As part of the ongoing development Northampton Motorsport has carried out back to back testing on Ford Duratec engines and 1800cc Zetec engines to allow us to gain solid performance data for these upgrades.  The Vauxhall XE heads have already undergone the same tuning and verification process with another respected tuner who has seen over 285BHP with his ultimate spec engine using one of these heads.

1800 Zetec test

The engine used was a standard 1800cc Zetec engine in a customers Westfield.  The engine was run on the dyno to provide some starting figures and made 153 BHP @ 6600 rpm and 137 Ft/Lbs of torque at 4700 rpm.  These are fairly typical figures for an 1800 running DCOE carburettors, 4 branch manifold and the higher spec Ford cams that were fitted to the last Escort XR3i’s and Fiesta RS 1800’s.

Once a baseline figure was established the standard head and cams were removed, the valves stripped out and cleaned up ready to be lapped into the new head, new springs and followers were also fitted at this point.  The inlet and exhaust manifolds were also matched to the head as the original fit was not good in this car. To top off the conversion a pair of piper 285 cams were also fitted.  Once back on the car the engine was started and the cams ran in for 20 minutes.  Even with the cams timed in on the standard settings the first run showed a significant increase and once fuelling and cam timing was optimised a final figure of 183 BHP @ 6700 rpm was achieved with torque up to 156 ft/lbs at 5010rpm.

The most pleasing thing about this conversion was that there was no loss of torque below 4500 rpm which is often found when just upgrading cams alone.

Duratec engine test

Again, in a customers Westfield we carried out an initial power run to establish a baseline against which to compare any gains.  This engine only managed 167 bhp which was quite low for a 2 litre Duratec.  Part of the reason for this was that the car was run with the bonnet on and we subsequently found that the air filter was being pushed up against the number one cylinder intake trumpet and heavily restricting airflow. 

As this was the first Duratec conversion we had done we decided to remove the engine before stripping off the head as the engine was also having ARP rod bolts and an oil cooler fitted.  Once out of the car the head was removed and replaced with the ultimate ported head along with cams, springs and retainers all to Simon’s spec.  Once the valve clearances had been set with new graded followers the head was refitted and the cams timed in.  The engine was then refitted to the car.  At this time we also decided to replace the standard exhaust with a one off 4 into 2 into one system along with a tech craft silencer.  A deeper filter was fitted and a hole cut into the bonnet to give clearance for the filter.

The engine was started and again the cams run in for 20 minutes.  As this engine was on throttle bodies the ECU was fully remapped to ensure the best power and torque delivery throughout the rev range.  Although the cam spec was as aggressive as the standard pistons would allow it was possible to achieve a smooth idle and progressive throttle response at all engine speeds.

Peak power was up from 169 to 227.4 which was a massive 58bhp gain and torque increased from 147 to 174 ft/lbs of torque.

This was all achieved whilst retaining the standard bottom end engine assembly (apart from fitting the ARP rod bolts).  This spec of head has produced over 290bhp on an all out competition engine with all steel bottom end wilder cams and pocketed pistons, which just goes to confirm the power producing potential of these heads 

We plan to have a full menu of prices on the page as soon as possible but in the meantime please contact Troy on 01604 766624 for more information.