BenHawkins

I have removed the oil pump from the bottom of the engine. It contains two pairs of gears, the first pair scavenges the oil from the sump and pumps it up to the oil tank. The second (lower) pair pumps oil out of the tank and feeds it to troughs above each main bearing and a feed to the timing case.

It was full of sludge but cleaned up well.

Next to come off was the sump. I scraped the worst of the sludge out.

Again, it looks a lot better for a quick clean. A proper clean will be needed at a later date.

I then marked up the connecting rods.

And with the help of the glamorous assistant was able to remove the connecting rods, making sure to keep the nuts, bolts, bearing shells and shims in their original configuration.

9 hours ago, MatchFuzee said:

Is this a London delivery van at The Museum of East Anglian Life? 

That has some similar construction details but the vans owned by Carter Paterson were of this type.

The CP&Co fleet appeared to have many variations on the design. I think the fleet number on this one suggest it was built a little later. They often carried adverts on the canvas sides and public service announcements on the bulkhead.

Some friends visited last weekend and we tackled another couple of tasks. The first was to have a better look at the cylinder blocks, piston rings gudgeon pins etc.

Three of the cylinder blocks look good, with minimal wear. However the press fit gudgeon pin in No.3 piston obviously became incorrectly aligned at some point. The scoring is not terribly deep but obviously it will need some remedial actions.

We also looked at mocking up the body construction by placing some temporary bearers in place.  This chassis batch was not supplied with Dennis built bodies and the holes in the chassis suggest a horse drawn van was repurposed.

There are three pairs of holes towards the front, where you would expect the turntable to be mounted, in this location I have put 3"x3" timbers.

In front of, and behind the rear wheels there are holes for 7/16" bolts at 2.5" centres. These are the timbers where the leaf springs would have connected and I have placed larger (3"x4") timbers.

Looking at horse drawn vans there are often two additional transverse timbers equally spaced between the spring mounts, but my chassis only has holes for one. Looking at the layout, it would obstruct access to the cover on the back axle so perhaps it was removed. Access to this cover is essential (via a hatch in the floor) as it is the only way to add lubricant to the back axle and rear wheel bearings.

The body length is 9'. The Bristol Wagon and Carriage Works catalogue states they make their 9' London delivery van was 4'4" wide (and could carry 45cwt). All the bearers have been left longer than required as I am still not entirely sure if the 4'4" is right. 

Thanks for all the help with the Zenith carb information. The lower plunger in the corrector was stuck solid so I decided to unscrew the corrector from the body. I wrestled with it for quite a long time before resorting to an impact driver. That sheared off the screw, so progress of sorts.

I drilled out the centre of the bolt, masking off the other holes so I didn't lodge swarf in them.

The remains of the screw has been etched out by submersing it in alum. This revealed it to be M6x1 thread, a standard pitch for once. The corrector assembly is soaking in a container of oil, hopefully the plunger will free off with the application of some heat as well.

I decided to tackle the cracked manifold this week. A few years back ESAB had a marketing campaign where you could have a free sample of any of their electrodes; I chose the pure nickel rods for welding cast iron so I had some in stock for this repair. The first stage was to clean things up and grind the crack into a v shape.

After some solvent cleaning I put it in the domestic oven (wrapped in aluminium foil, with permission from the glamorous assistant) at max temperature (ca. 230C) for about an hour.

Then straight to welding before it had a chance to cool down, the rods were 2.5mm and the welding current only about 80A. Once the welding was completed I wrapped the manifold in fibreglass insulation and allowed it to cool very slowly.

The cracks have closed up well with no damage to the inside surface. There is a compression ring that seals in this area.

I gave the weld a light dressing with an angle grinder before blasting and painting.

I am quite impressed with these rods. The only problem is that it will be expensive to replenish the stocks when the free sample runs out.

