Without the Liberty, the next choice was the the Napier W-Block Lion, and engine almost as old as the Liberty, but was a 1st Generation motor, like the Liberty and the rest of the WWI designs(individual cylinders), but was executed far better for more reliable operation, less leaks of both Oil and Coolant
Lion, with single head per bank,all bits enclosed and being DOHC, 4 valves per,
Liberty
SOHC with two valves, individual heads with the Cam housing bolted ontop.
For suspension, they would have the individual bogie, like used on the Churchill
Vickers 6 tonner, that the Japanese and Italians used on heavier tnaks
Vickers Slow Motion
Matilda
Vickers/Carden Loyd
This was a variation of the earlier
Horstman
That ended being beefed up enough for the heaviest UK armor, right up to the Chieftain
So what's all this mean?
UK Cruiser tanks will be slower, but have more interior space in the hull, that means they might have larger turret rings, allowing easier upgunning after 1940