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Getting back to mechanical things, it struck me that the tractor is looking a little scruffy and somebody may want to tidy it up. Because the engine is very much built in to the tractor, anybody wanting to repaint the tractor would have to undo all of the work that I’m doing, so I cleaned up the area around the engine and gearbox and painted it ready to receive the rebuilt engine.
That way it can all stay bolted together without needing to be disturbed.Attachments:
Now that that’s done I can get on and sort the gearbox and clutch out. If you recall I had found the clutch seized solid and so I needed to get at the actuating rods that are fitted inside the hollow mainshaft.
To access these rods it is best to dig down into the clutch until you expose the end of the rod, normally with a large round foot on it, then try to pour some sort of lubrication down the rod and work it back and forth until you can withdraw the rods. It is best then to clean them up, re-oil them and re-assemble.
As you can see from the photo the clutch rod is in three parts on this gearbox and I managed to get it out without too much bother.Attachments:
I’ve been working on various parts of the engine most of this weekend; I must confess that I haven’t taken many pictures of the tinwork in it’s various stages because they all look the same, you just have to keep flatting down and repainting until you’re satisfied with the finish. Needless to say that the pictures showing the panels in gloss black were only halfway there, I had to flat them down again and re-fill some blemishes that I wasn’t happy with.
The pictures this week show that the gearbox and clutch are now back together and working so I mounted them on the platform fixed to the rear engine mounting.
At the front of the engine I have added the timing chain and sprocket to the inlet valve cam; don’t be tempted to put the sprocket on first because the chain won’t go on the teeth once the sprocket is bolted down, so you have to do them both together.
The magneto was added next and the sprocket placed on the tapered drive shaft loosely; the magneto was moved on it’s slides to tension the chain then the mag could be timed up. I’ve been asked quite a few times over the years how this is done, so I’ve included a few detailed photographs to explain the procedure.
Firstly you need to turn the engine in it’s normal direction (anti-clockwise as you look at the crankshaft drive sprocket) until you reach Top Dead Centre (TDC) on the POWER stroke. This is when the piston can be moved up and down the bore either side of TDC without either of the valves moving. This is where some people go wrong- they put the piston on TDC with both valves “on the rock”, which means that the inlet is just opening and the exhaust just closing.
Assuming that you have found the correct part of the 4-stroke cycle for TDC you then have to move the crankshaft backwards until the piston has descended 3/8″ down the bore- this is known as 3/8″ Before Top Dead Centre (BTDC). When the engine is running this is where the spark should be triggered. The engine is now in the correct place for the set-up, so don’t move it from this position.
Next you turn to the magneto and remove the points cover (or contact breaker cover depending on how posh you are). If the mag has an advance and retard device set this to normal running, i.e. fully advanced. With a magneto you will find that when the points open the spark is generated, so to find when the points open the easiest way to tell is to put a cigarette paper in between the contact faces, turn the magneto in it’s normal running direction to allow the points to close, then keep turning until they just start to open again- this is where the spark will be triggered, so you stop turning as soon as you feel the paper coming loose, then take a tubular drift and tap the drive sprocket onto it’s tapered shaft to lock the engine and magneto in the correct positions. You can then tighten the nut on the magneto shaft to hold the sprocket onto it’s taper.
Notice I say “tap”; because the tapers are so well matched you don’t need to thump them to get them to stick together. Take a look at the photo’s and you’ll see that I’ve used a small tack hammer to achieve the result. If you use anything bigger you stand a real chance of damaging the bearings in the magneto.
The other photo’s show the completed engine and gearbox assembly with the sprockets lined up ready for the primary drive chain and also the other side of the engine with the timing cover fitted.
Nearly there!Attachments:
The primary drive chain is next to go on, but first it had to be treated. I already cleaned it in de-greaser then steam-cleaned it to get rid of all the dirt, but the one thing that I forgot was to protect the bare surface after I did it.
No matter, some of the links were showing a slight film of rust but no more; one thing that I always do with chains is to give them a boil in grease so that they are well lubricated from the start. As the grease heats up it becomes fluid and also heats up the chains. The air in the links in the chain is usually forced out and the grease dragged in as it cools. The only problem is that it’s a bit messy and smelly and so I usually have to do it in the garden.
