15cc Seal and 30cc Seal Major

[Jo]

The seal connecting rod being made from bar stock can have the spacing of the two holes easily drilled and reamed. However the Major's rods are castings so we need to part the rod leaving the distance between the centre of the small end to the cut line exactly on the connecting rod length 

Using the same jig used to drill and ream the position of the small end can be used to set up the distance to the cut line 

Jo

[Bluechip]

Getting on nicely now. 

But ... Ye Gods ..

What temperature have you got down there?  Given up 2 hours ago here. Just above 34^oC in the garage.
Too hot to be hungry so I'm sitting here with the fan on, Classic FM on the radio and reading a book about butterflies,    suitably fortified with whisky and iced lemonade.  Torture, I know but I must be brave and stick it .....   

Cap screws look nice ..... 

Dave

[Jo]

Thanks Dave 

Its 23 degrees in both the workshop and the house. Conservatory is claiming 40 degrees so I won't be sitting out there this evening to do my cross stitch    Green house has just been hosed down and is sitting at 30 degrees.

This heat does not encourage swarf making 

Jo

[Vixen]

Jo

Conditions are not bad in my workshop today because of all the extra wall insulation. 21*C when I went in to start after lunch, I left the door open to catch the breeze and the temperature started to rise sharply. Door now closed and it's nice and cool again.

The grapes against the outside wall think it's great. They are starting to turn from green to blue. Hopefully a good crop this year.

MIke

[mike mott]

Mike, The Insulation works both ways of course, here it really helps when it gets to -30c we are finally getting a little summer weather it will be 31c today.

Mike

[Vixen]

Mike

As you say, insulation works both ways. It does not prevent you from getting too hot or too cold; all it does is to slow the rate of change. After a day (or two) it will always reach outside ambient in your den.

Mike

[gadabout]

Jo, have you noticed if the Major needs a notch in the liner bottom? I will have to do a cad drawing to see how much interference there is with the Seal, may be a pain to machine the notch

Mark

[Jo]

Sorry Mark, I don't know I have not yet made the crankshaft for the Major.


Cylinder head nuts, as requested 

These are being taken out of 8mm diameter bar for the major. The 8mm is the diameter of the washer part of the nut. I first start by finding a number of bits of bar of the desired diameter and the plan is to make a nut on each end of each bar as we go - there is nothing more boring than doing them one at a time 

I normally start by turning down the end to the across corners dimension of the nut, drilling the tapping size and slightly counter sinking the hole at the top. (This is not actually necessary you can first mill the hexes.) Then off to Sexy for him to mill the flats for the nut. I have made them 5.5mm A/F, with 3.2mm height.

Back on Mr Silky and using a file with the lathe running carefully file the angle on the corners of the nuts, remove any burr below the hex shape and part off over length - these will have 1.6mm thick washers so I am parting off at 5mm.

Using the correct hex collet I can now hold each nut, with the stops set for the saddle, face the bottom of the nut, take off any burr with a file, counter sink the centre before tapping through 4BA. If you haven't got a hex collet you may want to consider drilling and tapping when you face the backs of the nuts so that the bottom is square to the thread.

Which results in 31 nuts for the Major 


In the meantime Surus tells me that that nice man from Waitrose had delivered him some nuts  and he too has been working on them 

Jo

[b.lindsey]

That's a lot of hardware Jo  . A lot of snickers too...good time to go after more of Surus' castings stash while his attention is diverted!!

Bill

[Jo]

He should be in a good mood later for our Thursday night casting fonding

Jo

PS. It is safer to not take any without permission

[bent]

Still following along.  I now have to forget that there is a thing called a Snickers Ice Cream bar, having restarted a weight loss regimen. 

[gadabout]

Jo,
Thanks that's great, always learning from you! I have milled out the notches(scallops?) on my Seal with a 1/4" dia 6" long carbide end mill, was fun . All spins over very nicely with pistons in but no rings on yet.

thanks

Mark

[Roger B]

Plenty of nuts there      I like the idea of using an assortment of sort ends of bar when machining more complicated nuts     

[Jo]

As the bar for the Major studs has turned up I can't delay it any longer  So I decided to start on the Seal studs instead.

The original plan had been to use 2.5mm bar to make the studs but it proved to be too tight in the existing holes and an experiment with using 2.4mm proved much better. The ones for the head all went in ok but then I remembered the two that cross over the manifold studs  Time to also mount the manifold.

If you recall the manifold cannot mount as the carb hits the main casting. My first thoughts was that on the bottom of the carb is an unnecessary breather lug that could be filed down and it would be nice to get the jet hole central on the casting. After that it still was not possible to put the needle in the jet so I phoned a friend  He said mount the carb at a slight angle.... So the mounting face of the carb was milled to 5 degrees.

Finally able to mount the manifold I could look at making more studs  and then securing the manifold. I chose to mount this first and because of that awful stud alignment drilling through the manifold studs from the head and re-tapping. This means that the head studs will have maximum engagement in the main casting. HOWEVER the stud material is harder than the casting so there is a tendency for the head stud not to fit true (drill wandered lower in the hole  ) so I will be using two false studs for the two crossing head studs 

Jo

[Jo]

The other thing I checked was the sparkplugs: No it is not possible to get the sparkplugs in place with the manifold in place  It may be possible with a thinner Chinese plug but not with the supplied old original ones. Looking from the other side the Chinese plugs are of a longer reach than the older plugs so I may be forced to use those anyway.

Having studded up the Seal it was time to start on the Major studs I had been putting off: The main problem here is that the studs are 4BA and that means they need 3.6 bar. I initially thought about trying to find a box tool that I brought from ArcEuro some time ago but it was not that good. When I remembered my Supplier had shown my capstan tools a lot of attention and one particularly he had felt the need to stroke. It was only when he mentioned it was Swiss did I appreciate his attraction to it 

This capstan tool is a running down tool  So having made a bush for 4BA, found a suitable carbide tool to fit the capstan tool a quick test to set the tip to cut 3.6mm and we are ready to go 

Still no casting sign 

Jo