1970
The Competition History of RAD 366G - Marcos 1600GT :1968-1974
Technical Notes:
Over the winter, I had given considerable thought on what the next step should be. Should I continue as I had been doing or should I make improvements to the car and increase our competitiveness?
I was referred to Stan Gray who had a workshop in Trowbridge and who, in just recent times, had race prepared Chris Boulter`s very successful Marcos for club racing. Stan`s knowledge of Marcos racing was profound and we hatched a plan for work to be done on the car during the winter of 1969. This amounted to the following:
This covers the first of a set of major modifications carried out by Stan and Tony at Trowbridge. I have taken the following work from his bill of 27th April.
- Remove and dismantle engine. Carry out modifications and re-assemble to racing spec.
- Install special fuel tank.
- Make up throttle linkage
- Baffle the sump
- Stiffen front suspension by welding wishbones so that channel section becomes square.
- Phosphor bronze bushes fitted to wishbones
- Fit anti-roll bar. Spax shock absorbers
- One AVA pump
- Tuftride crankshaft and rods
- Heavy duty rocker set
- BCF2 Camshaft. Broadspeed Crossflow
- Manifold and O-rings
- Valve springs
- 8 Tappets
- 4 pistons
- Heavy duty clutch plate and cover
- Anti-Roll bar
- Heavy duty bearings
- I have a feeling that Stan fitted 2 x 42 DCOE Weber (ex-Maserati) carbs that he borrowed from one of his projects. See later note.
Tyres:
The first set of racing tyres was 5.00 L 13. Type CR 65 Mk 2 compound 184 set on 5 1/2 " steel wheels and these were used from sometime in the spring of 1969 to the Thruxton meeting on 10th May 1970 (No.19). Start date vague because there were no records or photos. We then changed to 5.25 M 13 -970 and set these on steel wheels widened to 7". L tyres still used as wets.
Carburettor:
Almost certainly the 42 DCOE Webers, as I have an invoice (21st July) from Radbournes to cover overhaul and service of two 42DCOE carbs.
I continued to use the Marcos as a road car with my close friend Jolyon bringing the racing tyres separately.
Races:
Date | Circuit | Club | Comp | Time | Class | No |
| May 16 | Castle Combe | SOC | 2-L Sprint | 2.49.5 | 1/10 | 62 |
This was a 2 lap sprint and I won my class - just. Photo 1 | ||||||
Date | Circuit | Club | Practice | Race | Finish | No |
| May 3 | Thruxton | BARC | 1.43 | 14.00.6 (8l) | 10/25 (C4) | 19 |
| Uneventful race in the dry. N3 plugs. Photo 2 | ||||||
| May 24 | Thruxton | BARC | 1.43.2 | 14.05.0 (8l) | 16/26 (C7) | 95 |
| Sunny day. New Dunlop M tyres on 7inch steel rims. NGKB77EC Plugs. Oil pressure problems at Seagrave. Good dice with Amey and Gott. Ended in the middle. Photo 3 |
| ||||
May 31 | Silverstone | BARC | 1.14.4 | 11.41.4 (9l) | 22/24 (C11) | 62 |
| Not a great day. Very Hot Brakes. Spun at Copse and finished two from end. Not that fond of Silverstone club circuit. Photo 4 | ||||||
June 13 | Castle Combe | BRSCC | 1.23.9 | 13.55.4 (10l) | 1/1 (allcomers) | 66 |
| Lack of top revs going into Quarry during practice. Carb linkage fell to bits. Power loss coming out of RH bends. Did not race in Modsports race but was allowed to compete in Allcomers race at the end of the day which we won. Dry and Sunny day. I like Combe. | ||||||
July 11 | Castle Combe | BARC | 1.20.6 | 12.12 (9l) | 9/12 (C6/9) | 10 |
Carb float level raised to 8.5 mm. Pulling 6000rpm into Quarry. An improvement. Warm and sunny. N3 plugs. Photo 5 | ||||||
July 25 | Castle Combe | BRSCC | 1.21.0 | 12.31 (9l) | 10/15 (C10/12) | 105 |
| Warm cloudy day. Carbs rebalanced. NGK plugs. Photo 6 | ||||||
Aug 23 | Thruxton | WHDCC | 1.41 | Dnf | 116 | |
| A decent practice but disaster in the race when a valve spring broke at Campbell. | ||||||
Aug 31 | Castle Combe | BRSCC | 1.19.5 | 12.26.4 (9l) | 12/15 (C2) | 153 |
N3 plugs. New M3 tyres. Now on Castrol competition oil. Had great dice with Viney in Healey 3000. Came second. Just. See photo7. | ||||||
Oct 3 | Castle Combe | BARC | 1.19.8 | 12.18.4 (9l) | 13/16 (C5) | 117 |
| Quickest in year so far with 1.19.5 in race. 6200rpm into Quarry. N3 plugs. Photo 8. | ||||||
Oct 11 | Thruxton | BARC | 1.52.4 wet | 16.52.8 (4l) | 19/23 (C8) | 122 |
| A wet practice. Matters did not improve for the race when the throttle cable snapped at Allard. Somehow fixed this and re-joined to finish last but classified. Car going quicker with 1.40 in my 4-lap race. Photo 9. | ||||||
Oct 17 | Castle Combe | Hagley LCC | 1.19.6 | 7th but not sure | 68 | |
| Car going much quicker now pulling 6500 into Quarry. Fastest lap this year so far with a FL in race of 1.18.7 (84.16 mph). Photo 10. | ||||||
Nov 14 | Thruxton | BARC | 1.53 | 17.18 | 9/26(C4) | 121 |
The Championship Finals and all the serious contenders were there This was a BBCTV transmission with Murray Walker on commentary. To say it was wet is an understatement. It was SOAKING throughout the day. I used NGK plugs and the narrow L racing tyres Practice time of 1.53 put me 5th on the grid equal with Chatham. In front were Burbidge, Cuthbert and Ashford. The race was even wetter - passed Cuthbert and Ashford spun leaving me in second place for a while. I then spun at Kimpton and Club but finished 10th. Very glad it was all over. See photos10 and 11. | ||||||
Summary:
This had been a remarkable year with 12 races and 2 sprints. From a cautious start, I found I was quickly learning what was required of me as a racing driver. This included the skills to understand the mechanics of the Marcos car and the circuits we would be racing on. I had also to be aware of other (much quicker) cars that would be around me and was very much mindful that I was still only driving a road car and quite a heavy one at that with limited modifications.
© Ian Gemmell 2024