Where legends live on..

The world’s fastest Enfield

Rolling out of the pit lane at Cadwell Park my head was in something of a spin, as I tried to remember Steve Linsdell’s all too brief instructions.

Out of the blue Steve had called me a few days ahead of the Classic Racer Cadwell Park track day and, in his usual matter of fact style, asked if I would like a few laps on his Seeley Enfield.

Having always admired Steve’s ‘different’ way of doing things the opportunity to ride his 2010 development of the Seeley Enfield was a real treat, and something of an honour.

Up until my test at Cadwell Park only Steve and his racing sons, Olie and David, had ridden the bike, which added a little pressure, especially with the whole family watching from trackside at Hall Bends.

Although he has raced other, more modern, tackle with great success in the Isle of Man, (see box out), Steve’s racing career has been inexorably linked with Royal Enfield. His first race bike was a self tuned 350 Bullet on which he finished second in his first VMCC outing as a 21-year-old novice.

The current Seeley Enfield as tested is the ultimate, well for now at least, version of the machine on which Steve made his Isle of Man debut, in the 1981 Senior Manx Grand Prix Newcomers’ race. With four years short circuit racing under his belt Steve thought he would have a crack at the TT Mountain circuit and in a race full of much faster, purpose built two-strokes, finished second, with only a TZ500 Yamaha ahead of him!

That original Seeley Enfield, which with an estimated 40bhp was good enough to give newcomer Steve an impressive fastest lap just short of 95mph, comprised a second-hand replica Seeley chassis, a self tuned 500cc Bullet motor and a PGT five-speed gearbox. In true pioneering Linsdell fashion primary drive was by belt, common these days thanks to Bob Newby, but revolutionary in 1981.

The ‘Mk 2’, as Steve describes it, has the Bullet housed in a new Roger Titchmarsh Mk3 G50 Seeley chassis, which in itself caused some issues during build. “As the original bike turned out not to be a Seeley there were quite a few differences which caused some confusion with Roger, as I was requiring some more clearance that was already there on a genuine Seeley,” Steve explains.

On track the Bullet engine feels strong from the off, with just a hint more vibration than a ‘modern’ Manx. The one piece of pre-launch information I did remember was Steve’s instruction to ‘rev it to 8000rpm’. Both Olie and Steve admit over revving the Bullet on numerous occasions and when Olie took over four seconds off the CRMC Group 2 lap record early in 2010 he was using a ceiling of 8400rpm.

This seemingly excessive rev limit, for an elderly pushrod engine, is made possible by a lighter and stronger version of the original Royal Enfield system. “It was analysed by Ron Herring, with software from Dr Gordon Blair, and a cam form made that complemented it,” says Steve. The valve springs are from an aftermarket Porsche kit and have been 100% reliable.

As Steve admits, “I have seen the rev counter coming back down past 9000rpm and there have been no bent valves, so the system seems to work!”

The valves are titanium and originally Manx fitment from two different suppliers, and are modified in size and length for the Bullet and the rockers modified to run on needle rollers. Interestingly, the pushrods are from a Gipsy aero engine, obtained from an aero engine repairer, and Steve describes them as “probably very old”.

One regular question Steve gets asked is how much of the Seeley Enfield has Redditch DNA? “The major castings of the crankcase, head and timing cover are original Redditch made items,” he confirms. “The crankcases are 1959 and the head a little earlier. The head used is the earlier type, compared with the ‘big head’ used on the Mk1. Besides being easier to get the design has advantages, mainly in component weight.

“The cylinder, which has a hard plated 90mm bore, I made from a billet of HE30 alloy, and all the rest of the components were made by me, Olie, or Merv except for the cams. These were made in Australia.” Power to the twin plugs comes from a Pazon electronic system and sealed battery.

“There are no more parts modified (on the Enfield) than is normal for top level classic racing now. If you took a short stroke Summerfield, Molnar or ABSAF all parts are different from their original design,” concludes Steve.

One area that can cause concern on highly stressed current day classic racers, especially in the Isle of Man, is piston failure. Steve uses an Acralite piston running on an Arrow steel con rod. “It’s as light in the reciprocating part as the titanium rod it replaced and lighter overall,” adds Steve. The rod was fittedbefore the 2010 Manx Grand Prix and has a hardened big end eye without a liner. Piston life is also helped by oil being delivered to the lower cylinder and two, rather than the standard Enfield one, return oil lines help keep the top end cool.

The bottom end of the motor is courtesy of the skilled hands of Merv Hackett, who made and ground the shafts and fitted them to the flywheels, which he had already made for a G50 project. The crankpin is parallel to stop stress fractures at the change in section.

The Bullet has spent very little time on the Dyno, mainly because it was only finished after the Linsdell equip arrived in the Isle of Man for the 2010 Manx, but a short run on the Slick Bass Dyno, mainly to set carburation and timing, gave a reading of 50.3bhp at 7800rpm.

