Hi,

I have heard that the focus st170 engine is the best one to use for a ZVH conversion in a s2 erst, something to do with the pistons & rods allready fitted anyone confirm this ?

Duncan

 

thay have steel rods as std mate.

not sure on the pistons tho

 

ah yeah, thats what it was !

anyone know whether they'll take 15psi, with good cooling and plenty of fuel of course !

 

duratech mate !!!!!!!!!!!!!!!!! reverse head inlet at front flows better than cossie 16v, you buy a cosworth made 2.3 kit can made to run turbo 600 plus b.h.p. easy!!!!!

 

std zeted rods (not st170) are good for 270bhp anyway mate.

and yes, the duratec is a VERY good engine for tuning!

but they have the engine mounts in different places

 

I thought it was only one of the mounts needs to be modified ?

 

A lovely piece of information but whats that got to do with the ST170 engine

 

I was a bit confused about that as well !

 

the ST170 is a zetec mate, it just says duratec on the cam cover

the mounts are in the same place etc.

proppa duratecs tho have the mount(s)? in a different place, and have the inlet at the front, zorst at the rear

 

so the ST170 engine has the steel rods what the duratec has but is classed as a zetec?

 

The ST170 is a Zetec, the Duratec is a totally different engine.

 

so the ST170 enige is good for tuning as of the steel rods, and also the duratec is good also?

why?

 

http://www.sbdev.co.uk/History_files...atecTuning.htm

Good info on the Duratec.

 

i was testing the water :blonde:

 

so what about the standard pistons in the st170, anyone know about these, ie. are they any good, what boost can they take ????

cheers, Duncan

 

I imagine the compression ratio in an ST170 would need looking at for a turbo conversion? 10.2:1 is a bit high?

Extract from here... http://www.stownersclub.com/models/st170.htm ( note when they say duratec they mean Zetec-E )


"At its heart is a tuned version of the standard 130PS 2.0-litre Ford Focus Duratec engine, now producing 170PS at 7000rpm and 195Nm of torque from 2500rpm. Transmitted through a Durashift six-speed manual gearbox, this is sufficient to allow the Ford Focus ST170 to achieve 0-60mph in 7.9 seconds and a top speed of 134mph.

But it is the more refined driving experience that makes the Ford Focus ST170 special and is meeting the desires of customers.

"Overall, approximately 25 per cent of UK dealer sales in the small family car segment last year were performance or sporting derivatives so, as a performance version of UK's best selling car, the Ford Focus ST170 is a very important car", explains Andy Barratt, brand manager for medium cars, Ford of Britain.

Refined Performance
"With the Ford Focus, we couldn't ask for a better foundation for a performance vehicle", said Jost Capito, Director, Special Vehicle Engineering (SVE), which developed the ST170. "The result is a highly balanced performance car that is exciting to drive, but refined, understated and practical to own."

The 170PS 2.0-litre Duratec ST engine has been developed from the standard 130PS 2.0-litre Ford Focus engine with several new features, including:

New, high-flow aluminium cylinder head with larger inlet valves and higher lift intake and exhaust camshafts for higher peak rpm levels
Continuously variable intake valve timing
High compression, cast-aluminium pistons and forged steel connecting rods
Dual mass flywheel
New dual state intake (DSI) manifold, using long runners for low-end torque and shorter runners for higher peak power outputs
Larger bore free-flowing stainless steel exhaust system, tuned for enhanced performance sound.
Such enhancements mean a higher maximum power, but more importantly, 85 per cent of the Duratec ST's 195Nm of torque available from just 2200rpm, giving a useable, strong performance feel.

"People buy horsepower, but what counts in the real world is torque," said Bernard Steeples, the Ford SVE engineering supervisor responsible for its development. "That's what you really feel, how well the engine pulls. And that's what you feel in the ST170 - more torque throughout the speed range."

