Good day to all,

Can anyone advise the differences between the 2.5 engine in the Focus Mk2 RS and the Focus Mk2 ST.

Any comments is much appreciated.

 

Engine block, pistons, connecting rod, camshaft (inlet only I believe) flywheel, clutch, injectors.

Claude.

 

St runs higher compression than the rs and also they have different turbos

 

Thank for the info. I did not think the bottom end was different. I was thinking cams, turbo and injectors.
Cheers!!

 

The st bottom end is quite weak im led to believe. You can buy a girdle from jamsport i believe for the block. Im sure this doesnt stop the liner issues though

 

What liner issue. therefore I should autocrossing it.

 

Common for ST's to crack the liners, has happened to both standard and modified ST's.

 

As above, IIRC the exhaust cam is the same.

The RS had a re-work on the block to stop cracked liners, few people seem to know what was done, but it's been around for yonks with the Volvo boys!

 

A friend of mine in the automotive manufacturing trade told me that Ford "Value Engineered" the Volvo engine when they started using it, one thing was reducing the liner thickness. This has obviously had a detrimental effect.

 

Dam! does this mean that my high oil temperatures means, I have a cracked liner.

 

Oil temperature goes up when driving hard. and in turn the water temp. goes up also. I am hoping the Oil cooler is failing. This is an easier fix.
If its the liner, any one knows where I can get RS liners.

 

When racing my RS mk2 this year I would run with 110 deg C water and 130 deg C oil. Car still runs fine.

 

Is the RS block not "plasma lined"?

Martin

 

Am i right in thinking that the later ST's (around 08 onward) have had adjustments made to overcome this aswell as the RS engines, sure i have read this somewhere online. Although dont believe everything you read on the net!

 

The plasma coated liners are a new take on honing. In stead of the oil sticking to the block wall in small scores, it now sit on a porous "plasma" coating.

 

Also the RS engine uses a forged crank rods and Pistons from what I've read

 

I think he would of learned what's what after the two years he posted it

 

�� I always forget to check the thread date lol I hope he has learnt aswell