Lifespan of refurbished Austin 7 engine

[Howard Wright]

Hi All

Surely how long a rebuild last depends on how you drive it (or don’t drive it).

Regular sensible use is probably better than irregular thrashing.

Approaching septuagenarianism this year, like others I probably will never need to build another engine. On the other hand I quite enjoy engine building so I may build one or two just for fun  .

As the wife says “It gives him something to do”

Cheers

Howard

[Martin Prior]

My best estimate is that my RP has run 70,000 to 80,000 since its last major engine job. It's just beginning to feel a bit tired. I've always believed in thoroughly warming the engine at a modest idle before driving. Something seems to work!

[Bob Culver]

Warm up was traditon for decades. Then in the early 50s doing tests with radioactive rings it was determined that cyl wear almost ceased (as moderns) when fully warmed and it was reckoned better to drive away (reasonably) and so hasten the process. Modern oils and regular longish runs seem to hold off early mains wear. My car shows cyl wear after about 15,000 despite a lot of main road running; I suspect most of the time the block was too cold. From older books at least, it seems likely a thermostat will reduce wear more than any exotic oils.

[Tony Griffiths]

If a car without a thermostat is stationary, surely it will warm up faster than on the move?
One wonders how modern fuel-injected engines manage when, from cold, they have full power and can be thrashed to the red line - and beyond - on stone-cold oil? I suppose it must be the very thin synthetic oils that allow this and perhaps nobody is stupid enough to do it anyway but, knowing human nature....

[AustinWood]

We use fully synthetic 5/30 oil. Reaches places others can't.

[jpsmit]

We use fully synthetic 5/30 oil. Reaches places others can't.

Ooo Matron

[Alan]

Whether you want it to or not

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I think we need to differentiate between “the engine is worn out and needs rebuilding” and “I quite fancy rebuilding my engine now”. I’ve come across loads of engines where the owner was convinced they needed rebuilding but in truth they had a lot of useful life left. Nothing wrong with that. Working with engines is therapeutic- especially if someone else is paying for it.

[Tony Griffiths]

A friend in the USA who rebuilds Ford Model T and A engines says that, when asked by customers what oil to use, say, "Anything you like. The cheapest oils today are so much better than anything available when they were new."

[Bob Culver]

Hi Tony 
Very true. I dunno about the "classic" oils but I suspect these not too classic. In the early 1950s API SC was about the maximum. Dunno what cheap supermarket oils are now but way past API SC. From the mid 50s engine wear on cars new and old decreased markedly. Wear was mostly corrosion related. Presumably whatever protects the cyls also protects the roller mains which were a source of trouble on Sevens (My father used to recount how pre war Len Southward, later of motor museum fame, told him Sevens came in to his workshop with the flywheels rubbing on the crankcase!)
In the last 20 years cyl wear on moderns has almost ceased. Cylinders retain hone marks at mileages which to the early 50s qualified for a rebore.

[Graham Barker]

On the subject of warming up - I have wondered whether the thermosiphon acts a bit like a thermostat. The water in the block is not going to move out of the block and into the radiator in significant quantities until the block has warmed up. It wouldn't be as positive as a thermostat, but may be facilitating a faster warm up than a pumped system with no thermostat or a failed thermostat.