Craig Chima's Ginetta G4 Series Two Racecar
Owner: Craig ChimaCity: Akron, OH
Model: 1964 Ginetta G4
Engine: Ford Cortina 1498cc
Race prepared by: Craig Chima at CC Motorsports
Ginetta G4 Background Information
In about 1957, Ivor Walklett decided to build a sports car and he recruited his brother
Trevers to help. Their original one-off special was built largely from Wolseley Hornet
components. Shortly after completion, it was destroyed in an accident in the family driveway.
Undiscouraged, the two brothers decided to build a replacement. Their second design featured
a tubular chassis and a Ford "8" engine. In response to requests from friends, the two brothers
decided to duplicate the car and sell it in kit form. Once sales of G2 kits started,
brothers Bob and Douglas joined Ivor and Trevers. Together, the four brothers founded
Ginetta Cars Limited in 1958. Approximately thirty Ginetta G2 kits were sold. Another model,
was introduced in 1959. The G3 featured a fully-fendered fiberglass body. Approximately
sixty G3 bodyshells were sold.
The Ginetta G4 model was unveiled at The British Racing and Sports Car Club's "Racing Car Show"
at Earl's Court in London, in January 1961. Although the G4 was initially planned to utilize a
proposed but never commercially available Coventry Climax 750cc engine, Ginetta was quick to
recognize the qualities of the newest Ford engines: large bore, short stroke, lightweight
crankshaft, and an overhead valve cylinder head with eight individual ports. The Ginetta G4
was no larger or heavier than it needed to be to fit the Ford ("105e" 997cc) engine. In the
market and at the racetrack, the Ginetta would be competing with Elva and Turner models which were
somewhat larger and heavier, and with the Lotus Seven which had a more old-fashioned appearance.
Trevers has been quoted as saying that the Lotus Eleven racecar inspired the design of the G4.
Indeed, as originally introduced the G4 body had rounded tailfins which bear some resemblence
to the Eleven's. However, the G4 was marketed as a dual purpose "road and track" car.
The Ginetta G4 offered an exciting alternative to the kit cars that proceeded it. The Lotus Seven
had been the top of the class. Obviously, the Ginetta is much more streamlined and modern looking.
Buyers gave up nothing in performance or quality, and the G4 was attractively priced too.
The Ginetta G4 featured a spaceframe constructed of 1" x 18-gauge round steel tubing, and an all
fiberglass body. The center section of the fiberglass body was bonded onto the frame for
added stiffness. Fitting of doors, front clip, and rear clip were left to the customer. The whole
front of the car hinged forward much in keeping with the style set by the Lotus Eleven or
Lola Mark One. The rear clip didn't hinge, but it was designed for quick detachment. It had a
boot lid too for even easier access to cargo space, although Ginetta didn't provide a floor to
the boot area. The customer could fabricate their own, or could leave it open for lightness and
for suspension and fuel tank serviceability.
The Ginetta G4 design changed substantially over time. As mentioned above, the early Series One
bodies had small tailfins; but these were eliminated when the Series Two model was introduced
in 1963. The Series Two rear bodywork was instead stretched out approximately eight inches to
provide more cargo area. The Series 2 version also had re-located front spring mounting points
and a BMC rear axle in lieu of the original Ford Anglia axle. The BMC axle was preferred
because a better variety of gear ratios were available for it, because it weighed forty pounds
less, and because it was two inches wider. The axle was located by trailing arms above and an
A-bracket below. Independent rear suspension and four wheel disc brakes would soon be available
in the G4R ("R" for racing) model variant that Ginetta introduced in 1964. In 1964 Ginetta
also introduced a coupe version.
The G4 Series Three of 1966 marked a real departure in design. The original round-tube frame
was replaced with a new "square-tube" design, and the front suspension was redesigned to
utilize Triumph Herald wishbones. From the outside, the Series Three could be differentiated
easily because it sported pop-up headlights and a front bumper.
How was the G4 rated by the press? When introduced at the 1961 Racing Car Show, it was
voted the most beautiful car at the show. That seems to have set the tone for press coverage.
