Tuning it is very similar to tuning a holley but its not exactly the same. If running a ford automatic and the kickdown linkage is needed a spring and perch kit part 1954 is required.
Demon Carburetion Street Demon Carburetors 1901
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. Remove shipping screw fig. Demons are notorious for running rich right ou of the box. 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. I just installed a bg demon 625 cfm street demon on 302 mild cam210 212.
The street demon is a two piece design with all gaskets above the fuel level. Im almost positive that the pv is too big for my app. Press the screw retainer into position fig. The demon carb manual says. 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.
Street demon carburetors will not work with a ford aod transmission. The combination of these things means the street demon has great throttle response and the small primaries also means fuel economy is maximized. 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. There are two important signs which indicate that the carburetor needs to be tuned. I just switched from a 4 barrel quadrajet to a street demon 625 cfm carb. If the engine idles smoothly you should not get into any trouble.
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. If the engine runs rough. Mine is a 625 road demon and it runs rich as well. It runs really really strong only about 4000 miles on the 030 over rebuild. All street demon carburetors come with a ford kick down linkage. This can be done by adjusting the carbs performance screws idle mixture screws and float bowl screws and butterfly positions.
I havent taken mine apart yet but it will happen this spring. 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. 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. Besides a 625 cfm sounds about right for a 350 making 21 hg in idle. Ported stock heads stock comp.
Gallery of Street Demon 625 Running Rich
