Question about cams . Low lift vs. high lift

[Jackal66]

I've been looking at hyd roller cams.
Howards shows some profiles with .480 lift and 268° duration.
Then, they show .575 lift and a similar duration.
Both of these have rpm range of 2000-6000 rpms.
I know it's the ramps, separation angle, etc . that makes them hold the valve open for the proper time.

My main question is : If you went with the lower lift and AFR heads , would that be less stress on the valvetrain than going with a .600 lift and cheaper heads?

Just my thoughts, but some of you that have experienced this can tell me for sure.

Thanks for the info.

[Jackal66]

Here is an example for the lower lift cams.

[mt-engines]

What is the application?

[Tom68]

Cheaper heads are likely to have a range of other problems.

[mag2555]

First off how much hp are you looking to make?
Your always better off with a good flowing head that does not have too much port area for your needs then stressing out your valve train .

[rebelrouser]

I built several 350 and 383 SBC engines with stock iron heads with a little port work, 220 duration .520 lift hydraulic roller cams that made 400 to 425 HP, with good torque curves on pump gas, idled good and owners were impressed on how they ran. some for street rods, some for jet boats.

[Walter R. Malik]

An increase in especially Low lift air flow will help a mostly "stock" engine a lot because most original camshafts rarely have valve lifts more than .450" valve lift. The extra low lift air flow tends to make a production type camshaft act larger in those situations.

However, "racing camshafts" are a totally different story with regard to valve lifts ... in my experience, if you need to take duration away from the camshaft to get some torque back, (that you lost with going to a larger duration cam), then the engine WILL make less horsepower so, in those instances, more low lift airflow is usually not wanted.

Then, there are those "middle of the road" type situations where testing is the only alternative.

[cpmotors]

I've been looking at hyd roller cams.
Howards shows some profiles with .480 lift and 268° duration.
Then, they show .575 lift and a similar duration.
Both of these have rpm range of 2000-6000 rpms.
I know it's the ramps, separation angle, etc . that makes them hold the valve open for the proper time.

My main question is : If you went with the lower lift and AFR heads , would that be less stress on the valvetrain than going with a .600 lift and cheaper heads?

Just my thoughts, but some of you that have experienced this can tell me for sure.

Thanks for the info.

The whole reason for going roller is for more lift with minimal time spent doing it... .575" is nothing to be concerned about stressing your valve train about, .480" is a waste of money for the components used.
Use a quality spring and stable pushrod and forget about it.

[Jackal66]

It's going in a street machine .
383 stroker with flat top pistons .
Probably be driven on weekends in warm weather.
2500 stall .
Right now it has 4:88 gears from a drag racing past.

I'll probably go with some AFR heads no matter the cam .

I'm looking for 450+ HP.
Also, will run a tunnel ram with 2- 600 Holley.

[6.50camaro]

Just a word of warning on cheap heads and springs and other components. Buy Bare heads and use top quality springs, locators, seals, retainers, locks and valves. Too many horror stories of sub pare components on cheap heads. Buyer beware. Dan

[Jackal66]

If I go with the AFR heads from Skip White, get the bare heads and let my local shop do their thing?
Are the AFR heads that SW sells ok?

[Loftfan]

To me, .480" lift out of 268° duration at 0.050" is uncompetitive. I'd never consider that.

[mt-engines]

It's going in a street machine .
383 stroker with flat top pistons .
Probably be driven on weekends in warm weather.
2500 stall .
Right now it has 4:88 gears from a drag racing past.

I'll probably go with some AFR heads no matter the cam .

I'm looking for 450+ HP.
Also, will run a tunnel ram with 2- 600 Holley.

A mid 220s@050 .500 lift cam should do the trick and no it doesn't need a 106 lobe center. A 112 will do just fine, have great low end and cruise.

[Walter R. Malik]

The whole reason for going roller is for more lift with minimal time spent doing it... .575" is nothing to be concerned about stressing your valve train about, .480" is a waste of money for the components used.
Use a quality spring and stable pushrod and forget about it.

Not exactly true a lot of times ... case in point are the Dodge Magnum 318 or 360 and some other O.E.M. engines; I remember Pontiacs.
If one simply wished to change the cam without removing the heads, they are very limited.

The Magnum valve spring installed height is only about 1.610" and the spring pocket in the head is only 1.415" O.D. and .930 I.D. so,there is no valve spring available for using any more valve lift than about .495".

Mopar Performance used to have a couple springs available, (that had enough force), which took up to .560" lift but they are no longer sold.

The very first thing someone needs to see is "what will fit" the situation.

[Warp Speed]

The whole reason for going roller is for more lift with minimal time spent doing it... .575" is nothing to be concerned about stressing your valve train about, .480" is a waste of money for the components used.
Use a quality spring and stable pushrod and forget about it.

Not exactly true a lot of times ... case in point are the Dodge Magnum 318 or 360 and some other O.E.M. engines; I remember Pontiacs.
If one simply wished to change the cam without removing the heads, they are very limited.

The Magnum valve spring installed height is only about 1.610" and the spring pocket in the head is only 1.415" O.D. and .930 I.D. so,there is no valve spring available for using any more valve lift than about .495".

Mopar Performance used to have a couple springs available, (that had enough force), which took up to .560" lift but they are no longer sold.

The very first thing someone needs to see is "what will fit" the situation.

There will always be a case that fits well enough to counter someone's opinion, but I don't see how this adds anything in this instance. The OP is going to spend money on AFR heads, but put a cam a with less than .500 lift?!?
Waste of time IMO.
This isn't a SBM we are talking about, and this damn sure isn't the 80s anymore! Lol