MG Enthusiast – July 2019

http://www.mgenthusiast.com MGEAUGUST 2019

Tuning Guide

63

further than 1430cc. A feature in

Cars and Car Conversions magazine,

from December 1971, examined

the work of Graham Cooper Racing

in Birmingham who had managed

to produce a 1520cc and a 1556cc

A-series engine. The latter was

used for sprinting and would rev to

9000rpm. The problem with most

of these engines was reliability;

very long stroke cranks have a

tendency to break and overboring

the block to the limit means that

the cylinders get closer together,

causing problems with head gasket

failure. Big capacity A-series

engines became less popular.

But now they are back and readily

ABOVE: One of the key areas for attention, with any large
capacity A-series/A-plus engine, is crank and rod big-end to
block clearance. Despite the long stroke crank there is plenty
of room in the 1380 cc A-series cylinder block.

ABOVE: Clearance can also be a problem at the bottom of the

cylinders. Careful rod design and the short pistons eliminate

any problems here and no modification should be needed.

ABOVE: Here you can see that the crankshaft is held in position in the cylinder
block by a set of steel main caps. The centre cap is of four-bolt design.

A close-up on an end

main cap. High tensile

bolts and special EN24T

washers are used to

secure the caps to the

block. The cylinder

block and caps need to

be line-bored before

the crank is fitted.

ABOVE: This is an example 1460cc unit

being built by MED of Leicestershire.

Components can be supplied for

self-build but, bearing in mind the

value of the components, you will need

to be a competent engine builder!