Old Bill

Thanks for that but your core boxes put mine to shame! They are a work of art in their own right. I hadn't thought about casting in plaster but that might just be the way out for the onion shaped fan support casting that we will have to make shortly. The core for that one is still causing me to scratch my head.

From the photo, it looks that you made the male in two pieces and mounted each half on a board. How did you maintain the alignments so that the core didn't have a witness line along its length? Come to think of it, how did you make the male parts at all? I can turn a straight cylinder but a long bent one I would find quite a challenge! Please would you post a step-by step explanation of the process you used for this one as whilst it looks a simple shape, it certainly isn't and I would love to know!

Cheers!

Steve :cheesy:

Steve, why has the top core print an inverse taper rather than being just parallel like the bottom print? Does this part really need a core at all as you could mill out the water passage?

 

Barry.

Hi Barry.

Initially, I was concerned about the core floating off or simply moving. In hindsight, I think I would have got away without the dovetail but I am still not very confident about pattern making and make it up as I go along. Fortunately I have had some guidance from chaps on the Dennis thread and with my background reading have had some reasonable success. As you can see, though, my castings tend to be a bit thicker than the originals which is probably why the Dennis water pump weighs 31lbs!

Milling out the passage would have been possible but a lot of work. My mill is only a glorified drilling machine and doesn't have enough stroke on the quill to reach the end. Also, my lathe isn't big enough to have bored out the circular hole. Cutting the MDF proved a lot easier! Of course there was quite a lot of work in the pattern and I can't see it ever being used again unless we have a disaster. Still, it has served its purpose.

Steve

Colac is local to me and I have been looking for an excuse to go visit Merv.

If you get the opportunity to take a few more detailed pictures we should love to see them please!

Steve

I have just been digging through the early pictures for this project, from before the digital age, and have found this one taken whilst we were opening the crate. As you can see, it appears simply to be a resiliant mount for the handle. I find this a bit odd as it is massive overkill for the purpose. However, I am wondering whether it was originally intended as the front mount for the engine itself? The M4 engine doesn't show any signs of mounting holes in the front to accept it but we have always been a bit puzzled by the sub frame as it looks nothing like anything else we have ever seen. I am questioning whether the engine was a replacement mounted on the frame at a later date and therefore inherited the starting arrangement. We shall probably never know but I am now intrigued!

Steve

Steve,

 

Any thoughts on W.N. and a five pointed star?

 

A register of acronyms would be useful.

 

[ATTACH=CONFIG]72442[/ATTACH]

I'm sorry, I can't add any more about your markings. Shrewsbury and Challoner were a known wheel manufacturer and Ransomes Simms and Jefferies were traction engine makers so they would have the requisite equipment to do the job. Both, however, are guesswork on my part.

Steve

Your method of establishing TDC assumes that the cylinder C/L goes through the crank C/L. On older engines it was not uncommon for the cylinder to be offset a bit so that the force of combustion pressed more verticaly on the crank, reducing side thrust on the piston. The forces on the compression stroke were much less so a compromise could be made.

 

 

Gosh, thank you David. I had forgotten that they did that sort of thing and didn't give it a thought! I will check.

Thank you for your kind comments as well. We are always a bit concerned about going into mind numbing detail. However, we do hope that our friends might occasionally find a good tip. Better still is when someone says 'don't do it like that, do it like this. Much easier'!

Steve

That wouldn't be unlikely as the bearing and tyre sizes were defined by the Subsidy scheme. They were also manufactured by outside contractors. Our fronts are stamped 'S & C' and 'RS & J' which we take to be 'Shrewsbury and Challoner' and 'Ransomes Sims and Jefferies'. I understand that Thornycroft wheels were made by Taskers of Andover but I have never seen one on a lorry of another make.

Steve

Hi Matt.

There is no governor adjustment at all so I think it must just have been to protect the engine from inexperienced drivers.

There is a story of a convoy of FWDs moving up from the port and the last one taking six hours more to arrive than the rest. This was due to the driver not realising that he had more than one gear and doing the whole trip in first! With that level of competence, I can imagine him opening the throttle wide in order to try to keep up.

I'm making a new governor throttle actuating arm today. More pictures later.

Cheers!

Steve

Hi Barry.

Yes, I could have worked it out from first principles but there is quite a lot of friction in there so I thought it better to go from a known baseline. That does assume that it worked properly in the first place! I am surprised that there is no adjustment in there so the speed setting must be quite variable between vehicles. If it is just to prevent engine overspeed then I guess they could live with that.

