I am ready to ditch the Eddy carb for a Demon. 

I would like to know if anyone here has tried the Road Demon 525 on a street Y block with mild cam? 

It says that you can use it for cams up to 220 @ .050.  I have an E-4 so should work?  I like that the road demon has the 4 corner idle, & the adjustable air bleed, & also the quick access secondary diaphram cover.  The Jigantic fuel bowls don't really serve any purpose for me, but they sure are shiny!

I would like to order it soon, so I can put it on this weekend.

Also, do the demon's have a pvc port at the front of the carb??  I don't want to go backwards on the pvc since i use the eddy for that currently.

I would go with the "Road Demon Jr." 525 since it has the single fuel inlet and Vacuum secondaries. I have used these with a lot hotter cam than they say you should and have had great results.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

The single inlet is a plus..

Does the Road Demon JR have an adjustable air bleed??  I never saw where it did..

  I went with the "Road Demon" 525 and it has vacuum secondaries also,it's on my 272 with Crane cam,BT aluminum manifold,Red's headers,and MSD dist. and coil.It's a humongus carb,about twice the size of my Holly 600,I wasn't able to run a carb spacer,had to bolt it straight to the manifold(Blue Thunder) and ran a 1 1/2" K/N air filter an barely able to close the hood on my '57.Also it has dual fuel inlets on passenger side and duel vacuum ports in front on same side(one being ported),due to not having a carb spacer the chrome dual feed gas line set up wouldn't work(hit the manifold) ended up using a SS braided line from Jegs setup for the Road Demon. Also you'll have to reroute your fuel line from the fuel pump to passanger side of carb.But all n all it fires right up every time,runs great(I thought the cfm would be to much) no bog,and plugs read lite tan. KID

My ’55 Customline has the 525 cfm Road Demon Jr. on a +020” over 272 with the Isky E4 camshaft.  T-85 overdrive with 3.55:1 rear gears and runs great with good fuel economy.  There is a PCV valve port on the carb.  The only flaw I found in the carb was the hole for the ported vacuum being too high above the primary throttle blades and I simply drilled a new hole in the appropriate position with a new vacuum port to the outside so that the distributor could get a stronger vacuum signal during cruise situations.

Lorena, Texas (South of Waco)

Ordered and just rec'd the Road Demon 525.. This thing looks huge!  I love the different sized Annular boosters..

What did you fellas do as far as Jetting goes??

I like to get an idea of what someone else's baseline was compared to bolt on....

  See above for engine setup--- I'm running #68 jets in primaries(downsized)/secondaries are what came with the carb from factory. KID

If it argues with you on the initial tune - try shutting down the "four corner" idle on the back bores. I had one of the big bowl Road Demons on a 289 and the extra adjustment of the secondary "drips" were a pain. Finally just shut them off. But the huge bowls supply plenty of fuel for instantaneous demand - and the easy tune vacuum pot is good feature.

I've got the Road Demon Jr. on my 312 and the primary idle only - suits me fine. Bowls are smaller  - but they don't dwarf the engine either.

 
 Steve Metzger       Tucson, Arizona

ok, so the dual inlet is a PAIN in theA$$! I ended up slightly bending the front short tube to clear the manifold & the trans cooler line that goes to the factory cruise-o-matic. 

I did use my 1" spacer, & had to move the coil to the firewall to also clear the fuel inlet. 

Kid - you mentioned you used # 68 jets?  Mine came with 58's, & a 6.5 powervalve.  the thing is way rich & was chugging initially just to stay running so I swapped the power valve for a new 7.5.    The four corner idle is proving to be just as kid mentioned a pain initially.  I ended up closing the secondary's nearly all the way, & it really functions more like a 3 corner idle since the pcv port is in the rear, & points at the secondary bore on the passenger side.   That screw wants about 2 1/2 turns, & the other on the secondary side wants 1/2 turn... go figure since my secondary side of the spacer has 1/2 of the divider removed & nicely radiused.(I mimicked the stock 2 barrel spacer on the secondary side only)

It is still rich, i pinched my rubber fuel line to the carb with vise grips to help drain the carb for the power valve change, & about half way down the bowl as far as float level is where the vacuum came up & the idle became crisp.

I think i am going to drop 2 sizes on the primary jets, & run it to see what the plugs do. 

I think i need to work with the timing curve a little.  I am running about 24 at about 900 to 950 rpm idle, &  total timing of 38 with about 5 or 6 degrees of that being in the vac. pot.

Try one of these brackets for the coil:

http://www.summitracing.com/parts/FMS-M-12044-A2/



It works well for me with the Holley.









Lawrenceville, GA