When our neighbour cooks sausages (or bacon) for her kids she always seems to set her smoke alarm off; when they hear the alarm, her two boys shout, “Dinner’s ready!”
Anyway, I digress. The chains are now cooked so I fitted the primary tonight and tensioned it up using the tensioner provided at the top of the rear engine mount. There was nothing stopping me from putting it back into the chassis, so I struggled and dropped it in as well.
The next stage will be to fit the main drive chain from the gearbox to the rear cross-shaft, then slide the engine forward to tension it up and bolt it down.Attachments:
I’ve had a good weekend so far with the Steed. You can judge for yourself from the pictures and I think you will agree that it is definitely “coming on”.
First up this week was the fitting of the main drive chain from the gearbox to the rear countershaft. If you’ve ever done this for yourself you’ll not be surprised to hear that it took me a couple of hours; running the chain through the backbone chassis was easy, it was the joining of it that was the awkward part. You can see from the picture that the grease was very well smothered all over the chain before I started and after I’d finished it was all over me! Never mind, the important thing is that the grease is inside the chain as well where it needs to be and I’ve now broadened my vocabulary of swear words. Needless to say, Ruth kept well away!
Once the chain was on it was tensioned up by levering the engine/gearbox assembly forwards. It is quite noticeable on this Steed that the engine mountings have “T” nuts in the slots to help with adjustments and to keep the engine in line; the Steed that I have does not have these nuts and so I presume they were found to be unnecessary. You can see one in the photo’s.
With the engine firmly bolted down the right hand side plate can be fitted. The correct position for this is centrally around the crankshaft (it is on slots for adjustment backwards and forwards) and you can see now why I opted to paint the front of the chassis when I did. Don’t forget to fit the crankcase breather pipe at the same time and position it so that it drips onto the primary chain. The chain cover can now be fitted.
I went to the top of the engine next and fitted the cylinder head. You can see from the pictures that I tried a couple of plugs in first to see what reach I needed. These engines originally had an 18mm plug fitted (KLG M80 is the recommendation) but this one has been modified to a 14mm plug hole, so I’m going to have to do a bit of detective work to find what plug will be best. You can see what happens if you fit a plug that is too short- yes, it works, but you get a coke build-up in the threads that can be difficult to clean out. It’s better to do the job properly in the first place and make sure that all the threads are covered.
Above the piston there is also a tapped hole with a blanking plug in; this is to help in timing the engine so you don’t have to remove the cylinder head to measure the 3/8″ BTDC. On my Steed there is a little flat plate held down with a single screw to give you access to this hole, but this engine doesn’t have that plate.
You can see from the pictures that I put the air cowling on, held down by the two petrol tank supports and I even placed the tank on to it’s mountings to take the picture. I have got to make some straps to hold the tank on with (it was held on with large Jubilee clips) and find some felt for it to sit on; one of the original problems with the engine was that rust kept blocking the carburettor and so I have steam-cleaned the tank out with some fine gravel in it to knock the rust off and then I will treat it with a tank sealer (Philip Plotkin has recommended “Slosh” so I’ll try it out) to completely cure the problem.Attachments:
Not a good week, this week! Nothing wrong with the Trusty, but “She who must be obeyed” lost her car keys in a 6 acre hay field on Tuesday and it cost nearly £200 to sort it all out! Needless to say, I’ve spent an awful lot of time walking around looking at grass this week before finally admitting defeat and calling in the locksmith.
The engine is coming along well at the moment and I’ve mounted the starting hub/cooling fin carrier onto the crankshaft. There is a right way and a wrong way to do this, and I think it had been fitted wrongly previously. On the casting is a hole with a small cheesehead screw threaded through and a nut on the back; the main use for this is to provide a firm location for the starting strap so that it doesn’t slip, but it also has another use- when it points to the 12 o’clock position it indicates that the piston is at TDC. This is invaluable when you come to time it up with a replacement magneto. There are six bolts that hold the carrier on to the crankshaft sprocket carrier and so there are a potential six different positions that it can be mounted in, so beware.
Whilst we are talking about these bolts, you can see from the one photo that these are originally quite long bolts that have been shortened. Another indication that these tractors were largely hand-built.