After commenting on its beauty, press reports generally noted the car was only suited for true
enthusiasts, but they praised its performance. For example, for their July 1964 edition
"Practical Motorist" magazine commissioned 1963 Grand Prix champion Graham Hill to review the
new Ginetta G4 GT. He wrote: "From the appearance point of view, the Ginetta is one of the
prettiest small cars I've seen. Normally it is difficult to make a small car with the right
proportions, but this one looks good... Summing up, I would say that this is an enthusiast's
car, and at £650 in kit form good value for the money - I can't think of a cheaper G.T. car.
It has a lively engine, above average road holding, good brakes and steering, and should give
a keen driver a lot of enjoyment."
The magazine's editors continued: "On the road, the car's small frontal area and smooth
shape allow this relatively mildly tuned engine to push it convincingly faster than 100 m.p.h.
while the car's all up weight of less than 10 cwt. gives a 0-60 m.p.h. time of 10.7 seconds
and 90 m.p.h. from a standing start of 27.5 sec. For an engine capacity of 1,198 c.c. this is
a pretty respectable road performance."
Motor Sport magazine reviewed the Ginetta G4 in September 1962 and again in April 1964.
Their first G4 had a Ford Anglia 105e (997cc) engine, whereas the second had a Ford Cortina GT
1.5L engine. Noting that the larger engines seemed a much better value, they paused to explain
why many people would buy the smaller engines instead: to fit into their chosen racing class!
Specifically, due to homologation rules only the 997cc version was certified for national or
international competition as of 1964. To meet these rules, a car manufacturer had to build
100 identical and complete cars. Ginetta chose to meet this challenge for the 1-litre class
only.
Please support the sponsoring companies who make www.BritishRaceCar.com possible, including:
| 1964 Ginetta Pricing (as reported in Motor Sport magazine) | |
| £499 | Ginetta G4 kit, complete with Ford 105E (997cc) engine. |
| £517 | Ginetta G4 kit, complete with Ford Cortina (1200cc) engine. |
| £543 | Ginetta G4 kit, complete with Ford Cortina GT (1500cc) engine and gearbox. |
| £15 | optional upgrade from Series 1 to Series 2 rear body panel. |
| £5 | optional electric cooling fan. |
| £9 | optional tachometer. |
| £25 | optional Girling 9" front disc brakes. |
| £22 | optional convertible top with sidescreens. |
| £58 | optional fiberglass hard top and Perspex side windows. |
| £99 | optional performance kit for the Cortina GT engine, including: Ginetta-modified cylinder head, aluminum alloy rocker cover, chrome-plated exhaust manifold, upgraded oil pump, and a single Weber downdraught 2bbl carb on a suitable manifold. |
| £110 | optional performance kit for the Cortina GT engine, including: Ginetta-modified cylinder head, aluminum alloy rocker cover, chrome-plated exhaust manifold, upgraded oil pump, and dual Weber 40 DCOE carburetors on suitable manifolds. |
Ginetta's original production of G4 kits ceased in the late sixties, but you can still buy a
new G4-based car today. The Walklett Brothers kept the Ginetta company going until their
retirement in 1989, at which point they sold the company. It continues in business to this day.
In 1991 Ivor, Trevers, and Trevers' son Mark were persuaded to start another car company. They
named it "Dare" (Design and Research Engineering), and they resumed production of the G4 model.
The "Dare G4" combines classic styling with modern mechanicals. Dare is still in business too,
although management has changed.
It's difficult to determine how many Ginetta G4 kits were completed. We believe the number is
probably just over three hundred, and that approximately two-thirds of them are round-tube cars.
When people report higher numbers, they are apparently including continuation models such as
the Series Four G4 of the 1980's, the G4-based G27 model, or the Dare G4.
Only about two dozen original Ginetta G4 cars are believed to have come to North America.
Ginetta Cars Ltd., West End Works, Witham, Essex, England.
Craig Chima's Ginetta G4: chassis number 173
Craig Chima purchased his Ginetta G4 after it had been garaged, disused, for about twenty years.
The Ford Cortina GT (1500cc) engine didn't run, but there was no collision or rust damage to repair
and the fiberglass bodywork was in very good shape. The car had only been street driven, and it had
no racing history or modifications at all. Craig was excited to discover a car with so much potential.
