boat owner

M

y Bénéteau Océanis
381 Sacha, like other,
similar boats of its
age, was fitted with
the Volvo Penta
MD22L, a 50hp diesel engine. This,
and its derivatives – the TMD22 and
TAMD22 – were based on the Perkins
Prima engine, which was developed
for British Leyland’s Maestro and
Montego cars. It was also fitted to
the LDV 200 van.
The important factor for us is that
most of the spares for these vehicle
engines fit our boat engines. They
are a lot cheaper than VP parts! The
LDV 200 van engine in particular is
closest to ours, with the freshwater
pump and in some respects the starter
motor being the same. The difference is
that VP used a cable battery negative
return, ie the block isn’t connected
electrically, so earthing for the starter
and alternator is achieved by separate
cables. The glow plugs utilise a strange
system: they are earthed through the

block, so there is a relay in the system

that temporarily earths the block while

the glow plugs are used! The relays

and control box for this can usually

be seen on the aft port side of the

engine. In an emergency, I suspect

that an (early model) LDV 200 van

starter etc could be pressed into use,

but some serious temporary wiring

would have to be done.

The compression ratios were subtly

different in the various forms of engines,

ranging from 17:1 (MD22L) to 17.5:1

(TAMD22) and 18:1 (MD22P and

TMD22). The compression ratio on

the Maestro turbo is 18:1: mine is

17:1, not enough difference for me

to worry about.

The injector pump is a basic Bosch

EPVE. (The Bosch VE has been fitted

to millions of vehicle engines, so it is

familiar to most injector and pump

service shops.) The injectors are the

single-injection kind, known to all

injector workshops and simple to

test and service.

Sourcing an engine

Vehicle spares, as I have said, are a lot

cheaper than VP spares, and over the

years I have taken advantage of that fact

to service my engine cheaply and also to

write articles on which parts fit, where to

find them and how to fit them. Sacha is

now 16 years old, and so is the engine.

Consequently, the vehicle spares are

getting harder to find. (How many

Montegos and Maestros do you see

on the road nowadays?)

I knew from the green paint on my

engine fasteners that it had never been

apart: and while it was still going as well

as ever, at some point a rebuild would

be required. While engine parts are

still available at a reasonable price,

I decided to look for a second-hand

Prima engine so that I could rebuild

the basic block and cylinder head as

The

cylinder

head was

the first

thing to

come off

PRACTICAL

Stu Davies bought an oily Perkins Prima lump from

an old Austin Rover Maestro to use as a spare engine

for his boat: here, he explains his reasoning and

carries out a timely strip-down and rebuild

Over to you, Maestro