Considering a few psi, but I like the lumpy idle of my current cam. Specs are .590/.590, 245/245 @ .050, 110 LS, in at 106 ICL, solid. Will this cam have too much overlap if I decide to blow it? I want to stay away from the sanitary modern sound but would like the 'cheap' horsepower of a blower hangin' off the side. Motor is a 390 with mildly ported Ebock heads, RPM inlet, 750 HPDP, forged flat tops, balanced etc.

You can keep the lift and duration so the cam has the same character, but I'd suggest a new cam with an LSA of 114 rather than 110, to match up better with the blower.

The supercharged 490" FE in my Mach 1 uses a 266/272 @ .050" cam with .710" lift and a 114 LSA. Sounds plenty good

Jay Brown
1968 Shelby GT 500 Convertible, 492" 667 HP FE
1969 R code Mach 1, 490" supercharged FE, 9.35 @ 151.20, 2007 Drag Week Runner Up, Power Adder Big Block
2005 Ford GT, 2006 Drag Week Winner, 12.0 Daily Driver
1969 Ford Galaxie XL, 460 (Ho Hum....)
1964 Ford Galaxie 500, 510" SOHC

Pretty much what I thought. I have an old Crane Fireball something a rather (292 maybe) that I think is around 112 or 114 but probably on the small side. Might have to sell some parts to fund a blower. I got dusted by a rat motor on the weekend, not by much, but its got me thinking....just can't let that happen again

I ain't Jay, so I can't speak with the same authroity, but with a blower, you don't have to worry about exhaust. Many times, cams for FORD engines, especially FE's are offered with split duration, giving additional cam timing to exhaust - to make up for poor exhaust flow in FE (Ford in general) restrictions, etc. A blower covers a lot of ills...

 

I would have thought it more necessary as you have to get more gas out. Are you saying the blower pushes the last of it out during the overlap period?

i found a recomended street cam at one of the blower shops online.their recomendation was .525/.540 264/270 214/221 110*.looks like a little mor exhaust lift and duration.can,t remember if it was solid or hyd.think it was hyd though.

An LSA between 112-114 is ideal and an extra amount of lift, either at the cam or increased rocker arm ratios, helps as well. Short duration cams work well with blowers and turbos since they have less overlap. Blowers and turbos like to have valve events to happen quickly and a solid cam would be a good choice in a street blown application. Solid cams accelerate faster in the first 20 degrees than rollers. After 20 degrees, the roller is far superior. Thats why some guys run faster with a solid cam then a roller cam in certain instances.
Like the adage says "There's no replacement for displacement....except for boost"

Dave Walters
427 Galaxie Registry
Website
http://home.ptd.net/~pwalters

Let the supercharger do the work, thats what its there for.

Building a Naturally Aspirated engine is (or should be) different in may areas than building a dedicated Supercharger, Blower or Nitrous Oxide engine. In an N/A engine you encourage flow velosity based on atmospsheric pressure. When running an Oxygen/fuel enhanced engine the issue is more about controlling, containing and maintaining an efficent burn rate in the now enhanced mixture. Your original problem, as in an N/A engine has been solved. Now you just need to make sure it doesn't get out of control or overstress your basic engine components (pistons, rods, crank, ignition, etc) ablity to put it to good use.

I built my first, more or less, dedicated supercharger engine a few years back. I kept static compression at 8.5, ran the stock cam at first - kicked up the fuel system and called it done. Obviously I used forged pistons and worked factory performance rods (smoothed beams, shot peened, full-floating pin and steel heads - for stable heat profile). One day the belt cam off, I didn't carry a spare, so I had to limp-home. The engine was a dog without the supercharger - I was glad that I hadn't went with my first inclination to drop the static compression down even more. At first I was going to go to 7.0:1 static.