Contour Enthusiasts Group Archives Forums Modifications Duratec Performance 3-liter conversion

Brad, two questions for you:

1. Is there any good reason to use the 3L heads if you have the SVT 2.5L heads??? Is this the reason why Terry Haines was talking about the 3L Long Block (almost a direct drop in and ya don't have to slap all of the old 2.5L stuff back on)???

2. Will the SVT ECU hold this new 3L beast back from its full potential???

Also, if you use the 01' 3.0 longblock, would you want to switch the cams to the 2.5 ones? That would include either the regular 2.5 cams as well as the SVT ones. I know the SVT would be preferable, but what about the regular 2.5 cams? I already have those...

If the 01' 3.0 cams are the same or even real close to the 2.5 cams, that makes things a WHOLE lot easier! No heads to pull, timing chains to set, cams to degree, etc..

1. Going to have to come up with your own answer here. Use the 2.5 heads if you're cheap and on a budget and don't have access to SVT parts. The SVT cams(if you have them) can be modified to work with pre '01 3 liter heads, or used directly in the '01+ heads. Use an electric water pump (many discussions on thie topic) if you use the pre '01 heads. Use the factory WP if you use the 2.5 heads or the '01+ 3 liter heads.

2. Yes. Needs to be custom burned chip or have aftermarket manual adjustments made via fuel and spark computers. Will it run fine without it and not throw a MIL? Yes, but not up to full potential.

The 3L cams are more aggressive then the stock 2.5l cams. (The stock 3L is 10:1 CR)

What needs to be determined is if the stock 3L exhaust cam is better the the SVT exhaust cam? (IIRC reading the SVT may use the std 2.5L exhaust cams?)

Maybe SVT intake cams and 3L exhaust cams are the way to go??? Somebody get out a tape measure...

well, I'm not brad, but I'll see what I can do

1. Personally, I think the 3L heads are a better choice (over the 2.5L SVT heads) in most possible configurations of a 3L in an SVT (or non-SVT for that matter) for many reasons. The only real advantage of the 2.5L heads on the 3L block is a big jump in compression ratio. This can be a mixed blessing; it will help to make more power, but at the expense of much higher likelyhood of detonation due to the higher CR, as well as the effects the 2.5 head has on the squish band (several effects are involved there, and though I don't quite understand all of the stuff going on there, one thing is the increased likelyhood of hotspots that will contribute to det.)
The 3L head also comes with larger valves, allowing for increased flow into and out of the cylinders (SVE considered adding these larger valves for the 2.5 also, but cost and already having met the power targets kept them from doing so)

2. Any "factory calibration" will not be optimal on any modified engine, let alone a heavily modified one. A custom DYNO-tuned chip will be the best choice in most cases. Also note, the stock fuel system is not likely to be up to handling a modified 3L. larger injectors, compensated for in the ECU, or increased fuel pressure are likely to be necessary to feed the beast.

Honestly, If I was building a 3L right now (unfortunately I'm not in a position to right now) I would get an 01+ long block, balance and blueprint it (if I could afford it) port and polish the heads (I would at least clean them up a bit) use the cams from the SVT (or the unobtanium SVE cams that David Z managed to get)
beyond that, I would go with a heavily modified SVT upper intake manifold (Terry is working on something right along the lines of what I am talking about) a 65mm TB, 70mm MAF, headers and a 2-2.25" true dual exhaust w/ an X crossover.

Note, nothing but the intake manifold is really unobtanium or expensive from what I just mentioned is Terry's intake manifold, which hopefully he will make available after he finishes development.

I used a dial indicator to find that the 3 liter exhaust cams were a slight increase vs. my '99 SE cams. I don't know where the SVT exhaust cams stand in this comparison.

Alex, the '01 3 liter is almost a direct swap. However, you must swap over the 2.5 FEAD and accessories and still modify the crank to clear the input shaft.

DemonSVT, not sure how or why your mentioned the CR of a 3 liter as 10:1... CR isn't in any real way involved with camshaft opening size or operation.

Forgot... Added step 4a. to above...

4a. There's an extra mounting flange on the right bank of the 3 liter block (pre '01 anyway) that is not present on the 2.5 blocks. This must be cut off to clear the Contour alternator mounting area.

Most definitely yes. I dynoed at 180's fwhp (I don't even care to remember the exact figure) with stock brain and fuel delivery and all the stuff in my sig.

Ooo, that reminds me, I have to add more goodies to my sig!

The twin t/b manifold will work fine on the 3.0(Taurus,L/S,T/C-single or twin,& s/c!)

Thanks for the info Brad! I am totaly fine w/all aspects of the swap, except for re-timing the motor. With the 01', it sounds as though that hurdle has been removed from my path! Now to find a cheaper source for better rod bearings...anyone know if the LS block has better bearings than the Taurus blocks?

Alex in Boulder, CO
95 SE MTX

Is BNMotorsports now offering gorrilla's too