On track

With a little heat in the Avon tyres, after a couple of super cautious laps on a cool October day, it was possible to explore some of the Bullet’s potential. Having done hundreds of laps around Cadwell Park on a Mk3 Seeley G50 in the past the handling was exactly what I was expecting. Precise, but not too rigid, with the only issues being a front wheel slide on the still damp off-camber Barn Corner (my fault) and the Maxton rear shocks starting to ‘wind up’ around Chris Curve. From experience this had all the symptoms of a tyre issue.

After a debrief with Steve following my ride, and knowing how pressure sensitive the Avons can be, he raised the pressure before he raced the Enfield the following day and the problem went away. “One thing we do play around with a lot is tyre pressures,” Steve explains. “It stems from doing the R6 cup and Triumph 675 challenge where it is one of the few things you can adjust. Olie can heat the tyres very quickly to get a significant rise in pressure. We check the pressures hot to get the best performance. It’s always grip against chatter.”

The drum change TTI gearbox on the Enfield was both a revelation and a challenge. The former because despite a Linsdell built cross-over linkage, one of the neatest you’ll ever see, the change was ‘knife through butter’ sweet, and a challenge because it was on the left. And up for up in modern road bike fashion. I’m proud to say I didn’t miss a gear, especially as the same day I rode a Manx with a right change, down for up pattern and my own Ducati TT2 which is on the left but down for up!

With the bike prepared for Steve to race over the weekend it wasn’t a day for heroics on my part, but after a few laps I was finally getting up to a respectable pace, while trying not to hinder the serious classic racers getting some extra practice ahead of the CRMC meeting.

Impressive is the only way to describe the easy way the Enfield makes its power, with little in the way of a noticeable power band as the needle on the Krober tacho moved smoothly round to 8000rpm. And as I became more comfortable, and found myself exiting Charlie’s at something like a decent pace, I was pleasantly surprised at how easy it was to stay in the drag of what should have been faster machinery, with regular classic racers aboard.

Steve was running his new titanium exhaust and silencer for the first time when I rode the bike (at the Manx Grand Prix there is no noise restriction) and although untried is obviously very efficient and works well with the 40mm Dell’Orto carburettor. Driving out of Cadwell’s full circuit Hairpin and the ridiculous chicane before the Mountain, even when the revs were allowed to drop lower than they should, was clean and linear with my hand nowhere near the clutch lever.

With its years of development and the skilled hands of team Linsdell the Seeley Enfield would be an impressive classic race bike with any name on the tank, but given its humble and unlikely beginnings it’s doubly so.

He did it his way

Steve has never been a man to follow the conventional route with his racing.

After taking Historic racing by storm on the 350 Bullet, much to the dismay of many owners of more exotic tackle, Steve went on to build a great pure road race career from his 1981 Seeley Enfield debut in the Newcomers’ Manx Grand Prix.

Five years competing in the Manx was followed by a switch to the TT in 1986, giving him his first TT rostrum with third in the 600cc Production race.

The TT took over from 1986 through to 2004, with only 1990 – the year youngest son David was born and 2001 when the foot and mouth epidemic caused cancellation – missed, before switching to the Classic Manx Grand Prix in 1984/5 and 1992/3/4 and 2005/6/7/8/9 and 2010. Last year didn’t go quite to plan, when after achieving his hoped for 100mph pushrod Enfield lap in practice, the team had to withdraw after Olie’s huge Post Classic Race accident.

Just because he switched to the TT didn’t mean Steve would do things the conventional way either. His debut third place TT rostrum was aboard a Yamaha FJ600 tourer and he lists his GTS1000/FZR750 engined hybrid as his all time favourite TT mount.

With two TT runner-up finishes in the 400 Supersport class, a large hand, along with son Olie, in developing the Paton four-stroke twin of Italian enthusiast Giovanni Cabassi, a crowd pleasing ride on the two-stroke Grand Prix Paton in the TT, also owned by the Milanese businessman, and a fastest lap of the Mountain at 117.5 way back in 1992, on the same FZ750 which Olie crashed in last year’s Manx, Steve has made his mark on the Mountain by doing it his way.

Third generation

It’s hard to get Steve to open up too much on what he has planned for the next stage of development on the Seeley Enfield, except to say, “It will be different.”

When pressed he opens up a little, “It will be different mainly in the porting and compression. I have a problem with the piston crown thickness in the valve pockets, which is stopping me reaching the desired compression ratio,” he confesses.

“I could then put the existing engine into ‘Harry l’ to create a spare bike. I also want to change the gearbox position as the chain has to be run very slack to avoid locking up the suspension. And Olie will be doing a full season of CRMC events all being well.

“However, I may not get time to make the next engine, as a 350 may take priority. This would be in an Enfield frame to be eligible for more events.”

It looks as if the Linsdell Enfield development programme still has a way to go.

Words: Malc Wheeler Photographs: Joe Dick and Russ Lee