The oil tank has also been mounted on the front engine mounting; a word of caution here because the holes in the engine mount are tapped as well, so don’t go thumping them with a big hammer to get them out after you’ve taken the nut off because you won’t do any good!
Back to metal bashing again for this week and the final batch of cowlings that have to be finished off. There is the large fan casing that has to be repaired and flattened as well as the Burgess air filter and the clutch cover; looks like another boring week ahead!Attachments:
Boring is not the word, it seems like three steps forward and two back. After endless layers of filler, flatting down and ghosting over with paint, then flatting and repeating over and over again, I’ve finally got the lower cowling into a reasonable shape and finish. I then found that I had to take off the top cowling to fit it- fine, just four bolts to undo. Until the fourth one stuck in the head nut, that is, and brought the nut and stud out with it!
Cylinder head off again so that I could screw the stud back in without bruising the threads. Whilst it was off I checked the alignment of the starting pulley and the locating screw for the strap- if you remember it should be at 12 o’clock when the piston is on TDC- and this gave me some satisfaction as it was spot on.
Head back on again, but this time I thought that I’d check the screw holes that hold the cowling onto the side plate. These screws are 3/16 Whitworth and so are tiny, and I remembered that when they came out they were quite an assortment of odds and ends. A quick trip to the nut & bolt suppliers had 2 dozen bright shiny screws for £2! Being Whitworth I think they’d been on the shelf for a long time and I was really contributing to the storeman’s Christmas Beer Fund.
For the sake of taking four bolts out I thought it best to run the tap through them whilst it was on the bench, so that’s what I did and I’m sure they went in better for taking the time to do it.
Re-fit the side plate to the tractor, fit the clutch cover with it’s three screws and then fit the lower cowling with it’s seven screws; the two at the top on the front are bolts that hold the bracket for the governer vane, so don’t go putting screws into those!
Next was the governer vane that fits close in to the fan, followed by the bracket that fits diagonally behind the top holes of the lower cowling. Then I could re-fit the top cowling and the tank brackets.
A few weeks ago I mentioned that the spark plug for these engines should be a KLG M80. This is an 18mm plug and somebody has modified this cylinder head to take a 14mm plug- good idea because it is difficult to buy 18mm plugs these days, but what plug do I use now?
At work we sell NGK plugs and so I went through the cross-reference book to find the answer; the direct equivalent is the NGK A8, but as this is still an 18mm thread this was only halfway.
The “A” signifies the 18mm diameter thread, and “B” signifies the 14mm diameter thread so it had to start with a “B”. The “8” is the heat range of the plug and so I had to try to find one with a similar number, but talking to a kind man at NGK he suggested going to a “6” to compensate for the modern fuels.
Next came the length of thread, which in the case is 19mm, and the letter that denotes this is “E”, so I was looking for something along the lines of B6E as a basis. Nearest that I could find from stock at work is the BPR6ES- the “P” means that the centre electrode protrudes a little from the shroud, the “R” means that there is a resistor in the plug and the “S” on the end just means that it is a standard copper core electrode.
Problem solved!Attachments:
I seem to have finished the one side of the engine now, so it made sense to turn the tractor around to work on the other side.
First on was the support for the governor rod which I had already put on once; it didn’t look right, so I went back to the photo’s that I took before I took it all apart and it proved my hunch was correct. In a moment I took it off and changed it around and so now it fits as it did originally. I still need to clean the mechanism up so I haven’t put that back on the spindle yet, but turning the whole lot around will make it easier.
The fuel tank was crying out for attention next and so I made up some cork pads for it to sit on. It sound easy, but it took me hours to position the brackets so that the tank sat level and at right angles to everything else. I can only assume that it never has fitted properly because I had to open some of the holes into slots to make it all work. Anyway, back to the cork pads! While I was at it I also made up some cork strips to sit under the new tank straps so that the paint didn’t get scratched once it was all together.
Because the tractor originally came with some Jubilee Clips instead of tank straps, I decided that it needed some proper ones that looked like the originals. The straps were made out of strip steel, 3/4″ wide and 2mm thick. Unfortunately the steel supplier couldn’t do the original thickness which was 1.75mm and my choice was either 1.5mm or 2mm; seeing as the strip has to be strong enough to take a 90 degree bend in each end for the tensioning screw I went for the thicker metal.
