Friday, April 18, 2014

800cc Royal Enfield took the Interceptor to the max

Prototype Royal Enfield 800cc parallel twin motor.
(Allan Hitchcock Photo)
Royal Enfield's powerful and fast 800cc twin-cylinder motor, tested in 1969 at speeds up to 128 mph, would have been a magnificent follow-up to the then new 750cc Series II Interceptor. But the 800c motor never went into production. Instead, the factory in Britain closed.

The 1969 tests were run by factory rider Richard Stevens. The test bike now belongs to British racer Steve Linsdell. Allan Hitchcock of Hitchcocks Motorcycles Ltd. has put another prototype 800cc motor into the frame of a Royal Enfield twin.

It is a fascinating footnote to Royal Enfield history. It's one that Royal Enfield enthusiast Chris Overton, of Canada, has studied. Chris was kind enough to allow me to share an email with some of what he has learned:

"The 800 had a number of features to deal with the issues developing as the 700 twin was developed to its limits. The rocker tips had swivels so a flat surface contacted the valve tips, overcoming the limitations on valve train geometry imposed by keeping the engine height within reason (22 inches is tall!).

"Previous 700 and 750 twins have difficulty with the valve stem tips becoming pocketed from point contact with the rockers. This allowed the rocker to transmit lateral forces to the valve with wear consequences to valve stems and guides. The 800 could then have thinner valve stems for better flow through the ports.

"Another weak link was the clutch, designed decades earlier for smaller engines. The splined clutch resulted (and, although never put into production Series II Interceptors, it was available for retrofit). Ignition was electronic, with an early Boyer-Bransden system.

"I have had several conversations with Richard Stevens, the factory test rider who put so many miles on the prototype, and a visit with Steve Linsdell when I went to his shop in Flitwick, UK to see the 800.

"It is notable that both repeatedly use the terms 'quick' and 'right' when describing the 800’s performance. Both riders are using English understatement in the extreme. When questioned on the details, it seems both felt everything in the engine design came together. There were no issues such as 'peaky' power bands or temperamental tuning. Power delivery was strong and consistent — 128 mph from the 800 is consistent with 115 mph with a 750.

"There is more to winning than peak horsepower and max speed. Two experienced racers felt the 800 was especially quick because the engine was right.

"Richard can hardly contain himself when describing the 128 mph first test run of the 800. The Triumph team were at the MIRA track too and could not help but notice the 800’s performance, and potential for more. Richard struggles to maintain his polite, understated ways, and beams describing what I take to be surprise and competitive concern from the heavyweight competitor."

Chris concluded this way:

"The 800 would have been a contender, and Enfield could have done alright with it. If another 800 engine should turn up, I have a spare frame here...."

Tuesday, April 15, 2014

800cc Royal Enfield Interceptor prototype rides again

Allan Hitchcock's 800cc Royal Enfield.
(Allan Hitchcock Photo)
A prototype Royal Enfield 800cc twin-cylinder motor in a cafe style motorcycle certainly fires the imagination.

Factory tested in 1969 — at 128 mph — the 800cc motor was a development of the already impressive 736cc Series II Interceptor with its wet-sump lubrication, but with noticeably larger barrels.

What if Royal Enfield had gone ahead with production of such a motorcycle in 1970?

And what if such a motorcycle were produced today?

Allan Hitchcock of Hitchcocks Motorcycles Ltd. in the UK has one of the very few 800cc prototype motors. He has it installed in the frame of a Royal Enfield twin, and styled to match the motorcycle of 1969.

Hitchcocks displays the bike at events in the UK. I asked Allan to tell me more about it. He was kind enough to email this reply:

"The 800 engine arrived as some parts amongst a huge hoard of bits from the Royal Enfield dealer in Bristol in 1991. After many weeks/months of sorting through the parts I noticed that there were some odd shaped barrels and it was only the long skirts that gave them away as Enfield. This got me thinking and then checked some of the crankcases and one set of the Series II cases were different to standard along with some heads etc.

"At this stage I realized what it was and put them to one corner and forgot about them for some time. It wasn’t until some years later that one of our long time customers offered to put it together just to keep it together. All the key parts were there so it was just the task of putting the motor in a suitable chassis. (It is not actually an Interceptor frame but a late twin — looks the same, but the frame number gives the game away.)

"At this time no attempt had been made to get her running and I nearly parted company with it when the National Motorcycle Museum were after a Series II Interceptor. At the time, I had the 800 and also the very first Series II (engine number and frame number 1000 first registered to the Enfield factory October 27, 1967) and one had to go — and they chose No. 1000.

