9. Clutch Slip
"Clutch slip is caused by oil from the rear main bearing". This myth is one of the most common. The only way oil can enter the clutch is from the gearbox nosepiece and this is much more common with the 4 speed box. The 3 speed gearbox rarely gives any trouble. This myth also conflicts with the fact that the reason for the rear main engine bearing wearing badly is that it never gets any oil after initial engine assembly. If any oil were to pass the rear main bearing it would have to find it's way around the flywheel (the largest oil thrower in motoring history) and then double back into and behind the pressure plate!

10. Clutch slip can also be caused by overheating and melting the clutch centre plate. In the standard touring car the centre plate is sandwiched between two composition linings which act as very effective heat barriers. The result is that if the clutch is slipped for any length of time the heat generated builds up in the thin centre plate until the surface melts. This in turn is deposited along the edges of the radial slots. When the clutch cools down the deposits become radial ridges which then only allow point contact. From that time on the clutch will always slip, usually in top gear when the maximum torque is generated. The solution is to fit cast iron linings to the flywheel and pressure plate so that they act as a heat sink. Contrary to popular belief this will give a very smooth clutch with no further slippage.
The fitting of double or stronger clutch springs to overcome slip is not recommended. The extra effort required to de-clutch is transmitted to the crankshaft and front main engine bearings. This increases the risk of crankshaft breakage and overloads the front bearings whilst giving little extra grip
.
11. Head Gasket
Head gasket failure on tuned engines particularly those fitted with aluminium heads is often due to overtightening the studs. The correct load is between 20 and 25 ft/lbs. as anything greater will stretch the studs, pull them out of the top deck of the cylinder block or warp the head or any combination of the three.

12. Cylinder Heads
Aluminium cylinder heads on unsupercharged Austin 7 engines reduce the horsepower output by about 15% compared with the equivalent iron head. This is because the side valve engine has a very large surface area to the combustion chamber and the faster conductivity of the aluminium allows the flame to go out too soon to give maximum efficiency. The works supercharged racers were giving an output of 50 to 70 horsepower depending on their state of tune and
were running on alcohol fuel. In this state of tune an aluminium head was necessary to dissipate the additional heat. These works engines were fitted with 25 stud heads in 1931 subsequently increased to 32 studs in 1935. The additional studs were tightened to no more than 15 ft/lbs and were there to prevent movement rather than clamping pressure.

13. Balancing
Engine balancing of moving parts is unnecessary as it adds nothing to performance and is undetectable in operation. The only exception is the piston assembly where all four should be as nearly the same weight as is possible. The reason for this is that the instantaneous centre of rotation of the pistons around the crankshaft is infinity.

14. Half Shafts
Rear axle half shafts usually fail because the rear wheel hubs are not tight on the end of the shaft. It is almost impossible to overtighten these but it is necessary for them to be a good fit on the taper. Caution must be exercised when grinding them on to the taper as it can result in the half shaft being pulled out so far that it binds on the inside of the differential carrier. It can also result in the nut bottoming on the end of the shaft.

15. Crankshaft Oiling and Bearing Failure
"Crankshaft oil feed on pressure fed engines is restricted by centrifugal force so that the rear big end is starved of oil and fails!" This popular myth is probably explained by the use of the semi-circular bolt-on oilways on the "Ulster" engines which transfer oil between the 1st and 2nd big end bearings and the 3rd and 4th. It does not take a moments thought to realise that these oilways would, if anything, make matters worse if centrifugal force were a factor. In practice there is no problem as any effect is cancelled out along the crankshaft. Bearing failure can be caused by any number of factors but the bolt-on oilways are a very efficient sludge trap. Unless they are thoroughly and regularly cleaned out with a spring wire and solvent the residual muck can find its way to the rear bearing and block the oilway resulting in bearing failure. Other causes can be attributed to :-

a) The fitting of a "spit & hope" front camshaft bearing in place of the pressurised engine version which does not have an oil groove from front to back.
b) Fitting the incorrect rear camshaft bearing which locates the shaft but has a smaller diameter location in the crankcase casting allowing a serious oil leak back into the crankcase and is therefore not immediately obvious.
c) Misfitting the front crankshaft oil bottle and seal so that there is loss of oil flow.
d) Crankshaft end float due to the loss of the front bearing retaining flange can result in the white metal being extruded from the big ends and subsequent loss of oil pressure.

16. Oil Pumps
Austin 7 oil pumps are very efficient and it is not necessary to modify them in any way as they will happily deliver 60 psi of oil pressure and adequate volume. They need to be checked for wear to the pump body and blades to make sure they are not "grooved". On no account must the paper gasket be fitted between the pump body and lower cover, it belongs between the pump body and the crankcase. Increasing the capacity of the oil pump adds additional load to the camshaft and associated drive gears. The Austin 7 camshaft is very slender and is liable to twist under normal circumstances so any additional load is unwelcome.