1972
The Competition History of RAD 366G - Marcos 1600GT :1968-1974
Timeline on technical events (1972):
Over the winter, I had decided to continue racing but with a full race setup now.
Stan and Tony built up a new engine using a Ford block bored out to 85mm, which now gave us an engine capacity of 1760 cc. We also chose the Broadspeed BCF3 full race cam.
We needed to resolve the problem of failing oil pressure on fast right-handers, particularly Church Corner at Thruxton. The best way to remedy this was to install a dry sump system which Stan created. We had sump/scavenge tank, a collection tank and an overflow tank plus and an array of pipework. The battery had to be relocated to the passenger footwell. Quite a sight but it all worked.
We also put in a limited slip differential as the car was slowing dramatically at chicanes with the inner rear wheel lifting.
Stan also found a light weight bonnet and boot lid from somewhere.
This covers the third of a set of major modifications carried out by Stan and Tony at Trowbridge over the winter. I have taken the following details from his bill of 20th April.
- Carry out full engine rebuild to racing specification. Make up exhaust system and modify manifold.
- Make up dry sump system and reservoir tanks.
- Modify cylinder head
- Lighten and polish conn rods
- Machine new 85mm pistons
- Overhaul rear axle and fit Limited slip differential.
- Overhaul brakes
- Check front suspension
- Fit Perspex windows and panels
- Fit (borrowed) lightweight bonnet and boot lid
- Fit (borrowed) long range fuel tank - My guess is that it was added at this stage
- 1 special block from Hillthorne Eng. Bored out with liners for 85mm pistons.
- 4 conn rods
- 1 manifold
- 1 oil cooler
- BCF3 camshaft
- 1 cylinder head
- 2 SU Electric fuel pumps
- Perspex door bits
- 1 three core radiator
- 1 set brake pads
- 1 set clutch parts
- R 40 racing oil
Tyres:
I continued to use the 175x550 13 type 350 tyres from the previous year with the 7” Minilites.
From May 1972, I used wider wheels. 8” front and 8 ½” Minilites.
Races:
Date | Circuit | Club | Practice | Race | Finish | No |
April 16 | Silverstone | BARC | ? | 11.12 (9l) | 12/20 (C4) | 236 |
| No times recorded. Photo 25 | ||||||
April 30 | Thruxton | BARC | ? | ? FL:1.37.6 | ret lap7 | 323 |
| I am not clear why I retired on lap 7. Photo 26 | ||||||
May 21 | Thruxton | NSCC | 1.44 Damp | 17.00 (10l) | 4/17 (C2) | 17 |
| I came 2nd in class 4th in race and won £3. No other data. Photo 27 | ||||||
May 28 | Thruxton | BARC 100kms | 1.38.6 | 36.31.8 (18l) | 13/28 (C5) Heavy rain | 272 |
| 8½ “rear and 8” front minilites. Wet tyres for race. Heavy rain 36.31.8 race time including a spin at Club. Stiff neck at end. | ||||||
June 4 | Thruxton | JDC 100kms | 1.37.4 | 37.38.4 (18l) | 8/22 (C4) Wet | 166 |
| Another dry practice followed by a wet race. AG901R plugs. Photo 28 | ||||||
July 2 | Silverstone | BARC | 1.10.6 | 10.45 (9l) | 14/28 (C5) | 122 |
| This raced featured 3 Marcos cars, James, Norris and Ian. Great performance by Rory in a Healey. Photo 29 | ||||||
July 9 | Thruxton | BRSCC | 1.39.6 | 13.12.6 (6l) FL:1.35.4 | 15/15(C7) | 179 |
| I was involved in a start line collision with two other cars (not my fault) which put me at a serious disadvantage. Eventually finished the race and set my quickest time yet of 1.35.4 trying to catch up. Class fastest lap. Photo 30 | ||||||
Aug 6 | Mallory Park | BARC | 57.2 | |||
| Race abandoned before start as track was awash | ||||||
Aug 12 | Oulton Park | BARC | 2.01.4 | 19.58.2 (10l) FL:1.58.3 | 7/24 (C1) | 111 |
| A beautifully sunny day for this Modsports Championship round on the full Oulton Park Circuit and I will say a bit more about it. My practice time was Ok to put me on the 6th row at the start. However, there was a collision at the race start which took out some quicker cars in my class giving me the class lead which I held onto the end coming in 7th overall. Won a gallon of Chevron oil. Photo 31,32,33 | ||||||
Aug 27 | Thruxton | BARC | 1.34.8 | 13.12.2 (8l) FL:1.35.3 | 6/26 (C3) | 228 |
| Dry conditions. best time yet in practice of 1.34.8. third row on grid. Finished 6th Photos.34, 35 | ||||||
Aug 28 | Castle Combe | BRSCC | 1.15.2 | 12.51.2 (10l) FL:1.14.6 | 5/21 (C1) | 90 |
| Made it at last to the front row of grid with two Jags for company. Practice time 1.15.2. Personal FL in race 1.14.6. Won class. Finished 5th. Photos 36,37. In Paddock with Le Mans Marcos (85). Photo 38 | ||||||
Sep 24 | Brands Hatch GP track | BRSCC | 1.55.4 | 13.41.1 (7l) | 9/21 (C5) | 73 |
| Enjoyed the outing on the attractive Grand Prix circuit. No spectacular result. Photo 39 | ||||||
Sep 30 | Castle Combe | BRSCC | 1.15.4 | ? (10l) FL:1.14.3 | 5/ | 48 |
| No full records. Finished 5th with personal FL in race of 1.14.3. | ||||||
Oct 14 | Castle Combe | BRSCC | 1.13.8 | DNS | DNS | 215 |
| Quickest yet in practice with 1.13.8 No race as the sunshine roof collapsed. | ||||||
Oct 29 | Thruxton | BARC | 1.54.6 | 15.32.4 (8) | 10/25 (C5) | 160 |
| Championship finals and it was wet. Photo 40 | ||||||
Summary:
The season ended with 14 starts, 2 DNF and one race abandoned at Mallory Park.
Lap times became quicker throughout the summer with my quickest being 1.13.8 (89.7 mph) at Castle Combe and 1.34.8 (39.4 mph) at Thruxton. I was determined to reach the 90 mph mark next year.
© Ian Gemmell 2024