XR4Ti Archived Tech Articles
Post Date: Fri, 14 Jun 2002 Subject: N/A List: N/AVolvo B234F Head Conversion for 2.3L OHC Ford
The cylinder head off a Ď89 - Ď90 Volvo 740GLE B234F engine can be used on the Ford 2.3L OHC short block, commonly seen in a turbo configuration in the 1980ís Turbo Mustangs, SVO Mustangs, Merkur XR4Tiís, and Thunderbird Turbo Coupes. This is an effort to provide one solution, out of many possible, to clearly guide one through the conversion process. The B234F Volvo engine may have also been available in a '91 940GLE sedan or wagon. Early B234F engines had a mechanical cam belt tensioner. Later ones had a hydraulic tensioner. A head off of either engine will work as described below for this conversion.
In addition to the cylinder head modifications detailed below, intake and exhaust manifolds will have to be constructed as the stock Ford 2.3lt. manifolds will not fit. There was a turbocharged Volvo engine but the manifold is not suitable to this conversion as it places the turbo in the same location as the Ford starter. The head to manifold flanges and the parts of the individual runners containing the injector mounting bosses can be used from the Volvo intake but the runners will have to be angled up to clear the left hand drive brake hardware.
Overview and General Considerations:
Familiarity with every component is the key to success, so direct your attention to the Ford block, Ford and Volvo heads and head gaskets, the engine coolant systems, oil supply systems, fasteners, factory recommended maintenance (especially with regard to the Volvo cam tower sealants), valve train systems and components (including cam gears, belts, tensioners, their relative alignment with each other and the block, and piston-to-valve interference points).
Volvo Engine Overview:
740 Engine four cylinders gasoline engines: N/A 8v - 114 HP, Turbo 8v - 160 HP, N/A 16 valve: 153 HP
Volvo 16v flow (with the stock .430 cam and port matching): 240 cfm [unverified claim]
Esslinger Engineering aluminum head flow (with a .585 cam at 6500 rpm): 260 cfm
Stock Combustion chamber volume = 53cc
Volvo head maintenance: Breakdown of the gasket sealer (used in place of gaskets) on the Volvo 16V cause oil leaks onto the cam tower faces; solution - reapply sealer every 40K-50K mi.
Head fastener info:
head bolts 14mm.
manifold nuts 13mm
support bracket for intake 12mm
timing cover bolts are 10mm and 12mm
water pump pulley 10mm nuts
valve cover 10mm
the best tool for the intake nuts is a ľ" drive ratchet, extension, and 13mm swivel socket
Torque Specs: xx
Valves: The 16v is a N/A head and if turbocharged, the valves, especially the exhaust, should be changed. There is room to install larger valves, the stock sizes are 34.5mm intake and 31.5mm exhaust. Oversize valves up to 36mm on the intake and 34.5mm on the exhaust can be used. New cam buckets arenít needed for the conversion, but can be obtained.
Head Comparison: The Porsche-designed Volvo head, is noticeably shorter than the Ford. Fordís combustion chambers (and cylinders) are evenly spaced, the Volvoís are not. The head bolt locations, two of the three oil return holes, and some of the water passages holes match exactly and the others can be matched.
Oil: The Ford head receives oil from the rear, the Volvo from the front. Run a line from the pressure side of the pump, from the back of the block, where thereís already a tapped line, to the side (preferably the front) of the Volvo cam tower assembly. The actual cylinder head itself does not require any pressurized oil supply. All of the requirements for pressurized oil supply is confined to the cam tower assembly. The resulting drain back takes place through the lower main cylinder head. The Volvo bucket tappets are hydraulic with no lash adjustment shims. Higher performance cams are available but they may require changing to solid tappet buckets with adjustment shims.
Water passages: Water can be run externally, but many of the water passages already match and are all very close. The water passages in the Volvo head, quite possibly, can just be enlarged to be able to supply the needed water, however cooling at the back of the piston on #4 is less important than matching water passages to the gasket. The downward opening passage in the front of the Volvo head is the water pump bypass; it uses an o-ring between the passage and the pump. Seal the opening and install a connection to the heater core line.
Off the shelf:
Oil feed line: taps, fittings and a -3 pressure line to feed oil to the head from the block feed point. (Custom length)
Cam Sprockets: Volvo, round tooth from 16v made adjustable (vernier)
Timing Belt Tensioner: stock Ford mounted on a plate
Tensioner (2nd pulley) for Timing Belt: Volvo, from 8v motor
Crank Gear: new (round tooth) Ford Ranger crankshaft gear, spaced 5/16" (or 8mm) from block.
