Slowest RestoMod Ever

• Mid-'80s....Nigeria...Norton Commando discovered by oil worker late father. Exchanged for a tin of grease. Appears to be Nigerian ex-police/army(?)*;
• Enquiries with Norton Owners Club identifies the bike as a '74 850 Interstate Mk2A. Brought back to UK for bike-mad teenage son;
• '90-ish.Stripped down, cleaned-up, exclamations of "Bloody hell! That needs a LOT of work!"and boxed-up by young, newly married, (therefore skint) RAF mechanic (me);
• During the intervening years, the bike is stored. Half-arsed, sporadic work is carried-out, e.g. wheels rebuilt, forks rebuilt, etc., but big stuff avoided;
• Late-noughties beer-fuelled discussion between father and son..."We need to get that Norton sorted-out!. Bike goes into classic bike shop for restoration;
• Money spent (£several thousands). Late-father not happy with progress, bike taken back home. Sits in shed;
• 2014 father dies, son inherits bike. Bike transported to son's shed..."I'm definitely going to rebuild it";
• Son joins Norton Owner's Club, starts research, becomes inspired by "new" custom/cafe scene, dreams of Fullauto heads, modern brake conversions, etc.;
• Present day...late 2017...finally started(!). Ex-Norton riding '60's ton-up boy mate, helps to remove engine. Invaluable knowledge remembered after 40+ years since his last Norton strip-down.

Fast Eddie said:

That head and barrel are clearly scrap, order a new head from Fullauto and alloy barrel from Maney. Job done!

Ok, on a more serious level... a 74 mk11a should have the RH10 head (look on top of the head, you should see it stamped somewhere).

These are the good heads! So it’s worth asking the question as to whether or not it’s worth saving. And that looks like a tough call to me!

But, although the damage looks bad, you could easily cut out and file to shape some replacement fins out of alloy yourself, so if you know a competent alloy welder who won’t charge the Earth, it may not be the lost cause it initially appears.

One could argue the same for the barrel, but these do often come up on eBay quite cheaply, so my guess it’s gonna be cheaper to buy a bore-able second hand replacement.

But, whichever way you look a tad it, this project WILL be a money pit... so you’d better start taking a close interest in, and black marker pen to, your daughters wedding plans...!

BTW that must have been a very big, or very posh tub of grease...!

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quikbrew said:

FE, thanks for the very useful response. Yes, Fullauto and Maney would be my first choice...however, circumstances, three daughters, weddings, etc., etc.!

I'll check the head tonight for the the RH10 markings. The photos are being considered by a welder at the moment, so fingers-crossed.

On a positive note, the bottom end and gearbox are "in good condition", according to the classic bike shop that did the initial investigation

Can't comment on the grease, seems like a great bargain, but maybe they knew the true dangers of rebuilding knackered old Brit bikes, sorry, I mean"classic restorations"!!!

Don't be expecting any rapid progress on this saga...(youngest daughter's plans TBA! At least she's in her final year at uni, so that's one less expense!). Let's just say, it's going to be episodic!

Incidentally, the old man was called "Eddie" too, but he was never fast...at least not on a bike

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Torontonian said:

RH 10 means you are going to try and save it by sending one of your daughters to trade school to learn
aluminum welding . Try to save it. Someone will have to cut and make up the missing fins. I doubt if it will ever look original after the weldings and grindings are done. You could spray it in heat paint say black so nobody notices much. Or just make more money somehow.

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quikbrew said:

RH10. What's wrong with the previous cylinder head versions? Porous? prone to cracking? Heat distortion? As a clueless Commando owner, I'd like to understand the issues with the earlier heads . I've been scouring Fleabay, but no RH10s to be seen.

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lcrken said:

Really only two heads used on production 850 engines, the RH4 and RH10. Other 850 heads listed for high performance and racing use (RH6, RH7, RH8, and RH9), but not commonly available. The problem with RH10 heads is that they are very prone to crack along the valve guide boss. Usually attributed to the factory fitting the guides with too much interference fit. What you would like to find is a nice used RH4 head.

Ken

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