Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec Some additional 3.0 questions

I had a few more questions and wanted to clear a few things up before using some of the SVT parts in a 3.0 Duratec Taurus to gain some power. I read this post and still am a bit unsure of a few things:
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=3L&Number=398154&page=0&view=collapsed&sb=5&o=&fpart=1
It seems like different people suggest different things.

I haven't been able to get these FAQ pages to load for a few days:
http://airknightsonline.dyndns.org:8000/3LFAQ1.html
http://airknightsonline.dyndns.org:8000/3LFAQ.html
So, I can't use them to answer my questions.

If I'm going to use some SVT Contour parts in a 3.0 Duratec Taurus, should I:
1. Use the 3.0 Duratec heads because they have bigger valves or use the SVT 2.5 heads because I can use the SVT 2.5 intake? If I use the 2.5 heads, should I have them modified to accept the 3.0 valves?

2. Is the SVT 2.5 or regular 2.5 intake better than the 3.0 Taurus intake?
This is the 3.0 Taurus intake manifold:
http://www.vindustries.com/taurus/PICS/tw97engi.jpg
I have a die grinder, so I can do mile porting and polishing if necessaer.

3. Will the headers for the 2.5 work with the 3.0? If so, how much of a power gain would they give?

4. Are the 3.0 and 2.5 Duratec non interference engines? If I want to raise compression and deck the 3.0 heads(If I don't use the 2.5 heads), is removing a few hundredths of an inch from the heads going to turn it into an interference engine if its a non interference engine? I know on the 2.0 Zetec that removing 0.040" from the heads raises compression between 0.6 and 0.8 points. Anyone decked the 3.0 heads, how much and what did it raise the compression to?

5. I plan to get a custom chip made becuase I plan to use the SVT 2.5 camshafts and need the rev limiter and shift points raised to take advantage of the high RPM power. Any recomendations other than Superchips for this? I worked with Superchips in developing ships for a few limited production Fords before and they did good work. Is there another company that gets better results with the Duratec?

6. How high can the 3.0 Duratec be reved safely? Can the bottom end handle 7000 or 7500 RPM without a problem?

-- Decking heads on these motors is a bad idea.
-- The only reason to use the 2.5L heads is for more compression.
-- 2.5L exhaust valves are too small for a high rpm 3L motor, especially with SVT cams. They might be ok for the standard 3L intake and rpm range though as they will keep the low-end torque even higher.

-- SVT cams take advantage of 4K-7K+ rpm ranges. This requires the engine be able to breath at that high an rpm range. THe Taurus system is designed for lower RPM torque and hence requires less total airflow. The SVT cams count on a dual runner intake system to help keep the low-end torque high while allowing the high-end breathing to make large amounts of power. Using them requires that you open your intake and your exhaust.

-- 2.5L headers will fit the motor but will not mate up to your stock taurus exhaust system. They may also interfere with the driveline or frame so you would have to take a look and compare to some of the undercar pictures that have been floating around CEG.

-- The 3L engine is a bit oversquare and can rev very high. It should be no worse than a standard 2.5L for revving up to 7000+ rpms. Recommendations for max RPM range is about 7600 though I'd personnally play it safer and run it between 7200-7400.

Tom

Oh yeah, these are my opinions/recommendations and I support them with both fact and circumstantial evidence; they are not necessarily 100% correct. They are just "what I'd do" if I were in your situation, but then so far the stuff I do works out OK in the end.

Actually you can take up to about .006" off the 3L heads. Yes in other words enough to make the head true, but not enough to generate any significant compression increase (maybe 2 tenths tops & you risk safe clearance - I.E. don't rev it!)

After that point your pistons and valves will meet!!!

You have to remember the 3L has much less clearance then even the 2.5L does.


All Duratec engines are interference. Thus if your timing is set wrong/lack of clearance/etc you will introduce valve to piston in a very expensive manor.


As for rpm limit.
I would rate the 3L with a lower redline then the 2.5L because it has heavier pistons. Everything else is the same (stroke, piston speed, etc) so the heavier piston will induce critical fatigue levels (I.E. the rods) at a lower rpm level.

I'd use 7500rpm as a max. Maybe lower depending on oil results and powerband (stock or SVT cams, CR, etc)

Make sure to get a set of Quality aftermarket rings (I.E. total seal) I DO NOT mean someone's stock replacement aftermarket ring either. (Like Fed Mog/SP E series rings for example)
The stock rings do not like to spin past 7k. SVT rings seem to be able to go to about 7400-7500rpm before they start losing significant compression & oil sealing.

Interesting...

I have read 3 different tech articles stating the SVT uses upgraded piston rings.
The one that comes to mind the most is the Duttwieler turbo article (450HP at 6900rpm) where he stated he specifically choose the SVT rings to seal the custom made pistons???


Now what about 3L Duratec piston rings???
I know they are low tension design for long life & efficiency, but how much does that take away from high performance ability and subsequent reliability?


I need to find a good ring set.