Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec lower intake manifold

I was going to take the butterflies out so I can polish them up so they are a chrome like surface inside. I have the ports with out the butterflies done but in the others I can't get everything. I was thinking of putting in some countersunk screws and griding down the backsides of them so there is better air flow. I may not notice a whole lot but every little bit will help. If anyone has any suggestions let me know.

I have all the screws out but three. I don't know if I can get them out without stripping them. Any ideas? If I do get them out can I pull the rods out? I am not going to leave them out I just want to polish everything up and then get them all back together. I can't wait to get this SVT engine in my cougar . I will have it dyno tuned ASAP and post the results in two weeks, assuming there are no snags with the install.

Thanks,
Chris

Come-on people I know you know this!

You can search for optimized lower intake, perhaps in the performance section since it's not a 3 liter specific mod. I know someone has it done and posted pics. IIRC, they noted small gains.

To get your last 3 screws out, use a small tap hammer. The rails will slide out (assuming they're clean) once all of the butterflies are removed. Since I never planned on keeping mine, I just drilled out the stuck screws.

Alright thanks! I just figured that all the 3.0 people would have come into more contact with this since they have taken the engine apart.

If you have stubborn screws, then you can use a pair of pliers to grip the heads and remove them that way. I removed a few of mine with pliers.
When you remove the shaft, bear in mind that in the supports between the runners there are these little pins with rounded heads that are spring loaded and provide an upward force on the shaft. The keep the shaft from walking around. The shaft has smoothed motches where these pins apply pressure, so they wont stop you from removing it but they will require a little force. Make sure you TWIST and PULL on the shafts as you pull them out, and you should already have done a thorough cleaning on them. If the shafts are gunked up they wont come out past the roller bearing in the end.
When you go to push the shaft back in, you will need to make a small "L" shaped tool (I used a piece of coat hanger with a flattened tip) to press down the pins at each location to get the shaft in. Not hard at all, just much easier if you know in advance.

Since you are polishing the runners already, try to widen your secondary runner significanly MORE than your primary, then polish it up. The better airflow that will result should give noticeable gains. Don't worry if you widen them and there is a little gap on the sides of the throttle plate where the shaft goes into the wall of the runner. The throttle plates are slightly oval shaped and will still close fine in the long direction (perpendicular to the shaft). I have similar gaps and have had no trouble. It also alows a small amount of air to leak past and may help keep the secondary's cleaner. I have inspected mine twice in 7K miles, and they are dark colored but not gunked up whereas before I would HAVE to clean them every 7-10K miles for sure.

Good luck,

warmonger

Thanks for the info. I may try and find a place near by that will get the stubborn ones out for me. I got all but three screws out. I polished everything out that I could get, which is pretty much everything except right next to the plate where I couldn't get in. They turned out pretty good. I can see myself in them.

I measured the upper and lower and found that the upper was about 30mm and 31mm and the lower was about 35mm and 33mm. Why the big difference. Both are off of the same 2000 SVT contour engine. I figured I better portmatch them though.

Thanks,
Chris

Don't screw with the taper bores-they're there for a GOOD reason. Notice when installing the upper IM that there is play where the bolts pass through the upper and bolt to the lower. Notice also that it's basically impossible to know if the bores (upper to lower) are aligned. The mismatch means that airflow will not hit the "lip" and become turbulent. This applies at the lower IM to head interface also.

Another reason to leave the taper alone is that it causes the airflow to speed up as it is squeezed into the smaller bore area (Bernoulli's Law, IIRC).

well the air would slow down then going from the smaller upper to the larger lower

I think Bradness means that even though you are polishing your lower intake, try to preserve some taper in the bore. You would still want to enlarge the upper to fit as long as you have no overlaps.

warmonger