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Refitting a Matchless G3 / G3L engine and gearbox.

My intention with this post is to help,so please feel free to criticise or ad to it.30 years ago I rebuilt my G3WO engine and have long since forgotten how much work it was. I have just rebuilt my sons G3L engine and refitted it.I made the mistake of fitting the head and barrel on the bench,because of the weight involved its much easier to fit the crankcases to the frame and fit the barrel etc later. What I have typed below is merely an order of fitting,its not meant to replace the factory manual.It also assumes you have all the studs,nuts,bolts etc to hand. The main thing is not to have to take off parts you have just fitted ! My brothers G3L has a seized big end,so it is next job on the bike front,I'll be following this list and probably adding to it.
I can see why they were disliked by the REME workshops !

Assuming the crank is fitted into the cases;
* Check the necessary 3 studs and nuts are fitted before lifting cases into place.
* Lift cases into the frame and fit the long lower stud and nuts.
* Fit top front mount with 3 studs and the 4 1/2" wide spacers.
*Hang LH rear engine plate from the top stud.
* Fit gearbox on with top stud,also the stud and spacer that go through the primary chaincases.
*Loosely fit final drive chain.
*Add dynamo clamps and then RH rear engine plate.
*Fit gearbox adjuster with spacer.
*Fit dynamo loosely,and its F and D wires.
*Fit oil pipes,fill oil tank.
*Fit inner part of primary chaincase and spacer on large stud.
*Pour half a tea cup of engine oil into the crankcase.
*Fit barrel and piston.(I prefer to fit the piston to the barrel,then fit gudgeon pin and remaining circlip after.)
*Fit and time both cams,fit outer cam cover.
*Fit mag,sprockets and chain,set timing and fit outer cover.
*Fit cylinder head,pushrods and rocker cover.Adjust pushrods,fit cover.
*Fit carb and spark plug.
*Fit clutch pushrod,build clutch up,fit cable and adjust.
*Fit crank and dynamo sprocket with chain.
*Fit engine shaft shock absorber.
*Tension dynamo chain.
*Fit primary and tension primary chain,tighten gearbox fittings fully
*Adjust final drive chain,tighten rear wheel.
*Fit outer primary chaincase,add oil if you think its worth trying - I use spray grease.
*Fit exhaust and silencer.
*Fit battery.
* Fit petrol tank and fuel pipes.
*Fire it up,check for oil circulation.

email (option): joncvsv8@yahoo.co.uk

Re: Refitting a Matchless G3 / G3L engine and gearbox.

I'm sure there are others more versed in this than me but... I always fit the piston to the rod, fit the circlips then support the piston on a couple of wood blocks under the skirt and then offer up the barrel. The idea of holding the barrel with piston straight and square whilst pushing the pin in, often a tight fit and fitting a circlip with pliers is a trick I've never achieved. But if it works for you.
Richard

Re: Refitting a Matchless G3 / G3L engine and gearbox.

Richard, I've been using this method for years. Mostly because of building so many industrial and agricultural diesels where the pistons have to be fitted to the top of the bore.Makes an easy job with a standard piston ring compressor, I realised that the same method would be a help on bike engines. The point is a cast iron barrel is heavy and tricky to hold straight and square when easing it down onto the piston and compressed rings. The way I do it is to push the piston down the barrel far enough to expose the gudgeon pin hole.The barrel can then be sat on a pair of wood blocks on the crankcases. Then turn the crank slowly to bring the small end eye up into the piston.The gudgeon pin,(Which has been in the freezer in a plastic bag) will slide easily into place. With the crankcase mouth blocked off with clean rag, fit the remaining circlip.
It works very well and is easy to do,very kind to the piston rings too. Its an even bigger help on engines with long barrel studs as its often very difficult to get ring compressors in around them.

email (option): joncvsv8@yahoo.co.uk

Re: Refitting a Matchless G3 / G3L engine and gearbox.

Matchless army recon engines came as an assembled lump, complete engine, engine plates, mag, dyno, I doubt they disaasembled them to fit to the bike?

As a Matchless owner for over 50 years, I've never understood why people had so much trouble with this sort of thing.

