10-11-2021, 07:58 PM
For other cars with two oil rings when a multi section sprung steel oil ring was suplied in overhaul kits it was advised to fit in the top position. Would not be recommended for a rebored engine with tight bearings. Some 1950s cars were intitially fitted with just one conventional oil ring and the second could be fitted in place later (sv minx).
As above I doubt if oil can be over controlled in a jet fed Seven. The rings appear to be benign cast iron.
Oil consumption in engines can be very elusive. All rings have influence.
At one stage my car used almost none, but that was with the wide rings.
Even with a rebore and two oil rings I could not get below about 1 pint per 400 miles of brisk main road running.Cord rings were diabolical devices advertised in the best journals. Do not operate on the normal comp ring principle. With oils of the time the steel rings wore bores rapidly. Not used for top comp ring. When my car was very tapered and top rings loose had a Cords document which advised fitting a Cord ring under the top comp ring. The car immediately used about a pint in 50 miles and got worsewhen the ring above broke.!
At one stage Austin despaired and drilled behind the second comp ring rendering it just an oil ring. The RP parts book illustrates this. However the oil rings of the time were probably just stepped and not channel shaped.
As above I doubt if oil can be over controlled in a jet fed Seven. The rings appear to be benign cast iron.
Oil consumption in engines can be very elusive. All rings have influence.
At one stage my car used almost none, but that was with the wide rings.
Even with a rebore and two oil rings I could not get below about 1 pint per 400 miles of brisk main road running.Cord rings were diabolical devices advertised in the best journals. Do not operate on the normal comp ring principle. With oils of the time the steel rings wore bores rapidly. Not used for top comp ring. When my car was very tapered and top rings loose had a Cords document which advised fitting a Cord ring under the top comp ring. The car immediately used about a pint in 50 miles and got worsewhen the ring above broke.!
At one stage Austin despaired and drilled behind the second comp ring rendering it just an oil ring. The RP parts book illustrates this. However the oil rings of the time were probably just stepped and not channel shaped.