1949 Dennis F1 Fire Truck Restoration

Thanks onetrack, but as you've seen I rely heavily on the good advice received from you and other forum members!

There was a bracket near this plate holding the throttle linkage, which had a single bolt into the block. I started to undo it, but it had that funny feel about it that told me that if I went any further I would shear the bolt off. It was in the road of the tap handle, so I cut the bracket off ... I can easily reweld it back on later.

Beaver suggested that at this stage I should drop the sump and give the crankcase a good cleanout inside. I am now a bit hesitant to do this, due to the number of bolts I've had shear off already. The law of averages says that for sure a great number of the sump bolts will shear off too. I might just leave that, and rely on the sump screen, the oil filter, and the cleanout I've given it through the sump screen hole. If the engine was out it would be different, but still being in means that it will be a right PIA to drill and tap holes. I'll just give Dennis its first oil and filter change early. :

Yeah, that sounds like the deal to me. No point in making extra work for yourself.
Although, I would have thought that the sump bolts wouldn't have had the corrosion problem this plate had, because the sump bolts don't screw into any area where there's coolant in contact with the bolts.

The bottom end clean is important, but the oil pump suction screen is the vital part to clean.
It's mind-boggling the crap that collects there, and any buildup on the screen restricts the oil pumps ability to make pressure.
New oil, and running at operating temperature for a while, will clean up the engine internals satisfactorily.

It's important not to be too religious about cleaning up varnish and gum buildup, a lot of it is sealing leaks and compression, and a total removal of all varnish and gum, will often see leaks start everywhere, and oil consumption increase.

I got a Continental forklift motor rebored last year, and when I was trolling through the reconditioners shop, I spotted this really unusual-looking block.
Went for a closer look and realised it was a monoblock, with integral head (pistons had to go in from the bottom) .. and it had 4 valves in each combustion chamber.

What took my eye initially, was this block had full length plates on the outside of it, that were held on by about 100 x 3/16" bolts!
I was studying the dramas associated with this horrible-looking design, thinking it could only be Pommy .. when the boss walked past.

I asked him what the weird block was out of. He said it was a 1930 Bentley block .. rare as .. only about 100 made in total .. and he wasn't looking forward to reassembling it!! .. :
They would really have had some fun, doing inaccessible, multiple valve seats, at the bottom of a cylinder bore! .. let alone the bolt problems on the block plates! :'(

Yeah, that sounds like the deal to me. No point in making extra work for yourself.
Although, I would have thought that the sump bolts wouldn't have had the corrosion problem this plate had, because the sump bolts don't screw into any area where there's coolant in contact with the bolts.

The bottom end clean is important, but the oil pump suction screen is the vital part to clean.
It's mind-boggling the crap that collects there, and any buildup on the screen restricts the oil pumps ability to make pressure.
New oil, and running at operating temperature for a while, will clean up the engine internals satisfactorily.

I'd go along with that assessment, you should have no probllems in undoing the sump. All the oil leaks around the flange will have prevented any corrosion . I certainly wouldn't want the crap we have found in the bottom of our sumps getting back into the engine. The oil pump screen is pretty coarse, might stop bits of metal, but semi-dissolved sludge will easily get through to clog up yor nice new Rycos. : :

We've got an old Dennis chassis we rat parts off occasionally. It has been out in the open for the best part of 50 years, and we can still undo most of the nuts without resorting to force.

Little bit of an update on Dennis ...

I've managed to score a couple of weeks off work, and plan on spending time on Dennis. After much "shall I, shall I not" I have decided to take Beaver's advice and drop the sump to have a look inside. I picked up a few tubes of Loctite Master Gasket 515 ready for sticking it all back together again.

On another topic, and looking ahead to the electrical rewiring, what wire size would be most suitable? I am aware that 'auto wire' is sized according to the overall cable diameter, which bears little relationship to the actual conductor size.

Would the likes of Narva single core 6mm auto cable (4.58mm2 conductor size) be suitable? Should I beef up the battery (power) supply to the next size up?

I'll wire Dennis up according to the Lucas Wiring Code, which provides for:

Black: earth (ground) connections
Green: feeds to auxiliary devices controlled by the ignition switch, eg wipers,flashers etc
White: base colour for ignition circuits
Red: sidelights (parking lights) and rear (tail) lights
Blue: with white trace headlamp main beam, with red trace headlamp dip beam
Purple: auxiliary devices NOT fed via the ignition switch, eg horn, interior light
Brown: main battery feed

If purple is not available, I might have to substitute yellow.

As before, I would value comment from those who have walked this path before! :

Bugly - Now that you've informed us you're working on a Lucas electrical system, there's one very important thing you need in addition to the above .. Lucas Replacement Smoke.
No doubt your Lucas system failed because all the smoke escaped from it. Therefore, you cannot repair Lucas electrical equipment without the genuine Lucas Replacement Smoke.
The art of replacing the smoke in a Lucas system is also a black art, known only to a few ancient auto electricians, who usually take the secret of how to re-install the smoke, to the grave with them ..

Cheers - Ron.

Hey onetrack ... I heard that the smoke won't go in unless you use a Churchill Tool 18G548BS adapter tube and metering valve. Is this true? And if so, which end of the wire do I hook it up to? Can this be done during the day, or should I do it at night with the shed lights off?

Once on the road, Dennis will be driving around in Darwin and the Top End with a 32 degree ambient temperature. Does this mean I need to boost it with some sort of Ausmoke, or will the (presumably British-canned) Lucas Replacement Smoke be OK?

And if I get the smoke back in, should I look at (say) an annual top-up, or only worry about it when it all leaks out? :

Bugly - That's correct about the Churchill Tool 18G548BS adapter tube and metering valve.
However, I didn't want to overload your mind with excessive info, first up. I was going to ease you into it, a little at a time.

You hook up to the end of the wire where the smoke escaped from, of course! And yes .. doing it in the dark, is the recommended Lucas factory procedure.

As the Lucas system is British to its core, the British Lucas Replacement Smoke is the only recommended smoke to use. The addition of foreign smoke may not produce the desired results.

No need for annual top-ups, the system will let you know when more Replacement Smoke is needed .. it's when you see smoke escaping again.
As with all Lucas systems, this is a frequent occurence, and you're best advised to always carry a spare bottle of Replacement Smoke at all times.

Cheers - Ron.

Bugsy, choosing the correct size wire just takes a little bit of mathmatics. You need to work out the load on the circuit to know how many amps (current) that the wirw will need to carry. Watts is volts times amperage, so if your not sure how much a 55 watt headlight will draw, and you only know the voltage, divide the wattage by the voltage and you will have the amperage it will draw. The amperage is what governs the size of the wire.

Narva wire packs have the amperage shown on them, you will need to be looking at 10 amp and 15 amp ratings. Check in their catalog for colours available.

Two 55 Watt headlights (110 W) will pull about 9 amps, but probably better to go for 15A wire where you are feeding both of them.. We use 15A on the coil circuits, but 10A shouldl be more than adequate for anything else. If you have a Sterling or Grifcossiren you will need about 30 amp wire.

If you have multiple lights at the rear (tail, stop, turn, etc) consider using multi-strand trailer wire rather than individual wires for the long runs.

The smoke has been very hard to find lately, but if you do the job properly you shouldn't need to worry about it.