I'm working on picking a new cam for my 427 and am a little confused on a couple of things. First there are 3 cams I'm looking at. When comparing the first 2 here are the specs:
1) advertised duration 296/306 druation@.050 238/244 lift .532/.530 108lsa with a 104 cl. This is hydraulic. Intake open: 15btdc
Close: 43abdc
exhaust open: 54bbdc
Close: 10atdc

2) advertised duration 274/288 duratin@.050 242/252 lift .564/.587 105lsa 101 cl. This is a solid flat. Intake open: 20btdc
close: 42abdc
Exhaust open: 55bbdc
close: 17atdc

Now the questio is this, while both cams have totally different profiles, their valve timing is very close to identical, only off a couple of degrees here and there, does this mean they'll build similar cylinder pressure and run about the same in the engine or will one run stronger than the other and why? It eems to me they should make pretty similar power in the same basic rpm range right? Althought he hydraulic may have a slight advantage right off idle.Or how about this compare number 1 again to this one:

1) advertised duration 296/306 druation@.050 238/244 lift .532/.530 108lsa with a 104 cl. This is hydraulic. Intake open: 15btdc
Close: 43abdc
exhaust open: 54bbdc
Close: 10atdc
3) advertised duration 304/311 duration@.050 240/248 lift .557/.578 108lsa 104cl. This is hydraulic also, ball nose, and I don't have the valve timing numbers.

Now when comparing these 2, even though the second one (number 3) has a little more duration @.050 and a littl more lift, wouldn't number 1 make more torque from faster ramps?Or will these two run pretty identical as well? I've fried my brain today trying to pick a cam and working with static and dynamic compression ratios v/s gearing v/s weight v/s head and intake airflow, etc., etc. Thanks for your thoughts on this. I'm not asking for a cam recomendation (that's why I didn't list all the specs), but I was just wondering how these 3 cams compare to one another and how they'll differ in power.

http://www.amotion.com/tech/camtalk.html

First off, what's your compression ratio?

I wouldn't begin to pick a cam for you unless it was for a stock 1967 350SS engine!! BUT I have, he, he!!

And if you want a SOTA cam, then please hunt up UDHarold b/c he's starting to settle down after job switching and is posting back some over at Team Chevelle!

Great guy and you CAN'T go wrong w/ a cam spec'd by him!!

pdq67

Thanks, but you guys aren't reading my question. I'm not asking you to pick a cam, and I know all the termenology for cams like is in the link. I want you to compare the characteristics of the listed cams to each other, and if they'll all act the same or where will each one have an advantage.

dont run either cam you need a roller can with roller lifters it sounds to me that you want a high lift cam . you have to take a few things into respective . what rear gear ? what car ? tranny ? motor ? tourqe converter? size tire everything headers? buy a roller cam with a nice lift and duration @ 50 that is very important street cars run good with under 300@ 50 wile racers run a big duration cam @ 50 rember just call the cam company your buying it from i like crane they will give you what you need

296/306 druation@.050 238/244 lift .532/.530 108lsa with a 104 cl, hydraulic

274/288 duratin@.050 242/252 lift .564/.587 105lsa 101 cl, solid flat

304/311 duration@.050 240/248 lift .557/.578 108lsa 104cl, hydraulic

These are ALL duration at .050" timing numbers, aren't they??

Anyway, I always look only at the advertised duration numbers when dealing w/ DCR calculations!

And I know that the advertised - duration at .050" numbers mean Hydraulic-Intensity per Mr. Crane!

Therefore, I figure the solid cam will be a very good cam overall. It will run fine in a lower CR'd engine such as around 10 to 10.25 to 1!

Whereas the 296 will need like almost 12 and the 304 will need over 12 to 1 to really run their best like they are supposed to run. And I know that all of them will run in lower CR'd engine's but NOT to their best, omho.


Now LCA's and ICA's, All of them are darn close.. We aren't looking at say a 106/102 vs a 114/112 so they will all be very close, imho..

The 108/104 should have a schosh lower and wider power curves than the 105/101, but probably not enough to even worry about.

You really need to try to have UDHarold explain ALL this in depth b/c HE'S the Cam Guru around here!

I'm just a "book and thread reading Piker"!! And I fully admit it..

pdq67