etc

How to Rebuild an Engine


Take one old tired block,
Engine before cleaning

an equally tired cylinder head,
Cylinder head

some con rods,
Con rods

and a large selection of spare parts.
Engine bits

Remove the camshaft bearings, oil gallery and welsch plugs, and pickle the block and head for a week.
Bore it to suit the new 73mm pistons ( = 1360cc) and machine the block face so you know it's flat.
Cleaned Engine

Build up the rear seal area and line bore block for correct clearances. This will minimise oil leaks from rear main bearing cap.
Rear main cap

Fit new cam bearings.

Open up inlet and exhaust ports on the head,
Inlet Port     Exhaust Port

and re-shape the combustion chambers.
Reshaped combustion chamber

Surface grind head face so you know it is flat.
Flat head

Remove the oil pressure relief valve seat,
Oil pressure relief valve seat

and clean all the oil galleries.
Cleaning oil galleries     Cleaning oil galleries

Dynamically balance the crankshaft, flywheel, clutch pressure plate. Statically balance the pistons and con-rods. Fit new 73mm pistons to rods.
Pistons fitted to rods

Clean the crankshaft.
Cleaned crankshaft     Cleaned crankshaft

Fit new brass oil gallery plugs and welsch plugs. Don't forget to refit the oil pressure relief valve seat!
New welsch plugs     New welsch plugs

Fit the cam followers and camshaft, and coat the cam lobes with assembly lube to help bed in the new cam.
Cam shaft

Fit the pistons on the conrods, and the oil strainer
pistons, conrods and oil strainer

Fit the sump and roll the engine over. Fit the front engine plate, timing gears and chain, and timing cover.
Fit the oil pump, rear engine plate and flywheel. The flywheel has been skimmed and re-drilled to take a larger clutch plate.
Note new ARP flywheel bolts.
Engine flywheel with ARP bolts

Fit the 7.5" clutch assembly. Note the white balancing marks on the clutch cover and flywheel.
Big clutch

Measure the volume in the piston crown and the cylinder head, so you can calculate the compression ratio.
Measuring volume of piston crown

Fit some new ARP head studs.
ARP head studs

Fit the head, push rods and some nice new Titan roller rockers.
Titan roller rockers

Fit anything that's left over on the bench.
Completed engine

There's no point in rebuilding it if it doesn't look rebuilt, so give it a coat of paint. We painted this one in the original BMC engine green.
Note the additional timing marker on the side of the timing cover.
Painted engine

Add a 43D4 distributor, modify the advance curve, add a Pertronix Ignitor kit...
43D4 distributer and Pertronix Ignitor kit

...and modify a side-entry cap to fit
Side entry cap

Fit a nice Weber 45 DCOE fitted to a Russell Engineering manifold
45 DCOE Weber and Russell Engineering manifold

and add a good (mandrel bent, ceramic coated, long centre) LCB exhaust system
LCB exhaust

Put the engine on a dyno (photo taken at 6,000 rpm)
Engine doing 6,000 rpm - steady as a rock

and what do you get?
99ft/lb's of torque at 6,000rpm

You don't get a torque curve, more of a torque plateau, with almost 90% of maximum torque from 3,000 rpm to 7,000 rpm
revs3,0003,5004,0004,5005,0005,5006,0006,5007,000
torque94991021061041041039690
bhp5466789199109118119120

Noddy's torque curve
You now need to take out the old...
Engine bay

clean around the engine bay
Dirt!     Clean!

relieve the gearbox case for the larger clutch...
Modified gearbox case

drop in the new engine...
In with the new!

fit some nice PiperCross short ram tubes
PiperCross short ram tubes

but it's such a shame to cover them up!
Pipercross

fire it up... but don't forget to connect the oil pressure gauge line!
Whoops!

... and take it for a spin!
You can see the rest of the car here