1950 Dominator Model 7 engine

Early twins had the inlet manifold as a part of the head casting, not sure what year the separate alloy manifold was introduced, apart from this, the engine is almost identical to a Dominator 88 up to '54. From '55 (or when the new model was introduced late in '54), an alloy head was fitted, with other minor modifications. The range of possible engine modifications is endless, but, with little experience, and limited workshop facilities, you would be wise to stick with straightforward "bolt on" parts.

It depends what parts you are looking for but you should be able to find most parts through the owner's club just ask, but the Model 7 is getting rare especially the tin ware so if you have that you are onto a winner, alternativelytry RGM Norton

http://rgmmotors.co.uk/

Failing that ask John Jensen at Holy Norton http://www.holynorton.comhe collects lots of model 7 sparesnotron3003@gmail.com

Fraser

And if you need some mechanical assistance can I recommend John McGeachin in Glasgow, he specialises in nortons and you will not find a better mechanic with his attention to detail.

https://sites.google.com/site/classicbikerepairsglasgow/

The Model 7 and early Model 88 engines are easily interchangeable. Both used the same bottom end, barrels and could use either the iron or Aluminium head.

As John Shorter mentioned, the first Model 7 engines had the integral carb manifold but very few of thesae were made (only about 20) and most were exported. Those remaining in the UK were mostly kept by the Norton factory for testing. The test bikes quickly had their cylinder heads changed for the Mark 2 version and these and all the subsequent 1950s Model 7 engines all had the separate carb manifold. Anyone with a Mark 1 cylinder head has a very rare part.

As mentioned above, the Model 7 and Model 88 (dynamo) bottom ends were almost identical. The only differences that I have come across is inside the timing cover where the oil pump gears are off an ES2 and the engine gears and pinions are also machined differently. See the attachment. Model 7 bits of the left,,,,88on the right.

Most of the tinware is similar if not identical to ES2 parts. The problem that tends to catch people out with these early engines is pushrods. All the early motors had steel pushrods and valve clearances to go with iron barrels and iron heads. If you add an Aluminium head to the engine then you can still use the steel pushrods but an alloy set would work better. The bad move is to put alloy pushrods in an all iron engine.

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There is a model 7 head on ebay if you wanted to have a look

http://www.ebay.co.uk/itm/Norton-Dominator-or-model-7-Cylinder-Head-for-Iron-engine-Project-or-Spares-/191469235570?pt=UK_Motorcycle_Parts_13&hash=item2c9474ad72

Previously william_pryde wrote:

There is a model 7 head on ebay if you wanted to have a look

http://www.ebay.co.uk/itm/Norton-Dominator-or-model-7-Cylinder-Head-for-Iron-engine-Project-or-Spares-/191469235570?pt=UK_Motorcycle_Parts_13&hash=item2c9474ad72

Hello I would forget this heep of junk as there is alot of fins missing, its in bad shape too, you need a alloy 1955 head and paint it Black with PJ1 heat coat

then is looks like cast iron head , I rebuilt lots of early engines there not easy to rebuild if you do not know what your doing, to fit the time chains you need to set up all the three sprockets and the dynamo gears as well and fit them and time it that the same time so its got go on as one, set up, not easy, you have mark all the punch marks with a spot of white paint, and the best way is to have the bottom harf in a Vice on its side timing side up,

your Anna J

I think that gearbox sprocket has seen better days and would now be of more use, as a weapon, in a Kung Fu Film.