ALL the puma rally cars were 1.6 not 1.7, and for good reason.

The 1.7 uses nikasil linings in the piston bore, where as the 1.6 uses far stronger and durable steel ones. Whilst the 1.7 is a very revvy engine and good for road use, it can't handle the constant loads and stress that the steel lined 1.6 can : especially when rallyed.

Most people that do a turbo's puma, will use a 1.6 as it's not as frail as the 1.7