a bad finish on mine

[Jo]

Have you thought of doing a thread about painting models? After all you do it day in day out as part of your trade and the rest of us do it very infrequently as a hobby 

Fits: So why are you trying to confuse us with H numbers? What we need to know is the difference in measurements needed between a hole and a valve so that the engine will run properly. I personally use the feel of the fit.

Yes a 100mm hole is a bit of a non event but some members do not necessarily have the confidence to use their machines to their full capability. As you say even a hobby machine has no problem taking off a 1mm cut in aluminium with a suitable carbide tip.

Jo