Interference engine or not

[Mike-evans]

Is the 2.0l silvertop an interference engine or not?

 

Heard people say they are, and people say there are not.......

[Stu]

Yes it is. Wrong section.

[nullspace]

Yes it is. Wrong section.

 

Am I right in assuming this is true of the 1.6 and 1.8 silvertops too?

 

Just out of curiosity like - I'd like to know if the valves would do a Yuri Geller if the cam belt went.

 

John

Edited September 15, 2013 by nullspace

[nullspace]

Edit: actually, looking at the clearances between valve edge and head-face, I can't imagine how it could possibly avoid being interference.

[Mike-evans]

Edit: actually, looking at the clearances between valve edge and head-face, I can't imagine how it could possibly avoid being interference.

 

Cut outs in top of piston?

Edited September 15, 2013 by Mike-evans

[nullspace]

Edit: actually, looking at the clearances between valve edge and head-face, I can't imagine how it could possibly avoid being interference.

 

Cut outs in top of piston?

 

The standard silvertop 2.0 pistons are flat top. I've seen this in many a rebuild thread/diary. People do replace them with forged pistons from other cars, which do have the valve relief depressions, but these aren't relevant to the zetec. (In fact stu himself in his own 2.0 build thread notes that flatop forged replacements would result in better compression ratio).

 

From what I've read of his threads, stu does seem to know his stuff, and I'd be inclined to trust him on this. That, and the fact that like I say, at TDC I can't see enough clearance for at least the exhaust valves to be open much at all (maybe a few mill at best)

 

John

[Stu]

The 1.8 and 2.0 pistons protrude about 20 thou above the (virgin) deck. The 1.6 does too, but also has a raised dome profile crown.

[PeeWee]

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