Cosworth Conversion


After the original engine developed some running problems I decided to hunt out a new powerplent for it. 2.0ltr Pinto's are now getting harder to find which suprised me at first but the last car to roll out of Ford with one fitted is now rather old itself. The engine is a favourite with the banger racers and as most scrapyards are run by such people, the engines it appears now tend to get hoarded by them. That's what I found where I live anyway.

However, all was not lost as I heard of a '92 Granada Cosworth going for sale near me for not very much. A deal was struck and I became the new owner of a range topping motorway cruiser, which I immediately set to with an angle grinder! (there was something strangely soothing to the notion of willfully cutting up a car that probably cost it's first owner more than I earned in that year!)

So, with a quick flury on ebay to shift some of the left overs (interior and wheels) and a nice set of brake callipers and master cylinder now stashed away in the garage for a future project, I set to with taking my old pinto out and slotting the Cosworth V6 in.

2.9ltr Cosworth V6 ----Mk5 Ford Cortina----2.0ltr Pinto (at an angle)



The Cosworth developed 24valve quad cam 2.9ltr Ford Cologne V6

This engine is a develoment of the 12 valve 2.9ltr EFi Cologne V6 as found in the later Sierra's and Granada's. The engine was apparently initialy developed for motorsport use in the Pro-Sports 3000 single seater series by another tuning company called Brian Hart Ltd. Cosworth it turns out bought the rights to this company in 1987 thus inheriting the engine development program.The engine was then detuned and domesticated before being slotted into the top of the range mk3 Granadas in an attempt to take on the BMW 5 series. The reason behind the de-tuning of the engine was down to traction problems. The engine was never fitted to any other model and was always attached to a modified electronicaly controlled version of the Granada V6 automatic gearbox. Because of this, the engine is set up to favour this transmission and it is said that there is a noticable increase in power and torque above 3,000 revs.

Power - 195bhp @ 5750rpm
Torque - 191lb.ft @ 4500rpm

Although based on the 12valve 2.9ltr Cologne V6 there are no interchangeable parts with the exception of the main crankshaft bearings (not including the thrust bearing). Even the block casting is different, apart from the obvious lack of push-rod openings the cosworth block features additional and beefed up internal webbings to increase rigidity.

This Cosworth engine, named the BOA, was further developed itself later on to create the BOB. This newer engine featured among other things a re-designed plenumb, revised cam profiles, a different timing chain arrangement and a variable resonance induction system. It also featured a new engine management system which incorporated the 'PATS' system which is a security/immobiliser system requiring the correct encoded ignition key to be used to dissable it. This makes the fitment of this particular engine a bit more complex if you are using it's original engine management system and so the BOA is presently the preferred choice for ease of conversion.


The Conversion!

So, here's how I've been doing it including some hard to find information on the electrical side:


What's Required & Why

Parts Preparations

Engine Installation

Induction System

Fuel System

Cooling System

Exhaust System

Heater Box Modification


This is the bit that gives most people the fear about such conversion. I have to admit that information was rather thin on the ground on the internet regarding this part of the conversion and I ended up spending a lot of time with various books, diagrams and a multimeter to collate all the information in one place and present it here in the following pages. I'll start with the Pin-out list for the ECU:

ECU Pin-Out List

Print the above list off and keep it to hand whilst carrying out the next part, installing the engine loom:

Installing the Wiring Loom

That just leaves tidying up of loose ends. As mentioned in the above sequence, the Rev counter will not work with the new engine and so a hybrid unit nees to be made. Take a look below for details:

Rev Counter

And just to recap (and for completeness of the Electrical section), here's a link to the alternator page:


That I think should just about cover it!