Are there any specific perks or characteristics of a short lift w/ long duration combination that would set them apart from a tall lift w/ short duration combo or vice versa? I don't have much experience with a lot of aftermarket cams and was wanting some help on this. Thanks!
Scott

 

There are so many differences in cams, you would just about have to compare each grind individually. Usually, with rare exception, the numbers go up and down together. As the lift goes up, the duration goes up. The only reason I can think of that you would use a grind that has an extreme duration and a low lift is if you have some component that cant handle the amount of lift. The duration is going to mess up idle and vacuum, so if your engine can handle it, might as well have the lift. Maybe someone else will be able to answer your question better.

 

Cams take a long time to understand completely. High duration short lift cams should only be used in racing applications that have a maximum lift rule. How about you tell us what you have and what you want to do with it and we will go into GREAT DETAIL as to why we think a certain cam would work best.

Lobe center angles have a huge effect on performance also. Its not just about lift and duration.

 

Don't have a cam, intake or carb as of yet- building a 460, has ~9.8:1 computed CR, bottom end is complete- not worried about running pump gas- is goin in a mud truck will run high octane if neccessary. What would you suggest for a good combo of all three? It will run uncapped headers. I want the best power throughout the RPM range, but it's getting a 3000 stall in front of its c6.
Thanks
Scott

 

I would stick with a cam that has a 108 - 110 LCA as it will give you a good midrange powerband. The 110 LCA will make the powerband slightly broader but not quite as much torque will be produced. I am not a 460 buff and don't know how well the heads flow so I will let the others chime in. I know the stock Lima heads flow decent on the intake and horribly on the exhaust so you will want a cam with more lift and duration on the exhaust lobe.


You can't get too crazy with the lift and duration. I would guess that about 280 degrees would be max for advertised. It should have at least 230 degrees of duration at .050 with this much advertised.

Stay away from the cheap cams. Melling is a good example. Their bigger cams are well made and will probably last forever but they aren't very aggressive at getting the valve opened quickly.

A cam with a big advertised duration and small .050 duration will feel like a big cam while you are driving around town but it won't feel so big when you open the throttle up.

 

Heads have been ported...
Scott

 

Thats how my melling cam is. Its junk!!!!!!!!!!!

as a generalization, high duration is for horsepower and more lift with little duration is for torque. lots of both is pure performance (on the topend).

 

I am partial to the Comp 4x4 series of cams, they make 4 for the 429/460, either 2 or 3 would work well for your application, altho with the stall I would lean towards the 3rd one myself
CCA-34-231* Advertised duration: 256 intake/262 exhaust
* Duration at .050 in. cam lift: 210 intake/218 exhaust
* Gross valve lift: .514 in. intake/.514 in. exhaust
* Lobe separation: 111 degrees

CCA-34-235Specifications:
* Advertised duration: 262 intake/270 exhaust
* Duration at .050 in. cam lift 218 intake/226 exhaust
* Gross valve lift: 514 in. intake/524 in. exhaust
* Lobe separation: 111 degrees

CCA-34-239* Advertised duration: 270 intake/278 exhaust
* Duration at .050 in.: 226 intake/234 exhaust
* Gross valve lift: 544 in. intake/574 in. exhaust
* Lobe separation: 111 degrees

 

Actually, high lift and high duration for horsepower. Lower duration with as much lift as you can get for that duration for "low end" torque. Thats why a roller cam is a better torque builder than a flat tappet cam. You can get a higher lift with a short duration than you can with a flat tappet cam. The flat tappet cam has to gradually open the valve, a roller cam opens the valve in a much shorter radius of cam revolution.

 

thats pretty much what i said!

 

So, anyone have any ideas why no hydraulic roller lifter for the 385 series (429/460).. seems it would be such a nice functional addition.

Solid rollers are just such a pain.

Sam

 

Crane makes a hydraulic roller lifters for the 429/460, and both Comp and Crane make hydrailic roller cam grinds for the motor. Supposedly Comp's hydraulic roller lifters are "in development"

 

Also, with a roller cam much faster opening and closing events are possible. This is where the real power is to be had. Higher lifts and reduced friction are an added bonus. The drawback is very high costs. Most engines require valvetrain upgrades as well to withstand the much higher spring pressures.

 

Sheesh!.. Looking at Crane, the cam is $400 and the lifters are slightly more!.
There are millions of Mustangs out there with roller camshafts and lifters. I bought a used roller cam replacement for $50.. This is not new technology!!

so much for that idea!

Sam