The lorry governed to 30mph (!) is a Hallford and was rebuilt a good twenty years ago. Again, the governor is buried inside the timing case so you can't see it operating and the owner didn't take pictures like we do. You can see the lever arm on the Dennis move as the engine is accelerated but the engine has no butterfly or provision for one so there is no actual effect.

I have ordered the springs now so we shall have to wait and see.

Cheers!

Steve :-)

Hi Chris.

Yes, I did think of that one. I measured up the survivng springs and calculated their spring rate. I multiplied by 1.1 to allow for the relative densities of zinc and steel (7140kg/m³ and 7850kg/m³) and came up with a rate of 0.44N/mm. The original springs have a free length of 3 3/16" and an unknown pre-tension. I have been able to find an off-the-shelf spring with a rate of 0.45N/mm and an initial tension of 6.23N but a free length of 3 1/2". I am hoping to be able to reduce the free length by bending the eyes a little tighter as this free length has more effect than the spring rate. Now that Father has made up the weights, he can measure the closed and open lengths of the spring eyes and I can check what the forces will be.

Of course, this is all a bit academic as we don't intend to fit a butterfly in the manifold! It would be nice to see it work though.

Steve :-)

Thanks Jack. As soon as we know for certain, we will spread the word!

Cheers!

Steve

Piston manufactures in the USA

 

1 Egge

2 Ross

3 Aries

 

I have had poor luck with the first company. The other two are good, and now I usually use number 2. They all have web sites, just google their names and the word piston. They also provide rings and pins. We always order modern ring packages as they burn less oil and crank over easier. Ed

Thanks for the recommendation, Ed. It is always nice to hear of personal experience.

Cheers!

Steve :-)

I wouldn't give up on that pump casting without trying Alutight/Technoweld. Many of us have successfully repaired parts that would otherwise have been scrap.

Hi Phil.

Thanks for the tip. I have no experience of 'Technoweld'. Is it a welding process or some sort of special solder? How have you used it? It would certainly be another useful process to have in the tool kit.

Cheers!

Steve

 

Some form of khaki green would have been appropriate for the Western Front, while a yellow/brown tint may have been used in the Middle East. The replica I'm producing will be yellow/brown.

 

Jack

Hi Jack.

I am most interested in your suggestion that the colour in the Middle East would be 'yellow/brown'. Do you have any evidence for that? It is the most logical colour and the sort of thing we have in mind for our Peerless when we get around to it but we have never seen a mention of any colour except Khaki-green. We would love to see some sort of reference, even if only a written description.

Cheers!

Steve

Crank End Float

Thanks for that Tom. I will eye up the job the next time I go down and see how easy it might be to do.

Thanks also for the supplier suggestion. I had not seen their name before but they look like just the right sort of people to help us out.

This forum is wonderful for all the help so freely given!

Cheers!

Steve :-D

Thanks Matt and Lofty.

An instant explanation of how to do it! I shall check the timing the next time I go down to Devon and see what we have.

I think you are right, the numbers must refer to matching sets of gears. The gears are keyed to the camshafts so there is no adjustment. I guess they just selected sets in the factory. This might explain why the big ends are numbered 17, 18, 21 and 22.

Cheers!

Steve

At the point of timing all the cam sprockets to crank sprocket might be worth checking for TDC, on the crank. LOFTY

Thanks Lofty. You are absolutely right. Please may I have some guidance as to how to do it? There are no marks on the flywheel at all and the manual offers no comment. As the gears are a matched set, the two camshafts will be correct to each other but may, as you point out, be wrong to the crank. At the moment, we can set the crank to TDC using a square against the top of the case and I can put a follower and push rod in place so that we can see when that begins to lift an exhaust valve. The question really is when should it lift? One old motor vehicle manual we have suggests 49° before BDC. Does that sound about right to you? The Thorny manual really is no use at all for setting up the engine but the Dennis one gives a timing chart. This suggests 45° before BDC.

I think that I might put a datum on the crank case, then line the flywheel up to TDC and mark it with a felt pen. If I measure the diameter of the flywheel, I can work out the circumference and divide it into 45° positions using a tape measure. Then, if I put a DTI on the top of the push rod and slowly turn the flywheel, I will be able to see where it begins to open. A nice interesting challenge although I am not quite sure what I will do if it proves to be half a tooth out!

