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speed demon or mighty demon?

14K views 33 replies 13 participants last post by  htwheelz67 
#1 ·
I'm going to buy a new demon for my 408 windsor, compression is 10-1, hyd roller cam is 231 242 578 576 @0.50 almost 114 lca, 205 cc twisted wedge heads and a port matched stealth in a 67 must vert, lentech aod stalls about 3000.

I ran a 650 speed demon out of the box and it ran great, got a pro systems carb made and it seems too big, less throttle response and really rich and WOT BOG.

I am going to a 750 annular BG carb, my duration falls within a speed demon but the mighty demon is more tunable but no choke, not that I need one in So Cal. But I in the past I modify it (remove choke blade) but use it to keep idle high until warm.

Mechanical or vacuum? I actually liked the way vacuum runs better and I will be changing rear gears from 3.00 to 3.50 which should lower stall a bit, this car is a weekend cruiser only and never sees the track.
 
#5 ·
dawg said:
neither they are junk
look pretty but are full of problems.
theres a reason why you cant get one from a local speed shop.
they dont wanna deal with them no longer because of the constant troubles with those carbs.
get a Holley or go to the carb shop or AED and get a carb from them you wont be disappointed.
X2 -- I also learned my lesson - nothing beats Holley!
 
#6 ·
htwheelz67 said:
I'm going to buy a new demon for my 408 windsor, compression is 10-1, hyd roller cam is 231 242 578 576 @0.50 almost 114 lca, 205 cc twisted wedge heads and a port matched stealth in a 67 must vert, lentech aod stalls about 3000.

I ran a 650 speed demon out of the box and it ran great, got a pro systems carb made and it seems too big, less throttle response and really rich and WOT BOG.

I am going to a 750 annular BG carb, my duration falls within a speed demon but the mighty demon is more tunable but no choke, not that I need one in So Cal. But I in the past I modify it (remove choke blade) but use it to keep idle high until warm.

Mechanical or vacuum? I actually liked the way vacuum runs better and I will be changing rear gears from 3.00 to 3.50 which should lower stall a bit, this car is a weekend cruiser only and never sees the track.
What transmission are you using and if auto,how much converter?
 
#7 ·
dawg said:
neither they are junk
look pretty but are full of problems.
theres a reason why you cant get one from a local speed shop.
they dont wanna deal with them no longer because of the constant troubles with those carbs.
get a Holley or go to the carb shop or AED and get a carb from them you wont be disappointed.
Actually they can be bought from over 400+ dealers from coast to coast and in several different countries.
 
#8 ·
Tech @ BG said:
Actually they can be bought from over 400+ dealers from coast to coast and in several different countries.
That still does not cover the cost of a ruined 383 stroker motor, because somebody at BG forgot to put in a 5 cent plug. Then when I finally figured out what happened, all I got was to send the carb back and BG would install the plug, if I paid frieght both ways.

Look at my Photo Album to see the failed, defective carb!!!!
 
#10 ·
RPM said:
That still does not cover the cost of a ruined 383 stroker motor, because somebody at BG forgot to put in a 5 cent plug. Then when I finally figured out what happened, all I got was to send the carb back and BG would install the plug, if I paid frieght both ways.

Look at my Photo Album to see the failed, defective carb!!!!
My first and only BG carb was defective out of the box. See my post here at this website. My motor now runs excellent with a 3/8" aluminum open spacer underneath my Holley carb. A word of advice to anyone - whether or not you buy BG or not - make damn sure that you have a good working A/F meter on your ride - and having a tuned good working carb as a back-up, too!!!
 
#11 · (Edited)
People have had all kinds of different carbs fail, and fuel pumps, and pistons, and hair dryers and refrigerator compressors and all that.

I think that people get mad at BG because they feel that they are buying a premium carb at a premium price. I am sure Holley's and goldbricks all fail at the same or close to the same percentage of the time as BG carbs but people don't expect as much because those are fairly common. (and in turn are not expected to be perfect)

I am not touting BG carbs here but I am just saying that it is human nature to be mad that your 500 dollar carb isn't working the way it should, while you might not be as mad that your 250 dollar carb isn't quite right.

