2.5 to 3.0 questions

[wolfgraj]

I recently bought a cougar with a blown motor (oil starvation) and a slew of body damage(both bumpers are shot). I was looking at doing the 3.0 conversion but have a few questions. I understand the three alternatives but have some specific questions about each.

The hybrid seemed like a perfect solution for me but I'm not sure about the conditions of my 2.5 heads, the cost of cracking the engine open (gaskets, machine work ect) is quite high and compromising the reliability with 11:1 CR doesn't sound fun.

What I am looking at now is the '98-'99 Taurus full 3.0L swap. With this configuration I wouldn't have to port match because these motors already have the split port design (right?). But I still have a few questions....

I have to use the 2.5 valve covers, timing cover, UIM, LIM, and all the accessories (PS pump, AC, alternator) correct?

Does that mean that the IMRC will stay completely functional?

So the swap of one of these motors into a '99 cougar entails
-rewiring 3.0 knock sensor to 2.5 harness
-trimming for alt bracket
-trimming crank for MTX
-electric water pump

Some input would go a long way. Just to make sure I am on the right track and not forgetting something really important.

[SpookSVT]

When you use the Taurus UIM, the IAC should fit. If it doesn't, you'll need to relocate it. A new EGR tube needs to made. Vacuum line routing and PCV will need to be changed as well.

It sounds like a lot of work, I know, but it honestly isn't that difficult. The EGR tube may be the most challenging if you don't have access to a bender or welder. Any fabrication shop should be able to take care of it though. If you're not up to it you can always delete it and block off the passage.

[wolfgraj]

My plan was to use everything from the 2.5 from the heads up that way it would look like the stock 2.5 and all of the houses/vac lines/ect... would fit exactly as they had before the swap. Is that not possible?

[wolfgraj]

Also where would be a good place to get an electric water pump?

[SpookSVT]

Originally Posted by wolfgraj

My plan was to use everything from the 2.5 from the heads up that way it would look like the stock 2.5 and all of the houses/vac lines/ect... would fit exactly as they had before the swap. Is that not possible?

You can, I would advise against it though. The 2.5L's plenums are too small for a 3L and you would be compromising quite a bit of power.

[wolfgraj]

Alright. I was pretty excited about that setup. It seemed pretty straight forward and cheap. I have some concerns about using a newer (oval ported) motor. In this case I will have to remove the heads from the block for porting. Is it reliable to DIY port match? I can't believe that people are getting consistent air flow to each cylinder with a DIY job. Unless people have home made flow benches too? The alternative is use the LIM off the 2.5 and the UIM from the 3.0? This would entail what you were explaining before?

Aren't people oval porting their newer Taurus motors to reuse their 2.5 plenums?

[SpookSVT]

Originally Posted by wolfgraj

Alright. I was pretty excited about that setup. It seemed pretty straight forward and cheap. I have some concerns about using a newer (oval ported) motor. In this case I will have to remove the heads from the block for porting. Is it reliable to DIY port match? I can't believe that people are getting consistent air flow to each cylinder with a DIY job. Unless people have home made flow benches too? The alternative is use the LIM off the 2.5 and the UIM from the 3.0? This would entail what you were explaining before?

Aren't people oval porting their newer Taurus motors to reuse their 2.5 plenums?

Someone did run various manifolds on a chassis dyno and confirmed that, as a few of us knew, was inadequete for a 3L engine.

I'd recommend not doing the so called 'porting' to use a twin port manifold to an oval port head. Doing so compromises mixture motion in the combustion chamber. The offset injector position, spray patterns, etc...

Ford Contour & Mercury Mystique Forums - FordContour.Org I'd highly recommend getting an account over on FCO and view some of recent threads and start your own should you have any more questions. Investigate your options a bit further before making a decision.

[wolfgraj]

Thanks for all the input

[SicSE]

Originally Posted by wolfgraj

I have some concerns about using a newer (oval ported) motor. In this case I will have to remove the heads from the block for porting.

Many people have done the porting with the heads still installed. If you take the proper precautions, you'll have no concerns. Though, IMO, the ends do not justify the means - it's a lot of work.

Originally Posted by wolfgraj

The alternative is use the LIM off the 2.5 and the UIM from the 3.0? This would entail what you were explaining before?

If you're talking about the UIM from a 3L ovalport, it will not bolt to a 2.5 LIM.

Originally Posted by SpookSVT

I'd highly recommend getting an account over on FCO and view some of recent threads and start your own should you have any more questions.

Just be careful of the questions that you ask and be sure to not disagree or offer any counterpoints to anything Dom says.

[wolfgraj]

It seems that these sites (NECO, FCO, CEG) all have their STRONG opinions. Kind of hard to search for something when everyone (with a lot more experience then me!) is in disagreement. Right now I am leaning toward an '04 (you were right about the low price) Taurus engine full swap. Still reading away though. Trying to make sense of it all.