Well I finally got around to trying to see if the manifolds off a Taurus would fit on our cars this weekend. After getting a set dirt cheap from David Z since he wasn't using them (Thanks Dude!), I attempted a trail fit on the car. My main concern initially was with the front or LH manifold. It sticks out a good bit more than the stock one does. Well the good news is after grinding on the manifold some and moving the radiator forward a little with some spacers--the front one WILL fit!
The bad news though is there is no way in hell that the back one will fit! You could probably actually physically bolt it on, but there is absolutely no way that you could hook the rest of the exhaust up to it. The rear crossmember is in the way, as the 3.0 manifold basically comes straight out with very little angle downwards.
It's a shame though as I believe there is some decent power to be had in these manifolds. Now, I'm not saying anywhere near the level that a set of headers could give you. However, I do believe if we could find a set that would work--they would be way ahead of the headers in terms of dollar per HP.
Actually for a cast piece, the factory 3.0 manifolds don't look too bad. The ports are definitely bigger than the 2.5's, including the collectors. No real surprise there as it is what one would suspect being they came off a larger engine. I was surprised though at how smooth they were on the inside and the straight through design. While holding the manifold up you could look through any of the ports and see out the collector to the otherside. No casting flash anywhere and a realitively smooth surface. It is nice to see how the casting technology has progressed as compared to an old set of 289 manifolds.
I must say that the factory 2.5 set-up SUCKS!! This is from the manifolds on back, as I took my complete exhaust system off just looking at some things. No wonder this is the main restriction on our cars. The front 2.5 manifold is HORRIBLE! The primaries (if you can call them that) remain real close to the head itself and there are rough welds all inside it. After seeing how small the air passages are in the honeycomb of the pre-cats, it is a wonder the engine can even breath at all! I am telling you that the vast majority, if not all, of the headers power increase comes from the elimination of the pre-cats and the larger tube diameter alone. Not to take anything away from these companies actual "designing" abilites, but anyone that has had their manifolds off will know what I am talking about.
Now I'm not giving up yet as there are still some other model years out there to look at. The set that I have are off of a '98 Taurus. I know for a fact that the '00-up front ones are different as I have seen these. I don't know about the back one, but I am hopeful. Also, I know the '96 model year has a different part number though I haven't seen any of these yet either. At the very MINIMUM I am going to gut the pre-cats on my car, albeit with a different set of stock manifolds. Actually, the rear manifold probably wouldn't be too bad with the pre-cat gone. Maybe run the 3.0 on the front and the gutted 2.5 on the back. I'm really not very fond of that idea at all and would just like to find a 3.0 one that will fit.
So there you go--we are half way there. Anyone know what any of the manifolds off these other year cars look like? Anybody know of any other vehicles that the Duratec was installed in besides the 'Tour/Taurus that might have some different manifolds? (No Escapes as this is basically the same thing we have now.) What was the first year that the Duratec came out in the U.S.? How about anybody else that was attempting this swap (Bradness I think was one), anything to share? Maybe all hope is not lost just yet.
For those that are curious, I did this in my basement and Yes it was a B!TCH!!!! But hopefully in the end it will be worth it.