On 11/7/2021 at 8:26 PM, Doc said:

Hi,

These pages are from "Modern Motors, Their Construction, Management And Control" by H. Thornton Rutter.  c.1923

If nothing else they give an overview of the triple diffuser Zenith carburettor. 

Doc. 

Thanks, that is exactly what I was after and explains it well.

6 minutes ago, Asciidv said:

Ben, are you using tin plated steel sheet or tinned brass sheet? I think all the 'lead free' solders are not a patch on 'proper' solder.

Thanks Barry, it is tin plated steel. The lead free solder paste was rescued from a skip (ten years ago); if it had worked with that I would have been confident that lead-tin paste would have been better.

I have scraped the blemishes from the bore of the throttle barrel and the parts now rotate freely again. I need to give it a jolly good clean.

The exhaust manifold is made up of four parts, there is a compression ring at each joint. Three of the sections are in good condition (although the compression rings are broken, at least one by me trying to free it off). Those three have been blasted and painted.

The forth has a crack so I will attempt to preheat this and weld it with a pure nickel rod.

I won some oak in an internet auction so have been out one evening to collect it. The horse drawn van body Carter Paterson mounted on this chassis was oak framed so hopefully I can pick up some more at sensible prices.

No progress on this project has ever been quick. In order to punch out the radiator gills I needed somewhere to set up the fly press I had been donated and better space for ironwork would needed for the body ironwork. So, at the start of the COVID lockdowns we started clearing a raised bed at the bottom of the garden so we could build a blacksmiths shop. There are a few finishing touches required but it is now a useful new space for making things.

I had purchased a couple of sheets of 0.010" tinplate so we were able to test the tooling made by Andy Pugh.

The glamorous assistant and I found a rate of about 600 gills per hour was quite therapeutic.

And after a few short sessions this week we have in excess of 1250 gills. This is around 10% of what is needed for this radiator. We have used about 60% of the material I have but the sheet is a little bit awkward to handle. It looks like I will be able to get 108mm wide coil which will fit four rows and be cheaper than the sheet. However, I need to wait until another coil is being split to this size before I can obtain any.

I tried mounting a few gills on a copper tube with some (13 year out of date) lead-free solder paste and heated it up with a hot air gun (paint stripping type). Although much better than using a propane flame I still overheated and discoloured the gills.

I tried again in an oven, no discoloration and the gills were certainly fixed in place but still room for improvement. I will try it again with some new paste.

I have been donated a Zenith 30K carburettor (via team Gosling) that I would like to try on this engine. This is of the "triple diffuser" type and I hope it will give better performance than the single jet Claudel Hobson.

Most of it came apart reasonably easily once I made the special tools for the job. The exception to this is the lower plunger in the corrector. It is made of steel and so far has remained stuck solid. The corrector is the device with the second lever, I don't really know what it does but found it on a diagram (in French). Can anyone help with further information on this model?

4 hours ago, Asciidv said:

Ben, when I have had cast wheels rubbered the tyre bands were not removed but were wound in situ on the wheel and then the whole wheel put into the autoclave. When you had your tyre bands re-rubbered could they accept the tyre band directly or did it have to be mounted on a donor cast wheel? I am under the impression that the conditions for vulcanisation would always be too severe for a wooden wheel.

Some companies will apply the rubber to a loose band, others will insist that they are mounted. Certainly putting the wooden wheel through the autoclave for the vulcanisation process will destroy it.

I have led Steven down the wrong track with the wheels for ED-810, that has the lighter weight axle (used on 30cwt lorries). He appears to have the rear axle used on two and three ton lorries with larger hubs. It should all become clear as he dismantles what remains of the wheels.

Back in 2005 a friend of mine found a late 1920s Dennis chassis in Kent (I was in no position to take on a project at that point). It did not find a home but was broken up and virtually all the parts distributed across the country to help restoration projects.

Unusually the chassis still had the petrol tank mounted but after all these years it turns out it did not fit the intended project so was offered to me.

