What differences there are between these two engines? I know that RST has low comp pistons and sodium filled valves. Is there anything else that differs from other CVH engines like xr3 or 1.4i ?

 

the turbo block has an oil return. Obviously 1600 blocks are different from other capacities.

 

Thats the only difference in the block for sure. What else? what about cam? Some say thay are the same, others disagree

 

Cam isn't part of the block is it

The cam is the same as any 1600 cvh - 270 degrees duration. The pulley is different though. Marked KA, gives slighty retarded cam timing.

 

RS Turbo's dont have sodium filled valves!

Mfi cams are the same in N/A and forced induction, as are the cams in EFI N/A and forced induction.

Fitting a later EFI cam to an earlier MFI engine will see slight power gains.

 

s1 turbos up to 85 have sodium valves

 

Really?

Interesting.........

 

Yes, The S1 was fitted with Sodium Nimonic alloy valves

 

If only up to 85 though surely there can only be a handful of cars with sodium filled valves....?

 

All S1's had them.

S2's came out in 86.

 

Even Metro turbo's have moronic sodium valves.....

 

And of course it's only the exhaust valves in S1 that were sodium filled.

Other differences:
RSTs had thicker piston pins, better material 1st piston rings and HD big-end bearings.

 

I've studied haynes and RST workshop manual yesterday and now I'm sure the cams are the same on all 1.6 CVH engines... but not sure about pulleys.