Zen & The Art of Motorcycle Engine Rebuilding - Engine Builder Magazine

Zen & The Art of Motorcycle Engine Rebuilding

The book Zen and the Art of Motorcycle Maintenance demonstrates that working on motorcycles may be either dull and tedious drudgery or an enjoyable and pleasurable pastime; it all depends on the inner attitude, or lack thereof. Looking deeper into Zen and the Art, the narrator seems to point out that there are two different kinds of people in the world – those who do, and those who pay someone else to do it for them. Most engine builders could be described as those who do. Engine builders are the ones who pay attention to the little stuff like a “loping idle.”

While this type of character is not only applied to motorcycle repair, engine builders who want to enter into the motorcycle engine rebuilding market must pay attention to the signs. There are a number of approaches to the market that can work for the bike market, what you choose, and the path you take will vary on your style and personal interests.

The motorcycle engine building market is another avenue that automotive builders can choose to increase business and profitability, and the good news is, you don’t really need a lot of special tooling to get started. Experts say that Harley-Davidson performance engine rebuilds offer the most potential to shops because of the numbers and amount of aftermarket parts available. But vintage bike engine builds offer plenty of rebuilding opportunities as well. Although there is some rebuilding going on among the more complex Japanese bikes, experts say the market for machine work is smaller and more specialized.

Zen Master Builder: Colorado Norton Works

Matt Rambow of Colorado Norton Works is a master bike builder and engine builder of all things Norton. His company has a very distinctive and unique place in the market. In a market full of custom bike builders, CNW stands apart in what it does. They build very special bikes and offer other services such as engine building and transmission building. We talked to Matt to see not only how he builds the Norton Commando’s but how he approaches the market with his services. While we realize most engine builders will choose a different path than Matt, there are lessons to be learned.

“We don’t have a storefront or anything like that,” explains Rambow. “This is not a walk-in type of business. All the bikes that we build are made to order and we currently have a two year waiting list to get a bike. We also offer separate engine and transmission builds, as well as offer a lot of parts for the bikes. We have designed, developed and manufactured some of these parts ourselves. We are trying to be the ‘go to’ source for these hard to find items, the trick stuff, for the people who are wanting to make their bikes better out of the box rather than simply restoring a bike for concours events. There is a market for that too, but that’s not us at all.”

The Japanese bikes came out shortly after the Norton Commando and really put an end to their dominance. But in its day, Norton Commando was the bike to have. The Commando was the Viper or Corvette of the bike world in the early 1970s. And what Colorado Norton Works does is bring them up to date from the frame up. While CNW does do engine rebuilds, it prides itself on its holistic approach to building the whole bike as well. Not a stone is left unturned when one of their bikes is complete.

The Norton Commando lends itself very well to performance upgrades, according to Rambow. CNW has done extensive development work on the Commando engine. “It’s such a good road bike because the engine is rubber mounted as opposed to other bikes that are hard mounted,” says Rambow. “You go for a 100 mile ride on a Triumph and you are going to feel it, but with the Commando you’ll be ready to go for another 100 miles. The rubber-mounted engine is like a BMW, completely isolated from the frame.  At 3,000 rpm it is going to be a really smooth ride.”

Norton introduced the Commando in late 1967, and for its time it was considered a very modern bike. “The big thing was of course the rubber-mounted engine,” says Rambow. “But also they slanted the engine forward, which was more of a design element than anything. It gave it a little more modern look than an upright engine mount like the old Atlas or Triumph BSA, for instance.

The Norton 850 engine had a few issues after it was introduced, but people who owned these bikes enjoyed them and kept them for a long time. “Looking back at when Norton created the 850 engine you can see the changes through the years,” says Rambow. “There were no major changes internally, but there were minor improvements that you could tell were some issues early on. A lot of the issues had to do with bearing failures and strength of the cases, breathing, oil return, scavenge, all these things sort of evolved over the years. We feel that the best engines were the late model 850s that came out in late 1973. So what we do even when we get an earlier engine is we put it back to the specs of those 1973 850s.”

Rambow says they have updates for the main bearings and they always turn the cranks no matter what. “We don’t believe in saving a crank just because it has a decent surface. Most of them are compromised and not round anymore. Many out of the factory are oval when we measure them. We always cut the cranks to at least .010? or .020? under. We always bore the barrels (cylinders) out, and we always use the late model roller bearings because there were some issues with earlier bearings (early 1970s).”

Roller bearings in the early ’70s were a  little bit different style until Norton introduced a caged roller bearing. Norton used the caged bearing for a while and then came out with a new bearing called a super blend, which Rambow says is made by FAG. “It was actually designed by FAG for Norton,” explains Rambow. “If you look it up in a bearing book the description is a Norton bearing.”

Rambow says that CNW does not build engines to produce a lot of horspower, but prefers a healthy balance of low end torque and horsepower. He knows his customers are not looking for high-revving rockets that only last a few thousand miles. “People love to talk about horsepower. It’s very easy to embellish horsepower,” says Rambow. “When people start saying they are getting 60-70 hp out of a Commando, you’ve already lost them. The fact is, a stock Commando with a stock cam will put out horsepower in the high 40s, which is what the Harley put out for years with big twins. So imagine that in a 400 lb. bike. It’s really not too bad.”

What Colorado Norton Works does to a stock engine, when it’s done with it, is completely re-engineer the powerplant. “We run Web cams (www.webcamshafts.com) in all of our engines,” says Rambow. “We have a couple of different grinds, depending on what the customer is after. And the headwork that we do, the carburetion, exhaust – and then we also make performance engines, which are making about mid-60s hp on them now because we use fuel injection. We worked closely with the manufacturer to develop this system.”

The fuel injection kit that CNW is developing is not yet available but Rambow says they are putting the finishing touches on it, and it should be ready for sale sometime later this year. Rambow says the system is unique because it was designed from scratch specifically for a Norton Commando engine.

“It’s not something that was an existing system and modified for a Norton,” Rambow notes. “It doesn’t even use an electronic ignition, it reads the pulses directly off of the crankshaft. They guy who is developing it for us, Jim Comstock, developed the fuel injection for the Ecosse (ecossemoto.com). It’s an incredible motorcycle that sells for over $260,000. It looks like a sport bike but uses very exotic materials. It’s based on a V-twin, and the lower case is built by Patrick Racing. Ecosse told Jim not to bring it back until he developed 200 hp, which he did. The fuel injection system is taking it to the next level for reliability.”

Rambow says that CNW doesn’t have any trouble with cores. Norton made a lot of Commandos. In their heyday Norton was pushing out about 100,000 Commandos.

“The fact is a lot of people kept these motorcycles, as opposed to a lot of Japanese motorcycles, which had no secondhand value. The Commando owners had a love-hate relationship with their bikes. People loved them when they ran, but they were so unreliable. Because of this, people didn’t get rid of them. Now that these bikes are getting a second wind, people are bringing them back.

Rambow says what used to be a cheap donor is no longer the case with the Commando. He says they used to pay $1 a cc.

“When we could find a donor for $700-$850, that was a good price. Now we are expecting to spend between $2,500-$4,000 for a donor, and good runner for $5,000-$6,000. A nice bike is $8,000-$10,000, but when we are done with these bikes it’s a different machine.”

Everything is gone over, from the suspension, swing arm, engine, transmission, paint and electronics. Rambow says that the electronics on these bikes are a huge issue because they were so bad in the 1960s and 70s in the UK.

Colorado Norton Works is a great example of a builder taking it to another level. There’s very little on their bikes that doesn’t get considered. Not only is there a 2 year waiting period for CNW
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