1953 / 4 G3LS build

[EddieDay]

I mentioned to a few members that I would be buying "most" of a G3LS in Nairobi. I went over to pick up the parts today and have posted some photos of them here. I have unpacked only one of the boxes so far and laid the parts out on the bench. I say 1953 / 54 because the owner told me it was a 53 machine but the cases are 54. Not sure what the frame is. I will find out from the Club archivist. The parts were gathered in Kenya and Tanzania so it may turn out to be something of a bitsa. The previous owner has started painting some of the parts (kidney boxes, oil tank, fork yokes, chain guard) but ran out of steam about 20 years ago.

2023-11-20 17.11.10.jpg

I am sure that I will be asking for lots of help on the forum. Not sure how long it will take or what is missing (yet). I know I am lacking a dynamo, magneto, rear rim, front and rear lights, loom, switchgear, speedo and ammeter, carb, exhaust, pushrod tubes, and rocker gear. Anyway it should keep me amused.

[EddieDay]

I am not sure what is missing yet. I know that I need a dynamo, mag, lights, loom, rear rim, rocker gear, pushrod tubes, carb, exhaust and seat. Not sure how long it will take but it will keep me amused. I am sure I will be asking lots of questions on this forum.

[Pharisee]

I built up a '53/54 "Basket Case" G3/LS a few years ago. It took a while but I ended up with a very respectable bike.
If you're interested, I documented the whole build, from collecting the bits onwards on my website. It may give you an insight into the problems that I encountered (and the way I solved them).
You can find it here...https://www.whatfunnyhat.com/Frame_Stuff/Matchless.html

[EddieDay]

John, thanks. I had a look at your rebuild diary and can see that you were in a similar situation. I am sure it will be useful to me in my project. Some of your parts were worse and some better than mine. E.g my barrel is far less rusty than yours was but it has some broken fins. I have some excellent tinware, a restored swinging arm and an unused frame. But the mudguards are battered and I am missing some vital parts. And I now realise it will end up being a bitsa. I got 2 frames with the boxes of parts, one with a frame number and one which appears to be an unused factory replacement with no frame number. The trouble is I have found from the club dating service that the frame with an number, which needs a brazing repair, is from a 1953 G9. The engine is a 1954 G3LS. Eventually I will need a frame number for the unused frame. I have sent an email to the club dating officer explaining the situation and asking advice.

[SPRIDDLER]

.......buying "most" of a G3LS in Nairobi. I went over to pick up the parts today

Nice project, Eddie.
Is 'Nairobi' a predictive text error? It seems rather a long way to go for a G3LS basket case.

[EddieDay]

Hi Neville. No it is not a predictive text error. I will be in Nairobi for the winter and I like to have a project. The bike parts, and some complete bikes, have been gathered from around East Africa by a guy who lives here. He also has a Vincent, a TR6, an A10, an early BMW GS, most of a T100 and a WD G3L. I have known he had the Matchless parts for over 20 years but he has only recently been serious about selling them. I am planning to buy his surplus G3 parts as well.

[SPRIDDLER]

Hi Neville. No it is not a predictive text error. I will be in Nairobi for the winter and I like to have a project. The bike parts, and some complete bikes, have been gathered from around East Africa by a guy who lives here. He also has a Vincent, a TR6, an A10, an early BMW GS, most of a T100 and a WD G3L.

My word, if only they could talk I bet they'd have interesting tales to tell in a nice warm shed. (I see it's 25 deg there today).
My '54 G3lS was shipped direct from the factory to the Rhodesian police force and repatriated by its retired rider in 2003.

[EddieDay]

Now that I have had a chance to look at the engine components closely I have found that the barrel has a liner and the piston is close to standard. However the piston is also oval by quite a lot, a difference of 0.022" between the bottom of the skirt diameter measured in line with the gudgeon pin (2.700") and at right angles (2.722"). Also the liner is somewhat pitted although not badly scored. My first thoughts on the way to proceed is a rebore of the liner to +0.020" and a new matching piston. However I wonder if the liner is thick enough for the rebore. It is about 1.3mm thick (0.051"). So a +0.020" bore would leave a wall thickness of 0.041".
The alternative would be to fit a new liner. Any advice welcome please.

[SPRIDDLER]

Hi Eddie. First of all is there an issue with the engine burning oil or poor performance? If not then I wouldn't get too occupied with the bore being 'somewhat pitted' but a photo of the pitting would help to quantify 'somewhat'.

I have always left the matter of liner thickness to the reborer to whom I will already have given my new piston. However, WRT the bore and liner, the standard bore is 2.7187" so your piston at 2.7220" is already 0.0033" greater than a standard bore. It would help to know the diameter of your bore. Is the piston the wire wound type?
Have a look at page 3 in the Army Tech Stds (link below) which gives the relevant info including the O.D. of a cylinder liner, so if you deduct the standard cylinder bore of 2.7187" from the liner O.D. of 2.8460" it will give you a good clue to an acceptable liner thickness (e.g. 0.1273").

Army manual.......

http://archives.jampot.dk/book/Workshop ... ndards.pdf

However I wonder if the liner is thick enough for the rebore. It is about 1.3mm thick (0.051"). So a +0.020" bore would leave a wall thickness of 0.041".

If I'm not losing the plot then 20 thou off 0.051" would leave a wall thickness of 0.031" not 0.041".

The bit in blue above is nonsense. Ignore.

[EddieDay]

Spriddler,
Thanks for your reply.
The problem with the piston is that it is oval by 22 thou and will not fit inside the barrel. But skimming it with a lathe won't work because the small "diameter" is too small for the bore. 2.7187 - 2.700 would leave almost 0.019" clearance. I am resigned to the piston being scrap. Now a rebore of 0.020" is (I thought) + 0.020" on the diameter, which would mean 0.010" off the thickness of the liner. I.e. 10 thou off 0.051". N'est ce pas?