Thread: 2.25 Carburettors

Mark the Zenith gives the most power,the weber the least and stromberg holds it's tune.The Zenith is a really good carby,it has only one fault and that is it has an ""o"" ring between the top cover and bowl that can leak making it run rich,an easy test is to wind the mixture screw right in and if the engine still runs it's leaking.The stromberg,get the one made for the holden grey motor as they bolt straight on but they don't like angles,they are a cheap easy reliable carby.Forget the weber,I payed big money for one a long time ago,the only thing it will do is choke the motor into producing less power. Pat

The original carburetter is the Solex. This was replaced during 2a production by the Zenith, and later in Series 3 by the Weber. The first change was probably because of poor availability of the Solex, the second probably to meet emissions restrictions. Either Solex or Zenith performs well when in good condition, but parts for the Solex seem to be a problem. As mentioned, the Zenith can suffer from a warped top cover, which allows the O-ring to leak, giving an overrich mixture. This can be remedied easily by lapping it flat on wet and dry on a sheet of plate glass. Both carburetters can suffer from wear, particularly on the throttle shaft, and from ham fisted repairs.

A frequent aftermarket fitting is the Stromberg, ex-Holden. While cheap, readily repaired and reasonably effective, it is unsuitable for offroad use as it does not like steep angles.

John

Out of the solex, zenith and weber, I would pick the zenith. The weber seems to go reasonably well, but is prone to vapour lock. The zenith is prone to warping of the mating faces.

Don't even consider the holden stromberg for the reasons JD mentioned.

Other options are the Stromberg 1.75CD from a 6cyl rover engine. You need a custom adaptor which mounts them on an angle, but they work well.

Another option is the twin barrel Weber 36IV which was fitted to the 2.5P in the 110. IME this carby would be the pick of the bunch, but they are hard to find in OZ in LR spec, and you need a manifold to match.

Originally Posted by JDNSW

A frequent aftermarket fitting is the Stromberg, ex-Holden. While cheap, readily repaired and reasonably effective, it is unsuitable for offroad use as it does not like steep angles.

John

Easily remedied. Jigsaw a packing piece of petroleum resistant plastic to act as a packing piece in the float bowl. If you have ever seen the equivalent in a Rochester Quadrajet you will know what I mean. You do need a good fuel pump as the bowl will no longer act as a reservoir. You are filling the bowl with a solid and the fuel supply is then relying on flow. This is unaffected by angle. Normal practice in high bank and off-road racing. PM me if you need detail.

An oldie but a goodie was to use an 1 3/4" SU and a couple of flanges welded to a 90 degree bend bolted to the LR manifold. Jet and needle as per Austin 1800 works OK. A Carter YH sidedraft is also good. You could buy these from forklift companies. They usually have an adjustable main jet and are easy to tune. I have used them in the past in singles, and banks of 2, 3, & 4 on 4, 6, and 8 cylinder installations. The four carb. use was on a Buick Straight Eight in the early days of speedway hot rods/ modifieds. Gasoline fuel.

I have a Stromberg of a Holden and while it runs great, I can totally vouch for not liking angles....

Found that out the hard way - was very inconveniant and required alot of pushing to get it on the flat again

I have a Zenith and Solex on the bench at home - will get around to rebuilding them one day... If the Solex is complete is it worth rebuilding over the Zenith?

Originally Posted by Newbs-IIA

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I have a Zenith and Solex on the bench at home - will get around to rebuilding them one day... If the Solex is complete is it worth rebuilding over the Zenith?

My experience suggests there is no advantage of the Solex over the Zenith unless you are looking for originality on an early Series 2/2a.

John

As you may know Mark, both Ambrose and Gus have Weber carbies.

I don't notice the power loss that others speak of, but coming out of a bloodbox everything seems more powerful anyway. It's a bit hard to know how much to put down to the carby and how much is dimensional!

The vapour lock issue rears it's head occasionally, but only if you stop the engine after a long run on a hot day. Engine stops = fan stops = carby gets hot and vapourises the fuel out of the bowl. When you go to start again it coughs and splutters a bit until the fan and forward motion pulls enough cool air in to cool the carby a bit.

I have only had this problem twice. Once on the way to Corowa in 30 degree heat after driving at full tilt for 8 hours, and again on the way home from Singleton in similar weather after 3 hours at freeway speeds (well, as close to freeway speeds as an old bloodbox will go!)

I know of one prominent Land Rover mechanic / restorer on here who only uses the weber on all his series motors, but the general consensus here seems to suggest that the Zenith is best.

With the weber the venturi is only 32 or 34mm,I can't remember were's the zenith is 36.With 2.25's you really need the bigger carby. Pat