"It was not for another 10 years before it was actually attempted to get it running. This brings us up to 2013 and during the summer had her running for the first time. It has only covered a few hundred miles since as Hitchcocks Motorcycles takes up all my work and play time.

"From what you read they had a large number of advance orders (Ed: one source says 400 of them) for the 800 but it is immaterial as it was all too late to save the factory.

"Whether it was ready or developed enough, I do not know, but would suggest that there were no extreme changes between this and the already proved 736cc. It would not have needed too much proving.

"We have talked about reproducing a twin engine for many many years. The heart says make it the Series II, the business approach calls for the earlier engine as it will breathe some fresh air into the parts availability for the 500/700/736 twins. But we are a long way off this as it requires a massive investment in both time and money."

Started in Redditch, England, the ancestral home of Royal Enfield, in 1984, Hitchcocks has grown into the key supplier of parts for the English made Royal Enfields as well as for Royal Enfields from India. Hitchcocks gathers up old bikes and supplies of parts, sources reproduction parts and even manufactures new and improved parts.

Their catalog and very helpful parts books can be seen online.

Allan wrote:

"Next project will be a Clymer Enfield. I recently picked up a basket case with engine number IB1001X; the factory ledgers have this as a prototype engine sent to Tartorini in Italy. Hopefully this will not take over 20 years to get up and running!"

Friday, April 11, 2014

Royal Enfield history in the U.S. captured in a photo

1999 visitors to the U.S. Royal Enfield display included Siddhartha Lal,
at right, the young man who in 2000 would offer to save Royal Enfield.
(Kevin Mahoney Photo)
Books about Royal Enfield history always include photographs of distinguished looking English gentlemen in business suits posing next to the classic motorcycles of the day.

Some day fans of the brand might find this photograph just as interesting. Classic Motorworks president Kevin Mahoney came across it recently and shared it with me.

Taken at the February, 1999 Dealer Expo in Indianapolis, Ind. it shows Mahoney and Marty Scott — the original U.S. importer of Royal Enfields — with some visitors from India at the Royal Enfield booth.

Among the visitors is Siddhartha Lal, today the managing director and CEO of Eicher Motors Ltd., parent company of Royal Enfield.

In 1999 he was a college student.

In 2000 he would encourage his father Vikram to let him try to take Royal Enfield and make it profitable instead of selling off the money losing company. Today, he is credited with taking Royal Enfield from the brink to a raging success in India.

What else is visible in the photo?

"If you are sharp you will notice that the bikes are kickstart only," Mahoney wrote.

That's hard to see, but I can make out that the motorcycles are still labelled "Enfield." Not until the next year would new U.S. bikes be badged "Royal Enfield."

"If you are really, really sharp (and old), you may notice that the booth backdrop on the right rear is the Wilson Centers (psychiatric hospital that Doneen and I worked at) booth with Enfield signs Velcroed over it," Mahoney wrote.

Left to right are Marty Scott; Sam (Sarva) Bajaj; Sam's son (who is now a doctor); Kevin Mahoney; and Siddhartha Lal.

Monday, April 7, 2014

My Royal Enfield is reliable; it's just sensitive

My Royal Enfield Bullet, gassed up and ready to ride.
For me, Sunday's Royal Enfield One Ride day included, indeed, exactly "one ride."

On Saturday I cleaned the spark plug and points on my 1999 Bullet, checked the tire pressures and even examined the air cleaner — it looked fine.

I mentally planned what clothes to wear and what route to take. I knew I would arise early Sunday, in plenty of time, because I would be too excited to sleep.

It was still dark when I pushed the Bullet from the garage and began the starting procedure.

Switch ON!

Oh, oh. The headlight barely glows. The Bullet won't start without electricity. Kick after kick brought not even a burble from the motor.

Out came the battery charger. I gave it only a few minutes, as I suspect the charger is too strong for motorcycle batteries.

Switch ON! The headlight is bright. One kick. VRRROOOOOOOMMMMmmm!

The Bullet sprang to life. But it wouldn't keep running unless I kept the revs up. Left to idle the headlight would dim and the motor stall.

I went for a long blast up U.S. 1, hoping the battery would build strength. But it didn't seem to want to hold a charge. I took a chance and stopped to attend church. After mass the Bullet did start, but not willingly. I would not be going anywhere else today that would require stopping the motor.

I rode home and returned the Bullet to the garage. I'll give the battery another try in the morning and if it's dead I'll start shopping for a new one.

My theory: the poor Bullet just couldn't stand the pressure of having to perform on one specific day out of 365. It's not unreliable. It's just sensitive.