Anyone is running a Demon carb?

[COKE]

Hello,
I would like to change my  Holley 3310  750 cfm for a  double pump and mechanical secondaries carb.
I,m doubting between the Holley and the Street Demon.Also i could to consider the Edelbrock.
Really i don,t know what kind of carb is going to be the best for my use.
It is  for  a street car  with a 440,4 speed and 3.55.
The Demon is unknew for me.I have heard that it is a very good carb.It has not choke,wich is a thing that i don,t like,though my car starts fine without the choke...
Other doubt is ,Why are they  not longer available from Summit?

About the Edelbrock and the holley...I ,m always hearing the same history..The Holley is better but hard for tune it up-The Edlbrock is worst but easier for tune it...
I really don,t know waht to think.

Thanks for any comment.

[chrisII]

I have an edelbrock, its always run well without any hassles. I do have a holly that neads a rebuild and may get put back on, and am planning to try out A demon thatmy buddy has for his build up but will not be useing for a while so he offered to let me try it.

[Chryco Psycho]

I talked to Summit in person while in Atlanta , the explanation was that the Demons  are simply too problematic & they dropped the line due to always having to warranty them
the Best carb I have found in the 750 Range is the New Holley 750 HP street version , reasonable price & extremely tunable & you can literally feel the power increase with them , very smooth operating carb as well , 82751 is the part #

[jmichaelclark]

I ran a Street Demon on a 452 stroker, was great. Only problem I had was with the chock.  Called Demon, and they said, take it off. I did, and never had a problem after that.

[Lord Warlock]

The edelbrock is built very similar to the factory AVS Carter carb that came on the big block cars from the factory.  It tunes the same way, is very easy to adjust and tune, and so far seems to run just fine on a 440 car.  I have a Performer 750cfm carb, the factory carb was a carter 625.  The carter and performers were/are much much easier to tune than a Holley carb is, the Demon carb had a good rep in the 80s and 90s but I've never used one personally.  I've had a Holley 650 vacuum secondary carb on my 440, and a Holley 800 double pumper with manual secondaries, of the 4 carbs i've had I like the Edelbrock best...so far...but then again I haven't got the electric choke set up yet either (have it in toolbox if i get around to installing it). 

[Chryco Psycho]

the Eddy carbs are just AFB
the new Thunder carbs are far more similar to the AVS the factory used more often , once you understand carb tuning neither have anyhting close to the adjustability of the Holley , Demon , Proform style carbs 

[kamkuda]

I have had my 750 demon and 750 Edelbrock on both my 440 and small block 408.  Either will work with the Eddy being easier to tune.
The Edelbrock will run well enough out of the box.  The Demon works OK and has good potential but has a problem.  They seem to have a rich lean condition that needs to be tuned out.  It usually runs rich at idle, lean at part trottle and rich again at full throttle. 

I am using the Edelbrock on the street engine (408) I am going to a Holley for better performance with the 440

I will be selling the demon.

[firefighter3931]

I will be selling the demon.

Say it aint so  >>>> >>> >>>>



Ron

[kamkuda]

Are you interested Ron

[deputycrawford]

This is the first I have heard of the Demon problems. I just bolted my Mighty Demon on and slightly adjusted the idle. It runs, well, perfect. I have played with the jetting and put it back to factory specs. I love mine and would buy another in a second. What kind of problems do I look for in the future?

[firefighter3931]

This is the first I have heard of the Demon problems. I just bolted my Mighty Demon on and slightly adjusted the idle. It runs, well, perfect. I have played with the jetting and put it back to factory specs. I love mine and would buy another in a second. What kind of problems do I look for in the future?

The most recent issues with Demon carbs have been with quality control and poor assembly practices. Metal filings and debris inside the bowls has been a recuring complaint. As Chryco stated, Summit stopped carring the Demon line due to a high return rate. The earlier demons were often very difficult to tune as Kamkuda stated. I've worked on a few and couldn't get them to work properly. Oddly enough, most holley carbs i've used have performed very well right out of the box with a float adjustment and idle mixture/idle speed adjustments. The fuel curve on the holley carbs just seems to be dialed in better for most applications, from my experience.

That being said, if yours is working fine now, you shouldn't have any future issues with it unless you alter the engine build significantly and that carb is no longer compatible with the new combo. 