Also I would recommend checking out the guy on ebay who sells reman BG's. I feel like they are more carefully inspected and tested than their "new" counterparts. (that is just a hunch though)
 
#12 ·
Sixtyninemercury said:
My first and only BG carb was defective out of the box. See my post here at this website. My motor now runs excellent with a 3/8" aluminum open spacer underneath my Holley carb. A word of advice to anyone - whether or not you buy BG or not - make damn sure that you have a good working A/F meter on your ride - and having a tuned good working carb as a back-up, too!!!
Actually we do not know your carburetor was defective as you never gave us the opportunity to look at it. Yes, you did have a problem but you only checked for a vacuum leak and then made up your mind you were returning it to the outlet where it was purchased and did not give us the opportunity to diagnose what was going on. As stated in the other thread this was not a common problem as the car should not run for 7 minutes and then go lean all by itself. A carburetor does not work that way. You can continue to bash us but lets give them the whole story as we even offered to exchange it for a different one . As stated we are here to help those we can and we offered the same to you and you declined. Don't really know what else we could have done for you at that point. I think there was more going on than you have told us and everyone in all the forums you posted on as other members were suspicious as well.For those that may have an issue feel free to pm , email or call us and we will work with you to correct the problem.
 
#13 · (Edited)
Tech @ BG said:
Actually we do not know your carburetor was defective as you never gave us the opportunity to look at it. Yes, you did have a problem but you only checked for a vacuum leak and then made up your mind you were returning it to the outlet where it was purchased and did not give us the opportunity to diagnose what was going on. As stated in the other thread this was not a common problem as the car should not run for 7 minutes and then go lean all by itself. A carburetor does not work that way. You can continue to bash us but lets give them the whole story as we even offered to exchange it for a different one . As stated we are here to help those we can and we offered the same to you and you declined. Don't really know what else we could have done for you at that point. I think there was more going on than you have told us and everyone in all the forums you posted on as other members were suspicious as well.For those that may have an issue feel free to pm , email or call us and we will work with you to correct the problem.
Well BG tech guy - with what you just said you are starting to get me angry! You call it bashing - I call it stating facts:

1. I have a working tuned Holley carb with a A/F ratio meter used for reference. The car works with the Holley - felt through the gas pedal and the A/F meter. Change the carb to the BG - only and only change the carb - nothing else - after seven minutes the car drives in a very lean condition - felt through the gas pedal and seen on the A/F meter. Then increase the jet sizes on both the primary and secondary 8 and 9 sizes - to be equally jetted with my Holley. Restart - same problem. You have forgotten that I have been doing this for years (tuning Holley's). I did everything that you can tune on the outside of the carb. I changed back to the Holley that same day - car drove normal. Changed back to the BG - same problems. Tried the carb cleaner spraying for external vacuum leaks - none found. Added a non-conductive spacer to see if heat was causing the problem. Same problems after restart. Do not type like I just put on the carb - it needed an adjustment that anyone could do and I'm just a beginner and didn't do it and then got mad and sent it back.

2. While I was waiting for the carb to arrive in the mail to me - I looked on several forums and saw many many people's anger about their problems with BG. I started getting a little worried especially since I hadn't researched those forums until after I had ordered the BG carb.

3. The carb arrived - and you can see from my post here at this forum the problems I had with it out of the box. After reading all of the problems which I had too - my first one from BG - I kicked myself - and did not want to deal with BG ever again. That is why I didn't send it to them so they could test it on a flowbench that has vacuuming properties but probably not heat like when the carb is really attached to a motor and say that no problem could be found and that it's my motor's fault. The way this BG tech is saying that he doesn't know that it's his carb's fault even after my posting on the circumstances (Holley - switch to BG - put back on the Holley, etc)

http://www.hotrodders.com/forum/lean-problems-bg-speed-demon-carb-136382.html

warns me about dealing with BG. And believe me BG will get the carb with my description of the problem written on the invoice when the vendor sends it to you for their credit!

4. As far as suspicions from other members? Where? When they didn't trust my A/F meter? They don't understand what the word "reference" means and how it pertains to using meters like that. Same thing with a tachometer. What I read on my tach is not God himself validating the extreme correctness of the tach's needle - it is just a reference tool. I can feel the difference when the tach says 2000rpm versus 2500rpm. Is it off by a few rpm? Of course it is.

So me and the BG tech guy don't go round and round - I promise that I won't talk about BG anymore on any forums - so if you post a reply to this or that post of mine I will ignore it. If anyone to my face asks me about BG stuff I will tell them to buy Holley or Edelbrock.
 