The body layout drawings in the 1908 catalogue give the dimensions as 15"x9-1/2"x3'6" - exactly the size of this one. 

It has the Snercold patent filler described in the catalogues too. Snercold was the trademark for the Safety Non-Explosive Reservoir Company

More photos for comparison.

A wide single front on a Dennis hub. It is possible a wider rim and tyre were fitted at some point.

An "original" front. I just cleaned it up and painted it. New 100 for 720 tyre. It was necessary to press the tyre onto the rim with canvas between to get sufficient tonnage.

A professionally rebuilt front. All new timber with original hub and steel rim.

Some of the timber that was replaced.

Note the felloes are approximately the width of the tyre fitted. The heat shrunk rim is usually wider. In addition to protecting the wood from kerb damage this is also essential for pressing on the tyres - you do not want to be applying the load to the timber.

An "original" or at least not rebuilt rear. This is of much heavier construction than typically seen on a 3 ton lorry. Not the additional bracing band for the brake drum and how much wider the spokes are than the felloes. Heat shrunk rim protrudes on both sides of the wheel.

Rebuilt wheel, this is a copy of what was removed but a different design to the other side. Note the spokes are much narrower.

The "as found" spokes and felloes.

On this vehicle twin 120 for 720 tyres were specified. Note the felloes are approximately 230mm wide. The new ones ended up slightly wider. 

After several checks of the dimensions I drilled the radiator side tank castings for the mounting holes and then tried fitting it to the chassis. There is still some adjustment to be done and some more checks before drilling the tube plates.

I am not sure how much use the dimensions from LE9588 will help. Although a similar model yours is actually a heavier weight version. LE9588 has a similar back axle but runs on single rear tyres; the rear springs only have shackles at the rear; yours have shackles front and rear and the axle alignment is constrained by locomotive style horn brackets (not present on LE9588).

I believe according to the build sheets they were "860x90" (front and rear) tyres on the LFB pumps for 1911. I am pretty certain these are Avon tyre sizes, so the 860 refers to outside diameter rather than band size. I suspect the band size is 720 but can't be certain.

Although later, a better match for your wheels is probably ED-810 (owned by a member of this forum).

The engine picture you posted is an earlier version (probably 1907/08) but pretty similar. By 1911 the serpentine water connections had been dispensed with and the connections were made between the cylinders at the centre line. 

I hope the works production order for your chassis survives as it should answer most of the questions and I will finally be able to give you some definitive answers. The archive is once again welcoming visitors but I imagine there are still restrictions in place and as you know this made our last visit less productive than usual. Five hours of driving for a couple of documents (ordered in advance) means we have to continue with other projects at the moment.

On 4/10/2021 at 10:21 PM, Asciidv said:

Ben, I normally use the dry film resist material rather than relying on toner transfer. It certainly is quite tough and allows for long etching times if you need deep etches. I also have had good success with the brass chemical blacking solutions as an alternative to black paint. It will never flake off!

Thanks Barry,

I was keen to avoid the UV exposure and developing stage of the process so gave the toner transfer a go. There is a light box I can borrow but it is too small for the tread plates. I might give the dry film a go for the ID plate on the 1908 Dennis; that one is a slightly different design and it is always fun to try another method.

I would like to thank everyone for their support of this project. I know it does not completely fit the military theme of the forum but hope that it has been of interest and useful to other people attempting similar restorations.

To answer the question about etching, the toner protects those areas from the ferric chloride. I obviously didn't get it perfectly adhered as there was some shallow etching behind the toner (simulated patina?)

Following the etching I cut the identity plate out and painted it black. Fine silicon carbide paper stuck to the back of my steel rule was used to polish it back to reveal the raised areas before stamping the numbers. Two of the fields are left blank; I will stamp them if I ever find out the correct numbers (when new). I believe both numbers were a little bit below 800 from surviving Works Production Orders. The number is on the axle somewhere but obviously I don't have the original gearbox.

