Anyone using the Road Demon Jr 525?
- Thread starter mattri
- Start date
You'd be better off with three 250 cfm Demons, like this.
http://www.speedwaymotors.com/eCCStoreFront/smi/product_images//Full/91012099.jpg
The 525 is a 2-bbl with 500 cfm Holley throttle bores, isn't it?
The 500 is quite large, but can work well if its direct mounted. With a Stovebolt adaptor, its a little to big for the available porting. A 5200 Holley Weber, 38 Weber DGAS or 32/36 DGAV or 350 cfm Holley is better with the 1.5 and 1.75" log heads.
The 500 doesn't atomise fuel as well as the 350 cfm, but produces better power on the right engine with a good cam, header and the later 1.75" valves and large ports the post 1978 heads ran.
I tell everyone the bigger the better. You may loose 2 or 3 mpg, but a 525 Demon is really a 185 to 230 hp carb. If you won't see more than 130 hp, then go for a smaller, more economical carbs. A smaller carb will give better torque at low speed anyway.
http://www.speedwaymotors.com/eCCStoreFront/smi/product_images//Full/91012099.jpg
The 525 is a 2-bbl with 500 cfm Holley throttle bores, isn't it?
The 500 is quite large, but can work well if its direct mounted. With a Stovebolt adaptor, its a little to big for the available porting. A 5200 Holley Weber, 38 Weber DGAS or 32/36 DGAV or 350 cfm Holley is better with the 1.5 and 1.75" log heads.
The 500 doesn't atomise fuel as well as the 350 cfm, but produces better power on the right engine with a good cam, header and the later 1.75" valves and large ports the post 1978 heads ran.
I tell everyone the bigger the better. You may loose 2 or 3 mpg, but a 525 Demon is really a 185 to 230 hp carb. If you won't see more than 130 hp, then go for a smaller, more economical carbs. A smaller carb will give better torque at low speed anyway.
A
Anonymous
Guest
Outstanding performance with an entry-level price.
Carburetor, Road Demon Jr., 525 CFM, Square Bore, 4-Barrel, Vacuum, Electric Choke, Single Inlet, Silver, Ea
Road Demon Jr. carburetors are entry-level, general performance, 4 barrel carburetors designed to provide crisp throttle response, good top-end power, and maximum fuel economy at a budget price. Features include Max-Density rib-reinforced cast baseplates and metering blocks, vacuum secondary operation, concentric venturii, and float bowls with EZ-Safe sight glasses for safe float level adjustment. They also offer two-corner idle adjustability, a large transfer tube with dual-captured O-ring sealing, built-in power valve blowout protection, and vacuum ports. Every carb is wet-flow tested, baseline calibrated, and comes with a detailed tuning manual.
Vendor Demon Carburetion
Product Line Demon Carburetion Road Demon Jr. Carburetors
Number of Barrels 4
Carburetor Flange Square bore
Choke Electric
Fuel Gasoline
Secondary Type Vacuum
New or Remanufactured New
Fuel Inlet Single
CFM 525
Carburetor Finish Silver
Ford Kickdown No
Booster Type Annular
Throttle Linkage Type Universal
CARB EO Number (Not Specified)
Quantity Sold individually.
Carburetor, Road Demon Jr., 525 CFM, Square Bore, 4-Barrel, Vacuum, Electric Choke, Single Inlet, Silver, Ea
Road Demon Jr. carburetors are entry-level, general performance, 4 barrel carburetors designed to provide crisp throttle response, good top-end power, and maximum fuel economy at a budget price. Features include Max-Density rib-reinforced cast baseplates and metering blocks, vacuum secondary operation, concentric venturii, and float bowls with EZ-Safe sight glasses for safe float level adjustment. They also offer two-corner idle adjustability, a large transfer tube with dual-captured O-ring sealing, built-in power valve blowout protection, and vacuum ports. Every carb is wet-flow tested, baseline calibrated, and comes with a detailed tuning manual.
Vendor Demon Carburetion
Product Line Demon Carburetion Road Demon Jr. Carburetors
Number of Barrels 4
Carburetor Flange Square bore
Choke Electric
Fuel Gasoline
Secondary Type Vacuum
New or Remanufactured New
Fuel Inlet Single
CFM 525
Carburetor Finish Silver
Ford Kickdown No
Booster Type Annular
Throttle Linkage Type Universal
CARB EO Number (Not Specified)
Quantity Sold individually.
A
Anonymous
Guest
I would like to get that for my jeep with a cheap 4 barrel intake 8)
A
Anonymous
Guest
Jeg's has Road Demon 2bbls in 350cfm. You might want to look into that. It's the same Holley bolt pattern. From what I can see, it's the BG version of the Holley 2300 2bbl. I'm not a carb expert, but it's out there on the market. FYI
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=257366&prmenbr=361
--mikey
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=257366&prmenbr=361
--mikey
godheadcustoms
Well-known member
One thing to remember is that CFM is just a quick way to guesstimate an engine's fuel need. An engine can never have too much CFM, but it can have way too much fuel. Look at OE fuel injection systems, some have close to a 1000cfm throttle bodies and they run great. It's because their ability to presicely meter fuel for the given demands. You can run a much bigger carb than CFM flow would dictate, you just have to be very good (or pay someone who is) about getting the best signal from the least amount of pressure drop (.5"Hg or so). That means lots of dyno tuning and testing and $$$, but look at some of David Vizard's books- he has "mild" SBC's with 1050 CFM carbs that will idle at 750RPM and run circles around similar engines with the "recommended" 650 Holleys. It just all depends on how intimate (read $) you want to get with your engine. The aftermarket carb manufacturers give general guidelines based on CFM so the average guy can bolt on an average carb onto his average motor and get it to run acceptably, but not optimally for a given engine. Not a bad deal by any means, but if you are willing there is a lot to be gained by setting up a "too big" carb for a particular motor. How fast you want to go= how much money you're willing to spend 
godheadcustoms
Well-known member
I think I should add "within reason" to the end of that statement. Don't try to put a Dominator on a pinto motor and expect miracles...the premise still applies though.
