S2A bit and pieces.

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No. This style was used up to about 1969, which hardly qualifies as early. In any case, as with most parts, they are easy to swap between vehicles, so are useless for certain identification. The only certain method of dating is the chassis number stamped on the chassis.

The pictures, as far as I can see, are consistent with its being around the suggested date of 1968. Talking of the pictures, it seems to have a Stromberg carburettor, not one that I would favour.

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OK; I have yet to acquaint myself with the manufacturing history of these vehicles.

Yes, my vehicle as I obtained it was fitted with a Holden 6 air cleaner and Stromberg carburetor. This is only shown in the first picture (un-restored state) that I posted in my introduction thread, but any subsequent photos can only show a Solex carbie as that is what was fitted to the re-conditioned engine after it was bolted back into the chassis.

I managed to assemble the Solex (with the aid of a rebuild kit) with parts taken from three incomplete donor carburetors.

Other than having rebuilt this Solex, I have no hands-on experience with any Holden 6 or original Landy carburetor, but just from studying the specs and operating principles I figured that the Solex was the best pick of the three most obvious options (Stromberg, Zenith or Solex).

Funny story; I spent (wasted) a whole Saturday morning running around all over the place to no avail trying to find a (fuel line) hose-barb fitting that would screw into the Solex. It didn't occur to me to even try a metric fitting. Doh!

I have just finished uploading a whole bunch of high-resolution engine and gearbox photographs taken during the restoration process of my vehicle -over 60Mb worth. I get the impression that people around here like threads with lots of photographs, so this might be appreciated. I guess this could be considered Land-Rover pornography :D

http://www.glensstuff.com/68s2a/enginerebuild/
http://www.glensstuff.com/68s2a/gearbox/

Just follow the categorized folders directed to by the links above. Clicking on an "XX.jpg" photo filename should open the respective photo in your browser (use browsers "back" button to get back to main folder).

Cheers,
Glen

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Originally Posted by 68s2alwb

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Other than having rebuilt this Solex, I have no hands-on experience with any Holden 6 or original Landy carburetor, but just from studying the specs and operating principles I figured that the Solex was the best pick of the three most obvious options (Stromberg, Zenith or Solex).

The Solex was fitted to Landrovers up to the early sixties, and as far as I can see the only reason for change was the merger of Solex and Zenith. It was succeeded by the Zenith, and later in the 2.5 by a Weber, although I don't think this carburettor was ever sold in Australian assembled vehicles, so these are very rare here. The Stromberg was never fitted to this engine by the manufacturer, but was a common repair, as good, cheap, Strombergs out of Holdens that had rusted out were readily available far cheaper than a repair kit for a Solex or Zenith. They were never very satisfactory in this application, even if fitted with the optimal jets for the Rover engine not the Holden. But they did work (usually).

In my experience, the only difference between the Solex and Zenith is that the Zenith is a little easier to get parts for and easier to work on and understand, but is probably more prone to problems, mainly warping of the top cover, and the O-ring seal is critical.

(This discussion applies only to the four cylinder engines - the the six and V8 used either SU or Zenith-Stromberg constant depression carburettors)

Funny story; I spent (wasted) a whole Saturday morning running around all over the place to no avail trying to find a (fuel line) hose-barb fitting that would screw into the Solex. It didn't occur to me to even try a metric fitting. Doh!

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Surprisingly, it seems that most English carburettors have been metric from the very early days (~1900) when the centre of motor expertise was in France, although I suspect most threads are probably BA or French rather than ISO, and in fact Solex was a French company, and Zeniths original designs were French. (It is usually possible to screw these into each other, even though the thread profile angle is different)

John

In exasperation the last port of call that Saturday (actually then in the afternoon) hunt to find a suitable fuel fitting for the Solex was the performance shop I last had my modified 383 (not in a Land-rover) dyno tuned at. The shop owner looked at the carb and said "Solex, French, metric"!

The internal thread that originally accepted the "Special bolt" for the "Banjo union" is M12 with a thread pitch of 1.25mm (well that's what seems to fit perfectly anyway). I know this isn't the original fuel fitting, but I'm not particularly enamored with that hard-plastic fuel line to the carb that was the original equipment.

https://www.aulro.com/afvb/images/im...016/03/205.jpg


The Solex looks to me a more sophisticated design than the Zenith, with better accessibility for accurately tuning the fuel metering over the entire operating rpm range of the engine; jets for the various circuits (idle, main, "economy", accelerator pump) are all accessible. It's been a while since I looked but I don't think that is the case for the Zenith.

Another thing is the Zenith has a primitive "choke" in the literal sense - a butterfly that simply suffocates the engine to create greater vacuum to draw more (richer) fuel. The Solex on the other hand has (effectively) an auxiliary carburetor that supplies the enriched fuel supply when cold, rather than a butterfly that restricts air flow to the engine (much like my DCOE Webers).