Distributor Gear: new (round tooth) Ford Ranger distributor (auxiliary shaft) gear
Water Pump Sprocket (from new Ranger motor)?
Timing Belt: 3.0 Mitsubishi - 25mm wide x 55 7/8 long, pitch - 9.5mm or 3/8"
Gasket, Head: Fel-Pro 1035 (Performance Line) for the Ford 2300
Gaskets, Intake: Fel-Pro MS95263 for the Volvo B234F
Gasket, Exhaust: custom or none
Valves: Racing Engine Valves (REV)
Tensioner mounting plate
Tap and thread the rear oil return passage of the block and install a pipe plug. Rear jackets donít need to be blocked. Install pistons with custom valve reliefs or cut reliefs into stock pistons.
The front water outlet must be sealed at the bottom and fitted with an outlet opening towards the passenger side. Fill and cc the middle combustion chambers to better match the head gasket (.060). Match the necessary water passages with the Ford gasket. Tap the head to accept an external oil feed. Prepare and machine the block of aluminum, then tig weld to the back of the Volvo head. Appropriately surface and true the head. Install the external oil supply line from the added block to the forward tapped point.
Details of aluminum block attachment:
Dimensions Ė width of Volvo head x height of Volvo head x (length of ford head - length of Volvo head, sort of)
Details of tensioner mounting plate:
Shape, drill points, mounts points etc.
Install valve gear: Mount the Ford tensioner on a plate, mount the plate on the front of the Volvo head, fit the belt to the tensioner, and confirm all rotating belt parts are on same vertical plane. Belt Routing: A plate goes across the top, front bolt holes on the Volvo head, which has a locator pin hole drilled into it for the 8 valve Volvo tensioner. Tensioner bolt comes off of the left passenger side bolt hole in the head. Verify the intermediate and crank sprockets are spaced appropriately from the block for the belt to run true. Time the motor.
Install accessories, radiator, intercooler, a/c etc.
Cylinder head considerations:
1. Oil feed to the head: run hose from block or remote oil filter directly to the upper head section and plug the Ford block to the head in the left rear corner with an allen plug.
2. Instead of placing a small block of aluminum across the back of the head we will be placing a full length, top to bottom piece of aluminum across the back of the head to guarantee that we do not have any oil/water leaks. An additional oil drain hole will be drilled into the back of the head since one of the three factory oil drain holes will be plugged. We were going to also drill an oil supply hole and supply the factory oil feed hole with the oil supply, but we have decided against it and we will be running an external line from the outside, through the side of the upper head section, where no water lives, and supply the oil to the internal feeders at a better location in order to supply both sides of the head simultaneously.
Suppliers and Alternative Components
There are a lot of fuel management possibilities out there:
FELPRO/SPEEDPRO SEFI8LO is probably the best for the money,
EEC-Tuner is good on a variety of Ford ECMs (A3M1 is best but the wiring has to be swapped). The wiring kit complete from computer to sensor plugs is readily available at Painless Performance.
Richard Prince is the contact. The modified cam specs are: Advertised duration 268 degrees, duration at 0.050", cam lift 228 degrees. Lift 0.438" Cam lift at TDC 0.070" Intake centerline 109degrees ATDC. Lobe separation angle 112degrees
Stock cams and gears: A$100
Modify cams to specs: A$886
10% tax on $886: A$89
Modify cam gears to vernier: A$300
Subtotal A$1,375 plus shipping, customs, my service fee 10% A$135 import duty to your account
This configuration requires no change to cam buckets
REV can provide larger valves. Also consider using alloy valves and before the swap, also the valve faces could be coated, as well as the outside of the head for a little better heat retention, and the tops of pistons as well. Larger replacement valves: 36 and 34.5; they will require new exhaust seats, the intake will cut out far enough. One possibility: Porsche 928 S4(?), 7mm dia., hyd. Adj., intakes 37mm, exhausts 33mm
3.0 Mitsubishi 25mm w x 55 7/8Ē l, pitch - 9.5mm or 3/8", Hyundai 29mm wide, Ford 19mm. Use Volvo 8v cam sprockets if a square-tooth belt (like the stock Ford) is desired.
It is possible to use the Davies-Craig electric water pump and not even use a bypass, and use another electric pump for the heater core loop, like Mercedes and BMW are both doing.
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Published by Chris Anglin.