60’000 miles on cheap supermarket oil...

[Bob Culver]

Hi Austin
According to graphs in the book Which Oil the crossover point for 20W/50 and 30 is far below 0C, so the multigrade does indeed incur a considerable drag penalty in normal use. 
My car certainly gained performance after 20 miles or so.
Based on simple pouring viscosity 10W40 and 30 are the same at 0C.  Suspect the original recommendation was to reduce leaks, quiten the rollers, and reduce follower wear prior ZDDP or equiv. 
To get rid of much of the dirt (as distinct from water and acids ) the oil needs to be drained hot and the car rocked to stir it up. The impecunious can put through a filter and alternate or use as top up.
( A work colleague described tidying up his late fathers workshop. Apparently he siphoned old oil through ropes to recycle it and had quite an installation. modern additives may not make the pasage)

[Mike Costigan]

Hi Ruairidh, I can better that! This was the demoralising sight when my Lancia engine was stripped down - the result after just two hundred miles of (mistakenly) using a modern oil instead of the classic oil used previously. The results from the consequent blocked passages were a seized main bearing, disintegrating big ends, and scored pistons and bores... and an empty wallet 


  sludge.jpg (Size: 112.88 KB / Downloads: 403)

[Ruairidh Dunford]

Never ever put modern oil in an engine that has not been cleaned spotlessly Mike!!

[Ivangardiner]

Seems I logged in the wrong way or something and can't see a "New Topic" button. So I'm coat-tailing on this thread...
See the following link for what looks like a cast iron sump, with extra plugholes at the deep end. Perhaps it is for a marine conversion. Seems cheap enough and perhaps rare? I have never seen one like it.

https://www.prewarcar.com/301391-austin-...38#group-1

[Colin Wilks]

Well it's cleaner than Ruairidh's!

[AustinWood]

I agree Ruairidh, I know my engine is clean having had it in pieces recently to fix oil leaks that had developed over several thousand miles.

[Ruairidh Dunford]

The oil troughs on the Phoenix crank are still as supplied.

   

[Bob Culver]

Until the 50s and additive oils gooey sumps were not uncommon. Our Seven used for short runs used to accumualte an inch of grey sludge. Old filters in dumps were often gooey blobs. i recall an article in Pop Mechanics about police cars which missed oil changes. Were gooey as picture. Colleagues have encounterd fluctuating oil pressure traced to thick residue in sump of a mid 1950s Vauxhall and a later Rover 100. OK with justthe sumps cleaned but cars had filters. The oil firms used to claim that modern oils would not strip varnish like deposts, but I suspect now do.

[Ruairidh Dunford]

The sump had about 3mm of sediment at it’s deepest.

This is over 19 years of use and 64’000 miles.

[Bob Culver]

H Ruairidh

The Phoenix crank fillets seem nicely finished with reasonably uniform radii. Being very hard, is there any measurable crank wear?
It is curious that low cr cars seem to give trouble with ring lands. A common failure with Bradfords. Have others had same trouble, or does noone match your mileage? Have you gear to measure cyl wear? Can be assessed by filing lengths of wire or nail and measuring with a normal mike. With the regular longer distance running on modern oil something like modern wear may apply. My car 1940-55 developed .010 taper over 60,000 miles, and had been previously recon at 40,000.
I am surprised at the goo in Seven sump. I have run 1950s/60s cars as everyday transport for 50 years and used some very basic oils but never any goo formed, even with considerable blow by. Got solid carbon particles settled and packed beneath the intake gauze.