1908 Dennis Truck

[BenHawkins]

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

 

[BenHawkins]

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I tried mounting a few gills on a copper tube with some (13 year out of date) lead-free solder paste and heated it up with a hot air gun (paint stripping type).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.

[BenHawkins]

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.

[Asciidv]

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.

[BenHawkins]

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.

[Old Bill]

With my recent experience of the Peerless radiator, I think the solution is to dip the tubes in solder. This would get into every joint and seal up the edges of the tinplate to prevent rusting. It needs to be done fairly soon after assembly so that all the components are still clean. I must admit that I didn't fancy setting up a dipping tank myself so the guys at CPA did them all for me at £3.50 a tube. I didn't see it done, unfortunately, so I can't offer any tips but he did say that the tubes were 'acid dipped' first. I take that to be in Bakers fluid but now I am guessing. I know you are very independent but sometimes, it is worth buying in some expertise!

Steve  🙂

[mammoth]

The nearest 'tube dipper' to me is 10,000 miles away so in my case I have a good reason to learn how it is done.

[BenHawkins]

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.

[Old Bill]

Nice job Ben. Let's hope you don't have to use them too often!

Steve😁

[BenHawkins]

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. 

[MatchFuzee]

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

Photo from Graces Guide

[BenHawkins]

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.

[andypugh]

I was wondering about the splayed tops, but then read "flat projecting raves for top-loading" and all is explained.

Though you have to look at a few dictionaries to find "rave: a vertical sidepiece on a wagon"

[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.

[andypugh]

1 hour ago, BenHawkins said:

I have removed the oil pump from the bottom of the engine. It contains two pairs of gears,

The pinned-on collar on the idler gear looks unfamiliar. Did they drop that later (it seems rather pointless) 

[BenHawkins]

On 5/2/2022 at 6:48 PM, andypugh said:

The pinned-on collar on the idler gear looks unfamiliar. Did they drop that later (it seems rather pointless) 

Andy, I can't remember if the collar is on the 60hp engines typical in the 400 gallon fire pumps. I have checked and they are also used on the subsidy lorry version.

 

I have been studying all the photos I have of 1907 and 1908 Dennis vehicles and the drivers horn appears to be fixed to a Lucas pillar which is attached the the bulkhead by a strange bracket. As I was having some laser cutting done I added two profiles in 6mm steel to the list. I bent the strip piece with a series of steps.

And then welded the two together before grinding the welds back and blasting.

I have given it a coat of bonda primer and it looks a good representation of the original part.

[BenHawkins]

We lifted the crankcase out of the chassis and placed it upside down on a pallet.

 

The first task was to remove half of the oil seal that fits in the sump. This exposed a strip of felt I had not expected to see (not shown too well in the photo).

I then removed all the split pins and loosened off all the main bearing bolts. It was then possible to rotate the crankshaft to TDC on cylinder 1. I was expecting to find some marking on the timing gears in this alignment but I couldn't so added some of my own.

I marked up all the components for the main bearings and put them to one side so (with the help of the glamorous assistant) the crankshaft could be removed. 

The bearing shells are bronze, but only the central 3/4 is bored out to accept a thin layer of white metal.

And finally we put all the bearings back together to keep them safe.

 

[BenHawkins]

When I wiped down the crankshaft there is some corrosion to the journals, this is probably the worst area. Unfortunately that almost certainly means a regrind and therefore re-metalling of all the bearings. I really should have removed the camshafts by now but I have been getting distracted by events for the other vehicles. 

I have taken the clutch cone off the shelf and scraped the worst of the grease and grime off it. The leather clutch lining is quite hard and dry but hopefully a few more applications of neatsfoot oil will sort it out.

[Asciidv]

Ben, is the corrosion/damage just in the dark area shown in the picture? There is probably quite a lot of undamaged shaft area. For the number of miles it might do in the future, there must be a temptation to put it back the way it was and let someone in 50 years time do the regrind!

[Old Bill]

I concur! If it is still reasonably round, just give it a polish and put it back!

Steve😄

[BenHawkins]

I have been busy taking other vehicles to shows recently but decided to make the terminals for the Bosch D4 magneto.

To fit below the inlet manifold White and Poppe chose to supply angled versions (probably just to make my life difficult 114 years later).

 

The first task was to make myself a sketch.

Then I started to machine the brass parts. This shows a slitting saw on the milling machine.

For the screw thread I decided it would be easier to machine the heads off brass wood screws and silver solder them in.

I milled two vee grooves into a piece of steel to hold the angle for the second silver soldering operation (no, it is not a six cylinder engine - I made two extra so I could select the best four).

They all cleaned up nicely.

The insulators were turned/milled from black acetal.

Another small task ticked off the list, plenty still to do.

[BenHawkins]

Sorry for the lack of updates, I have been juggling a few too many projects. Since the last post I have cut 78 tubes to the correct length for the radiator core. The coil beneath them is the tinplate we need for the 12000 remaining radiator gills; that should keep us busy in the dark winter evenings.

 

When this chassis was converted to trailer use, the locomotive style horn guides were discarded. The drawings for the standard 3-ton model survive but the special Carter Paterson model were different to accommodate the wider chassis with underslung springs. Anyway I sketched up what I believe to be correct and had pieces laser cut; this is a trial fitment of the first one. The cast iron slipper block can be seen on top of the tyre and was made previously. The fence posts bolted to the chassis are just to help with my scaling of the body design.

  

There is a brace between the fore and aft guides; I fabricated these previously.

After welding I dressed the welds with an angle grinder. Three of these have been grit blasted and primed. They need mounting up on the milling machine to carry out the final machining operations.

I have purchased this photo of one of the earlier batches of Dennis vans at the Carter Paterson Kingston depot. 

[BenHawkins]

On the engine front, I have been struggling to strip things down without damaging anything. It took me several weeks to remove the timing gears; they are fitted to the camshafts with a shallow taper and woodruff key.

After using the puller, heat, malleting, penetrating oil, cussing etc. they finally gave in and I don't think I have damaged anything.

There are five bearings per camshaft, so far I have only managed to remove the front on on the inlet camshaft. 

The remaining bearings and carriers are all proving stubborn to remove. As the engine has been open for many years I am keen to strip it was fair as possible to make sure I can remove all the foreign objects.

[mammoth]

It might be included in my 1911 Dennis posts but in case not here is a pic of the horn guides. There are slight differences on each side, presumably due to repairs.

 

 

[BenHawkins]

We picked up a coil of tinplate for the radiator gills in the summer but decided to put the job off for the dark evenings. For about a month we spent 30 minutes each night (by which time we were cold), punching out another 12,000 gills (making 14,000 in total). I have not machined the tube plates yet; I will get that job completed before threading the gills onto the 78 copper tubes.

 

 

I have given the crankshaft and main bearings a bit more of a clean and reassembled with plastigauge to get an idea of clearances. They are between 2.5 and 4 thou which seems reasonable for this type of engine. So, I think we will be mounting it in the lathe and polishing the journals with 400 grit emery cloth and then proceeding with reassembly.