Wednesday, 25 May 2011

Shorrock Supercharger Metering Pins

The Shorrock Supercharger is lubricated with engine oil supplied via a connection at the oil pressure take off switch on the left hand side of the engine block.

The supercharger operates a total loss system, but the amount of oil used is carefully controlled via the selection of a metering pin located in the rear of the Shorrock. The metering pin sits in a 5/16" bore. The choice of pin will be dependent on several factors, such as engine oil pressure and the viscosity of the engine oil.

The largest pin is 0.311" and is stamped on the end with an "A". The pins decrease in diameter 1/2 thou at a time, so the next size down (stamped "B") is 0.3105" and the one after that (stamped "C") is 0.3100".

I just removed the metering pin from my Shorrock stamped "L" (0.3055") as the oil consumption (obvious in the blue exhaust smoke and sooted up spark plugs) was way too high and replaced it with a pin from my earlier Shorrock stamped "A" (0.311"). With any luck that will do the trick.


As a reference, here is a list of the metering pin sizes that can be selected -

StampedSize
A0.311"
B0.3105"
C0.310"
D0.3095"
E0.309"
F0.3085"
G0.308"
H0.3075"
I0.307"
J0.3065"
K0.306"
L0.3055"
M0.305"
N0.3045"
O0.304"
P0.3035"
Q0.303"
R0.3025"
S0.302"
T0.3015"
U0.301"
V0.3005"
W0.3"
X0.2995"
Y0.299"
Z0.2985"


Sunday, 22 May 2011

Something for the Weekend

After a chance discussion on the Isle of Wight a few weeks ago, this turned up on Thursday -


It appears to be in fair condition, but the only way to tell is to fit it and see.

Prior to installation, the manifold bolt threads have been cleaned out, new bolts sourced, made new manifold gaskets, switched over the pulleys, swapped the oil feed adapter, cleaned out the metering pin and flushed the internals with petrol.


After a lot of cursing, eventually got the shorrock installed with belts and manifolds. Battery is now on charge for another attempt at firing up.


Throughout the whole process, I've been ably assisted by Callum who was having more fun blowing up rubber gloves.