My shop is in an over-sized two-car garage attached to my home. My work is a calling, in the theological sense of the word. Ethical and moral questions arise every day – they are hard, sharp, unambiguous and unavoidable.

What I think of vintage British motorcycles

Posted: July 18th, 2010 | Author: Administrator | Filed under: Around The Shop, Editorial, Engine, Motorcycle Repair | Tags: | No Comments »

Art,

Repeat after me:

Vintage British bikes are like psychotic women; irresistibly attractive and impossible to live with – gorgeous nightmares.  Lovely to look at but don’t take one home.

I restored a ‘69 Royal Enfield Continental GT for my oldest and best friend.  The cam profiles were nearly square – looked like something out of a drag-strip engine.  But the valve train – pushrods, of course, was a bit of a Rube Goldberg weirdness so Harry and I mapped the actual movement of the valves – a dial indicator on the valve stem and a degree wheel on the crankshaft.  The weird rockers/followers translated the square cams into what would have been in it’s day – the engine design dates from the ’50s – normal moderately high-performance profiles for opening/lift/duration/closing.

I had a reprint copy of the original shop manual and compared the numbers we derived with factory specs.  Not even close.  The manual covered both the hot-rod boy-racer and the cooking-sherry model from which it was derived.  I happened to look at the specs for the plane-Jane engine and they were close to ours.

Suddenly, it was clear.  The numbers had been transposed between models in the original manual – and nobody at Hitchcock Motors in London – who are the chief stockist for vintage R.E. spares and who reprinted the factory manual – had bothered to correct this error.

By this time, I was getting matey – via emails – with Allen at Hitchcock and told him about my discovery – and that while my numbers were close to what I now assumed were the correct numbers, they were still different – beyond variation due to measurement error.  His response tells you all you need to know about vintage British motorcycles.

Allen thought it was amusing – said they had been sending out that reprint for 17 years and no one had ever mentioned the error before.  And don’t worry about the cam numbers, he said.  When they ran out of original spare cams and tooled up for another run, they measured ten different cams – and not one of them was the same.

Print this out and tape it in a prominent place in your shop.

Cheers,
Chris
Existential Motorcycles
Alexander, NC



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