Anyone have the Lightning cam specs? Looking for at least lift, duration @ .050, and lobe centers.... Also if anyone has stock 5.4 specs to compare to that would be great!

Thanks.

 

THey are the exact same cam specs from the 2000 Mustang GT. All windsor PI heads have the same specs.

.510" lift/201 degrees duration @ .050" (intake)
.531" lift/210 degrees duration @ .050" (exhaust)
114 degree lobe centers

Wimpy *** cams for a blown-application! Actually, wimpy-*** cams for any performance vehicle, just MO.

joe

 

Actually, thats pretty high lift for stock. More than an LS1.

-Spencer

 

If those specs are correct they are pretty good specs for a blown application. Why do you think that the tuners are only getting 12rwhp with aftermarket cams so far. They are still working on that though.
Also, I thought the cam specs for the 4.6 were different from the 5.4???

 

Why do I think the tuners are only getting 12 rwhp from aftermarket cams? Cam spec choices!! Thats why!

And the windsor PI 2V heads, share the same specs. Look up the part #s from Ford. They are the same.

Cam choices can wake these trucks up, but just because someone else hasn't chosen the right spec combo, doesn't mean it won't be done.

joe

 

Thanks, helps to see that they are the same on all p.i. heads. What doesn't help though, is I've also seen a couple sources claim those stock cams are around 182/195, along with a couple saying 201/210 but .505/.535, a little different than the lift numbers you gave. It amazes me that I can't find one dead set group of numbers, and makes it very difficult to model what a cam swap might gain when you don't know what you're starting with....

BTW since I haven't update my sig, the reason I'm looking is not for the truck, I'm thinkig about dropping a 5.4 in a '99 Stang I have now, and figure on needing some extra duration to feed the larger motor up high, but like I said hard to figure what you'd need when you don't know what you're starting with....

 

The 185-192 dur numbers looks like the stock '96-98 4.6L cams. And the duration is in fact, 510/531. Those were the measured numbers from the cams before they were re-ground. Crane Cams, Universal Ford, and several other sources have all given the same numbers.

As far as swapping a 5.4L into a Mustang, contact Al Papito (Boss330) on the Corral. He is currently running a 5.4L N/A motor in his 98 GT, running 11s, pushin 400+, I believe. He is located in South Florida, and is a very knowledgeable/friendly person. He should be able to point out some of the pitfalls on the swap.

Good luck.
joe

 

I'm going to keep ranting about this every now and then until the world understands my point!!! J/K. Everyone has a right to choose if they want to understand what they are doing or just throw money at something and hope for the best

For a roots style constant volume blower, the cam specs are relatively meaningless. You can really hurt yourself if you allow to much overlap to blow your fresh air out of the exhaust, but there's not a whole lot you can do to help yourself.

Since the blower moves basically the same amount of air independent of downstream obstructions (like rough ports, only 2 valves, not the right cam grind, etc.), and since power scales pretty damn close to airflow, changing any of those downstream things nets only small HP gains. By changing cams you might get a fractional (and I mean very small) change in airflow, and a small reduction in the power consumed by the blower. That's what shows up as a 12 hp improvement.

Its not so much that the factory go it so "right" from the beginning, or that aftermarket tuners just hadn't found the "right" grind. Its just that it doesn't matter.

Naturally apsirated engines need properly tuned cams in conjuction with similarly tuned intakes and exhausts to get best power. That's why cam changes can make large differences on those engines.

Analogy time.

A conveyor belt with apples (blower) is supplying apples to crates. The belt has some density of apples (air denisty) and some speed (blower speed). The crates are a certain size (displacement) and rotate by at some speed (engine speed). Each crate has an opening on the top that all the apples must go trought (intake, exhausts, cams, mufflers, cats, port and polish, and on and on).

Now you can make the opening bigger, you can change out the crates faster, or you can make the crate larger, but in the end, your moving the same damn amount of apples. The only way to make more power is to increase the density of apples on the conveyor (with filter, MAF, throttle body changes) or you can make the conveyor move faster (blower pullies).

Does everyone understand?

My analogy leaves out a couple of other obvious things like if the mixture is too rich or too lean, then you can pick up power. Also if your timing is less than maximum brake timing, you can pick up some power. That is why chips make a difference. There is a reason that blower pullies and chips make LARGE changes in power, while all the other little things do so little.

Obviously my post wasn't aimed at anyone doing a naturally aspirated engine application. In that case, knowing the cam specs is very important. At the time I started writing that post hadn't appeared yet.

It was aimed at this statement.

 

Nice conveyor belt analogy, but it doesn't end the argument...

Increased cam durations, lifts, changed lobe centers and all, won't give the gains alone. And I never said that! However, the proper cam specs, combined with the right porting, valve choices, TB, and well *****, the right combination of parts, will provide for significant gains.

But since you wanted to try to put it into "simple-minded" terms, I will elaborate on your above analogy.

If you speed up the conveyor belt, to increase the amount of apples moved, you also need to enlargen the opening to the crate, and move the crates out more frequently, or place the crates closer together, in order to meet the demands of the conveyor. If you don't use the right combination of processes, you are doomed to fail. Apples all over the place, union workers striking for beter wages, etc.

But back to the real world... If you increase the amount of air moved into the engine, you need to open the flow downstream. And while you do have more error in duration overlaps on a roots-style PA, you can still increase this to move more air through the conmbustion chamber, while not causing the cylinder pressure to bleed off from constant flow.

Now why you decided to go after my statements, is beside me. It was similar to the responses I got when doing alot of cam testing on Mustangs a couple years ago.

