Hitchcocks Forum

Not RE related but interesting I think.>br>I have been resurrecting a thirty year old air-cooled Lombardini engine - single 400cc. It's the motive force of a big 2 wheel tractor - the kind of thing that you still see in the Med doing all sorts of jobs on smallholdings and even on the road. It's built to be abused and everything is good and strong.
I'm working without a manual so am feeling my way but I find that there is no oil pump as such.
The big end gets a sort of supply from oil dragged up from the sump by a couple of cogs and is flung into the big end by a centrifugal cup fixed to the crank. Everything else at the bottom end is splash. There is no feed to the top of the engine at all and it must rely on oil mist coming up the pushrod tube and what little drips of the breather cap which is in the rocker box cover. This has a crude condenser to trap oil mist. This means that the top end gets nothing until the engine is good and hot.
I have no idea how many hours it's done in it's 30 years but it would seem to have been pretty well used but still the rocker spindle etc is fine.

It gets me thinking that we probably overestimate how much rockers etc need in the way of lubrication. I know the oil has an important cooling function on the REs but even so. It's certainly not worth worrying if the top end gets no oil for a couple of minutes after an oil change.

Incidentally, I was searching in vain for parts for the engine (exhaust box, points, condenser, dead man's handle) until I went on to Ebay Italy - the only problem after that was translation but Google translate was my friend there.

Yes Pete, you are absolutely correct, think back to the pioneer bikes with total loss oiling and occasional oil to the open rockers, they went on for thousands of miles without any problem.

In the 1980s I had a Rover 2600 SD1 straight six. They were renowned for their dreadful oil supply to the top end (they were OHC). It lasted about 90,000 miles until one day on the M1 the cam seized solid, the valves hit the pistons, and a con rod bent. I think on balance it's best to feed the top end with oil, but I do agree Pete that it's amazing what some engines will put up with.

I might add that, when the engine is back in service this summer, it will get a squirt of oil on the rocker shaft, valves and pushrod ends before starting up.(all are accessible from the filer cap)
At least this will give them something to work on till it warms up.
I have thought of fitting some kind of pump but it's a bit impractical to pick up a drive from anywhere.

mem memory ain't too good so can't give examples but I have seen open valve gear with grease nipples on the rockers