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Discussion Starter · #1 ·
I stumbled over this incredibly difficult problem, and hope some of you have some nice thoughts about the results....

I got my 5.4litre DOHC and it didn't quite fit into my project car. (I know, I know.. Not good enough research..but info about this engine is VERY difficult to obtain.)
The problem was not the extreme width, but the outrageous height. So the solution is as easy as it's difficult. Build another intake. The easiest would be to cut down the intake runners from apprximately 17 inches to about 6 (!!!) inches. How would this affect my engine? I know the low torque will suffer and top end will benefit. The question is how much?? Approximately of course. I have tried all week to figure out the combo on my EngineAnalyzer to see the effects, but that was NOT easy. Actually I haven't made it yet. Building longer runners is possible, but very hard because of the confinement.
If any of you want to try compute my engine, I can give you the data I have, and you have to guesstimate the others.
My biggest problem is the long stroke of the engine, making it expensive to rev above 5000RPMs. (4.17 inch stroke.) So keeping the RPMs down is important.

Give me your best..
Doc
 

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I think you're gonna effective kill the engines power band. Cutting the runners down nearly 60% in lenght can only be detrimental to any resonant tuning the factory probably had optimized for the motor.

I guess you could play around with cams and to gain some of it back but with that stroke, yeah it would be tough.

Interesting project though! Take pics and post em
 

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I'm not poking fun, really I'm not, but it sounds like it's going to be more of a hood issue than a intake issue.

I think 67stang is right, I think the motor will be a hack with the intake mods, without spending some serious money to have it engineered correctly.

How much does the intake stick out and of what is it sticking out of?

I seen pic in a mag a couple of months ago with a 5.4 out of a Lincoln in a early stang. Wow it stuck way out.
 

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Have you considered fabing a cross ram type set up? In essence, the runners could go across the engine to the other side and vice versa. You'd effectively have approx the same runner length, just going sideways instead of up. Granted, your airbox setup would have to go, but still has possiblities??
 

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One other thought: maybe you could mount the engine lower in the engine bay. Even going to the trouble of working up a dry sump system could be easier than doing the intake.
 

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I see nothing but driveability issues if you start hacking away at the intake.
Ford, (or whomever), spent millions of dollars, (ok, maybe hundreds), designing that intake to work the way it does.
I'm assuming you're using the stock electronics, (i.e. pcm), and other parts on this, right? Nothing is going to be the same. You might as well start from scratch with everything and redesign the works, if you modify the intake.
My .002.
I'd put a nice hood scoop on it, and also do what someone else said, and modify the oiling system to lower the engine..........
 

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Discussion Starter · #7 ·
Some good thoughts here, but not very applicable in my situation. Dry sump has been in my thoughts, but wouldn't lower the engine more than 1 -1 1/2" max. The stock intake is already a cross-ram split plenum version.

Like it is now I have to have almost 8" tall hoodscope. That's a ProStock look I don't want. And of course the engine is tallest at the front end. (Making the whole thing so much more interesting.)

I have the difficult rerouting of the intake option left, but this will not be easy. How much could I shorten the intake runners without killing off the low end torque???
It was because of the low end torque I wanted this engine in the first place.

And the car: German Ford Granada.
Soon to be holding a 5.4litre DOHC, T45 transmission and 8.8" rear end placed into a semi-trailing rear.

Doc
 

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One other option: At least one co in the U.S. is not making a individual runner type EFI set up. It basically consists of eight individual throttle bodies with injectors at each port. The one I saw was on a 4.6 DOHC Cobra engine and looked fantastic. (car didn't run too bad either: 9's w/o nitrous!). You could control the height of the injectors with your ram tubes. Good luck. Sounds like a cool project, but you've obviously got your work cut out for you!
 

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Discussion Starter · #9 ·
Let's say it this way,

I know what to do in my time off in the next couple of months.


I think I have to do the long hard walk, I can't find any shortcuts.

Thanx for the inputs.

Doc
 

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Your 5.4 is the same as my 6.8 V-10 but with 2 less cylinder and I've modified enough things to get the usable power band up to 5500RPM without any breakage issues. I have accidentally down shifted into 1st at much too high of speeds and actually burried my 6000RPM tach but that's because I eliminated the rev limiter and speed limiter so it will downshift(it's an automatic) at any speed if I manually downshift it. I believe if my V-10 will hold together with very freequent 5500RPM shifts and occasional 6000+RPM burnouts and accidental downshifts your 5.4 should handle at least as many RPMs without a problem. Unfortunately I'm still using the stock tiny runner size intake but looking for something larger. These mod engines are impressive and take well to performance tuning and traditional hot rodding modifications like Mexicans take to the Rio Grande river but intake tract runner lengths can really effect the powerband in a big way with only minor meddling but cutting that much off the runners may hurt you everywhere in the power band unless you get the operating RPMs up higher by porting the heads, bigger valves, bumping up the compression some more(mill heads), and a little bit larger cams plus headers really wake these 5.4s and 6.8s up. I'm currently looking for a nitrous kit for my V-10 with about 200HP or so. Our intakes really do suck though and those runners are very small diameter so try to check for an aftermarket intake if somebody makes one. Don't be afraid of that 5000RPM rev limiter, these engines will rev higher reliably. Ford just limits them to 5000RPMs for total safety and warranty purposes.
 

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It seems to me that if you half the tuned lenght of the runners, you double the optimal RPM range the runners are designed for. It should be somewhat proportional like that. Given this info, if you shorten the runners more than 20-30%, you'll push the intake's optimal torque range beyond the engine's operating RPM range.

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I remember reading an article that Windsor-Fox put one of these 5.4 engines into a 66 Mustang. Maybe you can get some ideas from them.
Here's a thought, maybe you can run a carb instead of FI. Just a thought.
 

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Discussion Starter · #13 ·
Hey 89Coupe,

This is good news to me. So a little revving won't hurt it? I like it...


What have you done to your engine, and how has it turned out for you? I am going to get more compression, but have not decieded if I will mill the heads or go for other pistons. Cam timing will change with milled heads. A little 'clean up' porting is also in my plans togheter with the standard port matching. Headers is not an option, it's THE ONLY WAY!! If you know what I mean.. Mine is going to be one-offs. Have you reprogrammed the EEC?

coupe3w: Ditching the EFI is not an option. (But I have to admit I did consider it for a very short time when I saw the intake sticking out above the 'hood-line'.)

Doc
 

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I am assuming that you got your 5.4 from a ford truck and it has a tall truck intake. Are you familiar with the newest mustang cobra r? It has the 5.4 in it..you can probobally get an intake like the one in it. The truck intake with the tall runners is setup for torque and probobally wouldnt be the best option for a car
 

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Discussion Starter · #16 ·
Pat Lazansky, that was interesting.....very interesting.
 

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Discussion Starter · #18 ·
I'll try to post some pics of it when it starts looking like something.

And the Cobra intake....Nah, too tall. So it's back to building my own, placing the alternator down by the side and the plenum down between the heads. This is the only way if I'm going to keep the intake as low as I want to. If any of you wonder, the alternator will end up where the power steering pump is originally. No PS and no AC on my car. It's gonna be a daily driver old fashion kind of muscle car. No luxury or extra weight. (I will have a radio of course, but that's it)

Doc
 
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