2 replies to this topic

[BuckeyeSVT]

If there's one question that I continually get asked on PM and at the shop - It's how will ST220 parts help my 3.0L? I've done some digging around and haven't found much except where people "believe" there are some magic properties behind the 3.0L ST220 engine in the 2001-2007 Mondeo. This thread in multiple parts will explain the differences and the myths that surround this engine.

Let's start off with a little history. The Mondeo 3.0L engine comes in 2 flavors. First flavor is the SE version. This is a 197HP 3.0L V6 that is basically a ringer for our 2004+ Taurus/Sable Duratec engines. It puts out 197 Crank HP (at 6000RPM) and 193 ft/lb TQ (at 4900RPM), which is very close to our late model Taurus/Sable which stock puts out 201HP (at 5,500RPM) and 207TQ (at 4,500RPM). Right off the bat you can see the Taurus 3.0L puts out better numbers - However the range is a little lower that it does it.

Next is the ST220. Stock form it puts out 222 Crank HP (at 6,100RPM) and 206 ft/lb TQ (at 4,900RPM). The ST220 engine is a modest 25HP and 13 ft/lb TQ bump. One would think that there must be alot of revised parts in order to make an extra 25HP and 13TQ? Right? Different intake manifold? Camshafts? Valves? Hmm... really what could it be? Read on, we'll delve far into the SE and ST220 Duratec engine to find out where they found this extra power and if you should be concerned with the parts for your 3L for more performance.

On paper, the specs for the SE (197HP) and ST220 (222HP) engine are very similar. They are almost identical in the internal engine parts category. Let's take a quick look at the specs:

On paper the engines look very close in specs. Believe it or not, they are really close. Next post will dive into the ST220 engine itself and what makes it so "special".

-Dom

[BuckeyeSVT]

Second part of this multi-part post: The ST220 engine.

Let's start off with a brief technical primer from Ford about this engine:

Warning: Crappy Torque curve and engine dyno ahead!

Now, for those of you who bash full oval port 3L's for dropping off after peak TQ lookout!!! The ST220 does exactly the same thing! The HP curve looks good, but the torque curve is horrible... I'll take my 2005 Taurus setup all day long over this graph!

Anyways, getting on with the show -> ....

220HP from the same engine as the 197HP? Could this be the same trick SVT used for the 2.5L where better exhaust, intake and tuning netted another 25-30HP? You betcha! Let's look closer at the internal differences from the SE base 3.0 to the ST220 3.0L.

First, let's look at the cylinder heads. Perhaps the valves are different? Luckily they have the part #'s for the complete cylinder head assy's with valves - If there's a difference in the heads/valves it'll be here:


Nope, nothing there. Meaning the valves, springs and heads themselves (including the ports) are the same! Hmm... How about those camshafts? You know, the all endearing all powerful camshafts!! I bet it's there...



Hmm, not there either? Strange the lowly 197HP engine shares the same cams as the more powerful ST engine? Well, let's keep digging! How about the Upper Intake manifold??....



Wow! No Extrude Hone tricks? What! How'd that happen.?.... Hmm, maybe the lower intake manifold?.....



Don't blame me for the pic, the 2.5's were still floating around in this grouping! Anyways, nothing here either! How about the throttle body?....



Nope, damn! So where else could power be hiding? It absolutely has to be an internal engine part that makes it... or is it?

Discuss in the discussion thread and I'll post more stuff shortly....

-Dom

[BuckeyeSVT]

Since we've eliminated all the internal possibilities, lets look external. There are no reasons that Ford couldn't uprate the air intake system, the exhaust and calibration to gain 25HP. This leads back to the SVT PCM in an SE 2.5L. With the proper accessories (i.e. intake and custom exhaust) the engine was putting down SVT numbers at the dyno. That meant, no Extrude Hone, no extra special camshafts, throttle body or any of that. Hmm....

Here's the only two things I could actually find that were different....

Air Intake system (different between SE and ST220)...



Then there's the exhaust. Both the SE and ST220 have quasi duals... However how they accomplish that is quite different. Take a look....



Believe it or not the 3.0L SE exhaust is the same as the 2.5L exhaust...lol. Now onto the ST220 exhaust....



Very much reminds me of the Mazda 6 3.0L exhaust... Hmm. Well, what have we learned? First off, the actual ST220 engine parts do not lead to some type of special "upgrade" to the stock Taurus parts. There is nothing special about the cams or the intake itself. Honestly after seeing that dyno it would be a gigantic waste of time using those parts as most are getting much better gains out of parts that can be sourced locally. But if you strive to be different, good luck with that.

All in all a good exhaust, intake and calibration do wonders. It's clearly evident here - That cannot be ignored.

-Dom