HirenRS

Hi I currently own and drive as a daily my mk3.5 fiesta 2.0 zetec turbo.

Engine;
Silvertop zetec 2.0
Stock rods
Stock Pistons
Arp Conrod Bolts
Arp flywheel bolts
1.8gti escort sump
1.8 pick up
Decompression plate
Two MLS head gaskets
Silvertop head;
Three angle valve seats
Port and polished heavily
Adaptor plate allowing use of escort rs turbo t3 manifold
Hybrid t34 garret built turbo
Efi manifold on adapt or plates o suit head
Beige injectors
Air tec cooled
Emerald k3 management

So this set up works, I have covered thousands of miles, for the last three years straight it covered 2000miles a month the only thing she suffered was wheel bearings every now and then, particularly the front. Car was driven as a turbo should be and was amazing !

Anyway, the car was never fully set up, mostly set up as well as i could on the road with the use of live wideband reading and det cans anyway it works well running a bar boost never had any issues, however now I feel like doing a new build.

I have been trying to find out about the bits and bobs required to use a st170 block, black top head to build a more robust zetec turbo engine, I would retain as many parts as possible from my current setup.





I got some questions that new answering,

Can anyone confirm if st170 pistons and rods fit a silvertop crank and block, I believe I am being mislead, if someone can clear this up great otherwise in going to measure this out and inf out my self.

Can you use the st170 sump with a cvh t3 down pipe?

Engine mount in a mk3 assuming it's the same as a cvh mount with mods like I currently have ? I have seen a great guide about mounts in fact but I am lead to believe mk3.5 could carry extra threaded holes to allow use of the st170 mount? Is this true otherwise I will find out and clear it up my self and post here. I'll probably use the cvh mourt as mounted to my silvertop now,

Definately going to go H/O manifold if I can get the bits in time it's my daily so the engine will Be put in over a weekend might stick to my current inlet setup until I get bits together to do a swop ie; injectors throttle cable etc etc, i got all the bits aroundme to make it work all be it more restrictive than a H/O manifold.

Why can't I use the 1.8 gti pump as I use on my silvertop? To correct direction water flow is the pump different in the way it mounts to the block. thi would avoid making a idler right?

Let's get some thoughts on this there are no comprehensive guides I want to build one.

Plan;

St170 block
FRS head gasket
Blacktop head

Everything will be rebuilt, stock components I plan to change all bearing, rings, seals, retain Pistons rods crank,


Head will be rebuilt aswell,
Apparently using the st170 springs is the way to go?


In a nutshell.... What do i need to know and start gathering to know before I take this one on anyone done this?

im a competent mechanic i served for 4 years as a engine builder on the ford world rally team, i can definately crack this on my own but any knowledge is always a bonus! so please tell me what you know guys but i will make a good guid out of this, basically a fairly cheap but reliable engine is what i aim to achieve.

studabear

ST170 sump fits with escort down pipe. Alloy part requires mods to clear starter motor and offside inner cv joint.

Silvertop and ST170/blacktop waterpumps are totally different affairs.

Will the HO inlet fit a ST170 head? I was led to believe that the stud patten is different from none vvt zetec heads?

studabear

Just had another look at your post now I'm not on my phone, to be fair there is a pretty comprehensive guide on building a blacktop/ST170 turbo combination engine in the Rs turbo section. You posted in the thread last night.

elPaulio

The ST170 lower inlet manifold is used by a lot of people to mount bike ITB's on the Silvertop so I would say the HO will fit an ST170 head also.


Paul

HirenRS

I'm planning to use the blacktop head and yes its a great thread I have read a few things that refer to mk3.5's specifically I didn't want to cloud his thread, so the st170 sump works with Mods to clear no problems, so am I right in understanding there is no way to get around the water pump so you can't use the three pulley setup as you would with a cvh alternator with zetec pulley running the pump off the crank, it seems to be a directional things I assume

studabear

You might be able to convert the engine to a silvertop pump the engine would need a bit of surgery. I have seen it done but can't remember the details. My mate I think he had to make the hole in block bigger and then drill tap for the bolts. Then I think he said there was a discrepancy with the cambelt.

HirenRS

Okay looking into things a idler to get the pulley spining the right way is the way to go using cvh alternator bracket and Zetec pullied alternator like my current set up, anyway....

Question of the day is will a silver tophead fit a st170 block? I have one heavily worked on I can't seem to find a clear cut answer

So a sliver too head with silvertop cam sprockets on a st170 crank, is the sprocket in the crank the same? If it's different why can't I use the gear off my silvertop engine ?

This would be nice to know !

SiZT

The ports on an ST170 sit higher than other zetecs

Be careful with the rear engine mount, if a 3.5 is the same as a 3 then you'll have to take an angle grinder to it as it will foul the cam belt tensioner