RCA engined Hawkstone

[John Wakefield]

This pic of an RCA Hawkstone has appeared on the IKBA (Real Classic) forum, anyone know anything about it? The poster did not say when the pic was taken, so may not be recent.

[druid]

RCA Hawkstone

John,
I believe the picture was taken at the Kempton Park Autojumble last Saturday, The bike has been up for sale at the last 2 or 3 Kempton jumbles. Far too rich for my blood, I didn't even like them when they were current.

Druid

[John Wakefield]

Thanks Chris, maybe the owner is GRA member & will come on & tell us all about it, maybe not!!

[John Pattinson]

RCA Hawkstone

I did speak to the owner at Kempton and he had a photo of him riding it on display. It was not for sale at the first Kempton that it appeared. He used to be a South Midland ACU Centre Rider but I cannot remember his name!...John P.

[John Wakefield]

RCA engine

More on the 350cc RCA engine fitted to a Greeves roadster

http://www.dolphinengines.co.uk/data/uploads/64.pdf

http://www.dolphinengines.co.uk/data/uploads/69.pdf

[John Pattinson]

RCA Hawkstone

Very interesting John, seems like a much better engine than the Villiers 2T/3T. The separation is the problem with the Villiers, it all gets too hot and bothered if you thrash it! All that nice unit construction looks neat but retains so much heat. Plus this engine has loads of torque unlike the Villiers, I wonder why Greeves didn't carry on with the RCA, maybe costs? Anybody out there know? ...John P.

[Colin Sparrow]

The RCA engine was tested in a Greeves roadster (Fleetwing I think), but it wasn't anything to do with the factory, just a convenient test-bed vehicle.

[John-Boy]

I remember seeing a DOT scrambler with the RCA engine in 1958-9, it was a nice looking bike but terribly unreliable.

http://www.dot-motorcycle-club.co.uk/gallery.htm

There was an article in one of the bike mags that the engine had an inherent design fault, I think it was the crankshaft.
Apart from that, a two-stroke twin is not the easiest thing to ride in mud. One or two Adler 250 twin scramblers were tried about the same time, not very successfully.

[bult360]

Rca

My Father raced a Dot RCA for many years and to be honest it was extremly reliable , the crank was very modern in design and he never had a big end failure . The biggest problem was that it wasnt realy quick enough and lack of suitable pistons , tuning it was limited due to the side facing exhaust ports and in the end we had to cut the one piece cylinder in half and mill extra transfers on the the inside face of the now 2 piece cylinder . It went round the manx with no trouble all week and ended up with a 6 speed villiers box ,lightweight frame and starmaker primary drive before it was stolen !

[greeves246]

Rca d.o.t

colin flashman in st annes chappel callington used to race and still owns a RCA D.O.T he also has the 17th mx1 challenger made were there any recoded wins with the RCA bike also think not sure these were developed in cornwall they were also used as a boat engine (water cooled) with siba dynastart

Seems a long time ago in 1962/63 that the forerunner of the Dolphin Yacht Auxiliary engine was
beating all the competition to win the British Hydroplane Champs two years in a row !! This all done with
a 350 cc engine against the 500cc Konigs etc ! The engine was then producing over 45 bhp at 9000
rpm running on methanol ! Not only that, but it used to go all season with only minimal maintenance
compared to the major regular engine strip downs of the competition.
The internals of this early engine formed the basis of the much derated 12 bhp Direct Drive Dolphin
engine which was produced in North London for several years until the Company was moved to
Bodmin, Cornwall. Dolphin engines have been made in Cornwall for over 20 years now and go back,
when produced in N London, as far as the late fifties. The engine was originally designed as an air
cooled unit for use in the small Berkeley 3 wheeler car and later in a motor cycle scrambles machine
From this came the Hydroplane engine referred to above and then, after a brief excursion into outboard
manufacture (never actually in production) the Direct Drive was born. This only after the Mark IV (with
decoupler-no clutch) and Mk V ( Mk IV with centrifugal clutch, both using a 2:1 reduction gearbox to
reduce prop speed) were found to be too powerful for the application at the time. (Stellas etc ).
Production was fairly steady with no shortage of customers right through from 1966 to 1977, then the
small Japanese diesel appeared and sales fell away quite dramatically ! Obviously yachtsmen did not
seem to mind having their fillings loosened !!
Not to be deterred by this, and quite rightly assuming that there would always be a small market for
petrol engines no matter what, myself and the original designer of the engine, Peter Hogan, purchased
the remains of RCA Engineering (R Christoforides & Associates), from the Receiver in 1978 and
continued to date to produce engines in small quantities and provide a spares and repair service for
existing, and new, owners.
In 1986 I redesigned the engine, using all the well proven internals, to become the new Series II. This
removed the dynastart and the sailing clutch, did away with the need to stop and restart the engine to
go astern, brought the water pump to the front of the engine, and introduced a 2:1 gearbox, electronic
ignition and an alternator. Conventional single lever control to the Hurth gearbox to move ahead or
astern. Being petrol powered response is now instantaneous!!
This

just for your interest

[Colin Sparrow]

were there any recoded wins with the RCA bike

I'll keep an eye out for it as I research the sixties in the motorcycle journals. During which years was it racing?

That's an interesting post - stunning what connections a forum can make!

[johnrunnacles]

More likely need to look into the late 'fifties, Colin.

I seem to recall the Rickmans having some success on RCA-powered DOTs around about 1958.

Good luck!

John R

[trialrider17]

RCA engined Hawkstone

I know the owner quite well he raced in South Midland Centre in late 50s and early 60s on this bike.He then went on to sidecar grasstrack.The RCA is in the next Cheffins Auction 27th July.Cheffins advert in this months OBM has a photo of him riding the bike in 1959.