DaveyBoyS1

Hi,

Does anybody know of any zetec turbo conversions with a ST170 head on ?

Will it work ok?

Will it fit on a 2.0 silvertop bottom end?

I read the standard silvertop head will only flow enough for 300bhp... and can get my hands on an ST170 head.

Cheers.

stuart collins

iTrader: (7)

yes two

DaveyBoyS1

Im off to but it then

Ta

sas

If you use a ST170 head you have to decide if you are going to run the VVT or machine up a blank for the VVT pully.
You have a chalange to find an inlet manifold with big enugth port to match the massive ports on the ST head.
S.

steven botes

300bhp out of a 2 l 16v zetec???? cvh's run more than this with work!

there is a yellow xr3 down here with a t34 and nos which makes 365kw atw , not too kind on the box though

Red16

yes but he didnt say a worked zetec head he said a standard zetec head

DazC

iTrader: (1)

The ST head is the best head out of all the Zetec heads for flow capability and port sizes.

inis

Hi from U.S. , we have a guy here that has a completely stock svt engine(St170 for you guys) boosting 21psi dynod 370 whp, 330 tq at the wheels.


can some one tell me if the st170 pistons/rods are the same as the focus rs?

marky_g

nah i wouldn't have thought so st170 is n/a focus rs is turboed

inis

but the svt/st170 has forge rods/pistons that are made by mohle, focus rs does to, the difference between the two is mostly the head. Focus rs uses a 48cc combustion chamber and the svt/st170 uses a 40 or 42cc chamber. Sounds to me as the short blocks are the same and the heads are different.

inis

standard zetec head 47.7 cc's, svt/st170 head 42cc's

sas

I have a Focus RS block and it is a different casting to the ST 170 block that I also have? The RS block has no core plugs while the ST does.

The RS pistons are dished and the ST pistons have a slight concave with valve cut outs.

The RS rods are weedy and dont think they forged.

Thats my observation.

Simon.

inis

is there anyway I can get pics of everything that you have ? I'm creating a database of pics and comparisions of all the different blocks and heads for the zetec.

send pics to inis@kctuners.com , I'll link you once I have the database/comparisions up.

AustenW

you will strugle to fit the ST head to a silvertop block as the newer blacktop and ST's positions the cam belt in the middle of the block and it will foul the waterpump housing.

You can get round this by fitting an electric pump though

Johnny Knoxville

Like so, my friend will be fitting the ST170 head at a later date so he's planning ahead

JimmyBoy

iTrader: (1)

Can I just take this slightly off-topic a bit

What would be the disadvantages of replacing a 2.0 head with a 1.8 head?

Thanks.

Johnny Knoxville

Not 100% sure but i would of thought the combustion camber would be a bit smaller?

mp1

What are the st 170 rods like?forged??

Rsturbo james

St170 block and black top head with focus rs head gasket 350 bhp simples

SBT83

Be good for 12 psi max. Better valve springs to conquer valve float and now your talkin!

studabear

st170 springs sort that out.

SBT83

Yep! That's where I'm heading rather than 106 springs. I imagine frs springs are cheapish compared to devil development springs

Rsturbo james

Yeah sorry forgot about that. . St170 valve springs

rsmark86

iTrader: (3)

worked zetec heads do 550/600bhp so no comparison
and with a punchy low lag zetec set up it would leave the laggy cvh for dead



i would go full st170 engine turbo'd or with, make it easy with forged pistons and rods and look to keep the vvt with the correct management

will be awesome

rsmark86

iTrader: (3)

old thread alert........

dd valve springs are only Ł150 for a silvertop, but thats the only advantage i have lol

Billybob1982

I have both engines and plan to build a blacktop head with st170 block, I also already have a cast blacktop turbo exhaust manifold with t3 flange and inlet manifold both rwd set up, I'll be getting a decomp plate, gaskets arp bolts and studs butI was just wondering if there is any else that I can use from the two engines just to keep my build a bit cheaper, I've read somewhere that I can use my blacktop fuel rail with vxr injectors, was wondering if there's anything clever I can do with the water rail pump etc and the engine is going in a mk2 escort tia

big_wasa

The idea with a Bt top end on an St bottom end is the 1.8mm gasket gives Cr of 9:1 ( good response but will take modest boost ) if you swap the gasket for a decomp plate and two head gaskets your going to have a very low Cr. ( laggy but still with out the ability to handle big boost ).
I personally wouldn’t go to the expense of Arp stud and nut kits on a decomposing build. I would spend a few quid more on Rs pistons and forged rods at least

Mk1 Focus Rs injectors are are 440cc and could be had new for not a lot.

Blacktop fuel rail works fine. And are designed for the above injectors.

There are several firms making water rails and sumps ect.

My Rwd hybrid turbo. But I am already building a more capable engine.





.

Carlitos

I can't offer experience with a completed engine as I'm still working (slowly) on my ST170-turbo-with-a-blacktop-head build also. I have gone with the ARP bolts, I couldn't find the 1.8mm gaskets so found a 2.0mm Comet gasket which I had to buy in from the US. I couldn't find any alternator brackets these days but somehow came across a company called DA Performance Engineering which does various parts for this kind of build, RWD applications as well and specific Ford models. The bracket kit I bought includes an aux-belt idler pulley
which is mounted above the waterpump which allows me to keep the pump direction correct due to the location of the alternator. For injectors I went for Deka IV 630cc.

A lot of the parts I've been buying have been more when I find a good deal as I'm in no rush to complete the build. I've been taking time trying to source good parts but at a fair price (except the clutch... bloody hell) and some unplanned stuff like a lightened Zetec flywheel just because the opportunity came up.

What I will struggle on acheiving is the downpipe for the 2WD Sierra Cossie turbo I have. Not sure how to tackle that one. Might just phone a bunch of local places for help.

studabear

Loads of places can make you a down pipe, or you could buy a .48 exhaust housing and then use a Rs turbo exhaust elbow and down pipe.

Carlitos

Thanks. I guessed it's probably common enough to ask around locally, just haven't got to the point of the build to do so. Also need the o2 sensor boss welded into it. Is the RS .48 exhaust elbow different to the standard one or the same? The cossie turbo I have I think from memory is also .48 and looks well fllowed but I have no practical experience with either.

studabear

A cossie exhaust housing has a 3 bolt flange to mate to the downpipe. Where as the Escort T3 .36 or .48 exhaust housing has a 5 bolt fitting which bolts to a cast elbow 90° then the Escort rs turbo downpipe connects to that with a 2 bolt fitment.