Ron

[deputycrawford]

Thanks for the info Firefighter. I have had the bowls off many times for jetting and it seems fine. I'm sorry to hear about the quality problems. I guess I got lucky with mine. I hope I don't out date my carb by further build ups. I have a .575 solid lift cam on a 383 already. It is a Mighty Demon so It should take low vacum idles in the future. Thanks again.

[Chryco Psycho]

 agree with the Fuel curve , I just swapped a demon for a street 750 HP Holley , it now idles in gear 200 rpm lower than before without stalling & the curve is much smoother as you open the throttle up , noticibly better response

[RT/SE]

Chryco and others who have used the new street 750 holley(#82751).  I saw this info on the carb from the holley website:

Mechanical Secondary Double Pumper
Contoured Venturii Inlet
Screw-In Changeable Air Bleeds
High Strength Sealing Surfaces
Power Valve Blow-out Protection
Tumble Polished Shiny Finish for Great Looks
Street/Strip Calibration
Lightweight Slotted Mixture Screws
Two Corner Idle System
Spun-In Down-Leg Boosters
Ford Kickdown Linkage
100% Wet Flow Tested
Fourth-Generation Power Valve Design
Built-in Secondary Fuel Filter System
Four Corner Idle

It appears that the street 750 does not have a choke.  I'm on the east coast and it can get pretty cold during the fall/winter.  Do you think this carb would work well during the colder times of the year?  I have an older holley double pumper with a manual choke.  This new holley looks pretty nice and I really like the finish.  Any thoughts would be greatly appreciated.  Thanks.

[dodge freak]

Well I live in Michigan and drive my car until the salt trucks hit the road in mid November and have no problems with the holley hp 750. The metering blocks are a little different for the idle circuit gives a better idle. It will start ice cold with 1-2 flooring the gas pedal before you turn the key. Idles ok - rough but idles ok for a few mins, untill the motor heats up .Now I have a MSD 7 box with the 8251 coil, before when I had a MSD 6 box it would stall once and a while when cold but not anymore with the 7AL box.

[Chryco Psycho]

the Carb is definatly worth getting , it get friggin cold where I am & you can start them until it is too the point where you would be driving it anyway
the carbs work Extremely well , the jetting & metering is usually very close & the carb is extremely smooth & works excellent on long duration cam /low vacuum engines

[deputycrawford]

I don't run a choke either. I live at the Ohio, Michigan border. I drive mine until it snows and never have a problem. just start it and warm it up for a minute or so. You will be surprised what a correctly metered carb will do for a car.

[bull]

That must have been a helluva hit to Demon getting pulled out of the Summit catalog. Or maybe that's why they were having problems to begin with -- too many carbs to produce due to demand so the quality dropped off.

[Steve P.]

There just is NO EXCUSE for poor quality control in America.. I believe that is one of the biggest problems with stuff MADE IN AMERICA today..   

There was a time when quality meant more than quantity..  I can remember it....

[dodge freak]

Yes but don't rush and blame the American worker. Look how many shops have foreigner workers today and how much the mangers push to keep the parts line moving.

[Ghoste]

I thought the Demons were Barry Grants Holley knockoff made to correct problems with the Holleys??

[Chryco Psycho]

Demons Are BG carbs that are holley based in design

[Ghoste]

Right.  I guess I should rephrase that.  What I meant was that it seems a little strange to read about quality issues with Demons when BG began by addressing shortcomings in the Holley line.  The issues were engineering not quality so much, but I still find a little irony in it.

[Chryco Psycho]

It is ironic

[mally69]

i run  a mighty demon 750  i always heard good about them until now i just dont understand 

well when i was first trying to start my 440 for the first time it backfiered BADLY throught the carb blowing the power valves so i had  them replaced  with holley power valves seemed good other than that

[kamkuda]

Right.  I guess I should rephrase that.  What I meant was that it seems a little strange to read about quality issues with Demons when BG began by addressing shortcomings in the Holley line.  The issues were engineering not quality so much, but I still find a little irony in it.

My understanding was that BG was sued by holley for copyright infringements and had to make some design "adjustments"  The inability to use some of the basic Holley designs precluded him from building a better Holley Carb.

[Chryco Psycho]

my experience has shown that the bleed size is too large on the Demon carbs so they need oversize jets to cvompensate , this seems to make the low end responce very soft not crisp like the Holleys & Proforms , Profrom seesm to be the Most responsive of the 3 

[Ghoste]

Weren't Barry Grant's original modifications never meant for the street anyway?

