Skip to main content
English French German Italian Spanish

1950 Dominator Model 7 engine

Forums

I have a 1950 Model 7 and was wondering what other Norton twin motors would interchange with parts? I bought this as a basket case, motor torn apart and I'm not very mechnical. I had a friend look at is and he said its missing quite a few parts. Was wondering if maybe model 88 or atlas engine parts would interchange? Has a lead on a model 88 engine, was wondering if any of those parts would fit mine. Would rather keep the model 7 engine to my frame, rather than put another none model 7 engine in. Hope this makes sense. Any help would be appreciated...Steve

Permalink

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.

Permalink

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

Permalink

Previously william_pryde wrote:

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

Permalink

Thanks for all the info. I have most all of the tins, freshly painted. New India gas tank that I had painted locally here in the States. I think I will try and find a M88 donor motor, which will be easier than a M7 motor & still use my motor which matches the frame. * I've added a couple of pics of gas tank. Steve

Attachments np%20006.jpg np-007-jpg
Permalink

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.

Attachments model-7-bits-bmp
Permalink

Phil--thanks for your input and information. I'm going to keep my eyes open for a M88 donor engine if I can't find a M7. My bike is pretty complete, other than finishing the engine; which does have the iron head. Finding parts for the model 7 here in the States has been a challenge, but also fun..thanks again..Steve

Permalink

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

Permalink

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

 


Norton Owners Club Website by White-Hot Design