KNOW YOUR OIL PRESSURE
READINGS
The Austin Seven has a splash fed lubrication system,
i.e. The big ends are fed oil through oil squirting through 2 jets and catching
the lubricant as the crank-shaft rotates. This set up is fairly unique to the
Seven.
When the engine is cold the needle flies off the end of
the gauge, which is quite normal. However, when the engine is good and hot, the
needle should read within the parameters of the gauge, even reading next to
nothing when ticking over.
If it should ever rise u
nexpectedly
above “normal” readings when drivoing along, you may well have a blocked oil
jet. You must stop and sort it, otherwise you run the risk of overheating a
starved bigend bearing with expensive results. Observing the diagram, the oil
jets are marked “A” on the off-side of the engine. Remove the two small jet
bolts. They are under the side water manifold along the top of the ally
crankcase. If you have a forward facing starter motor, it is advisable to
disconnect the battery, so you don't short your spanner on the terminal. You
will need a stiff piece of wire about 1/16 inch diameter about 7 inches long.
(always worth keeping under the seat). Fiddly and awkward, you need to push the
wire down past the gallery into the top of the jet and then on down about 2
inches, (patience and persistence is needed to locate the hole). This will
ensure the jet hole is clear. Repeat on the other one and reassemble, noting the
fibre washer under each bolt head. Do not overtighten the bolts.
Start her up and check for leaks and hopefully oil
pressure will be back down to normal. It might be worth doing a dummy run of the
procedure in the warmth of your garage to get the hang of locating the jet hole.
Don’t panic, in all the thousands of miles I have covered in a variety of Sevens
it has only happened twice and, yes, I did run a big end! Make sure you change
your oil regularly and do not use high detergent lubricants . Gary Munn
(GM Seven Services)
Also see an excellent hint on poking through the jets.
Click here.