[greenrt_se]

when I put 750 mechanical demon in my 440 ,I have to put 5 number smaller jets on it( I have a oxyygen sensor in exhaust pipe)

[Challenger340]

I gave up on DEMON carbs and BG in general !

I did have some reasonable success with some of their annular discharge units on engines with BIG bumpsticks, good throttle response down low/midrange power.

But, for the most part, I just couldn't get what I wanted for A/F curves, and EGT's on the dyno. I'd get it "right" somewheres, and it would go for "shat" elsewheres !

Too persnickity for me, need more patience I guess, but dyno time is pricey, and customers get mad !

[dkn1997]

750 mighty, out of the box runs fine.  from what I can see, a major problm with demons is that people constantly pick the wrong one.  a majority of threads I see where people have problems they list their combo and the carb is wrong.  not just a little either.  guys running an 850 speed demon on a 360 with a wild cam.  things like that. 

It happened to me, I thought I was doing the right thing and asked a performance carb vendor for a carb recommendation and give him all of my specs.  he sold me an 850 speeder for my pretty stock 440.  ouch!! did not run well despite changing jets and other tuning.  sold it and got this 750 mighty from don at www.4secondsflat.com and never looked back.  That brings up another point.  All of these carbs can be great for you if you buy them from a vendor who races/uses them and is willing to help.  I am sure that if you bought a holley from Jesse at Bigs you would be sold on holley forever, or it you bought a TQ from demonsizzler, that would be your thing.  If you want to save a few bucks and buy one based on what the pimple faced kid who answers the phone at summit tells you, then you will probably not end up happy.

with do many different demons to choose from, I cannot believe that the guys at summit/jegs are really researching it and getting the specifics of everyone's combo before recommending a carb. 

[whitehatspecial]

 

[Chryco Psycho]

I agree to a point , picking the wrong carb can be the start of the problems but I have seen cases where the carb is not wrong & it still will not work

[dkn1997]

You have a good point, and from what I hear, the tech support at BG is not that great. 

I am biased because I really like my demon and I think a major factor was asking someone who knew a hell of a lot more about it than i did and having him pick it and prepare it for me.  I can tune a carb about as well as I can perform brain surgery, so if a retard like me can get one to run, then It can't be all bad, right?

I started out years ago on this motor with an eddy 750 and that ran ok too.  not quite as good as the demon, but still ok.

[bull]

Some of you guys keep saying BG. What the heck is BG?

[Silver R/T]

Ive got 850 speed demon laying around, never installed

[dave571]

Some of you guys keep saying BG. What the heck is BG?

BG is Barry Grant Fuel systems.  The manufacturer of Demon carbs

[dave571]

As for the thread.

I run demons on everything I have, and like them.

750 mighty on my 440 car

I had a 650 speed on my 400 cid van

A 625 road demon on my 440 tow rig.

I agree with the statements that most of the issues with demons are people buying the wrong demon.   Yes there has been some quality control issues also, but I don't think that is the heart of the bad rap they have gotten.

Too big and the wrong series, is often the problem.  Just like DKN and his 850 speed demon when he should have had a 750 mighty.
850's on small blocks even worse.
Example, guy does some research, and finds for his cam and engine size he should have a 650 mighty demon  on his fairly cammed/hopped up  318 car with 410 gears.  Goes to the local speed shop and see's that the 650 mighty demon is a fair bit more money than the speed demon.  So he figures he will go with the speed instead, but bump up the size to compensate for the wrong series, and his buddy tells him he should have a vacuum  secondary on a  street car.  Goes with it.
Puts it on and can't tune it.  Idle is the pits, it bogs like heck when the secondarys open...etc.  He never will tune it.  The carb is waaaaayyyyy to big, and with a  big cam and gears.  The mighty is more sensitive to the erratic air flow of the bigger cam.
Sorry to ramble...LOL
   
Everyone has an opinion on carbs.  For me it's  What ever works. 
I've used eddy's and find they work well, for a throw on and go type of thing.  But wouldn't want one on my drag car.
I've never had a holley that the float didn't stick on, but I don't hate them for it.  I can understand why Chryco P likes them.  I have never under stood why a lot of holley guys dislike demons, but different strokes for different folks.
Some even  love Thermoquads, while I think they are idealy suited for long distance tosses into the garbage can...LOL.. to each thier own.

As for why they aren't at summit anymore, there are a few stories.  One is that summit was tired of the QC issues etc.  The story from BG is that they dropped summit, for a number of issues.  Both were happy to rid of each other in any case.   .02