We feel very fortunate to have been able to see Craig's Ginetta on its very first outing.
As would be expected on any shakedown weekend, some minor technical issues required attention.
Nonetheless, the car comfortably lapped Virginia International Raceway in about two minutes
eighteen seconds, for an average speed of 85mph over the circuit. Craig reported that he was
seeing about 137mph before braking at the end of the long straightaway. Incidentally, Craig
has also owned and raced Lotus and Caterham Sevens with similar drivetrains. He explained
that the Ginetta's superior aerodynamics appear to give it a twelve to fifteen mile per hour
advantage in top end.
Enjoying this article? www.BritishRaceCar.com is partially funded through generous support from readers like you!
To contribute to our operating budget, please click here and follow the instructions.
(Suggested contribution is twenty bucks per year. Feel free to give more!)
At V.I.R., Craig was paddocked directly across an alley from Kent and Jesse Prather of
Prather Racing. One of the Prathers' customers, Bob Bramlage of Kansas, was there too
racing his Pontiac Firebird. Apparently the Ginetta impressed Bob, because he decided
to purchase Craig's Ginetta G4 and add it to his stable of vintage race cars.
Craig tremendously enjoyed building this Series Two G4. He has a couple original Lotus
Sevens in his garage to restore, but after that he'd like to return to another Ginetta G4
project. Given his choice, he'd like to tackle a Series Three next time because the box
tube frames are a little bit stiffer and because in vintage racing the Series Three cars
are permitted to run later and more powerful Ford Cortina crossflow or twin-cam engines.
Features and Specifications
| Engine: | Ford Cortina (1498cc) engine, bored 0.040" over.
Steel crankshaft (designed by Craig and made by Moldex.)
CC Motorsports connecting rods.
Midwest Motorsports (George Bauchman) custom ported cylinder head and custom designed camshaft.
Titan roller rockers.
Static compression ratio is ~14:1.
Dual Weber 40DCOE carburetors with short velocity stacks.
MSD Blaster 2 ignition coil.
Accel Hi-Temp Super Stock Spiral Core 8mm spark plug wires.
MSD6AL capacitive discharge ignition system.
Titan cast aluminum dry sump oilpan.
TDC Oil Pumps (from Fast Forward Components) 3-stage external oil pump.
Patterson Enterprises dry sump oil reservoir.
Laminova C43 Series water-cooled oil cooler. |
| Cooling: | AFCO Racing "Scirroco Style" dual-pass aluminum radiator. |
| Exhaust: | CC Motorsports four-into-one step-up headers. |
| Transmission: | Taylor Race Engineering's "TRE Inline" H-pattern 4-speed transmission.
Custom bellhousing and annular clutch release bearing. |
| Rear Axle: | Morris Minor rear axle housing.
Double bearing hubs and billet axle shafts.
Tran-X limited slip differential.
3.9:1 ring and pinion. |
| Front Susp.: | converted from rear-steer to front-steer configuration.
standard Triumph Spitfire (Alford & Alder) forged uprights, switched right-for-left.
Stock Ginetta lower A-arms.
CC Motorsports fabricated upper A-arms with Heim joints on inboard ends to facilitate
caster and camber adjustment. (Spherical bearings at the outer ends.)
Spax adjustable coilover shock absorbers.
Triumph Spitfire steering rack, strengthened and shortened and remounted to facilitate
height adjustment to eliminate bump steer.
CC Motorsports anti-sway bar. |
| Rear Susp.: | stock Ginetta lower A-link. Adjustable (Heim jointed) upper trailing links.
Spax adjustable coilover shock absorbers.
CC Motorsports adjustable anti-sway bar. |
| Brakes: | (master) dual Girling master cylinders with bias bar. (front) stock Girling calipers and nine inch solid rotors. (rear) stock BMC 8" drum brakes. |
| Wheels/Tires: | Kodiak FX 13x5.5 three-piece modular aluminum wheels (forged centers). Avon ACB10 Sport 7.0/21.0/13 tires. |
| Instruments: | (left to right)
AEM UEGO digital air/fuel mixture gauge,
VDO coolant temperature gauge (100-250F, black bezel),
VDO oil temperature gauge (100-250F, chrome bezel),
VDO oil pressure gauge (0-100psi),
Stack tachometer (0-10400rpm). |
| Electrical: | Tilton Super Starter.
