Whats with these different SOHC engine Cover's

[X24]

So who can explain what the benefit is from the VIS? I understand what it does, but how does it work? What does it do for power and such?

 

[X24]

I just did a search on google and found this... It states the opposite of what John said. I wonder which is right?

A tuned variable-induction system, in which a vacuum-actuated valve varies the effective length of the air-intake tracts by separating or combining the two halves of a split-intake manifold plenum. At lower rpm, the closed valve separates the intake pulses from each bank of the engine up to the throttle body, providing a longer effective tract length for better low-speed torque. At higher rpm, the valve opens, allowing the intake pulses from all cylinders to combine in the plenum and optimizing high-speed power

 

[yob_yeknom]

Heh, I probably got it backwards. Been awhile since I read anything on it and my memory isn't the greatest thanks to a certain beverage. Guess I better change the picture and the post...

Okay, I fixed it now.

 

[Slush Box]

Even its the difference between 203-205 horsepower thats not much of a difference i even hear the Sport Tracs have 207 not enought to worry about.

 

[Black Magic]

Hell, People pay big bucks for 2-4 HP!

 

[Slush Box]

The SOHC motor i have is a Flex Fuel Engine according to the sticker on the new 2004 Sport Tracs. Plus i found out the motor is from Germany i have a Euro truck yay. I need some BBS wheels now and i'll be set.

 

[STANN]

So the older model has VIS? Why would they get rid of it on the newer ones?

 

[yob_yeknom]

Cheaper to produce.

 

[X24]

Maybe it's something else, but I think I can feel when that valve opens. When starting from a stop and flooring it, when it gets around 3000 rpm it suddenly gets a second wind and goes.

 

[Slush Box]

The new ones like mine and ones i have seen on the new Sport Tracs are called Flex Fuel.

 

[Doug904]

Ford has used 3 different style intake manifolds on the SOHC's and two different style valve covers, along with PCV systems.

The first is what I refer to as the figure 8 style with its long runners. It was the original style, upper and lower seperate peices and had a aluminum throttle body. It was on 97-00 maybe some left on 01's.

The second is what I refer to as the Bread box intake because of its large volume design. Its a one peice intake with a plastic throttle body. This is also when ford switched to plastic valve covers and swapped sides on the oil filler tubes and switched PCV systems.

The third style, from which I've seen very few, were on most Sport trac's and newer Explorer's from 01-02up. It looks very similar to the old style 94-98 V6 Mustang upper intake as it swoops over the driver's valve cover. it to is totally plastic. I'm not certain on the rest of the engine.

Later Doug904.