Lewis Maudlin Posted March 6, 2002 Share Posted March 6, 2002 OK, I have a 390hp 355sbc with the Edelbrock Performer RPM set up. I had a Holley 600 but I didn't like the gas smell all the time. I switched to a Carter 625 which doesn't smell as bad but is old and doesn't have the WOT punch that the Holley had. Also, it doesn't fit under my hood as well as the Holley. I am thinking about either one of Barry Grant's 625 Road Demons or a 670 Street Avenger. Do the Road Demons have the power valves that blow out? The price is relatively the same. Does anyone know which works better and needs the least attention? Any suggestions? I don't get along well with carbs so which will require the least set up? Quote Link to comment Share on other sites More sharing options...
Guest heinera Posted May 23, 2002 Share Posted May 23, 2002 If I remember right what I read in Summit, the road demon has power valve blow out protection. Adam Quote Link to comment Share on other sites More sharing options...
Mike C Posted May 23, 2002 Share Posted May 23, 2002 All new Holleys have PV blowout. If it was my $, I'd go with a 4779C Holley. 750 double pumper with all metal parts and mechanical choke if you are looking for max power. If you want best driveability, go with the JET stage II street Q-jet or stage III designed for Stock and Super Stock racers. Quadrabogs meter part throttle better than any of the "high performance" carbs. With nearly 400hp, IMO you could benefit from a bigger carb. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 23, 2002 Share Posted May 23, 2002 I have a Road Demon 625 on my 302. It runs great starts up, idles like a top. I don't think you can get away from the gas smell unless you go with FI. jon Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 23, 2002 Share Posted May 23, 2002 Where does the gas smell come from on the Holley? I believe the answer (if the bowl and metering block gaskets aren't leaking, and the float levels are correct and the power valve isn't leaking) is that the gas smell comes out of the bowl vent, at the for and aft of the main body. I was considering running some fuel hose from the vents, out of the bottom of the air cleaner, and into my charcoal canister. That brings up a question. With a 3310-2 Holley, with only a ported, PCV and baseplate vacuum tap, where should I run the purge line to my charcoal canister? Would the ported vacuum tap be a good choice? It seems that the charcoal canister is a pretty big leak and hooking it to even the ported vacuum source would cause low engine vacuum. Maybe put a restriction in the line? I have the stock 240Z vent line from the evap tank and teh return line to the tank run into the charcoal canister now. Quote Link to comment Share on other sites More sharing options...
fl327 Posted May 23, 2002 Share Posted May 23, 2002 i run a holley and get the gas smell too. very strange, i tore it down replaced gaskets and set floats and it wont go away, maybe it is a hollley thing? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 24, 2002 Share Posted May 24, 2002 No, it's just you. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 24, 2002 Share Posted May 24, 2002 Sounds like a great idea Pete... I don't know anything about hooking it up though. jon Quote Link to comment Share on other sites More sharing options...
JohnG Posted June 7, 2002 Share Posted June 7, 2002 I just got done replacing my Speed Demon 750 double pumper with a new Holley Street Avenger 770 on my 406 SBC. The new carb uses vacuum secondaries. It's smoother in the transition off-idle...no stumbling. Something about the cam I'm running. Don't get me wrong...the Demon is a great unit, well built, lots of adjustability. It just wasn't the best carb for my particular engine. It's for sale if anybody wants it. --JohnG CraZ after all these years! Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted June 7, 2002 Share Posted June 7, 2002 Ok I've got to ask what type of cam and what size is it? Mike Quote Link to comment Share on other sites More sharing options...
JohnG Posted June 10, 2002 Share Posted June 10, 2002 Mike, It's a hydraulic cam, flat tappet, 231 deg.intake, 236 deg.exh, .512" lift intake, .505" exh, 112 deg. LSA. Roller rockers are 1.6:1 ratio. I also run a port-matched Vic Jr. intake. --JohnG Quote Link to comment Share on other sites More sharing options...
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