I always have my newly built engines tuned on a chassis dyno. The LR won't be an exception, even if only to make sure the carburetor is working as good as it should be.

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Originally Posted by 68s2alwb

In exasperation the last port of call that Saturday (actually then in the afternoon) hunt to find a suitable fuel fitting for the Solex was the performance shop I last had my modified 383 (not in a Land-rover) dyno tuned at. The shop owned look at the carb and said "Solex, French, metric"!

The internal thread that originally accepted the "Special bolt" for the "Banjo union" is M12 with a thread pitch of 1.25mm (well that's what seems to fit perfectly anyway). I know this isn't the original fuel fitting, but I'm not particularly enamored with that hard-plastic fuel line to the carb that was the original equipment.

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Hello 68s2alwb ,

So does this mean that your problem is solved and you are back on track to getting your fuel delivery issues sorted out?

If so congratulations .:) :banana:

Series Land Rovers tend to breed either desperation, patience, insanity or blind faith.

Kind Regards
Lionel

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Originally Posted by Lionelgee

Hello 68s2alwb ,

So does this mean that your problem is solved and you are back on track to getting your fuel delivery issues sorted out?

If so congratulations .:) :banana:

Series Land Rovers tend to breed either desperation, patience, insanity or blind faith.

Kind Regards
Lionel

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LOL, yep all sorted. I had to put a re-build kit through the fuel pump (the one-way valves were leaky and the pump couldn't keep the carbie float bowl filled with a bit of sustained engine revs) but she's all hunky-dory now.

Incidentally, the fuel pump takes the same M12/1.25-pitch fittings. I bought the fittings from here: Speedflow - Manufacturer of Aluminum and Steel Hose Ends and Adapters - Australia

https://www.aulro.com/afvb/images/im...016/03/204.jpg

Though the fancy blue anodization does look a bit "hotrod" and out of place in the old girls engine bay............

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Originally Posted by 68s2alwb

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The Solex looks to me a more sophisticated design than the Zenith, with better accessibility for accurately tuning the fuel metering over the entire operating rpm range of the engine; jets for the various circuits (idle, main, "economy", accelerator pump) are all accessible. It's been a while since I looked but I don't think that is the case for the Zenith.

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I'm not sure that more sophisticated is how I would put it. Rather the Solex operating principles are more elegant. But it does have the drawback that there are a number of diaphragms that are potentially susceptible to failure due to their being designed for hydrocarbon fuels, not ethanol, which is likely to be in any fuel we buy today.

The Zenith has only a single sealing O-ring that is submerged in fuel and critical to operation.

You are right, the Zenith needs the top removing to access any jets. As I said, in my experience, as far as performance goes, there is no significant difference.

John

Well, the cold-start system on the Solex is definitely more sophisticated than the Zeniths choke butterfly and I don't see anything in the Zenith that would be equivalent in operation to the "economy" circuit in the Solex, which serves to improve the accuracy of the fuel metering over the engines full operating rev range.

Though how much the latter translates to better out-right performance in comparison to the Zenith is not necessarily significant; a more apparently sophisticated (or rather complex) design is not necessarily better - it depends on the implementation.

Though I know that the primitive operation of a number of popular Stromberg models doesn't help with their performance. If the single-throat Holden model popularly fitted to these Land-Rover engines is based on the same functional design as the twin-barrel Stromberg WW model fitted to the Holden 253 V8, then that can't be a good thing.

The WW couldn't meter fuel accurately over the engines full operating rpm range (they progressively leaned out), so as a compromise the factory had to set them to run rich at low revs (you of course don't want to compromise the other way around - properly tuned down low but lean up top). 253 engines fitted with the 4-barrel Rochester 4MV (Quadrajet) that could actually meter fuel properly not only produced more power but returned significantly better fuel economy around town - so the cheaper, lower-performance option was actually a false economy for the buyer.

See if you can find a description of how a Zenith works - it is actually fairly sophisticated, although certainly different to the Solex.

John

G'day Glen,
You have done a nice job on your resto.
However, I need to correct you on your post regarding the Solex carb and the AC fuel pump.
Yes the thread for the fuel input on the Solex 40pa10 is M12 x 1.25.
However the input and output threads for the AC fuel pump is 1/2" UNF. Yes the M12 x 1.25 will thread in but is a very loose fit and dangerous.
The fuel pump in and out ports are designed to fit CAV fittings. If you look into the port you will see they seal on the bottom of the thread in a chamfer.You can get CAV to 5/16" hose adapters.
Now the Solex is a different story. The castings are over 50 years old and can soften. You will find the seal of the fuel input will always leak and drip on the exhaust manifold.
I re threaded my input to 1/2" UNF and use the CAV fitting to seal the same way as the fuel pump. Yes the Solex jets are metric in thread and jet size. An example is Air correction jet 185 means 1.85mm. Chris