Rochdale Olympic - Ford Overhead Valve Engine Options

Introduction

This section covers the range of Ford overhead valve 4 cylinder engines that was available during the nominal Olympic manufacturing period of 1960 to 1974. It does not include the side-valve engine which was an option for a very short period after the Olympic was launched, nor the Lotus twin cam derivative. The engines under review were generally manufactured at the Ford plant in Dagenham.

Also excluded is the range of similar engines using the collective description 'Valencia' after the plant in which they were made, as they are outside the defined time range and intended for front wheel drive applications only and not interchangeable.

The objective is to outline the similarities and differences between the various types covering displacements from 997cc to 1598cc and to provide information relevant to the maintenance of overhaul of these types. The information is targeted at the detailed specifications of the engines at the time of their manufacture, but where appropriate, updated information is also made available.

All the engines share the same overall construction concept with cast iron crankcases and cylinder heads, a pressed steel sump, two valves per cylinder operated by pushrods, oil pump and distributor drives taken from a skew gear on the camshaft between cylinders 1 and 2 and a mechanical fuel pump driven by an eccentric on the camshaft between cylinders 3 and 4.

In each case the nominal cylinder bore is 3.19" (80.97mm) with the various displacements being achieved by varying the stroke.

The 997cc, 1200cc and 1340 cc versions have three main bearing crankshafts whereas the remainder has 5 main bearings.

Firing order is 1243.

 

The 1340cc version is generally considered to be the least desirable due to its imperfect balance, and hollow crankshaft (in early production) resulting in relative fragility and poor refinement. It also restricts the potential for significant levels of uprating. However, to put this into context, Cosworth developed a version delivering in excess of 105bhp.

Prior to mid 1967, the engines featured conventional bathtub combustion chambers in the cylinder head. Later variants had 'bowl-in-piston' combustion chambers with flat-faced cylinder heads or in some versions small machined recesses in the cylinder head face. These are the 'crossflow' (XF) engines, so called because the induction system is on the right hand side of the engine and the exhaust on the left. The pre-crossflow (PCF) engines had both induction and exhaust systems on the left hand side of the engine.

In many instances, low compression engines were made available for export markets and commercial vehicle applications but these are excluded from this chapter.

Nomenclature

This is sometimes confusing as Ford used the designation '1XXE' to denote both engines and car models as summarised below:-

It is therefore important when discussing details to differentiate between the two and check the specifics of a particular engine especially since they are essentially interchangeable at a unit level or by substituting cylinder heads between different capacities or even using a crossflow crankcase with a pre-crossflow cylinder head.

When the crossflow engines were introduced, they were designated the 'Kent' series, but latterly the term has been applied, retrospectively, to the pre-crossflow range as well.

The bowl-in-piston concept is sometimes referred to as the 'Heron' head after its inventor.

Conventional motor industry definitions are used with cylinder numbers counting upwards from the front of the engine and 'left' and 'right' being referenced to the centre line of the car in the direction of the seated driver.

In the table below, data is listed in engine capacity order: 997/1200/1340/1500/GT for PCF and 1300/1600/GT for XF.

1) Ford offered pistons and rings for up to a 30 thou overbore, but aftermarket pistons up to 90 thou overbore are available for use with thick-wall block castings.

2) The block identification number is cast on the RHS of the crankcase above the breather outlet. On later engines this might be obscured by the PCV system separator tank. The 105E block is less strong than the 109E variant and some of the fasteners used with it (eg for the generator mounting bracket) are smaller. The most desirable 1500cc blocks originate from the early MkII Cortina period. Designated 'L block' they have thicker walls than earlier versions and a conventional crankshaft oil seal rather than the asbestos rope type used previously. They are less prone to oil leaks.

3) The cylinder head casting number is on the underside of the head below the thermostat housing, requiring a mirror to read it in situ.

4) The figures given for the PCF are for setting under 'cold' engine conditions. The 'rule of nine' applies. On worn engines it often proves difficult to achieve the correct clearances, resulting in noisy operation. Under these circumstances the rocker gaps should be set with the engine hot and idling when it is easier to detect a slight 'nip' on the feeler gauge when the valve is fully open. In this situation , the gaps are 10 and 17 thou for non GT and 14 and 21 thou for the GT - inlet and exhaust respectively.

5) High compression engines only. Some engines had minor variations from these figures.

6) High compression engines only. Some engines had minor variations from these figures.

7) High compression engines only. Some engines had minor variations from these figures.

8) Early 997cc engines had a Solex ZIC-3 type carburettor which was replaced after a year with a B30 PSE type. This has an accelerator pump to eliminate the flat spot that was associated with the earlier version.

9) 997cc engines had a small diameter pump with a metal cover over the filter screen. Later PCF engines had a larger diameter pump with a glass bowl over the filter screen. These may be fitted to the earlier engines. Note the delivery pressure for the Weber carburettors is higher than that specified for Zenith/Solex types (see chart above) and so checking for the correct pressure is recommended. Excessively high pressures can be reduced using 'Petrol King' types of device.

Later crossflow engines featured a Ford-sourced equivalent of the AC-Delco pumps, with metal filter covers.

10) Three styles of Lucas distributor cap were used, each designed for 7mm OD HT cables. The early type had the cables exiting horizontally to the rear. Contact with the copper conductor was effected by insulation piercing screws from inside the cap. This type of cap is generally reliable. The second type has the HT cables exiting vertically. Brass washers are located on the end of the copper conductors and then knurled collars are screwed into the cap for retention. This is not a reliable design as water tends to collect in the cable retention towers and the brass washer, copper cables and steel insert corrode. Also the phenolic material used to mould these caps has a high percentage of wood-based fillers which are hygroscopic and cause tracking and breakdown. This is the cause of the legendary 'won't start in wet weather' reputation of Fords from this period. If this style of cap is preferred, modern replacements are available in epoxy, and rubber boots can be fitted over the knurled collars to prevent water ingress into the towers.