EverStart lead/acid lawn tractor battery.
(No charging system.) |
| Fuel System: | Fuel Safe 8-gallon fuel cell.
Facet electric (cube type) fuel pump.
Holley fuel pressure regulator.
Mr Gasket fuel pressure gauge (0-15psi).
JEGS in-line billet fuel filter. |
| Safety Eqmt: | G-Force safety harness.
FireBottle fire suppression system. |
| Weight: | ~1075 pounds.
Approximately 50/50 weight distribution. |
| Racing Class: | 8CP |
Engine Installation
Ford Cortina (1498cc) engine, bored 0.040" over.
Craig Chima works closely with his friend George Bauchman of Midwest Motorsports to build highly
tuned race engines. George ported this cylinder head and paired it with a custom camshaft profile.
Afco "Scirroco Style" dual-pass aluminum radiator and Laminova C43 Series water-cooled oil cooler.
Series One and Two Ginetta G4 cars featured spaceframes constructed of 1" x 18-gauge round steel tubing.
This particular chassis has been restored and extensively strengthened by Craig Chima of CC Motorsports.
No tubes were removed from the original spaceframe chassis, but more than a few were added.
Directly above what appear to be Derrington intake manifolds, we see one of the newly added tubes.
Dual Weber 40DCOE carburetors with short velocity stacks.
The 4-into-1 header tubes step-up in diameter three times before the collector, based on
exhaustive development and testing. Details are a trade secret of CC Motorsports.
Both above and below the remote oil filter, we see X-bracing where the original Ginetta G4 design only had
single diagonals. The steering rack has been relocated from its original location, to convert the car from
rear-steering to front-steering, which made more room for the engine's harmonic balancer and for
accessory pulleys. The removeable cross brace just behind the oil filter is also a new addition.
Custom fabricated coolant filler.
Holley fuel pressure regulator. Mr Gasket fuel pressure gauge (0-15psi). JEGS in-line filter.
This top-of-the-footbox access panel (for pedal adjustment, etc.) is a new feature.
Dual Girling brake master cylinders with bias bar.
MSD Blaster 2 ignition coil. Note also: a new steering column was required to suit the new
steering rack location. Craig decided to make it easily adjustable as partly shown here.
Super Starter by Tilton. Titan cast aluminum dry sump oilpan.
(CC Motorsports is an authorized distributor for Titan.)
Taylor Race Engineering 4-speed transmission, mounted on a custom-modified Ford bellhousing, utilizing
a custom annular clutch release bearing. The Taylor Inline transmission is a dog-ring box with Hewland
or Webster gears. All four gears can be changed in under an hour to get any desired combination of gear
ratios. Over a hundred gear ratios are available. The transmission weighs only approximately 45 pounds.
Suspension
The narrowed Triumph Spitfire steering rack is mounted on a very robustly braced structure.
Its mounting height is easily adjustable to eliminate bump steer.
CC Motorsports fabricated upper A-arms have Heim joints to facilitate caster and camber adjustment.
Front and rear anti-sway bars were custom designed and made by CC Motorsports. The necessary stiffness
of the bars was estimated with a computer model that considered corner weights, wheel rates, etc. The
front bar's stiffness is about 400 pounds per inch. The rear bar is adjustable from around 100 to 175lb/in.
Spax adjustable coilover shock absorbers are installed front and rear.
The bottom of the pumpkin is connected to the chassis by an A-shaped link that locates it both
laterally and longitudinally, and also defines the rear suspension's roll center.
Adjustable length upper radius rods and a choice of two forward mounting points on the chassis bracket
facilitate precise alignment of the rear axle and also accomodate dialing-in a little anti-squat.