Six weeks ago I did the artwork for the tread plate and sent it off for manufacture. I am lucky because the original drawing survives, it could have been made from that but I didn't want to pay someone else to have the fun. There are plenty of etching services available to do this sort of thing but I wanted some for both of my Dennis vehicles with a deep etch and someone who could deal with a CAD format (such as DXF) rather than a Corel EPS. Originally I tried some steam model people but ended up using a machine nameplate company in Scotland. They worked out at £27 each (delivered) and their production line laser cuts the profile and does the blacking and flatting back. All that was left to do was countersink the holes and screw it down!

So that is two ways to get the job done. The tread plate is bigger than the transfer paper so would have been more difficult for me to do, also I wanted a few of them so was able to split the cost of the mask they have to produce.

I am running out of things to make for this vehicle; it's been fun and hopefully we can get it out a bit more in the near future - the speedometer calibration needs testing!

I have been working through the "finishing touches". Originally there was a small brass plate fastened above the bonnet carrying the vehicle details. These survive on other preserved Dennis vehicles and I had taken measurements and rubbings in the past.

Using Computer Aided Design I was able to generate the artwork and print it onto some "press-n-peel" film. This is basically a plastic film with an emulsion on one side. It has to be printed on a laser printer; apparently some brands of toner work better than others. The artwork has to be a mirror image of what you want to retain when etching and you have to make sure you print onto the matt side with the emulsion (the CP&Co asset tags are for the other projects).

The brass plate needs to be free of all contaminants; this was a piece of polished brass that had been protected with a plastic film so there was no need to clean it back.

With the brass on a wooden board and using the "garage projects" iron the brass was warmed up (being protected with a sheet of paper).

The blue film was then placed on the brass, toner side down with the sheet of paper on top and given a further ironing. The instructions warned not to press too hard or the edges might smudge.

The instructions then said quench in water and peel off the film. Not quite the result I wanted.

Second attempt, ironing for longer with more pressure.

Some of the artwork was rectified with a marker pen and I inked in the back so it would not be etched. It was then immersed in ferric chloride for a couple of hours.

Finally it was washed under running water.

Thanks Doc,

CP&Co bought several batches from Dennis and I think I now have photos of every batch but the one mine was in (end of 1908). They did not have Dennis bodies fitted so there were no factory photos taken, originally I thought the motor vans were used in central London, but the picture of the Addlestone district probably suggests that they were used where properties were further apart.

I decided to stitch a leather belt for the speedometer drive. This started with a hole pattern and scribing lines as described in a lathe manual.

Then stitching in-situ with waxed twine.

And finally putting it in place.

To make the speedo cable I turned up some brass ends and soldered them on to some 1/2" brass flexible conduit I purchased at an autojumble. Steel ends were turned up for the inner and crimped on by placing them in a vee block and punching it down with a centre punch.

That is another thing to test when lockdown ends. I have a speedometer app on my phone to check I got the maths right.

I found this picture of the odometer used on the early Thornycroft BT. It appears to have a plate that swings over the number to protect them.

We have been digging trenches and mixing concrete this week so I  have been looking through old magazines when I need a rest.

This is a 1906 notice from Carter Paterson advertising their investment in speedy motors.

And some Dennis vans in Addlestone, these ones were built in 1911. They still have the horizontal tube radiator but mounted on trunnions rather than shackles.

Dennis must still be busy as they cannot supply me a replacement gearbox. Their standard answer is they sold the last one yesterday!

On 2/28/2021 at 6:57 PM, andypugh said:

I can make balls really easily. 

Just send me a drawing. 

Thanks Andy, I will dig out the original factory drawing and annotate it for the new diameter, or is a new fangled step file better?

I have finished machining the speedo drive parts and fitted them to the lorry. The next jobs are making the flat drive belt and flexible drive shaft. The tensioning spring is a bit too long and weak but it should be easy to sort a replacement.