#14 ·
Sixtyninemercury said:
Well BG tech guy - with what you just said you are starting to get me angry! You call it bashing - I call it stating facts:

1. I have a working tuned Holley carb with a A/F ratio meter used for reference. The car works with the Holley - felt through the gas pedal and the A/F meter. Change the carb to the BG - only and only change the carb - nothing else - after seven minutes the car drives in a very lean condition - felt through the gas pedal and seen on the A/F meter. Then increase the jet sizes on both the primary and secondary 8 and 9 sizes - to be equally jetted with my Holley. Restart - same problem. You have forgotten that I have been doing this for years (tuning Holley's). I did everything that you can tune on the outside of the carb. I changed back to the Holley that same day - car drove normal. Changed back to the BG - same problems. Tried the carb cleaner spraying for external vacuum leaks - none found. Added a non-conductive spacer to see if heat was causing the problem. Same problems after restart. Do not type like I just put on the carb - it needed an adjustment that anyone could do and I'm just a beginner and didn't do it and then got mad and sent it back.

2. While I was waiting for the carb to arrive in the mail to me - I looked on several forums and saw many many people's anger about their problems with BG. I started getting a little worried especially since I hadn't researched those forums until after I had ordered the BG carb.

3. The carb arrived - and you can see from my post here at this forum the problems I had with it out of the box. After reading all of the problems which I had too - my first one from BG - I kicked myself - and did not want to deal with BG ever again. That is why I didn't send it to them so they could test it on a flowbench that has vacuuming properties but probably not heat like when the carb is really attached to a motor and say that no problem could be found and that it's my motor's fault. The way this BG tech is saying that he doesn't know that it's his carb's fault even after my posting on the circumstances (Holley - switch to BG - put back on the Holley, etc)

http://www.hotrodders.com/forum/lean-problems-bg-speed-demon-carb-136382.html

warns me about dealing with BG. And believe me BG will get the carb with my description of the problem written on the invoice when the vendor sends it to you for their credit!

4. As far as suspicions from other members? Where? When they didn't trust my A/F meter? They don't understand what the word "reference" means and how it pertains to using meters like that. Same thing with a tachometer. What I read on my tach is not God himself validating the extreme correctness of the tach's needle - it is just a reference tool. I can feel the difference when the tach says 2000rpm versus 2500rpm. Is it off by a few rpm? Of course it is.

So me and the BG tech guy don't go round and round - I promise that I won't talk about BG anymore on any forums - so if you post a reply to that post of mine I will ignore it. If anyone to my face asks me about BG stuff I will tell them to buy Holley or Edelbrock.
Not here to argue with you but simply stating the facts. We had several questions that went unanswered and trying to get you to return the carburetor to it's baseline you refused. The Demon has completely different airflow characteristics than your stock holley as well as different calibration and you cannot jet the Demon based on what your Holley wanted for jet. The particular meter as noted by many fellow members is not that accurate when trying to tune although we ourselves never questioned that. Ever think maybe the car had too much fuel and it was burning it in the exhaust giving a false reading? There can be any number of possibilities but we did offer to exchange it with no reserves for you.
 
#15 ·
Holley's are more tuneable, bt I have NEVER heard of a guy having a problem with an Edelbrock. Sure they may need to drill throttl eplates or something for an unusually large cam on the street- but that's expected. Holley's are great and have a lot more tunability and aftermarket support, but Edelbrocks will not die.
 
#16 ·
Sixtyninemercury said:
A word of advice to anyone - whether or not you buy BG or not - make damn sure that you have a good working A/F meter on your ride


I have an A/F meter on my ride...ME. With careful consideration of the plugs, exhaust gases, timing, camshaft, rpm, fuel efficiency, and carb settings. I get the perfect A/F mix every time. It might not be green or yellow or red. But I know for a fact it is right.
 
#17 ·
I bought a used 650 speed demon last year and can't wait to try it. It should allow me to have a big cam and still have good low rpm characteristics with its 4 corner idle. I believe the mighty demon is designed to handle larger cams than the speed demons.

I also agree with ap72 that edelbrocks are generally trouble free when finally tuned. The holleys have power valves and gaskets that can wear out and give problems while the edelbrock only has the accel. pump.

I bought the speed demon because I like to try new things and see how they are. I have a holley spreadbore on my 74 camaro and the only real complaint I have is gasket problems.

Check the BG website to see the cams the carbs are designed for. I am thinking you could use the mighty demon. Another great feature now is the idle-eeze which my demon does not have.
 
