in my opinion.the Demon carb is the biggest piece of **** ever made. bad gas mileage, rough idle,and over sized. I know there are ways to work these problems out, but i ask ...why? when you can get a edelbrock out of the box and in 20 mins be on the road. ive had 3 friends with demons..one is stuborn..his still dies on him all the time. The other 2 put edelbrocks on and both doubled their mileage....no more choking out...better aceleration at low RPMs. i dont want to argue on which is best,(everyone likes what they like) i just think this post was really one sided and i was worried about some new car guys getting ****ed into the worst carb (in my opinion) because it had a "wicked" name. (as all 3 of my friends did)
Could those problems be caused by having the wrong Demon carb or incorrect jets? I know that if you ask 20 people about which carbs they like, you'll get 20 different answers. I've heard horror stories about Holleys, and the Edelbrocks...and I've heard each was the greatest ever. I guess it's a trial and error thing, but if you can call them and they tailor a carb to your needs, I don't think it'd be any worse than grabbing an Edelbrock from Autozone that is set to a generic operating range. The engine in this thread is still on the run-in stand, and that's a far cry from being in a vehicle with a load in a real life operating range.... (keep us posted on how it pans out!) In the mean time, I'm still shopping around...
Yeah sounds to me like you and your friends don't know how to tune a carb, so since the Demon didn't work off the shelf it ****s... as for the Edelbrock, well just think how good it would run if you knew how to tune it... I like the Edelbrocks, I run one, and have used them in the past, I also like Quadrajets, when set up correctly I think they are the best carb ever, they're just a bit harder to set up than the Edelbrock for me, Holley's for me tend to need fiddling to much, Barry Grant got the Holley right with the Demon and if the time is taken to set it up correctly it's an awesome carb...
Here's the latest on this carb, and yes make sure you get the right Demon Carb! The CFM has not as much to do with Demon carbs as the type of Demon (Road, JR, Speed, Mighty, etc.) Unlike stock Holley and Edelbrock, they're all made for specific cams, not just CFM. In my case, mostly because my cam at duration.050 has exhaust at 224 and intake at 218, I need the Speed Demon, even though it's only 575 on the CFM. If the exhaust were down below 220 I'd go for the Road Demon. And yes these demons do give you more CFM compared to other carbs, so buy lower than you believe you need. And call Barry Grant first with your specs before you buy.... The run in over the weekend was not on the enigine stand but in the car. First firing brought back some poping and things were a bit too lean/ too hot regardless of al***ude. Replaced the primary jets with 62's up from 58 which I thought might be a little low in the first place. Fired again and ran for 5 minutes at 2500. This time sounded perfect and never got above 135 degrees. She runs cooool... Checked plugs and they were a nice light cocoa brown. Ran again at same speed for ten minutes and still runs very cool. Time to put in the thermastat and take it for a ride latter this week. The rev's come on very fast, in fact it snaps to over 5000 in what seem likes less than one second! The secondary jets are at 66 and I may move those up to 70 depending on how well she gets going on the highway when I put the peddle down. So far so good. Was the Demon carb worth it? Well with proper jetting and fuel lines in place, I don't think you spend more than 100 dollars over Holley or Edelbrock and in fact if you buy one of their carbs, built as well as Demons, you may spend more. All in all it seems very efficcient and I expect great gas mileage. Every time I ran it there was no smoke whatsover and no noticable fumes. Thanks! for all the replys and if anyone out there knows about putting in a late 90's Impala front end in to this 64, please let me know if it's simple bolt in or complicated mess??? I've heard that it will transfer over without much trouble, and that it lowers the 64 front end by about an inch and a half.
guacamole, Thanks for the Kind words. We build our carburetors more specifically than other manufactures do. This gives us a tighter window of where they are going to work properly in comparison to other brands. That being said, if you go with the carburetor we recommend vs. what they do we'll out perform them 9 times our 10. As far as air flow goes our carburetors are less restrictive, which lets us run a smaller carburetor than you might run in another brand which gives us better performance (WHEN USING WHAT WE RECOMMEND). If a guy isn't going to use the proper part, and then complains it's too this or that. That is not the manufactures fault. We generally make more power, which it takes fuel to make power, it's a matter of what you're looking for. My carbureted Pickup gets better fuel economy than my new injected one. It's all a matter of reading the directions, and tuning. As far as what we buy, and who we buy from whether it's a carburetor, or VCR (I guess that should be DVD showing my age) we as consumers need to realize the people on the other side of the counter are only going to know so much. We need to do as much research as possible ourselves to make sure it's going to work. We see this on a daily b***is with people getting parts that aren't matched to what they are doing. Word of advice spend a little extra time up front on research, and you'll be much happier in the end. Always check with the manufacture.
welcome to the HAMB, now read the rules and do an intro, this isn't your manufacturers forum. Unless you have more to offer than pimping your wares you might want to step back...
Zman, Sorry to have offended you. Didn't say anything bad about anybody elses product, just trying to clarify confusion about ours.
Hum, with all of the questions (some of them REAL basic) that get asked around here about carbs, I'd think you'd welcome a tech rep from a manufacturer instead of trying to run them off. I've been building modified engines for customers at my shop for about 30 years and still call manufacturer techs every week. Noone knows their products like they do.
