My 4G Restoration Blog

[paul.wirdnam]

Lovely project Paul. You do know that the first thing you must do is to strip the engine and clean out the sludge traps.....?

Thanks Paul. Yes, it's one of the many things I've learnt on this Forum.

[GuyH]

What a beautiful machine - and you've got the hard to get 1939 parts such as the oil tank, toolbox and rear guard with the valance which goes all the way to the end of the guard.These took me years and a lot of money to find!

[paul.wirdnam]

I've got as far as looking at the contents of a cardboard box that came with the 4G.

This cast iron pump puzzled me since I'm only familiar with brass bodied ones. A colleague who lives close by has a '38 4G plus a pile of spares, including pumps, but he had not seen a cast iron bodied one before. The pump seems the correct size for the 4G and seems to have no wear at all. I have no idea yet if the engine in the bike has a pump installed in it.

So, whats the story with cast iron oil pumps? Is it related to a shortage of brass in the war?

[simon.holyfield]

My '42 has a brass pump - surely if these had been successful (i.e. cost effective) they would have used cast iron? Odd that the valve caps don't have the two screwdriver slots like the brass pumps do. Different supplier perhaps? Did Ariel make these themselves?

[nevhunter]

I would guess they are outsourced, like the big ends, pistons etc. Cast iron is a good pump body material and is used for gear pumps. The worst material is diemetal, as it warps and cracks and is unreliable when old. Nev

[paul.wirdnam]

Some recent progress on my 4G.

I thought I'd sort out the exhaust system before dismantling the bike. In '39, the standard pipes were Siamese pipes with separate pipes as an option. The bike came with an unused but 14 year old grubby offside fishtail silencer and, to my surprise, cleaned up well with Autosol, so although I don't really like the styling of the 4G Siamese pipes, I thought I'd save the expense of a second fishtail and go with them. Armours had them in stock and only 40 mins from my house:







Another '39 peculiarity...the rear number plate and lamp. Adrie to the rescue --- many thanks. Rubber boot for the lamp from Drags and car MT1130 from local autojumble; latter will need modifying to allow some downward lighting for the number, and a red lens to replace the white one:

[Steven.Carter]

That small crossover pipe had a terrible habit of falling off my Huntmaster. I'd lost two until I made a small stainless P. Clip to the frame. The one on my current Huntmaster with the alloy head turns inside the down tubes so can't fall off. Might be different on the Sq though.
Looking very good Paul. I do enjoy reading these kind of blogs.

[rein.heerkens]

Paul, what’s the number of the rubber boot at Draganfly?

[paul.wirdnam]

Paul, what’s the number of the rubber boot at Draganfly?

6130-39

[paul.wirdnam]

Centre stands, rear stands, side stands....fed up with stands .

'39 4G has a centre stand...except my 4G came with a rather crude homemade tubular affair. According to Drags, Ariel only made centre stands in 1929 and 1939; I've owned a '29 Model F and the centre stand was awful and prone to breaking....maybe that's why Ariel waited another 10 years to have another go...except they forgot to update the design:



Still, I want to restore the '39 4G as accurately as possible, so I bought a new rough casting of a '29 centre stand and hoped that it could be made to fit the '39 4G. Judging from the spare parts diagrams, it looked promising.

A bit of machining for the mounting holes in the two top lugs but when I put a 1/2" bar all the way through both holes, it was clearly going to be very lop-sided even though my 1/2" bar was parallel with the crossbar of the stand. This is what you get when you use a worn part as the mould for new part . So a padding out of the left foot:



But everything else worked out well. The gap between the frame centre stand lugs was perfect for the new stand and the return spring mount point were also spot on. So yes, a '29 centre stand will fit a '39 bike even though the parts number are different:





But the bad news is that hauling the 4G onto the centre stand is as bad as I remember hauling the '29 Model F onto its centre stand, so I decide I needed to investigate what it would take to fit a rear stand to the 4G. As its a plunger frame, there were no mounting points for a rear stand on a '39 frame but Ariel introduced some bolt-on brackets in 1940 for a rear stand. Got a couple of those --- left and right versions and they went on fine (thanks Andy!):

'39 Plunger back-end without rear stand brackets:



Brackets after fitting:





And I have a plunger rear stand on its way to me. That's the Stand Story for far...let's hope I don't need a side stand.