Lister A Junior

Hi All

Trust you all are well.
Can someone pleas assist in how to remove the head of the Lister A Junior.
I am thinking of repainting all the parts.

The taking apart should not be an issue, my main concern is to how will one get the piston with rings back in the head.
I am so scared to break a ring and in South Africa are no spares.

All help will be much appriciated.

Thanks.

peice of cake. disconnected the fuel.
pipes from carb and remove it with 2 nuts normally and the plate and throttle slide behind it. HT lead off too, there is 3 large nuts that holds the cylinder on. Take them off and pull cylinder off!

Matt

Thanks Matt

You make it sound very easy.
How do one put it all back again. Talking about piston and rings into the head.

Thanks.

The reverse of taking it apart ...

What do you mean about the piston rings ? Dont quite get you .

Matt

Some people use piston ring compressors, I never bother, I just compress the rings with my hand as they go into the bore & have never broken one yet. Most pistons go in from the bottom & most barrels have a tapered start (chamfer) to avoid damaging the ring, at the bottom, so usually a little squeeze with the fingers gets them in no problem, just be careful not to hurt your fingers. If you are careful you should easily get the piston back in without causing any damage (to your self or your rings).

Piston ring compressors aren't that expensive though, but you can easily achieve the same with a jubilee clip (or even 2 jubilee clips joined together) (jubilee clips are hose clamping clips, just in case you call them something different there). You can even use plastic cable ties to compress the rings as they go in, just cutting them off once it's in the bore.

Personally I wouldn't buy a ring compressor. I bought a set of piston ring pliers, which don't work, so I just carry on using slivers of thin metal (like old feeler gauge leaves or pieces of metal cut off a CV boot clip, or even pieces of an old tin can) to remove piston rings, the pliers I bought are now nothing more than an ornament, I didn't bother sending them back as they only cost around a fiver.

Yes you can spend out on these fancy tools, but you don't have to. I haven't broken a piston ring in a very long time, & I've dealt with some very stubborn ones.

Also, when you put the piston back in, try to space the ring gaps well apart. I'm told it doesn't make much difference, but it's usual practise to space them as far apart as you can. From an engineering point of view most compression is lost around the ring through the groove, very little actually goes through the end gap. So the fit of the ring in the groove is far more important than the end gap.

Good luck, hope this helps.

Matt that seems odd with your piston ring pliers mine work fine

Il take a picture to see if the same design ...

With an A type its better to use your fingers with the rings and slide piston into cylinder 1st with conrod on and lower onto block and the compress a valve to be able to pull the conrod down and place the big end shell back on . The heads are pretty heavy to do with the conrod still connected to the crank unless you hand from a crane or get a helping hand from a friend .

Matt

These were the ring pliers I got....



But, TBH I just don't see the point in them. They don't work because they're cheap, but even if they did I wouldn't have that much use for them. I just don't see the point in paying out for these things when I can do exactly the same job with some bits of cut up tin can.

It was worth a gamble for a fiver, but it's the last time I bother with these kind of things, I'll stick to my little slivers of steel, I got some off a CV boot clip, which is stainless steel, very thin but strong, perfect for the job & is basically made from something I would normally put in the bin.

Somewhere I've got a picture of me using the 3 slivers of metal method of piston ring removal, but I can't find it right now. It's pretty self explanatory though.

Here it is! I found it. It's not exactly what the OP was asking, but he may well need to take the rings off at some point....

It's always best to be careful with old piston rings as they can break very easily, but once you have taken your engine apart you might find the piston rings are worn or damaged and need to be replaced anyway. When I stripped my Lister A down I found that the oil ring was broken and there was a small piece missing from it, luckily this hadn't damaged the bore. Also, the old compression rings were worn too much to refit, so I had to buy new ones.

There is a company called Cox and Turner here in England and they usually have 'standard size' piston rings for the Lister A in stock for immediate dispatch, but I don't know how much it would cost to send them to SA (or what the money exchange rate is like!). It might well be cheaper for you to find somewhere that sells rings for vintage engines in SA? However, it can be more difficult (and expensive) to find rings for engines that have been rebored +20, +40, etc. so do be careful when taking things to bits!

Here's a couple of interesting links about piston rings & why the end gap isn't as important as you might think. It's an American company, but their info is very good....

http://www.ringspacers.com/tips.htm

http://www.ringspacers.com/ringspac.htm

But it's also worth remembering that these engines are never likely to be worked again, so sloppy rings aren't really that much of an issue IMO, just so long as it runs reasonably well. It's always nice to have these things absolutely perfect though, if you can, but it's by no means necessary.

My Scott 2 stroke engine is supposed to have 3 piston rings on it, but one had a broken piece stuck in the groove. I managed to get a replacement but it was very sloppy in the groove & made a lot of noise when the engine was running, so now it just has 2 rings, & runs just as well as it did before. (mind you, 2 strokes generally do have just 2 rings, the message here is that these engines can run quite satisfactorily without having perfect pistons, or perfect rings, or even perfect bearings & seals. They are pretty bullet proof, I've heard all sorts of stories of things people have done to get engines running in the past).

Best of luck & be careful, these rings are very brittle on these old engines, be gentle with them.

Well I have to say I use both a piston ring clamp and a ring remover, I first used them at 16 when I worked on large diesels so thumbs weren't much use at 4 rings per piston then 6 or 8 pistons not much thumb left I have done them by hand but you get a feel for using the expander and I've never snapped a ring since I was 16 and first learning. I use the clamp because I can't see the point of messing about with hose clips when you can put the clamp on little knock and it's done, more chance of damage using hose clips etc.
The correct equipment is not expensive so why risk snapping a ring and it costing about 3 times more to replace the rings that's if you can buy the proper kit.

Stu.

Bit different for a multi cylinder diesel Stu, I don't see the point in spending out for a single cylinder Lister sidevalve.

Personally, if I needed to, I would use cable ties first, before hose clamps, but usually fingers will do nicely.

Obviously if you're running a garage or doing lots of these things then the right tools come in handy, but as you can tell from my experience, the cheap tools are rubbish, so why spend good money on something you'll probably only use once?

I've rebuilt 6 engines in the last 8 months or so, all of which have had the rings taken off & some of which have had the pistons in & out maybe 2, 3, or even 4 times or more & I haven't broken a single piston ring.

You can, of course, make your own piston ring compressor with some thin sheet metal (like an old can or something) & a large hose clamp. It's not that difficult to do.

Hi All

Thank you All for all the info, this is what I was looking for.
I will only have to remove the A type engine head to paint and maybe clean the piston.
I will try to use my fingers to insert the piston back into the head.

Shouldent be that difficult to refit all the parts.
My main concern was to use a ring compressor or not.
According to what I have read here,it will not be necassary.

Thanks for all the help guys.

Have a good one.

Raymond.

Generally, the bigger the piston, the easier it is to get it back in with rings intact. These older engines tend to have big chunky rings, which are easy to compress by hand. I put a piston back in a barrel of a small 2 stroke engine last night (I've got one in bits on the bench), I didn't even have to compress the rings as there was such a good taper leading into the bottom of the barrel. But, this particular one will not go into or out of the top of the barrel, it just refuses to fit. I think this is probably due to the wear groove that all engines get at the top of the barrel. So, as far as getting it out is concerned, the top is usually harder than getting it out the bottom. With a very old engine, sometimes the piston just doesn't want to come out past the top, it shouldn't be much of a problem on a Lister A though.