Racing a Lotus 79 Formula One

Prelude to F1

Lotus 23B ...

Metcalf Racing was recently contacted by Richard South, team manager of Regogo Racing, who asked us to provide track support for their Lotus 23B sports racer.  Regogo Racing is owned by Paul Rego.  We were pleased to discover they had also secured Doc Bundy as driver of the car.  Additionally, they had Cliff Jennings of Jennings Racing Engines to build Lotus twin cam engines.  We were among quite notable company.

 

                  Doc Bundy in the Regogo Lotus 23B
              Photo by Bob Chapman used courtesy of Paul Rego

The first race we did was an SVRA event at Savannah's Roebling Road.  Although we qualified well, we encountered difficulty getting under the 104 db sound limit imposed because of the close proximity of residences around the track.  We opted to run a Lotus Elite instead.

... and Lotus Elite ...

The Elite had not been raced in about ten years and had only been started once in the last two.  We didn't hold a great deal of hope the race would turn out well.  After a quick check of the brakes, ensuring the engine would run and that it sounded acceptable, Doc ran a hardship lap on Sunday morning and then immediately formed up on the grid for the race.  To our astonishment, not only did he continue to complete laps, he passed several cars in the process.  By the race's end, he was leading.  Doc piloted the Elite to a win in the car's first race in a decade!

We took both cars to the Walter Mitty at Road Atlanta.  We didn't have to worry about a noise limit on the 23B even though we had taken steps by then to quieten it.  During the weekend, the twin cam developed an erratic misfire which we had some difficulty in solving.  Changing the carbs and the entire ignition system did not cure it and the misfire caused an early retirement from the race.  When we returned from Atlanta, some runs on the chassis dyno resulted in the same misfire, so we changed the engine for another of Jenning's mechanical masterpieces.  The original was shipped back to Cliff who ran it on the dyno and found no problems and then shipped it back to us.  We were perplexed, left with some big questions.

The Elite worked well at Atlanta aside from a glaring lack of power on the long straight.  Tired shocks eventually caused us to retire the car and put it away for a long needed  restoration.  We are really curious to see what kind of power Cliff can coax out of the 1100cc Coventry Climax.  Stay tuned and we'll let you know.

At Bobby Rahal's Legends of Motorsport race at Barber Motorsport Park, the 23B worked flawlessly.  We never found the source of the erratic misfire but it ran perfectly all weekend resulting in a win for Doc.  We never found the cause of the misfire and continued to be perplexed.

Main Event ...

the Lotus 79 Formula One!

The big event of the weekend at Barber, however, was the delivery of a long awaited Lotus 79 Formula One car.  The Lotus 79 has been voted the best looking Grand Prix car of all time in numerous magazines and websites for many years.  It won the 1978 World Championship in the hands of Mario Andretti.   Paul found the car in 2010 and shipped it to England to be serviced by Classic Team Lotus.  We had arranged for some test time at Barber on Tuesday and Wednesday.  Unfortunately, the car showed up from England on Thursday morning.  After a quick look over and missing the first session, we got Doc into the car.  Our "test" time had to be among the other F1 cars of the Historic Grand Prix.  Before the day was done, however, we began to encounter some of the issues residing under that beautiful skin.

      Doc keeping James King (March 761) behind him

            Photo by Bob Chapman used courtesy of Paul Rego

Richard South, Robert Metcalf and Nick Yallop

(L to R) starting the Lotus 79

Photo by Bob Chapman used courtesy of Paul Rego 

After only 140 miles, we began to experience problems with the rear wheel bearings.  Here is a brief description of the bearings:  Take a Lobro CV joint and machine two rounded grooves in the OD.  Machine the ID of a section of large diameter steel tubing with matching grooves.  Slip the tubing section over the CV joint and add ball bearings between them.  Add plastic ball separators and grease, and then place seals on each side.  Presto - you have a wheel bearing with a CV joint inside.  Collin Chapman's intent was to let one part do two jobs and reduce weight as a result.  An additional benefit was a very narrow upright which left more room for tunnels.  While it's a noble goal, the execution of the part was a little less noble.  To start with, the grooves must be spaced quite close together. due to limitations of the CV.  Secondly, most double row ball wheel bearings are "angular contact" bearings which take axial loads.  The Chapman bearings take radial loads well but are not well suited for axial loads which, of course, wheel bearings must accept.  The third problem is that the particular parts which were used to assemble our bearings were not properly heat treated.  The result was an all-nighter on Thursday night by the guys at Classic Team Lotus to build two new bearings and fit them into the uprights.  They really went all out for us and it was much appreciated.

