Ford SOHC (Pinto) Tuning Guide
Introduced by Ford in 1970, the Pinto was one of the first production engines to carry the cam on top of the head, driven by a toothed belt.
There are two main versions - Cortina / RS2000 and Sierra. The latter was mostly unleaded.
The Pinto was manufactured in Cologne and was naturally fitted to many German cars such as the Taunus, including the 1293cc version also fitted to early Sierras. The most common to us are the 1593 and 1993cc derivatives. A 1796cc version was introduced in mid-life Sierras and an E-Max 1.6, introduced in 1984, sharing the 1.8 and 2.0 litre rods.
You're likely to find a Pinto in Mk3 / Mk4 / Mk5 Cortinas, Capris, Mk1 / Mk2 Escorts, Granadas and Transits. All engines have a rear-bowl sump with the RS2000s being alloy.
The engine is crossflow type with the carb on the right, exhaust left (when viewed from the front). Cam geometry can be a problem so it's recommended to use a complete kit to ensure components match, such as the ones we stock by Kent. The non 2 litre engines are particularly troublesome in this area so we wouldn't recommend fitting anything more than a base, mild / fast road cam in these. A new spray bar is also valuable insurance on any engine.
As usual, the 2 litre is the tuner's favourite with the 205 'Injection' block being the most suitable base - these are better at taking the maximum re-bore of 93mm and are most suited to 2.1 litre conversions. Cortina blocks usually have the capacity in small numbers on the side - 16 and 20 respectively. Later Sierra blocks have 165, 185 and 205. The early Cosworth YB also used a 'selected' 205 block.
It is fairly common to use 2.8 V6 pistons coupled with a 93mm bore but traditionally, machining is involved - the block needs decking, whilst the rods need the small ends narrowing. We stock Accralites especially for this purpose, which removes the need for additional machining.
Skimming can raise compression to a 10.5:1 maximum and beyond this you'll need forged pistons, to a safe 12.0:1. It is best to check the size of the combustion chamber on any used head by having it cc'd first. This not only guarantees the compression but can also help with checking the valve to piston clearance too, which can be an issue with previously skimmed heads.
The Pinto's crank is able to out-rev the rods, which can be a weak link - 7500 is the absolute maximum we would recommend, although this really only applies to the later wider injection rods, which are stronger than the early type.
The 2 litre heads have massive ports to start with so good gains can be had by merely fitting a Kent FR32. Even the best standard Pinto carb a 32/36 DGAV twin choke, is enough to power the engine to 135bhp. Our Stage 1 heads, suitably set up, will reach these levels and feature proper valve guides in place of the standard cast-in type and raised compression. All our heads can be ordered ready converted to run on unleaded fuel.
After this level, the next step is side draughts and it's best to go straight to 45 DCOEs since the inlet ports are huge. 44 IDF down draughts are a good alternative, but they are much more expensive.
Add a Kent FR33 and our stage 2 head and you should see 150-155bhp. Beyond this and you're into fast road bordering on race, which means, depending on carb size - 48s and even 50s - you should be seeing an easy 185-200bhp, plus.
At this level, we would only recommend steel components for reliability because you're on the limit of standard type components. We stock Farndon Cosworth YB cranks for this purpose, which is essentially the same except that it carries a 9 bolt flywheel fixing instead of the standard Pinto bolt pattern. We also stock special Pinto 9 bolt flywheels to match. However, on this point, if you use a Pinto crank it is advisable to have it double-dowelled for safety - it can shear! We also stock std length steel H-section conrods to match this crank as well as YB length rods which are 1.5mm longer.
A great engine with loads of potential.