That makes three of us.

Does it need more running in? 85 compression isn't much, I have 120 on a second hand engine with low comp head.
How worn were the pistons and bores when you started work on them?

Location: On a hill in Wiltshire

I've recently been involved with the re-building of an Austin 7 engine and the first thing I did was get hold of a copy of Doug Woodrow's book, following advice here.
I'd never been involved with 7s before and found it invaluable along with help from the folk here.

I'm now involved with a very smoky bull-nosed Morris. The tail pipe looks like it's a 2-stroke. Have to do some research on that.

I would think 85 psi per cylinder in a Ruby engine properly assembled with good fit pistons, new rings and honed bores is low - should be nearer 100 psi.

Try working on an Austin Seven using only Pitmans 'Book of the Austin Seven and Eight'.

Cheers, Tony.

Location: Melbourne. Victoria, Australia.

As others have mentioned Woodrow assumes a general knowledge of car practice. It is now very hard to find any book which will guide the newcomer from scratch. Mechanics and busy amateurs build up over years of observation (and blunders, many of which mechanics never learn about). Older manuals used to give reassembly tolerances but these were quite stringent and applied to more conventional engines. Modern tolerances when given are almost nil.

Various sources reckon honing unnecessary with plain iron rings and I never did on other cars, but with modern oils and low use probably good practice with Sevens. Scrubbing with detergent and water after is recommended.

In my limited experience, for main road running it is difficult to reduce oil use to very low figures with the current narrow rings, even with 2 single piece oil rings There are various ways of tweaking but not to counter your situation.

As with other makes the reason for wide variation in consumption is often hard to determine. But with Sevens at least the oil feed is relatively consistent.

Is there some gross defect with the oil jets? Is the wrong dipstick in use and the sump too full? Just what was state of bores in taper and piston fit? Bores are sometimes barrel shaped which escapes notice. Do all bores oil up? Some/many c.i rings can be distorted if opened too far, or twisted. Were the rings truly +60 or something bigger gapped down? All rings influence oil use. If block was lowered over pistons, were rings broken? Broken top rings can often be seen with a strong light and fine scriber. Are you using rings sensitive to which way up? Or multi section oil rings which can be assembled wrong? Is a piston riding on a ring? Were the pistons finished wrong with no oil relief? Rings must have definite minimum clearance in grooves. Is the gauze filter panel fitted? Etc

The crew handle is a good test device for compression bounce.

Location: Auckland, NZ

Test

Location: Sheffield

If you have double checked the quality of the bores and the rings and you have low compression pressure and high oil usage I would check the valve timing. If it way out you could get a vacuum in the combustion chamber and be sucking up the oil

Location: Fremantle, Australia

David,
What is the history of the engine? Was it very smokey before, do the pistons have very large ring groove width allowing the rings to pump oil through?
Dave.

Location: Sheffield