?Biggest Cam for Emissions?
- Thread starter jimilane
- Start date
Daniel50
New Member
the only real way to ensure a pass is to get a custom cam. i know they are pricey, but they can make the car pass though...
89MustangGX
I have nothing productive to add!
The E-cam is certified emissions legal I believe, but you can certainly pass with other cams. As mentioned above, if you can swing it, a custom cam would get you the best compromise for both worlds (power and emissions).
89MustangGX
I have nothing productive to add!
jimilane said:
I used to pass emissions with this cam in a Carb'd engine:
Wolverine 1087 (289º 299º 222º 232º 0.510'' 0.534'' 112º)
Every car will be different, as will each setup, that's why the whole setup is important (thus, the custom cam would be an excellent choice).
Other companies make emission certified cams, for example CompCams. Basically, for emissions you need to minimize overlap and duration. A general rule is that cams with 220 degress or less intake duration at 0.050 inch lift will work for emisions. This is exactly the specification for the E303 cam, all the other Ford choices have a longer intake duration.
With heads that flow well at high lifts, you can get power by increasing lift; otherwise it is necessary to increase duration (which runs into the emissions problem). But an option is a dual pattern cam with a higher exhaust than intake duration. This is especialy helpful on stock or near stock heads where the exhaust is noticably more restricted than the intake. To avoid too much overlap from the longer exhaust duration, go for a cam with a larger lobe separation. Another advantage of such a cam is that it puts more of the power (and torque) at the low end, which is an advantage with the stock intake system that does not supply enough air for high RPM power anyway. Cams such as this are typically made for supercharger applications, but also work well on a stock engine.
Flow in the stock cast iron heads does not increase above about 0.49 inches, so high lift dosn't help (and will also cause spring binding unless modificatons are made). The E303 cam has a relatively low lift and so is suited for the iron heads, but higher lift cams a better choice for aftermarket heads. Another option with aftermarket heads is simply changing to 1.7 ratio rockers, this increases both lift and effective duration (measured at 0.050 inch lift) without changing the cam.
With heads that flow well at high lifts, you can get power by increasing lift; otherwise it is necessary to increase duration (which runs into the emissions problem). But an option is a dual pattern cam with a higher exhaust than intake duration. This is especialy helpful on stock or near stock heads where the exhaust is noticably more restricted than the intake. To avoid too much overlap from the longer exhaust duration, go for a cam with a larger lobe separation. Another advantage of such a cam is that it puts more of the power (and torque) at the low end, which is an advantage with the stock intake system that does not supply enough air for high RPM power anyway. Cams such as this are typically made for supercharger applications, but also work well on a stock engine.
Flow in the stock cast iron heads does not increase above about 0.49 inches, so high lift dosn't help (and will also cause spring binding unless modificatons are made). The E303 cam has a relatively low lift and so is suited for the iron heads, but higher lift cams a better choice for aftermarket heads. Another option with aftermarket heads is simply changing to 1.7 ratio rockers, this increases both lift and effective duration (measured at 0.050 inch lift) without changing the cam.
18mustangs
New Member
jimilane said:
Jim, out of the three that you mentioned only the E303 is e-legal with a CARB number. FRPP says their other cams are not e-legal. Like others said, Crane Cams, Comp cams etc make good aftermarket e-legal cams, and naturally a custom cam is the best. BTW, it' not the lift but duration that affects emissions compliance which is why the E cam at .498 lift and 220* duration is e-legal and the B cam at .480 lift and 224* duration is not. (FRPP also claims that the B cam makes 5 more HP than the E cam with less lift and more duration).
Tim
sodaking663rd
New Member
i am running motorsport 1.6 rr's with an E cam and trick flow heads...should the rr's be changed to 1.7?
I bought the E303 cam new here locally in Raleigh, N.C. at Carolina Mustangs for $175. Pretty good deal if you ask me.
I have it in the car now and I'm putting the upper manifold on now.
I bought the idle control spacer that goes between the throttel body and the IAC valve. We'll see if I need it.
The rest of the engine is stock, including the valve train.
Jim
I have it in the car now and I'm putting the upper manifold on now.
I bought the idle control spacer that goes between the throttel body and the IAC valve. We'll see if I need it.
The rest of the engine is stock, including the valve train.
Jim
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