Dominator 99 engine?

Hi Dale,

i have just purchased some 99 Dominator parts from a fellow member. i'm now in the process of building a cafe racer and including the 99 engine.

i've got a 1961 engine with number 95809 14 (99C 6887) believed to be a 600cc 99 engine?

could you confirm what components are different in this engine to a 500 Dominator and how i can identify them.

Regards Ian

I have a 1959 '99' and the Daytona cam was first fitted that year. It is identifiable by the letters "QR" stamped (not cast) on it. This stand for "Quietening Ramps".

When I first rebuilt mine in 1965 I wanted an SS camshaft - didn't we all? I bought a secondhand complete 88 engine for £5 with an SS camshaft in it, split it and used that in my 99. I still have most of the old 88, apart from half a crankcase - lost when I married and left 'home'! I sold the QR camshaft (probably for at least a fiver!) to Barry Lawton - Syd's son and racer - who used it in one of his racing Dommies. I live in Southampton so Lawton and Wilson's were one of my regular Norton shops - as was Alex Bennett's. (Where have I heard that name before?)

Long story short - I still have the SS cam but am intending to restore the engine with a "QR" which I bought at a jumble. When I sort out my old shed and new workshop I will have quite a lot of spares to sell - 2 x 88 engines for example but I will almost certainly split them and sell the components. No good asking me what I've got and what I'll sell it for yet!

As to bore and stroke - well-documented everywhere, including this site. The 88 is 66 x 72.6mm, Bore x stroke and the 99 is 68 x 82mm (introduced in 1956).

Good luck, Lionel

Previously ian_legg wrote:

Thanks Anna,

Does anyone know the difference in components in the engines bottom end of a 99 engine compared to a 500cc. i understand they have a Daytona camshaft? a different stroke from a 500cc? 82mm. If there are differences in components haw can they be identified?

Ian.

88: 66 x 72.6

99: 68 x 82

One way to tell the cranks apart is that the 88 flywheel is a full circle, the 99 has a flat in it.

You can't tell an engine just by the engine number. There are 99s in 88 crankcases and vice versa. As Anna mentioned, count the number of fins on the barrel to work out what the engine actually is.

88: 66 x 72.6

99: 68 x 82

One way to tell the cranks apart is that the 88 flywheel is a full circle, the 99 has a flat in it.

You can't tell an engine just by the engine number. There are 99s in 88 crankcases and vice versa. As Anna mentioned, count the number of fins on the barrel to work out what the engine actually is.

Thanks Anna,

Does anyone know the difference in components in the engines bottom end of a 99 engine compared to a 500cc. i understand they have a Daytona camshaft? a different stroke from a 500cc? 82mm. If there are differences in components haw can they be identified?

Ian.

As the Daytona is obviously more versatile than an SS camshaft it would be better to find one of those. My "old" SS one is an "X1", which refers to the case-hardening depth. If Barry Lawton raced his Dominator using a Daytona cam I reckon it's a very versatile cam!

Cheers, Lionel

A few errors there. The pushrods are longer for the 99, and the conrods are the same part for 88 and 99. The 99 barrels can be used on a mild 650 with a little work to the bottoms and the tunnels. 650 pistons can be used in the 99 although I had to work on the tolerances. 600 Nomad HC pistons have been used in 650's ,not sure if the skirts need shortenning. The short answer to your question re 88/99 the differences are barrels pushrods, ,pistons , crank. gearing and carb .The exhaust pipes should be different but pattern replacements are the same.

Just as an addendum, John Hudson told me that the 99s performed better with siamese pipes - which is what mine had on when I bought it from Pride & Clarke.

A few errors there. The pushrods are longer for the 99, and the conrods are the same part for 88 and 99. The 99 barrels can be used on a mild 650 with a little work to the bottoms and the tunnels. 650 pistons can be used in the 99 although I had to work on the tolerances. 600 Nomad HC pistons have been used in 650's ,not sure if the skirts need shortenning. The short answer to your question re 88/99 the differences are barrels pushrods, ,pistons , crank. gearing and carb .The exhaust pipes should be different but pattern replacements are the same.

Hi Lionel, my 99 performs well on siamese pipes, the only issue is a poor fit ,almost wish i had them made in stainless to fit.