Ideally suspension brackets should be located at joints in the spaceframe, and aligned so the forces they
apply translate into pure tension or compression loads in frame tubes. In that situation, round tubes are
most efficient in terms of strength to weight ratio. When designers have to compromise and feed loads
into a frame member along its span, that member is subjected to a buckling force. Weight for weight,
box tubing is better than round for resisting buckling. Ginetta certainly had these suspension links
attached at mid-span, although the original brackets have been replaced. The almost horizontal
braces you see behind the shock absorbers, here and in the next photo, were added by Craig.
The rear anti-sway bar's stiffness is adjusted by sliding the attachment of the connecting link,
but that's hidden from view in these photos because the bar extends into the wheel wells.
EverStart lead/acid lawn tractor battery. The car has no charging system, so the battery must have
sufficient capacity to power the ignition thoughout each race. Then, it's recharged in the paddock.
Morris Minor rear axle housing with double bearing hubs and billet axle shafts. Stock BMC 8" drum brakes.
Interior
(left to right) AEM UEGO digital air/fuel mixture gauge, VDO coolant temperature gauge (100-250F),
VDO oil temp gauge (100-250F), VDO oil pressure gauge (0-100psi), and Stack tachometer (0-10400rpm).
Momo steering wheel. Note: the entire steering assembly is adjustable for position and length.
Rather than have a driver's seat per se, the Ginetta G4 has padding that covers aluminum panels.
The TRE "Inline" transmission has an H-pattern gear selector. A sequential shifter is under development.
The transmission is available in both four and five speed versions.
Lightweight pedals make the most of a narrow footbox.
Patterson Enterprises dry sump oil reservoir.
FireBottle centralized fire suppression system.
MSD6AL capacitive discharge ignition system.
When contemporary magazines reviewed the Ginetta G4, they seemed particularly impressed by the doors.
They close securely and they don't rattle.
Land Rover "pudding spoon" door latches are only operable from inside of the car.
It's normal to see exposed chassis tubes when you open the door of a Ginetta G4. However,
this car has rather more than usual. All tubes above waist level in this view are new.
The rearward roll hoop brace is detachable so that the whole rear body section can be removed.
Shoulder harness attachment.
Exterior
The Walklett brothers summed up their approach in an early press statement: "For a small manufacturer
to keep alive he must have a product which doesn't compete with the big boys, is attractive to look
at and drive, and, above all, is competitively priced." (as quoted in MotorSport magazine, April 1964.)
The Ginetta G4 fiberglass bonnet pivots forward for excellent access to the engine.
This is a Series Two Ginetta G4. It has a 6' 8" wheelbase and an 11' 8" overall length. (The Series One G4
looks similar except it has small tail fins and is eight inches shorter in the tail section.)
Ginetta G4, viewed from the rear. (3' 11.5" track, 4' 8" overall width.)
A pin restrains the boot lid on this race car. A keyed lock was usually installed on street-driven cars.
The boot lid opens neatly, plus the whole rear section of the body is easily removeable for chassis access.
This Fuel Safe 8-gallon fuel cell. (This cell is the same size commonly used on Lotus Seven racecars.)
At the 2009 Heacock Classic Gold Cup's SVRA Group 8 feature race, we watched this Ginetta lap
V.I.R. in 2:18.107, for an average speed of 85.24mph over the 3.27 mile circuit. That's a great
debut for a newly restored car. The course workers voted Craig winner of the Optima Battery Award.
Kodiak FX 13x5.5 three-piece modular aluminum wheels (forged centers). Avon ACB10 Sport 7.0/21.0/13 tires.
All photos shown here are from June 2009, when we viewed the car at The Heacock Classic Gold Cup at
Virginia International Raceway. All photos by Curtis Jacobson for BritishRaceCar.com, copyright 2010.
All rights reserved.
| If you liked this article, you'll probably also enjoy these: | |||||
 |
Andy Seward '62 Marcos GT |
 |
Vic Schuster '65 Turner MkIII |
 |
Derek Chima '66 MG Midget |
| You're invited to discuss anything you've seen here on The British Racecar Motorsports Forum! | |||||
Notice: all the articles and almost all the photos on BritishRacecar.com are by Curtis Jacobson.
(Photos that aren't by Curtis are explicitly credited.) Reproduction without prior written permission is prohibited.
Contact us to purchase images or reproduction permission. Higher resolution images are optionally available.