Incidentally, another question arises. Why are the timing marks on the gears marked '3' and '4' rather than 'I' and 'E' or '1' and '2'? Might the factory have been assembling matched sets?

Cheers!

Steve :-)

Hi John and Barry.

RE: End Float

Many thanks for your comments regarding the end float. 0.030" does seem a bit much. Unfortunately, there is no way of adjusting it except by replacing all of the white metal shells and line boring again. I really don't want to do that and feel inclined to leave it alone. I don't think that float was what stopped them using the engine although, I guess that it might make setting up the clutch brake a bit tricky. The timing gear end load will tend to bias the crank in the same direction as the clutch so there will be little end movement when I hit the pedal. I think we will leave it alone and see what happens.

Cheers!

Steve

Hi Ed.

You are one step ahead of us! Yes, we will need new pistons because we have lost 3/16" on the bore diameter due to the liners and the original pistons do not have enough meat on them to skim them down. My intention is to make up a pattern and have them cast in grey iron at our local foundry. Then I can machine them to suit the rings that we have bought. The biggest challenge will be the gudgeon pin hole as it is 2 1/2" below the crown but the clearance over the saddle on the lathe is only 2 1/16" so between centres boring is out. My mill does not have enough vertical stroke to go right through either so we may well be knocking on doors. Come to think of it, one of our friends has just retired and as a retirement present, has bought himself a large vertical mill. Time to invest in a few beers!

Do you know of a company that makes iron pistons as specials? It would be most interesting to find out what they could do for us.

Thanks for the tip-off!

Steve

Hi Barry.

I think that the bearing caps were machined at the same time as the crank case so they are non-interchangeable and non-reversible. The shells are white metal die-castings about 3/16" thick and would be a real pain to replace so I have simply put the originals back. I measured up the crank, which comes from the other engine, and found that the journals are only 0.001" smaller than those originally fitted so I have simply set the shims so that the crank is gripped when the caps are tightened down. I then blued and scraped the white metal back until i achieved a good contact and the crank turned freely at which point I did them up 'tight' and then gave them a bit more until the split pin holes lined up. Not very scientific but I have confidence that we will be OK!

The end float is set by the centre bearing shell and is non-adjustable. The float appears to be about 0.030" which feels OK but I don't know how much it should be. How much would you expect?

The reason for leaving the flywheel on was that we couldn't get it off!

Cheers!

Steve

Hi Terry.

What a splendid machine! I had never heard of Lombard but I might recognise one now!

That engine is quite something and I can certainly see how big a project you have taken on. I have had a very quick look at your thread and the work you are doing is most impressive. I shall read it through in detail shortly. Your attitude to it is great: When something new comes along, just read up and have a go. Everything is possible if you really want to do it and you are proving that. The family resemblence between your engine and our model 'A' is striking and I know exactly what you are doing. Good luck with it all, thank you for sharing it with us and I shall look forward to watching future progress.

All the very best,

Steve

Thanks! I'll have to keep them in mind.

Cheers!

Steve

Beautiful job, Tom!

How did you extend the valves to go all the way through the rims? On our Autocar, they barely poke through the timber.

Cheers!

Steve

The bottom of the liners were not quite flush by a couple of thou in some places so I think the bolting flanges for the blocks are slightly distorted. I didn't want to risk distorting the flanges further and possibly cracking the iron although I think that risk would have been very low. There is no gas seal at this end and the contact only need prevent the liners from dropping out should they come loose. The flanges on the end of the liners are 1/8" bigger in diameter than the hole in the top of the crank case so they could not fall out in any case. The liners are not as tight as our motor mechanic friend would have liked but I just wasn't brave enough to specify a solid interference fit. These have all gone in with a good push which is exactly what I had hoped for. I am, however, very glad that the job is done!

Regarding gaskets, I intend to use a paper type one that is a cross between thick brown wrapping paper and very thin card. I haven't come across shellac coated paper. What effect does that have?

You have intrigued me with your big Wisconsin engine! What sort is it and what is its history?

Cheers!

Steve :-)

Hi Barry!

We haven't been completely idle! We have cleaned up the magneto drive shaft and yesterday, we fitted the cylinder liners (successfully!). However, Tim posts all the pictures but he has limited access to a computer at the moment. Hopefully he will be able to put them up today. We have guests today but tomorrow, we plan to fit the timing gear to the crankshaft and then fit that into the crank case. At last we will be putting things back together!

All the best,

Steve