Ford SVE's approach to achieving improved performance in a normally aspirated engine was through a combination of improved flow characteristics, higher rev capability, combustion efficiency and a higher compression ratio.

Duratec ST's new aluminium cylinder head features enlarged intake ports to increase its flow potential. It is fitted with larger intake valves (33.5 mm) to further Duratec ST's free-breathing character. Stiffer springs on both the intake and exhaust valves help to facilitate a higher red-line. Focus ST170 has an indicated red line of 7,200 rpm on the tachometer and rev-limiter intervention beginning at 7,350 rpm.

Fuel is delivered to the cylinders via an electronically controlled, high-output fuel pump. With precise electronic control of the fuel delivery to the injectors, no return fuel loop is required. The system contributes to ST170's Euro Stage IV emissions capability.

Variable valve timing technology gives Duratec ST combustion efficiency that eliminates the need for a close-coupled catalyst in the exhaust system. This enhances its flow characteristics and performance capabilities further.

Duratec's intake camshaft is equipped with an electro-mechanical control mechanism that allows the cam's maximum opening point, relative to crankshaft degrees, to be varied between 85 and 145 degrees after top dead centre. Variability is calibrated according to engine speed, load and operating temperature. It is accomplished by changing oil pressure on either side of a piston in a helix between the cam and its drive pulley.

On cold start-up, VVT helps to provide a precise combustion calibration that facilitates quick light up of the underbody exhaust catalyst before adjusting to a profile for high combustion efficiency. As a result, SVE could position the catalyst unit - incorporating premium metallic elements - approximately 900 mm away from the cylinder head face to give Duratec ST its free exhaust flow with reduced back pressure. A second catalyst unit is located downstream in the exhaust.

The exhaust system is constructed entirely of stainless steel, tuned for its throaty performance sound. Its exhaust manifold, cleverly designed for package efficiency in the Focus engine bay, is created of equal-length tubular headers in a four-to-two-to-one configuration. The design combines the first and fourth cylinder exhaust tubes and the second and third cylinder exhausts, respectively, before the resultant two pipes are combined into one to enter the catalyst. The exhaust pipe diameter is 65 mm.

Despite its performance characteristics and the lack of a close-coupled catalyst, the new Focus ST170 retains its Euro Stage IV emissions performance.

Ford SVE engineers used the production 2.0-litre Duratec engine as the foundation for the Duratec ST performance version. Its cast-iron block provided the ideal strength, rigidity and durability necessary for higher output.

Robust elements were incorporated in Duratec ST's top end to reflect the additional performance demands being placed on the engine. These include stronger, lightweight, cast aluminium pistons with larger, 20 mm wrist pins and robust, sinter-forged connecting rods."

 

interesting info there mate

In regard to the compression I suppose its either fit low comp pistons or get the original ones skimmed. I think I'm definately going to do this conversion over the summer, st170 bottom end, cvh big valve head + kent 36 cam, stage 3 turbo etc....

Has anyone fitted a st170 bottom end, what pistons & boost are you running ????

Duncan

 

the ST170 bottom end is pretty tough, the german touring car version of it was running 240bhp (normally aspirated) with exactly the same bottom end, but it had a much better head etc.

its weak point is the dual-mass flywheel but you can get uprated flywheel and clutch (easiest to get one for US SVT focus)

i know a few people who have got over 190bhp from ST170's, by just putting on an adjustable exhaust cam pulley and having it set up at power engineering, bigger throttle body, UDP, induction kit, chip and exhaust.

the ST170 has better stuff over a normal zetec/duratec 2.0 (mk3 mondeo's now call the normal 4-pot a duratec) such as bigger valves, variable valve timing, better inlet manifold with variable tract (sort of like "secondaries"), tubular exhaust manifold, better cams etc. but even with all this they only rung 35bhp out of it over a standard 2.0 zetec (but now we know its fairly easy to get another 25bhp on top!)

you can get a jackson racing supercharger for it which will take it over 220bhp (costs about Ł1500 for the full kit) or the vortech supercharger kit gives it more like 100bhp but costs alot more.

throttle body conversion would work well on it also. GSXR750 TB's fit almost perfectly onto the ST170 inlet piece minus the variable inlet section (handy bit of info for anyone who wants to do this on a normal zetec!)

