Board logo

ST170 or ST150
Barksavon - 27/6/17 at 09:25 PM

Having had some good advice recently on the forum regarding a replacement engine for my Avon I'm leaning towards a 2 litre ST150 from a Fiesta. However also looking at a Focus ST170. I've done quite a bit of reading on both engines and am fairly up to speed with the differences between them. Second hand prices for the ST170 are considerably lower than the ST150 and was wondering whether anyone with either engine fitted has any view on the one to go for. I'm looking for 180ish bhp and hoping to use the megajolt ignition (TPS) and bike carbs from my broken Pinto.
Thanks
Ian


Mash - 28/6/17 at 07:21 AM

ST150 has the advantage of being the same configuration as the Pinto, i.e. exhaust/inlet on the same side, plus it's lighter. stock power is less, but according to the Burton catalogue it's "it doesn't take much to tune the duratec to around 200".

I have an ST170, an it does go well in the Focus, but guys on PassionFord seem to do loads to them to get the power levels that you're looking for.

Big_Wasa is probably your man for advice


chris - 28/6/17 at 07:36 AM

i was running my st170 on zx9 bike carbs and megajolt and Mtech vvt controller it did go very well i dont know wot power it was making i am now struggling to match the power with the megasquirt if i hadnt of sold the carbs manifold and megajolt they would have been refitted by now

[Edited on 28/6/17 by chris]


peter030371 - 28/6/17 at 07:53 AM

ST150 is a Duratec and the ST170 is a Zetec with a Duratec badge on it and some other changes to get more power out of it.

ST150 has more potential with less money and is a more 'modern' engine design (if that really counts for anything) plus is slightly lighter. As has already been said the ST150 has the exhaust on the same side as a Pinto so that may help. Bikecarbs on an ST170 will not get you 180bhp, on an ST150...closer I guess but its down to how well they are tuned/matched to the engine after build i.e. you will need a rolling road session with someone who can tune bike carbs in cars.

ST170 has VVT, you will need to disable this as I don't think the Megajolt can control it.

Not sure about the ST170 but the ST150 will need a different bell-housing to the Pinto.


Barksavon - 28/6/17 at 10:54 AM

I've seen a you tube video from motorsports electronics about their vvt module and they seem to say there's an input on it to connect a megajolt to it.?
Also would I need to sort out the pats immobilizer .... I'm not too familiar with ecu stuff, do I need to retain the original ecu or could I replace with megajolt and vvt controller etc...apologies if these are very basic questions for you guys


big_wasa - 28/6/17 at 12:59 PM

If running an st170 on carbs and mjl then you don't need the oem ecu. Its just an engine.

Do a search on the vvt controller there seems to be some debate on the level of support there is for it now it's been sold on.?

The other option is to fix the timing.

Also do a search on the number of st150,s getting broken for spares due to bottem end failure. For the power you want I doubt there is much advantage of an st over a mondeo duratec other than single mass flywheel and manual thermostat.

What you save on one you will spend on another. Look for the best example you can find and go with it. Both are great engines but my opinion is the zetec base is very solid and reliable if a little older and heavier.


snapper - 28/6/17 at 01:25 PM

If your running a 4 branch on the Pinto simple cut off the manifold plate and weld on a Duratec one, the pipe spacing is very close


24vseven - 28/6/17 at 02:18 PM

I used to run an st170 engine in an old rally car. twin 45's piper cams vvt deleted and megajolt ran 235bhp.

although I have gone for a duratec on this build just being a bit more modern


Barksavon - 29/6/17 at 07:56 PM

quote:
Originally posted by big_wasa
If running an st170 on carbs and mjl then you don't need the oem ecu. Its just an engine.

Do a search on the vvt controller there seems to be some debate on the level of support there is for it now it's been sold on.?

The other option is to fix the timing.

Also do a search on the number of st150,s getting broken for spares due to bottem end failure. For the power you want I doubt there is much advantage of an st over a mondeo duratec other than single mass flywheel and manual thermostat.

What you save on one you will spend on another. Look for the best example you can find and go with it. Both are great engines but my opinion is the zetec base is very solid and reliable if a little older and heavier.


So if I go down the ST170 or zetec route would the best way be a 10yr old ST engine with 100k on for £200 (+ no doubt more £££ refreshing it) or a new 1.8 crate engine for £900 ish


Ugg10 - 29/6/17 at 09:18 PM

For st170, why not just by a running car (can be had for £500-1000), you can then do engine servicing in situ, check everything is ok and you have all of the bit for OEM fitment following the guide on here. Sell on bits you do not want.

A "new" blacktop will still need all service parts including a cam belt change give new us actually 10 years old and been sitting in storage, also go for the 2.0l, externally the same as the 1.8l but with another 200cc free, 175hp stock with new manifold and re-use you mj and bike carbs, zx6r work well on this engine.
[Edited on 29/6/17 by Ugg10]

[Edited on 29/6/17 by Ugg10]

[Edited on 29/6/17 by Ugg10]

[Edited on 29/6/17 by Ugg10]


chris - 29/6/17 at 09:32 PM

if i was looking at running the st170 on carbs i think i would go for the nodiz ecu because you dont need an edis and the use the vvt controller
i am presently trying to refit my vvt controller because my megasquirt ms3x was supposed to control it but i just cant get it to work so two steps back