The third type of cap was designed for resistive cable terminated with a crimped brass connector which pushes into the cap and is retained with a friction-fit rubber boot over the tower. This style of cap is generally reliable.

All the early Lucas distributors used rotor arms moulded from phenolic material which suffered in the same way as the caps. The brass conductive element was retained by a rivet which created high dielectric stress and possible breakdown. These should be replaced with modern epoxy rotors which are usually moulded from a red coloured material.

The Ford/Autolite/Motorcraft distributors do not suffer the problems summarised above and used either 7mm or 8mm OD resistive HT cables.

Access to the distributor on XF engines can be very restricted when dual side-draught carburettors are used. The Lucas horizontal lead distributor cap can help here but even so, checking the points becomes impracticable and it is recommended that electronic ignition is fitted (eg Lumenition Magnetronic). Alternatively Ford 'electronic' distributors from the Valencia engines can be used.

11) Set by aligning a notch in the front pulley with a mark on the timing chain cover. Early engines had one mark at 10deg BTDC. Later engines indicated 12deg, 8deg,4deg,0deg BTD. Note: compromise timing is best established by trial and error as regular unleaded petrol has a lower octane value than the leaded fuel for which these engines were designed, and fuel is now en-leaned by the presence of alcohol. Without re-mapping, advance the timing such that the engine just starts to knock when hot with wide open throttle in top gear from 30 to 40 mph, and then back off by 2deg.

12) Originally Champion N5 and N4 plugs were specified, to be replaced by N9Y and N7Y projected nose versions. The latest evolution of these in the Champion RN9YC and RN7YC which are copper-cored and contain an internal suppressor resistor. These are becoming rare as Champion has retreated from the UK market and a good alternative for the N9Y is the NGK BP6E

13) The later cartridge type of pump is a direct substitute for the replaceable element version. Filter types are Ford EFL 500, Halfords HOF 264, Filtron OP269, and Fram PH966B.. Sandwich plates are available for fitting between the pump and the filter to provide connections to an oil cooler.

To change an oil pump in situ in a phase 2 Olympic without releasing the engine mounts, the pump end cover must be removed to provide sufficient clearance to withdraw/insert the drive gear.

14) Anything above 35psi hot at 2000rpm and above 5psi at hot idle is normal. If something above 40psi is preferred, a quarter inch spacer can be fitted under the pressure relief valve spring (accessible in the oil pump mounting face). For competition use, high pressure and high capacity versions of the pump are available.

Phase 2 Olympic engine removal from car.

First disconnect the battery from the car and remove it if its position is likely to interfere with the engine removal.   Remove the bonnet from the car and put in a safe place for storage. Drain the coolant from the cooling system, this can be done using the block drain on the engine located just under the exhaust manifold. Undo and remove the bottom hose of the cooling system and collect the remaining coolant in a suitable container. Remove the top hose from the engine/radiator. Undo and remove the heater hoses if the car has a heater.   Remove the fuel line from the carburettor and secure it out of the way under the nearside wing. Remove the choke and accelerator cables from the carburettor and secure them out of the way. Undo and remove the exhaust downpipe from the exhaust manifold and support the exhaust under the car. Undo the exhaust manifold nuts and remove the large washers holding the exhaust/inlet manifold in place, the exhaust/inlet manifold can now be removed and stored in a secure place.   Moving to the drivers side, remove the plug leads from the spark plugs and remove the distributor by undoing the pinch bolt on the distributor housing. The low tension wire from the coil should also be removed from the distributor at this point.   It is now possible to get at the starter motor from the engine bay. Remove the starter main feed cable on the starter by undoing the brass nut on the back of the starter main body and secure it out of the way. Undo the two bolts (one top and one bottom) on the starter and remove the starter from the engine. Note the later XF engines had 3 securing bolts for the starter.   On the passenger side of the car, remove all electrical connections to the dynamo.   On the drivers side of the car, remove the wire to the water temperature sender. Remove the small bore capillary tube for the oil pressure gauge and place under the front wing for safe keeping.   Undo the engine mountings from the brackets on the inner wings, these are generally held in place with 2 5/16"" UNF bolts and nuts, leave the nuts in place until you are ready to lift out the engine.   The engine in the phase 2 can be removed with the gearbox attached so it is now necessary to turn your attention to the gearbox ancillaries. Firstly from inside the engine bay remove the hydraulic clutch flexible hose and put it in a safe place for storage.   With a suitable jack lift the front of the car off the ground and support the weight on axle stands. From underneath the car, support the back of the gearbox using a suitable method and undo the bolts holding the gearbox mounting to the car and gearbox. Remove the gearbox mounting making sure that the gearbox is supported. Undo and remove the speedometer cable at the gearbox end. As the prop shaft is on a spline located in the gearbox extension housing it is policy at this point to drain the gearbox oil into a suitable container to avoid it spilling out of the gearbox extension once the prop shaft is removed.   From inside the car remove any trim etc to enable you to remove the gear lever and remove the lever.   With a suitable lifting strap it is now possible to lift the engine and manoeuvre the engine/gearbox up and forward to slide the prop shaft out of the gearbox, once it is free you can carefully lift the engine and gearbox, you will need to gently lift and pull it forward to clear the engine bay and front inner mouldings before eventually lifting it clear of the car. Once out the engine should be fitted to a suitable engine stand for safety/rebuild.

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