 

Im definately getting it turbo'd but using a cvh head, just need to know if the standard pistons are up to it.

 

your might be better off asking on the FFOC.co.uk forums, some on there know all there is to know about the ST170's and its limits. would need to know what power and PSI you want to put through it.

also www.focal-jet.com (a USA focus site) has zillions of turboed and supercharged focuses on there, they will know the limits of the pistons (their SVT focus is exactly same as ST170)

 

ask burtonpower?

 

would it be worth all the hassel

 

 

its no more hassel than doing any other ZVH, in fact Ive been told its easier ! the tuner who Im going to use specialises in using these engines for conversions. Ive been told they have massive low down torque.

Duncan

 

oh ok

 

Some poeple talk a lot of shit.

Id LOVE to see someone try and ZVH a ST170 engine, or any focus type bottom end for that matter PMSL.........Anyone thought about WATERPUMP? No, didnt think so

Yes they have steel rods, but theres an ST170 engine ont he stand in my mates garage with a big hole in the block and two banana shaped forged steel conrods .

 

who's talking shit, its been done mate, racepower motorsport do them, from what he was telling me he's had good results. He does them with one of his ported heads and a specially developed cam.

 

You sure he didnt use a mondeo block with ST170 internals?

The Focus block's (inc ST170) have external waterpumps, and you couldent mount a CVH waterpump onn there at all!

 

I dont know mate, I might be going to see him soon so I'll ask him. Im pretty sure he uses the st170 block though. Im still not sure what engine Ill go for, Ive heard the american 1.9cvh engine has very good low down torque can I use efi with this engine ?

Duncan

 

1.9CVhs can run EFI heads mate yep...Rudey has this on his s2 not so long ago I believe

 

for 1.9 info give specilsed engine's a ring on(01375) 378606

 

for the money i wouldnt bother. A well spec'ed and built CVH turbo engine will produce as much power and be as driveable IMO

 

true power curve wont be as good and 1.9 mite b more relialbe and more torque.......me tinks

 

I had one like that aswell!

Why can't the Focus waterpump be used on a ZVH conversion out of interest?

 

No offenece but most of this info is complete tosh, supercharger for Ł1500?, not quite tad more then that try around 3-4k . And 190bhp from cam pulley!!!, 20bhp from a pulley

Whats that meant to mean?, the mondeo mark 3 runs a duratec HE lump, the real deal, one that is good for tuning

The ST lump itself is average for tuning, would rather use a standard 2lte zetec tbh.

 

i would slap in a alloy decomp plate from ferriday engeneering and keep it a propper st170 engine down to the fact that the head flows like a cossie head

i wouldnt think the cam profile is verry well suited to turbo dnd i would think a reprofile would do the trick

there was an article about one that was done by power engeneering that got 280 ponies without too much boost

sticking cvh head on one is going backwards tbh

 

So guys,just to get this clear in my head.An ST 170 engine would mount up anywhere a Zetec would?

 

I got a brand new Focus RS short motor from Ford to do a ZVH conversion. It was badged as a Duratec although it is a Zetec!
I ditched the std con rods but kept the crank and pistons. I had to cut a huge hole in the side to fit the Escort water pump.
I am running with 8.8:1 CR but have found that the std Mhale pistons melt at 26psi of boost.
S.

 

Are you nuts??? You are going to throw away the best part of the ST engine and replace it with a shitty cvh head???

If you ever do this i will have the St170 head of you!

 

Utter bollocks i'm afraid.

A stock zetec E (non st170) head flows much better than a stock cossie head. If you then look at the st170 it is streets ahead and out performs the YB head by miles.