Another problem Doc told us about was a brake pedal that just did   not inspire him with confidence that he would be able to get the car shut  down.  The 79 has eight brake calipers.  Two standard 3/4 inch master cylinders just were not enough to displace adequate fluid  to move all those pads out to contact the rotors.  Doc nursed the wheel bearings in the race and endured a scary brake pedal to finish third in his first Historic Grand Prix.  The finish showed what a magnificent car the Lotus 79 is and what a talented driver Doc Bundy is.  We found a solution for the brake problem in Indianapolis.

1st - Charles Nearburg - Williams FW071B
2nd - Chris Bender -March 821
3rd - Doc Bundy - Lotus 79
Photo by Bob Chapman used courtesy of Paul Rego

Our friend Greg Elliff showed us some stepped master cylinders which use a 1 1/8 inch piston to initiate fluid displacement.  When the pads have contacted the rotors, a check valve closes and a concentric 3/4 inch cylinder takes over to apply force to the caliper pistons.  We installed a set of these cylinders for the race at Circuit Gilles Villeneuve in Montreal.
 
Canadian GP

If you are not familiar with it, the Historic Grand Prix is a series run by Phil Reily and James King for Formula One cars of the three liter era built from 1966 to 1983.  Watching these races brings back great memories of seeing the same cars driven by Rene Arnoux, Niki Lauda and John Watson.  Oh, and of course Mario Andretti in our Lotus 79.  Grids are many times around 25 cars.  Needless to say, an Historic GP race is a fantastic event.  The series supports some great pro races such as Indy Cars and ALMS.  HGP was asked to run a support race for the 2011 Canadian Grand Prix in Montreal. 

We expected additional problems with the 79's wheel bearings in Montreal.  Instead, the wheel drive pins in a rear hub worked loose resulting in a loose wheel.  The pins are only pressed into the hub (the same part which is also the wheel bearing and the CV joint).  Most cars use threaded wheel pins which screw into the hubs.  The Lotus pins are pressed in.  Our only option at the track was to glue them back in with green Loctite.  We were not really comfortable with that fix but it worked throughout the race with no loose wheel re-occurrences.

 

                        Doc Bundy in the Lotus 79 all alone
                    Photo by Bob Chapman used courtesy of Paul Rego

Doc had not driven the GP track in Montreal.  A tour around on the pit cart promised a real driver's track with long straights and heavy braking.  One section was particularly tricky with a fast entry to a left-right switchback for which you could not really position the car in the optimum spot.  He did a great job in qualifying fifth.  Now with good brakes on the car, we expected that he would move up when the green came out.  Unfortunately, the Cosworth DFV developed a misfire and he dropped back to finish seventh.  It turns out one head gasket began to seep water into a spark plug well and shorted out a plug.

Back in the shop, Nathan Thompson and Robert Metcalf pulled the Cosworth DFV out and shipped it to Phil Reilly for fresh head gaskets.  Phil is the engine builder of this particular engine and we are certain he will do just as stellar job as Jennings has done on our Twin Cams.  Our next adventure is set for the weekend of June 25th with the Lotus 23B at Mid Ohio.  We have just blueprinted the Hewland MK6 gearbox from the 23 and done some suspension tweaks for the car.  We hope this will be a calm weekend in which we can bring home a win and not be perplexed by any re-occurring issues.  After that, we will take both  cars to Mont Tremblant followed the next weekend by the Kohler Challenge at Road America.  Check us again for reports of the Lotus 79 at these races.

Robert Metcalf (right) of Metcalf Racing

is crew chief on the Lotus 79
Photo by Bob Chapman used courtesy of Paul Rego