18-24 Rallycross Bug

1303 RALLYCROSS BEETLE 1303 RALLYCROSS BEETLE
The Retro class sounded perfect for James Harrold
from Great Ellington, near Attleborough in Norfolk,
as he and his father, Paul, had the Beetle you see here
sitting in a barn. Now, you don’t just have a car like
this sitting there for now reason, and in this case it
is because the Harrold family has been involved in
Rallycross for a very long time. This car is the last in a
line of VW Beetles campaigned under the PPJ Rallycross
Team banner. As Paul explained, “It all started in
the early ’70s. My late brother, Peter, raced in the
BTRDA (British Trial Drivers’ Association) and Castrol
Championships, along with the European Rallycross
Championship in Beetles. They used normally
aspirated, 2.1-litre, VW-based engines, which were
competitive at the time.” So, what is PPJ, we asked?
“PPJ came from the three people involved: Peter, myself
and the late John Worzencraft.
“We first built this 1974 1303 in about 1983. It started
out as a turbocharged, air-cooled flat four, but we had
a lot of problems with cylinder heads. We tried every
head available, from re-worked VW heads to various
performance heads, such as those from Scat. But
because it was blowing quite hard (by this Paul means
the turbo boost was very high) the heads always got too
hot and knocked valve seats out. We also had issues
with cylinders splitting.” It was clear to be competitive
they had to find a way of building a reliable VW-based
engine that could withstand high levels of boost.
The Lotus connection
The answer came from a friend, Trevor Chinn, a
development engineer at Lotus Cars in nearby Hethel.
Paul explained: “Trevor felt we had to have watercooled
heads to keep the cylinder head temperature
down. At the time, Subaru was campaigning the Legacy
in the WRC, with cars built by Prodrive. These cars
were making a lot of power, and a rally stage is a lot
longer than the three- or four-minute races we were
doing. Trevor found there was only 1mm difference
in the bore centres of the Legacy heads, and felt they
could be made to fit. It was a lot of work though, and
took over 18 months.” At this stage you need to take a
deep breath and get ready for some serious technical
wizardry. The first thing to take into account is the
Subaru heads feature two overhead cams per side, as
opposed to the single in-case VW cam, which drives
the valves via pushrods. The engine is based on a Scat
three-piece crankcase, which has two halves and a
bolt-on front section. The front part was binned and
an aluminium plate made that incorporates crankdriven
take offs to drive the four overhead cams, as
well as take offs for the oil pump, Ford Essex V6 water
pump and Audi power-assisted steering pump. As
the VW camshaft, lifters and pushrods were no longer
required, Trevor designed two 13mm blanking plates
that were bolted to each side of the case. To cure
the issue of cylinders splitting, the team made their
own barrels from 500cc Jawa speedway bike cylinder
liners, machined down and sleeved into Porsche
911 barrels. They measure 90mm ID and use Sierra
Cosworth pistons and rings, as well as copper sealing
rings between the head and cylinders. The cylinder
machining work was done by Trevor Hedge Racing, a
speedway bike specialist in Bawburgh, Norfolk.
The Subaru connection
“We contacted Subaru in Japan and explained what we
wanted to do,” continues Paul. “They were very, very
helpful, and supplied all of the parts we needed – the
heads, cams and hydraulic tappets.” The crank is a
Scat forged 82mm stroker, which was supplied by Geoff
Thomas at the now, sadly, defunct VolkSport. With
the 90mm pistons, this means the engine is 2087cc.
Fuelling is supplied via a Zakspeed mechanical fuel
injection set up that features a rack that takes care of
boost enrichment. The turbo is a Garrett T4, on the
subject of which Paul told us, “It’s out of date.
The T4 is a plain journal bearing turbo. The
advances in turbocharger technology mean
today they use ball bearings, which spool up a
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TECH INFO
Body: 1974 1303S
Beetle; glass fibre
wings, bonnet
and boot lid;
PPJ rear spoiler
with integral
intercooler
Engine: 2087cc;
Scat three-piece
‘Killer Case’;
Scat 82mm
forged crank; PPJ
90mm hybrid
Jawa/Porsche
barrels; Cosworth
pistons and rings;
Subaru Legacy
DOHC watercooled
16-valve
heads; Zakspeed
mechanical fuel
injection; Garrett
T4 turbocharger
Gearbox:
Hewland
DG300 5-speed,
magnesiumcased
gearbox;
ratios dependent
on circuit
Suspension:
PPJ A-arm
conversion front
and rear; Bilstein
B16 PSS Mk2 Golf
coilovers with 9 /
10-point damping
and rebound
adjustability
Wheels and
Tyres: 9 x 15-
inch Revolution
five-spoke alloys;
Avon Racing
ACB11 215/580-15
Rallycross tyres
The Harrold Beetle is back, and has been instantly
competitive in the Ripla Retro Rallycross class.
Having around 600bhp on tap helps!
Naturally, the Beetle has
great traction on the loose
The Hewland gearbox and Garrett
T4 turbo are accessed through a
removable panel in the rear
Last minute adjustments before the next round
“We had to have
water-cooled
heads to keep the
cylinder head
temperatures
down”
Rallycross is dirty business, so a
huge air filter is mounted in the car
Not one, but three temperature gauges
Although now
defunct, the old
sponsor, Volksport,
was added to the
new livery
James mentally preparing for another wild ride
A Porsche 911 fan is used to cool the cylinders,
but the Subaru cylinder heads are water cooled
James Harrold waits in line to head out
onto the track behind Ray Morgan’s RWD
Mk3 Escort with 2.0-litre Ford BDA power
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