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Hey Marcus, thanks a LOAD!

I have some numbers of my own that I wanted to compare to some real life Duratec numbers. I'll settle for a mildly hopped up Zetec. The data are from a 3rd gear run on a level road as logged by the ECM and entered into Bowling's Highway Dynamometer Calculator. All HP and torque numbers are "corrected" by the program. Here they are:

RPM - HP - Tq
1574 - 35 - 118
1967 - 47 - 124
2360 - 58 - 129
2754 - 69 - 132
3147 - 79 - 132
3540 - 89 - 132
3934 - 99 - 132
4327 - 101 - 123
4721 - 90 - 100
5114 - 84 - 86
5507 - 88 - 84
5901 - 101 - 90
6294 - 103 - 86

In comparison, it looks like my engine is doing okay (I had serious doubts) up to about 4000.

The intake ports are "D" shaped with the periphery of a 1 3/4" dia circle. Not only are my runners 1 1/2", I am pretty sure (won't know until the manifold is removed) that I squished them down to the point they would fit INSIDE the ports. No, I don't remember why I thought that would be a good idea. Anyway, I've decided to try to make the new manifold with long 1 3/4" runners, shaped to match the port configuration and size. If that is not a major help I will make a set with runners about 15" long. Its the only way I know to find out what is happening.

Bill

Nice numbers. It seems consistent with the way mine pulls as well. That nice flat torque curve up to 4k definitely makes the car nice to drive.

If you do another manifold, I'll be anxious to hear if it helps the high end torque.

I saw this intake manifold from a Ranger Duratech. Maybe this would be usable on your motor BBlue? I thought among other things you were having engine height issues...

Marcus, I think that is a stock Focus intake. I looked at them, but I don't have the room. Believe it or not, I have more width than height issues. Here is a photo of my "boiler room". Note how close the brake master cylinder is to the intake. It would not help to move the MC, the steering box is directly under it and just as close. The Alpine is a terrible choice for engine swaps. The lower you go in the engine bay the worse the width problems become. If I remember correctly, the Alpine measures 22" between the rails and the Duratec is 14" wide.


Bill

Will spare you the details, but it appears I will be able to fit a tunable manifold to the Duratec. Runners are 1 3/4" I.D.. Will start with total runner length of about 23" and work down, one inch at a time until results start going the wrong way.



I plan to make a "dyno run" and post results for each runner length. Should be fun.

Bill

Bill-
Interesting project! Variable length runners, slide 'em in and out until you find the sweet spot... I like it!
But tell me, are you a trombone player, or were you inspired by the trombone section of "Blood, Sweat and Tears"???

J/K...

No and no.

Bill

You could also use short, straight sections of radiator hose to tune the length. You can also buy rubber couplers with clamps for plumbing from home improvement stores.

To balance the flow without restricting the center tubes, consider using mandrel bent exhaust tube for the outboard tubes, curving toward the tb and protruding into the plenum, while keeping the tubes parallel outside the plenum for easier length tuning.

Form a bell mouth inlet with a small ballpeen hammer and the horn of a 50# anvil.

You might also consider .050 sheet steel instead of exhaust tubing for the plenum and tb transition, to allow for an easier taper to the plenum and outboard tubes. A 4x8 sheet is around $50 and is useful for many things including brackets, firewall, flooring, and heat shields, to name a few.

Great project, this will be fun and informative. Can we take a pool or vote on the outcome.

I am going to vote for "the longer the betterer". I think this is a good approach, just going on my own experience with the perverse difficulty of getting things to go your way in these ( actually almost any for me ) level of projects.

Just finished the fabrication, still have a lot of finish work, but this is what I have. These are two inch exhaust tube bored to slide over the 1 7/8" runners, then bell mouthed. Easy to do after its been thinned twenty thou or so!


And the plenum. This was formed from a length of 3" exhaust tube.


Work in progress:

That stuff was .080" and tough to work. But it was free.

All assembled.


There is only 3/8" between the tubes, so radiator hose is out. I am going to slice up lengths of inner tube, butt glue the ends together and use gear clamps to hold everything in place.

I am going to be able to shorten the runners about 3" simply by loosening clamps and adjusting the throttle cable. Any more and runners will have to be shortened. That will happen only if testing reveals that Marcus is wrong.

But I don't think he is.

Bill

Any chance you have the stock Ranger Exhaust Manifold laying around still?

I need one for our LeMons car.


Let me know,

Mark(at)eFishers(dot)com

Yes, I still have it and have no plans for its use. Did you receive my email?

Bill

Here is the new manifold, installed and ready for the road. But that won't happen for at least a month. Have some brake work to do and there is still a ton of salt on the roads.



Bill

How does anything grow in the areas of the country who have to salt heavily in the winter? Didn't the Romans salt their enemy's home ground so nothing would grow?

Heck, we have to pave the roads just to keep stuff from growing there...