Things I've learned:

They mostly seem to have at least -10deg overlap (-10 to -18 being average)

Also the more Neg overlap there is, typically = a smoother idle or is associated with Cams of smoother idle (usually on a 114-115 LSA)

Are these observations correct?

 

yup

so ya leaning toward one yet?

 

Leaning towards this today:

Dur @ .050 214 intake and 222 exhaust
Lift is 545 intake 550 exhaust
Lobe seperation 115
Intake centerline 111

maybe with a little more intake lift.

 

This is my #2 choice as of tonight:

DUR @ .004" 278*/ 286*
DUR @ .050" 216*/ 224*
* LIFT .551/.551
LSA 115*

 

go with the first one i think you will be happier with it

 

I say second one ... I low end isn't gonna matter much with that blower sitting on top of the engine. Trust me. As small as these cams are too ... you won't have to worry about any drivability issues.

 

i still say first one... power under the curve is what everybody wants but true with either one driveabiltiy would not be an issues

 

Remember this. The lobe seperation angle is "A" key in idle quality. Take this camshaft.

210/210 @ .05, Comp Lobe. With a lobe seperation angle of 115*, it has -20* of valve overlap @ .05 valve lift. Tightening the lobe distance to 110* creates more overlap... -10*. Take a look at that chart. It helps. Move the seperation closer, and you see how the lobes overlap. Move the seperation apart and you have less overlap.

So for example, a 220/220 on a 115lsa, may have the exact same idle characteristics of a 210/210 on a 110lsa.




Simply put: Overlap = duration vs. lobe distance (lsa)

 

^^^ fantastic man beautiful work that even helped me out two enthusiastic thumbs up

 

Personally ... I still don't like the huge split going on there knowing your gonna be putting headers on there. I would go with the 218/224 without a question or second thought. The only 2nd thought I might have would be going to something a little bigger.

There will be plenty of power under the curve with the blower on top.