Its on a newly rebuilt stock 283. The primary bores are small in comparison to a standard 4160 holley and it has triple stack boosters.
Comparing The Street Demon With A Traditional Holley Carb
Street demon 625 running rich. I have the same cam as you basically but its a speed pro not a blue racer but the specs you posted are the same as mine mine has a 114 lsa. All street demon carburetors come with a ford kick down linkage. The demon carb manual says. The combination of these things means the street demon has great throttle response and the small primaries also means fuel economy is maximized. Everything is running great its just idling to high i read on here that it should be in the neighborhood of about 500 600 rpms. Demon carburetors offer several options to adjust the engines performance.
Tuning it is very similar to tuning a holley but its not exactly the same. I just switched from a 4 barrel quadrajet to a street demon 625 cfm carb. Demons are notorious for running rich right ou of the box. I just installed a bg demon 625 cfm street demon on 302 mild cam210 212. Im almost positive that the pv is too big for my app. The street demon is a two piece design with all gaskets above the fuel level.
It runs really really strong only about 4000 miles on the 030 over rebuild. I havent taken mine apart yet but it will happen this spring. Remove shipping screw fig. Its an 89 302 ho ford racing f cam stock compression ported roller rockers knockoff polished intake ff headers and a older barry grant 625 demon carb that looks all the world like a holley to these aging eyes. There are two important signs which indicate that the carburetor needs to be tuned. The car ran fine before the carb change after the change its idling at about 980 rpmsmy timing is set to 32 degrees total advance.
If the engine idles smoothly you should not get into any trouble. Press the screw retainer into position fig. If the engine runs rough. Ported stock heads stock comp. Besides a 625 cfm sounds about right for a 350 making 21 hg in idle. If running a ford automatic and the kickdown linkage is needed a spring and perch kit part 1954 is required.
Got the four idle mixure screws at abt 34 turns out idles fine comes off idle fine seem too rich they say they are jetted 70 primary and 78 secondary. Mine is a 625 road demon and it runs rich as well. Street demon carburetors will not work with a ford aod transmission. Unless you live in a state where your car needs to meet tight emissions standards it will not matter if your afr is a bit lean or a bit rich in idle. This can be done by adjusting the carbs performance screws idle mixture screws and float bowl screws and butterfly positions.
Gallery of Street Demon 625 Running Rich
