tarmac terriost

would a st170 head fit my silver top zetec? 97 mondy
as to get hold of a st170 head would be alot easier and cheaper than to moddify the std head
i know that the st170 have bigger valves and ports,i know that the head runs vvt and solid tappets etc
i cant remember if the engine is belt drive or chain driven as this will be a problem,would the std st170 cam gear mate up with the silver top stuff ?
just need to know if this will work?
has anyone done this conversion yet ?
i know i would see some good gains in power if this works

pa_sjo

It will bolt on. You'll need to do a custom belt tensioner arrangement. There's the VVT to consider too, but if you're smart you can block it off and get a normal cam pulley to fit (with an adapter).

ShandzS1

I run a st170 in my mk3 and i would run the vvt if ur managment can do this.....

tarmac terriost

so the head fits the silver top block cool
what is envolved with the tens/pulley set up ?as it is a custom set up needed
how does the the vvt work on the st is it driven off the cams or the inlet set up
what modification is need to bypass it etc
would the vvt work with throttle bodies or not etc

ShandzS1

heres a pic of the timing belt set-up



It works by letting oil pressure into a vairiable inlet pulley, and advancing the timing to improve bhp, yeah u can run it with bodies, just all depends if ur mangament can do this.....

tarmac terriost

does anyone know the diameters of both inlet and exhaust valves

pa_sjo

Exhaust are the same as any blacktop zetec.. 28mm.. inlet are huge at 33.5mm!! (if i remember correctly..)

AustenW

The timing belt will fowl the water pump pulley mate

tarmac terriost

hmm
swear i have seen a a silver top motor running a st170 head in a red rs tubo which didn't have any problems with the water pump issues

G2RSR

yeah electric water pump

pa_sjo

Here's an ST170 hear on a silvertop block....



As I said in my first post, it fits but you need to dick around with the belt tensioner setup.

Phil2002

iTrader: (3)

what alternator bracket is that? is it a custom one?

ShandzS1

Its a mk5 escort one, modified....

Phil2002

iTrader: (3)

In what way is it modded?
Thanks for your help on this i can now see the light at the end of the tunnel.

ShandzS1

Thought it was the timing belt set-up u needed?
Realy it just cut and one of the top holes drilled bigger, then spaced away from the block 20mm and the tensioner turned.