Can any help, Silvertop and Blacktop have different conrods but silvertop are chunkier at the top where you need to machine it out to 21mm for the bigger Calibra turbo gudeon pin. A guy at an engineering place says the blacktop one is too thin and may crack once machined out. Any one ever done a ZT 2.1 Blacktop if so how did you go about it? I would prefer a blacktop.

 

Ł200 conrods from USA, you will also HAVE to change the valve springs

 

you will deffo need the uprated valve springs i got mine from ian howell,and theres no point putting a good piston on a standard rod .
you can get a rod piston combo from the usa for about Ł600
i run focus wrc rods in mine .
p.s you dont want to bore it out to 2.1 theres no need

 

I know i need to uprate the valve springs. And i have some C20LET pistons to put in but as above will they work in a blacktop with those weedy rods or shall i do a silver top as they have thicker conrods.

 

the rod angle in the silver top is pants tho ,im sure you can put them on the black top

 

So i can use the silvertop rods on a blacktop crank?
are 1.8 and 2.0 silvertop conrods the same?? my mate has a scrap 1.8 (Cracked piston)

 

How much were your springs? As Ian Hwoell has told me ST170 heads use odd sized springs so normal ones he does cant go in and must get special sized springs/hats which cost Ł270.

Iam going for Piper ST170 uprated springs now I think, only Ł150 and direct replacement.

 

yes both the silver top and black top crank are the same but i wouldnt use the silver top rods there shit imo.

 

Cranks are the same in both engines, and 1.8 and 2.0 rods are not the same as far as i know.

My rods cost Ł210 delivered fron USA.

 

I dont plan on having mental power but think this option would be better than a decomp plate.

 

the springs have a finished height 3mm less than the black top ian has a little shim cnc'd that sits on the stem seal and the spring sits on that.

 

find out if you can fit them on the black top rod there much better and rev nicer.

 

get yourself a set of focus rs rods and pistons, much better than dicking around with calibra stuff.

 

Fair enough, so thats the going rate then!

 

But thats just it ill try and find a pic of a blacktop rod there a bit thin. And only only have a 19mm gudeon pin by the time its been drilled to 21mm they dont look great witch prompted the engineer to say he didnt think they would last.

 

And hope you got a VERY low mileage engine!