Nitrous generally favors cams that have more exhaust overlap and duration.

GENERALLY

I wouldnt lose sight of the cam that would work best in your 5 liter OVERALL (meaning off nitrous performance) for one that will pick up more on the nitrous due to its grind.

I mean you arent going to be on the bottle 100% of the time so picking a camshaft that is going to run harder on the bottle versus off the bottle is not really a wise thing to do on a street car.

If this is a track car, different story.

So when picking the cam that works best for your car off the bottle, or with your overall combo I would go for whatever one favors exhaust overlap and duration over the other.

So if you have a cam with say

220 intake and 232 exhaust at 50 and then a cam that is 220 and 228 at 50 you would want (when looking at overlap as well) to probably choose the cam with 232 if it is going to suit the motors needs better or if it wont make much difference.

Also remember that the good thing about this and one of the reasons I feel that stock motor 5 liters run very very hard on the bottle for being stock is that the stock heads and even most aftermarket ford heads are going to like this added event as well.

they have a whole N20 section.

btw, the stock cam will make great power with N20, I dunno if I'd stress over a cam unless you're trying to squeak the last 10-20 HP on a nicely built up drag-mobile. Otherwise, so much wasted tirespin when you hit the switch, ya know?

btw, Dan, overlap on an N20 cam is not a good thing. You tend to blow cylinder pressure out the exhaust. I totally agree on extended exhaust duration though, but not at the price of creating more than just a smidge of overlap.

[ March 21, 2002: Message edited by: shade-tree ]

Uhhhmmmm

Joe it is really not possible (unless you have found one) to design a cam with added exhaust duration without added overlap.

Remember that overlap doesnt mean the valves will be hung open together on the up stroke of the piston. That is only true 40% of the time.

if you run the numbers, just increase the LSA, and the overlap becomes less and less.

e.g., from the comp cams catalog

nitrous HP 274HR
224/236 @0.05, .555/.570 lift, 114 LSA

quote:

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Originally posted by customN2O:
I have found that setting the cam timing to allow fresh nitrous to come in on the intake stroke, cross the piston, and exit on overlap, to help cool the top of the piston.

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Well Scott you have put it to use and I have only put it to theory.