A sunny day in June

My Square Four tank, and it does appear to be a Square Four tank (very large and of the appropriate width; large filler, pressure gauge hole) has as I said two taps (it also has a drain at front RH and no crossover pipe). What I neglected to mention (or even realize) was that the taps are forward of the tank mounts:

As you can see, on a Mk1 these are very close to the back of the rocker covers and will get frighteningly hot, I suspect. It looks a little odd; the closest reference I can find to this arrangement is a rather nice '51 KH shown in an article in RealClassic, which has two Ewarts taps in a similar location. The curious thing is, I have scoured all the KH and SQ4 parts books I can find and they all describe a single tap.

Hmm... Is this really a Square Four Tank?

So, one plan is to use a pair of Ewarts type plunger taps, 3/8" BSP into the tank with horizontal outlets. I will then make a copper/rubber tube assembly to tie the two taps together into the single inlet to the Solex. An alternative would be to blank the tap hole on the RH, and use a two-level plunger tap on the nearside - but I am not sure I have room for that.

I will need a supply of tube, nipples and gland nuts to make up this assembly - and I guess I will make a tee out of some brass barstock. I'm not sure where to buy these parts yet...

On a brighter note, she is a very handsome machine:

Max is nonplussed

Ariel do not seemed to have paid a lot of attention to the maintainability of their machines. Two maintenance items in this picture, neither of them easily accessed AND I have removed the kick start lever. More positively, the oil tank is now hooked up.

The valve timing is done, with a little help from my daughter - assembling the cam chain tensioner is not a one-man job:

And the exhaust pipes are looking good. The eagle eyed amongst you will notice the clutch dome is still off:

I have discovered however that when I straightened the RH footrest hanger, I straightened it too much and it now fouls the exhaust pipe.

More wiring done this weekend too. Horn and Lucas 529 rear light fitted:

and I am not sure what to do about the throttle cable abutment:

The head is on!

So we are all set. The sun is shining, I have a day free (after cutting the grass and making the family dinner) and I have all the parts, plus a very nice text from Bruce Longman via Draganfly with explicit instructions. Max is in bed, so he will be happy for a bit:

A Chocolate Sprocker, feeling very 'Sunday Morningish'

I have some high temperature silicone gasket as recommended by Bruce. Loctite say this is suitable for operating temperatures up to 275 degrees C (sustained) with excursions to 300 C:

So as recommended by Bruce, we start by laying a band of sealant around the pushrod tunnels, on both sides of the gasket. Actually easier to lay one bead on the gasket, and one bead on the block, making sure you have the handed gaskets the right way around:

No picture, but next I placed all the head nuts in position between the cylinder block fins, under their holes, with the flanges upward. Next, manoeuvre the head under the frame tube and drop it into place over the studs, making sure the extended, rounded ends of the studs drop into the nuts. Add the sleeve nuts inside the rocker boxes, and the 5/16" CEI reduced hex nuts outside the rocker boxes. You hand screw these down finger tight.

And as Kees Knegt pointed out in a comment to an earlier post, this would have been easier without the rockers! You cannot fit the pushrods with the rockers in place either (they don't slide sideways far enough) so I may as well have left them off... although I do like to trial fit everything at least once.

Next, with your thinnest 5/16" CEI open spanner, engage all the nuts on the downward facing head studs and turn them as far as they will go without using and force. You will realise now that if you leave one undone, and tighten the others, you will crack a fin by virtue of the loose nut pushing downward onto the fin below.

Once you have all the nuts finger tight you will see the head finally come down onto the gaskets. continue going around all the nuts inside & outside the rocker boxes until they are all snugged down finger tight.

You will need a variety of spanners to achieve this. The reduced hex nuts in the middle of the head, under the inlet tract are particularly inaccessible.

So, when everything is snugged down, use Bruce's torque figures and sequence to tighten down the head.

Job done.

A word of warning...

Original Amal handlebar grips smell a lot like dog toys...

 

 

A Good Thing

Aside from motorcycles (and we have yet another MZ in the family) we have a fabulous event to announce, helping to fill the hole left by the dear departed Ruby, our Cocker Spaniel.

This is Max. He is a 6 month old chocolate Sprocker (Springer Spaniel x Cocker Spaniel):

Isn't he great!