Just yesterday I did a test of Mighty Demon carbs: 650, 750 and 850. They were on a 470hp 350 Chevy with 11.25:1 compression, a 258-at-0.050 solid flat-tappet cam, and a Victor Jr. intake. They all made the same power from 3,000-7,000 rpm, they all flowed the same lbs/hr of fuel throught the curve, they all flowed the same air as measured through the engine, and so they all had the same air/fuel ratio throughout the curve. However, the 850 needed jets that were something like 10 sizes bigger than the ones used in the 650. why? This points to a tuning problem a lot of people have. They think, "I have a big carb, so I better put smaller jets in it so it does not flow too much fuel for my smaller engine." Wrong. Because the 850 has a larger venturi area than the 650, the airspeed through the carb is slower with the 850. Therefore, there is less pressure drop across the venturi. That means there is less suction at the booster in the 850 than there is in the 650. Therefore, the 850 needs larger jets to flow the same volume of fuel. The airspeed situation also points to why the 650 will have better throttle response than the 850. In fact, on my 350, the 850 carb couldn't handle low-rpm loading at WOT (like foot-braking a car at the starting line of a dragstrip). The airspeed was so low that the carb could not meter properly. And, in my test on the 350, why did all three carbs move the same amount of air through the engine if they are rated at different cfm numbers? Because any given engine can only move a certain amount of air, and if the carb is not posing a restriction to that airflow, then going to a larger carb will not make much more power, all other things being equal. Just FYI. DF
Well said David you should be a writer See you at PRI. Doug PS. Do you know when you'll be releasing the Drag Week Schedule?
I did welcome him, but asked that he not just come here to pimp his product. Can you guys not read? Are you emoticon challenged? Can you not contact the manufacturers tech depts.? All I was saying is if you want to be a part of the HAMB cool, if not then step back... Yeah, that you can't comprehend what I wrote... and here is another emoticon that you may not get...
Well **** Zman, why not gripe at Freiburger too since he didn't do an intro either? Grow up- not all of us are so **** that we have to see an intro. I didn't see anything saying he was "pimping his product" in his post. Just some clarification of the carbs they sell.
I used to be a big Qjet nut- and still am an expert at tweaking one- but back in 1997 I put a BG "Golden Claw" (when BG still tweaked factory Holley castings) on a roller-cammed, Edelbrock-headed 455- it was dead nuts on jetting out of the box. I gave BG my cam specs, vacuum reading at idle, gear ratio, car weight, head flow numbers at 28"- he hit the nail. I turned the idle mix screws 1/8 of a turn on primary side if that. The jets, float level, power valve, and secondary kickdown were all flawless. Kick that Pontiac and we'd be hanging on for dear life, trying to control it on the street. Shortly thereafter, I sold all my Qjets on Ebay. I had a few dozen of them- first went all the "good" numbers, then at the end, I was packaging up 4 in a box for $25 a lot, just to get rid of them. moral of the story- BG makes a damn good carb. I highly recommend them- well worth the coin- and actually cheaper in the long run over messing with a factory carb.
Still only one problem... they're ugly! Why did they knock off all the corners? I guess to differentiate them from the Holley, but the Holley is 1000x better looking. If they want to introduce something angular and gold colored, I'd consider one. In other news; fascinating thread. My dad is always griping about how the BG carbs are nothing special, just a smoothed up Holley. It sounds like there is a technical advantage to them as well. However, since hot rods are as much an aesthetic exercise to me as they are a performance project, I'll stick with Holleys and Edelbrock/Carters.
Well a big **** you to you to... If you had been around or paid attention you'd know that he's been on here before (when he ran R&C) so it's not like he just showed up. So why don't you grow the **** up dip****...
Like I said in another thread, the key is ordering from them and not just buying off the shelf from a dealer... It'll make all the difference...
I know ! (laughter...) WTF designed those rounded off corners ? well, I guess BG wanted to be different and get some attention ??...but I get your drift...putting a Demon on a vintage 50's rod motor, may end up looking like a laser ray gun on a Sherman tank...a bit out of place
Actually the rounded edges were done for a couple of reasons. First being we were in the middle of a law suit, based upon apperance so changing it made sense. Second, having rounded edges is simplier in the casting process for the molds to pull properly, and consistently. Thirdly, Moving around some of the material allowed us to strengthen some of the weaker areas, and improve quality. Some of us here weren't big fans of the design when we first finished, but like a new car they grew on us vs. the older angular carburetors we built. It's actually been a great thing for us, we've had more people like them than dislike. It's all a matter of taste of what you're looking for. That is what's great there are people making OEM style stuff, and just about everything else you could imagine. Zman, Didn't mean to open up a can of worms here. We're just trying to support people who are, or might be using our products to get them the proper information.
I'm pleased to see a manufacturer come on board and answer questions. The exposure doesn't hurt him and the information is good for us. The BG carbs have some interesting features. I suggest you go to the site and read through the info. Home page: http://www.barrygrant.com/default.aspx A trouble shooting chart that should help any carb: http://www.barrygrant.com/demon/default.aspx?page=28 Fine tuning touches http://www.barrygrant.com/demon/default.aspx?page=10 The BG's have some extra features that should help in tuning. Even so, right out of the box ought to work for most of us. Downloadable manuals are available. They're PDF files so you'll need Adobe Reader. (A freebie.) Go to the site and take a look. It's well done and very apparent that they put a lot of work into it. At the least, it's an interesting read. And fwiw, I don't own a BG carb and have no financial interest in the company. Although giving one a try is on the agenda somewhere along the line.
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