Re: Refitting a Matchless G3 / G3L engine and gearbox.

ken
Matchless army recon engines came as an assembled lump, complete engine, engine plates, mag, dyno, I doubt they disaasembled them to fit to the bike?

As a Matchless owner for over 50 years, I've never understood why people had so much trouble with this sort of thing.
Ken, when I said feel free to criticise or add, I was hoping for constructive criticism. Your post is not much help,and frankly what Army recon engines were supplied with is now pretty much irrelevant as there are none left. Perhaps you could help us out a little. A very good friend of mine is just starting a WD G3L build -From parts he has slowly amassed. I mailed him my list and he is very pleased as like me he doesn't have hours and hours of workshop time to waste, I still run a garage repairing Landrovers and my friend maintains a large fleet of agricultural machines and vehicles.
Having a simple list to follow is not because it is a difficult task,its just about saving time and the frustation of having to take off parts you have just fitted.

email (option): joncvsv8@yahoo.co.uk

Re: Refitting a Matchless G3 / G3L engine and gearbox.

At my age Jon I much prefer to fit the crankcase assembly into the frame and then build up the engine, even sometimes if it means fitting the pistons into the barrel first (Indian's for instance). I struggle on my own with gammy limbs and all to lift a complete engine and put it in the frame, especially as I'm paranoid about my paintwork.

Matchless's are not my favorite bikes to work on, but I'm currently doing a tidy up and get it going on a friends G3L that hasn't run for 2 years after it was turned upside down in a trailer incident at the 2017 W&P show. Ron
DSCF1732

email (option): ronpier@talk21.com

Re: Refitting a Matchless G3 / G3L engine and gearbox.

I've restored and re built many g3ls over the last few years, I always fit the rear engine plates with bolt loose to the frame, i always fit the bottom half engine, I fit the front engine plate with the horn and spacers, leave bolts loose, then put the engine in the frame, fit front mount bolt, fit bolts to the rear mounts with Dynamo strap, and the fit the front lower engine/frame mount with the two spacers. Tighten all bolts, fit the Dynamo and bolt for the chain case, then the gearbox, fit barrel and rest of the engine top end, then fit the magneto, fit timing side case, fit spacers and then inner primary case, fit clutch and dyno chain etc and then another spacer and bolt, then outer primary cover, fit seal then allot band. Fit foot rest bar with spacer between the engine plates, fit carb and exhaust, kick start and gear lever, time the engine, add engine oil.

I have fitted the engine complete a few times but you do need help and plus you could scratch paint etc
I spoes thees bike are easy to work for me and ken and some others on the forum as we do em all the time but if you do t know much about em it can be a pain, knowing all the bolts and spacers

Thanks and all the best, Barry

email (option): fullerbarry@hotmail.co.uk

Re: Refitting a Matchless G3 / G3L engine and gearbox.

John, the long stud that goes through the primary case has a spacer between the engine plates, another as you say between the engine plate and inner primary and then a spacer and washer inside the primary case. Cheers JT

email (option): Tinley@btinternet.com

Re: Refitting a Matchless G3 / G3L engine and gearbox.

John Tinley
John, the long stud that goes through the primary case has a spacer between the engine plates, another as you say between the engine plate and inner primary and then a spacer and washer inside the primary case. Cheers JT
Damn I forgot to mention that extra spacer in the primary bolt

email (option): fullerbarry@hotmail.co.uk

Re: Refitting a Matchless G3 / G3L engine and gearbox.

Thank you Ron,John and Barry. Yes I did forget that spacer ! And I didn't add it in my list - Which I will edit. My problem is that I work on so many different things I just can't remember all the little bits. I currently have a 1948 IOE Land Rover engine to build, a TD5 Landrover head in bits,2x G3L's,a Stihl chainsaw engine and a part built B44 Bsa. Then there is a 1950 Chevrolet pickup and a 1959 SII Landrover to finish restoring...
Too much to do !

email (option): joncvsv8@yahoo.co.uk

Re: Refitting a Matchless G3 / G3L engine and gearbox.

Each to their own,

One thing that I find helps assembly is to not faff about with fitting the various studs. I have a selection of long tapered rods which I use to bash into the various holes to get the engine into place, better that trying to strain bits into place to get the studs through.

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