The hardest part was getting the profile correct because the tank is an oval one. The only way that I found to do it was to bend a little at a time and try it against the end of the tank, then do a little more and keep going until I had gone all the way around, then make the bend at the end. Once I had made one strap I put the second strip in the vice alongside it and copied the shape; from the photo’s you can see that I took a great deal of care in setting up the strap in the vice, making sure that it was perfectly square to the jaws otherwise it would end up as a giant corkscrew.
I haven’t quite finished the straps yet as I still have to paint them, but I thought that I’d do them silver instead of black so they stand out a bit.
Putting the side plate back on presented a few problems in that it wouldn’t go past the bracket for the weeder bar, so I had to undo that and drop it down out of the way. Eventually I ended up taking off the footplate to gain access because it had been put on with an odd assortment of bolts and nuts. Some were too small in diameter and had UNF threads as well; this does sound a bit daft, but when you come to undo something and find that the heads are AF instead of Whitworth (or even worse, METRIC!) then it does make sense to keep them all the same type. After all, it was built in Whitworth sizes so it should fit together better using them.Attachments:
It seems ages since I last wrote anything here, so here’s the catch-up.
As I said in the last piece, somebody in the past has done some pretty major surgery on this tractor. I’m guessing the gearbox has been replaced at some point and the new one didn’t quite fit; it’s the right one (an Albion HR3) but where the gear change linkage fits on to it’s square location there seems to be an extended piece that protrudes about 1″ out of the box, whereas the original’s was a flush fitting. To accommodate this somebody has taken a hacksaw to the side plate and taken a chunk out of it, then rebuilt it with odd nuts and bolts.
I decided to leave the surgery alone, but one thing that always annoys me is the mixture of sizes of bolts. The only way to re-assemble it was to do so with the correct bolts, so a trip to our local supplier provided me with the correct sizes and threads; besides, five of the bolts holding the footplate down were countersunk and only Whitworth countersunk heads would fit the holes- everything else had heads that were far too large. Look at the photo’s and judge for yourself at the ones I chose; I think they were the best option.
Whilst we are talking about these bolts, the only ones I could find were 3″ long and so needed shortening. The easy way is to just take a hacksaw to them, but then they would look to be different lengths and tatty, so what I did was to mark them with a hacksaw cut and then put them in the lathe as shown in the photo. The parting tool was lined up with the cut, but before it was wound into the cut I brought the tailstock in with another chuck holding another bolt to act as a length stop. In this way it was quick work to part off the first bolt, take out the remainder and replace it with another so that the heads touched; all five bolts were then cut off to exactly the same length.
Pleased with myself, I replaced the footplate and ticked off another job.
I was dying to try the fuel tank sealant after Philip Plotkin had recommended it. I tried POR15 some years ago and found that it has a short life of two to three years before it started to peel off, so SLOSH was going to be the next trial. As you can see from the pictures I took a lot of care to keep it away from the paintwork and wound a plug of paper into the outlet hole as well. Once poured in it is easy to chase around the tank inside and sets to a hard finish very similar to fibreglass resin. Even though I had put a plug of paper in the outlet hole, the resin had hardened in the thread and so I had to tap the thread out again- if you need to do this the thread size is 1/2″ BSP- but once done the tap has gone in and fits a treat. All I have to do now is to find some bolts to hold the tank straps together that are the correct size and the tank will be done.
One big setback has been the carburettor; if it wasn’t so rare I would have looked for a replacement, but considering the rarity I am determined to recondition it.
The first stage was to dismantle it carefully and clean it in an ultrasonic bath. One thing that I couldn’t budge was the slow running mixture screw and so I left it there for now. You can get behind it by removing two blanking screws, so I left it to soak.
Because it is such an awkward shape putting it in the vice was out of the question; the only way to hold it firmly was to mount it onto the engine, so I did that and then tried to undo the stuck jet. The jet that is in the hole is not the correct one and so the thread is probably a mis-match; that would explain why it sheared off despite using all of my reserves of patience, skill and know-how. Damn!
I’m now going to have to borrow a Dremel power tool to try to drill it out. Wish me luck!Attachments:
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