Its a 6-speed 97 LT1 and daily car.. What will be the best cam specs for 383ci LT4 210cc AFR Competition Heads.. Cam will be hydrolic roller not solid roller , LSA will be 114 because I will use 200 wet shot nitrous ,but I don't know what should be the duration & lifts number to work well with 210cc flows..?? (I want ~~550hp at flywheel)

any suggestion will be great
thanks

 

Way too little info. How will the caer be used, IOW - what do you want to optimize? What rpm do you plan to run the motor too? Any porting on the heads? What are the valve sizes? What is the static CR of the motor (or can you still change this)? Any unusual considerations like emissions? Also, specifying the LSA without knowing the duration is not logical. And so on. the more info you provide, the more likley you are to get a useful answer.

But in general, a good nitrous cam isn't very different from a good NA cam. The main difference is a bigger "split" between exhaust and intake duration. This necessitates a slightly wider LSA than would otherwise be optimal to avoid excessive overlap.

Rich

 

Alos: do you have springs, or are you going to purchase them to match the cam?

Rich

 

Its a 210cc COmpetition Heads with CNC Porting.. So every part is installed..
-2.08/1.60 valves.
-11:1 Compression Ratio.
-springs are AFR's springs.
-max RPM that I plan to run is 6700.

LSA should be 114 because I will use nitrous. You can decide number of LSA before you decide duration/lifts number its nota big deal..

 

Well, I am not sure where to start since your premise is wrong. It is completely illogical to "pick" LSA without considering duration. The main reason LSA is important is that it determines overlap along with duration. So, you can't decide one without the other - what you are after is the desired overlap. Since duration has such a large influence on rpm range, what you do is consider duration first, then adjust the LSA to provide the desired overlap (and dynamic CR). Overlap has an effect on peak power and the width of the rpm band.

A common misconception is that an N2O cam should have a wide LSA like a forced induction car. This is also false. Basically, a good N2O cam is a good NA cam with some extra exhaust duration and a slightly wider LSA to avoid excessive overlap with the bigger exhaust lobe.

What are the spring specs, specifically, max lift?

In general, I would look for a cam with ~230 degrees of intake duration and between .550-.600" lift (assumiong you have appropriate springs). The exhaust duration should be in the 245 degree (@ 0.050") range with an LSA of ~112 degress. FWIW, the CC306 is pretty close to that.

Rich

 

Firstly thanks for a long reply Rich!

Springs: pressure 160lbs on seat, max lift .670" ..
If I wouldn't use nitrous (200wet shot) I probabily would go with 112 LSA ,but everybody says 114 is better for nitrous..! For that reason I chosed firstly lobe separation understand me? So you say I can go with nitrous by using 112lsa cam.. This is a great new because 112 lsa = more horsepower

 

I think the CC306 or something similar would be an excellent choice. Unless you want to go the "custom cam" route, that's what I would suggest.