#18 ·
Double_v23 said:
I have an A/F meter on my ride...ME. With careful consideration of the plugs, exhaust gases, timing, camshaft, rpm, fuel efficiency, and carb settings. I get the perfect A/F mix every time. It might not be green or yellow or red. But I know for a fact it is right.
Well said .There are a lot of good air meters out there. Innovate for one has some real accurate ones that can be used in the aid of tuning a carb. With any reference you still have to read the plugs and use common tuning procedures as well like you mentioned..
 
#19 ·
chevyv8_power said:
I bought a used 650 speed demon last year and can't wait to try it. It should allow me to have a big cam and still have good low rpm characteristics with its 4 corner idle. I believe the mighty demon is designed to handle larger cams than the speed demons.

I also agree with ap72 that edelbrocks are generally trouble free when finally tuned. The holleys have power valves and gaskets that can wear out and give problems while the edelbrock only has the accel. pump.

I bought the speed demon because I like to try new things and see how they are. I have a holley spreadbore on my 74 camaro and the only real complaint I have is gasket problems.

Check the BG website to see the cams the carbs are designed for. I am thinking you could use the mighty demon. Another great feature now is the idle-eeze which my demon does not have.
Yeah typically the Speed Demons are good up to .240 @ .050 while the Mightys range is .240 - .260 . Our carburetors are a little more definite when it comes to camshaft and engine modifications based on the amount of vacuum and signal as opposed to a carburetor that is calibrated to cover most anything that it goes on but at a loss of power in doing such. Let us know once you get the Demon installed and if we can help in any way will be glad to.
 
#20 ·
Tech@BG, the trans in my mustang is a lentech AOD, with custom 10" converter which used to stall at 2300-2600 with my 351w now with the 408 its 3000 or a bit more BUT that is with the 3.00 gears, I will be swapping rears and going to 3.50 gears also if it still stalls higher than I like I may get a tighter converter as I want OD not to slip on the fwy.

Thats why I'm thinking of vac sec, but what is your recommendation for carb?

I guess I'm lucky as I've had great luck with demon carbs, out of four I did have one problem (casting hole on venturi arm) a dab of jb weld fixed that......
 
#22 ·
htwheelz67 said:
Tech@BG, the trans in my mustang is a lentech AOD, with custom 10" converter which used to stall at 2300-2600 with my 351w now with the 408 its 3000 or a bit more BUT that is with the 3.00 gears, I will be swapping rears and going to 3.50 gears also if it still stalls higher than I like I may get a tighter converter as I want OD not to slip on the fwy.

Thats why I'm thinking of vac sec, but what is your recommendation for carb?

I guess I'm lucky as I've had great luck with demon carbs, out of four I did have one problem (casting hole on venturi arm) a dab of jb weld fixed that......
That's good to hear and keep in mind generally you only hear about a product when someone is having a problem with it. There are plenty of threads out there with complaints on everyone elses products as well but unlike the others we do monitor and try to help on the boards and also relay the information to our production people to continue improving our qc. In regards to your carburetor choice with converters 3000 and up [as well as manual tranmissions] we prefer the mechanical secondary carburetors for response and driveability as the engine has a different type of load on it. With this difference the vacuum secondary carburetors can sometimes act eractic.
 
#23 ·
32hibo said:
Send me one for my drag car out your RD pile and I will try it....
Wish we could but you wouldn't believe the number of requests we get every day for this... We have taken carburetors before that were returned as defective right out of the box they were returned in and bolted them on one of our house cars only to find no problems. These will then go through the reman process and then go back through our dealers as a reman.
 
#25 ·
Tech @ BG said:
Wish we could but you wouldn't believe the number of requests we get every day for this... We have taken carburetors before that were returned as defective right out of the box they were returned in and bolted them on one of our house cars only to find no problems. These will then go through the reman process and then go back through our dealers as a reman.
So in effect the customer does´nt have to prove the item defective.
I assumed if you made a wrong choice in a purchase that was no ground for return.
Defective, yes. :cool:
Wrong choice, no. :nono:
 
#26 ·
Just hilarious. People buy Demons thinking they are just like their holley, tune it the same way, size it for the engine the same way, and then wonder why they don't run. Big joke!

Before anybody says what about the aluminum shavings I found in my carb, unfortunately it can happen. A powerwasher fails in the plant and something doesn't get flushed like it should. You would be amazed how often it happens at the Big Three in their transmission plants on valve bodies. Part of the game when machining aluminum. BG and Tech@BG always answered my questions promptly. Problem with customer complaints is 5% of satisfied people let a few people know they are satisfied and 100% of people that are unsatisfied left everybody know it.
 
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