I will leave it at my original statement... Cam choices can wake these trucks up, but just because someone else hasn't chosen the right spec combo, doesn't mean it won't be done. But I will amend it by adding that the right complimentary parts must be added to the equation.

Have a nice day!
joe

 

I didn't choose to attack you. It was just an opportune time to restate a point. We've been through this on the board before.

To make my analogy follow the real (physics based) world I will add... No matter how big the opening in the crate is, or how long the crate stays there, the apples will all end up in the crate and not fall on the floor.

The reason that works is because to the type of blower. The blower takes some amount of air (the swept volume) and dumps it into the manifold. The mass of air that it brings in is the swept volume and times the inlet density. The rate that the air is put in is the mass times the rotational speed of the blower. Now in order for you to understand everything else, you must except that simple fact. If you won't take my word for it, then consult a book on compressors. I don't have a title to give you, but they are out there.

There are also some assumptions that have to be made by saying that. If I don't state these then someone will find fault in a small part of what I say and then use that to prove that everything I say is wrong

The outlet (downstream pressure) will affect the airflow by a VERY small amount (less than 2% at higher rotational speeds). Things like tip clearance, the silencer slots, and other small things add up to VERY small differences also.

Since Power is made my moving air and fuel and burning it, the main thing to effect power is airflow. I'll also assume that proper tuning has taken care of the right A/F and timing. So now I ask you, if you change cams, how will it meaningfully effect airflow. Keep in mind my statement before about how to calculate mass flow into the manifold. Nowhere in that equation was downstream pressure (which is what a cam change will affect). The only advantages you can gain are: reduced effort to turn the blower, lower outlet temps, and MARGINALLY higher airflow. Those things are why SMALL changes in power can be seen with a cam change. That is why no cam grind will be super special and suddenly make a large difference.

If the mustangs you were tuning were naturally aspirated, then I agree with what you say 100%. But on a mustang, Helmhotz tuning of the intakes and exhuasts, along with port sizing and valve sizes all make a difference as to what cam you use. Properly selecting a cam can make 10% changes in power on highly tuned engines. But you can not take that generalization about what a proper cam can do and apply it to a completely different system. As soon as you bolt on a ROOTS style blower, many of those other things go away. Its not just dumb luck that none of the aftermarket cams really makes much of a difference (and to me 12 hp on top of 350+ is a small change).

 

Interesting stuff.
I am eating lunch, and just realized I left my apple at home.
Chris

 

You guys are great! This thread sure beats the usual "my @#*% is bigger than yours" debate that goes on everywhere.

 

Then riddle me this batman...

How can a cam thats used as a stock part in a Naturally Aspirated 4.6L, still apply to the Supercharged 5.4L Lightning? It can't. It is a generic part, that doesn't offer the best specs for the application. Can you tell me that the stock cams are the perfect spec choice for the SC 5.4? Does it allow for optimum airflow in this application? If it does, how does it then apply to the naturally aspirated 4.6L 2v engine? Can it really be that Ford defies your reasoning, and obviously the reasoning of many other physicists? hmmm...

Airflow is obviously a topic you have done some reading about, but that doesn't solve the issue of how much a properly tuned cammed motor will gain. Because a point you are missing, is that the stock cams are not the optimal specs for the engines in our Lightnings. They are restriction in the airflow track, and you can argue the physics behind airflow all you want, but the last time I checked, restrictions in airflow usually caused decreased performance.

I guess its pointless to argue about this any further, because you are asking me to accept the airflow theories above to be The Truth, which I obviously can't. And rather than have this turn into flame-fodder, I will just say good day. And good luck with the stock N/A cams in your S/C engine.

joe

 

Hopefully you'll stop back by so I can answer you question. Don't reply if you don't want to, but this should answer your questions.

The cams are obviously some sort of compromise when on the 4.6. They are a compromise between drivability, emissions, economy, and power. If you choose to give a little in an area, you will get it back in others (on the NA 4.6). On a [roots] supercharged engine, those compromises aren't there.

Don't know where that came from... what did the physicists say that defied my reasoning.

First of all, you're assuming the cams are not optimal. This is probably because in other applications you can throw money at a cam and usually see some nice gains. But that doesn't mean they are not. Even if they were designed for another application, you can't apply a blanket statement that they must not be what's right.

Second, yes the valves are a restricion in the path. But because or the type of blower you have, the same airflow will still happen. By restricted the airflow, you are creating a pressure drop across the valve. If you create more of a pressure drop (by installing non optimal cams) then the measured boost will be higher. The pressure in the cylinder will still be the same (i.e. if the pressure drop across the valve goes up 1 psi, so will the boost). The increased boost obviously won't increase power. It will actually decrease power since the blower has to work harder to move the air (and heat the air up more). But before you say I told you so, the HP change will be fairly small. According to eaton specs, probably about 4 hp. So airflow and indicated power from the engine the same, brake hp lower since blower took more power to turn.

The same thing happens going the otherway except the power will go up slightly. I'll definately admit changing the cams will make small changes in power. You'll just never see the large changes in power that a Naturally aspirated, centrifugal supercharged, or turbocharged engine would. There is no "special" grind that needs to be invented for our engines.

 

A few past threads dealing with cams:

https://www.f150online.com/forums/sh...threadid=82999

https://www.f150online.com/forums/sh...threadid=76892

https://www.f150online.com/forums/sh...threadid=67892

https://www.f150online.com/forums/sh...threadid=29526

https://www.f150online.com/forums/sh...threadid=29155

https://www.f150online.com/forums/sh...threadid=26034

https://www.f150online.com/forums/sh...threadid=24388