Are Blacktop and Silvertop cranks the same?

I know the rods are different length, are they shorter?

If so, using silver top rods with a black top block/crank/low comp. pistons would actually give lower comp then?

Cheers

 

id imagine the black top would be slightly higher comp having a longer rod to stroke it different? cranks are all the same as far as i know thought si

 

Paul what size do Zetec rods have to be made to fit C20LET pistons? Is it 19mm or is that standard Zetec size do you know?

 

Black top rods are longer, giving a better rod ratio. Piston pin is rasied to compensate.

 

Same dimensions yes. Interchangeable, yes.

Blacktop = longer rod, shorter compression height on piston to compensate

 

si when i got some rods done to take the c20 let pistons ,i am sure it was 21 mm

 

Cheers thats what I needed to know!

 

yep, as said last night mate, 21mm gudgen pin .

p.s- cheers for dropping battery off si