My old Qjet is on its last legs. My mechanic suggested a new carb would be preferred over rebuilding the old one. I've read good reviews on Demon carbs and was wondering if anyone here on the forum has one. Are they easy to install? I was wondering about the fuel lines and fuel filter and air cleaner. Do all the connections match up? Will the air cleaner fit? :confused: :confused: Any input would be greatly appreciated. :yesnod:

 

Demon carbs are great IMHO. I have a vacuum secondary 750 on my small block and it works great. I had to bend up some custom steel lines to go from the fuel pump to the carburetor. I have a standard mechanical pump, and it has an inverted flare fitting. The Demon takes a strange thread size fitting that they sell "logs" for that end in -AN fittings. So, I built a fuel line with an inverted flare fitting on one end and an -AN on the other.

Took a little work, and it uses a larger size stud for the air cleaner nut, but it was worth it. :smash:

 

I have heard that the demon carbs are really nice. but i have also heard that if you have any problems with them the support really sux. just make sure you get if from a place like Jegs, so you can return it if there are any problems.

 

I have a Speed Demon 650 with mechanical secondaries and I love it. After running a Holley 4150, a Holley 4160, and a Rochester, this Demon is by far the best carb I have put on my motor. Installation is easy. You will need a dual feed fuel line setup like on any dual feed Holley. I am not sure if an L-48 air cleaner will fit or not. My stock L-46 air cleaner did fit, and there are numerous aftermarket air cleaners that will fit for sure. :yesnod:

AC

 

No one has mentioned that the Demon is a square bore carb and your stock intake manifold is a pretty specific spread bore configuration.

Did all you guys use adapters or did you swap out the intake? Any clearance issues?

:smash:

 

I have a square bore intake. I just take it for granted that everyone on the C3 board knows the difference between square and spread bores. :yesnod: The Demon is pretty much the same height as a Holley 4150.

AC

 

I have an intake that will take either square or spread bore...

 

For my stock intake, I would have to purchase a $15 adaptor....

 

My Holley 650 is a spread bore and I get a little rub on the hood. I'm thinking a square bore carb with an adapter won't fit, so I need a square bore intake. You may have a little more room under our 76 hood.
:cheers:

 

Edelbrock performer for the money and ease of tunning is pretty hard to beat. You might want to at least look at one.

:cheers:

 

I had the 625cfm Road Demon on my L-48 and now on the ZZ4. Great carb! Easily tuneable, excellent throttle response, and awesome start-it-and-go performance. (no waiting for the engine to warm up a little.) This was the first carb I've ever touched and I was able to set it up in a matter of minutes.

There were a couple issues though. Demons take a duel feed. I went braided SS hose with AN fittings. Some have made their own steel lines. I do not recommend the Y-Pipe that comes with it. They want you to use a rubber hose and clamp but the inlet for the pipe is right in the way of the heater outlet on the intake manifold. I had trouble with that pipe leaking too.

Another consideration is your intake manifold. As mentioned, you would either have to change manifolds or use an adaptor plate. I highly doubt the plate would fit. If you are using an EGR valve I would suspect the linkage for the vacuum secondaries would hang up or not even clear it. I know the Edelbrock Performer 21011 has a bolt on a plate that covers the EGR hole and just that bolt doesn't clear. I wound up using a small "heat spacer" and a tiny air cleaner and still wound up rubbing the top of the air cleaner on the hood. :rolleyes:

Like I said, it's a great carb but there might be several small issues involved in getting it installed.
My Road Demon is actually too small for the ZZ4 and I may be selling it. If you're interested let me know.

 

cookie - are you saying you had the Demon carb mounted on the Edelbrock intake? And you had some clearance problems with that setup...
BTW, check your mailbox.... :yesnod:

 

I also thought the road demon was too small for my zz4. However, my friend came over and discovered that I wasn't getting full throttle. This was caused by the kickdown cable. Once this was adjusted the carb performed extremely well. I no longer think the carb is too small. :crazy: