More cam Thoughts

thanks for keeping the topic going.i dont know anything to keep it going from here. i guess i will pack some more boxes.i am moving.

i would only embarrass myself by letting you think i could explain it.
i thaught it may be a cracked port leaking for all i knew.a cam change made it better and i left it at that going from cam 1to cam 2.

from jegs helpfull tips on blower cams.
it is to help retain cylinder pressure with 112/114 lsa.

edit:i forgot to drag it back.
Supercharger Engine Camshafts
The choice of camshaft can make or break a blower motor. A legend in the industry, Lunati offers several camshafts specifically designed to work with Weiand blower kits. In addition, the following are a few basic guidelines for selecting the proper cam for your motor. Obviously, the amount of boost your supercharger produces is going to be a factor in choosing a camshaft. Weiand offers three different levels of superchargers, and each requires a different type of cam.

The "mildest" of Weiand's blowers are the Pro-Street superchargers, which are set to produce from 5 to 7 pounds of boost. The company recommends a hydraulic cam for these applications - where the engine will not be spun past 6,500 rpm and has several grinds available. All of these cams are ground on a 112 to 114° lobe center line, which helps maintain cylinder pressure to maximize horsepower at these lower boost levels. Keeping the cylinder pressure up also gives you excellent throttle response. The milder cams that Weiand offers are great for street performance enthusiasts who want to gain about 100 to 120 streetable horsepower. The company also offers slightly "bigger" cams for the next performance level up.

For 6-71 and 8-71 blowers, Weiand again recommends running a hydraulic cam, as long as you keep the boost level below 10 PSI. Weiand also offers cams for these type of applications. For your higher boost levels (which includes all 10-71, 12-71, and 14-71 applications) in gasoline burning engines, the company recommends running a flat tappet or roller cam with a 110° lobe center line. This cam design provides good overall power on pump gas and also aids in engine cooling. Plus, the 110° center line provides even sharper throttle response and helps lower initial cylinder pressure (you won't miss the cylinder pressure with these blowers, since they make plenty of boost).

440 and metalstorm, Could the boost increase that metalstorm saw an indication that the new cam wasn't flowing as much? The only way that I can see a cam making more boost on a blower motor is it is not using as much of the intake charge and it is backing up more pressure, seen as boost; as the supercharger will always be pushing out the same amount of air as long as the pulleys are not changed. Or another reason is if the motor is being wound out at a higher rpm to spin the rotors faster to make more boost, ie. flow more air. Am I thinking correctly? I've followed metalstorm and am building a blown 440 and am trying to pick a cam/lifter setup. I have a procharged SBC that I put a 110 LSA cam in and seem to have no issues, with the reason being that the overlap will keep the street driven exhaust valves cooler. Dan.

it could have even been valve spring psi that i could not gain psi.150# seat with cam 1#.the springs were spec from bds with that cam.
as for the restriction and gaining boost psi yes that would be a possibility in some casses like overlap and less going out the exhaust.an added note that my cranking psi went from 100# to 130 with the cam change #1 to #2.

Boost is just a measure of restriction in the system. I ran 452 heads on a 383 with a 224* flat tappet cam and 7.5:1 comp. It ran 12.64 at about 13 psi. Built a new much more free flowing combo same degree duration cam better heads and little higher compression. 9:1 and ran 12.36 at 4 psi. My point is who cares what boost is as it is a measure of restriction. What did the car dyno or run on the quarter with the same pullies and the different cams?

i cant recall the ET gain but it was a couple tenths.[.200 i think]