Rob Posted June 8, 2000 Share Posted June 8, 2000 Does anyone run a Speed Demon Carburetor, and are there any problems with them? Are they worth the extra cash? I need to switch from my side hung float bowls to center hung, and am thinking about just getting a new carb with the bowls I need and mechanical secondaries. Currently I'm running a Holley 1850 600 CFM vac secondary carb. My biggest problem is cutting out on sweeping left turns during autocross events. Pretty sure it's due to the side hung bowls. I'm thinking a 650 double pumper or Speed Demon "twin squirter" may be a nice upgrade from my current set-up. I've got a 350 with 10:1, aluminum 1.94 intake heads and a t-56. Any comments on the topic would be appreciated. Thanks!!! Quote Link to comment Share on other sites More sharing options...
Mikelly Posted June 8, 2000 Share Posted June 8, 2000 My current BG Sport CLaw series carb was the forerunner to the Speed Demon. After all the fuel headaches I have had, and after talking to virtually everyone in the automotive Fuel delivery and tunner/ builder arenna, I can only tell you what they all told me. Barry Grant has NOTHING to do with his carbs. His name is on them and thats about it. They LOOK great, but bang for the buck, they aren't. My advice would be to research the AED (http://www.aedperformance.com)line of carbs. I've had more people tell me in the last few weeks how great those carbs are, and how poor BGs are... And you cannot go to any local speed shop and get fittings for your carb. All BG parts must be ordered from BG. Fuel logs, inlet fittings, pump fittings, regulator fittings.. everything that touches that carb must have a BG thread (9/16X24) pattern. My advice...don't do what I did. I bought it thinking I was getting a great carb... Hopefully when I'm done with it, it will be. Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted June 8, 2000 Share Posted June 8, 2000 B&G sent my engine builder a Speed Demon to test, before they came out. They were having a problem with them from the begining. My engine builder said that they were crap, and not to buy them. He still says the Holley is the best carb out there. Quote Link to comment Share on other sites More sharing options...
John Scott Posted June 8, 2000 Share Posted June 8, 2000 Rob, Have you looked at the new 4150 PRO series Holleys? I know this isn't the answer, but if you want to try my 600 Dbl. Pmpr. for a weekend you'd be welcome. It wouldn't be that big of a deal to "pop it off". The jetting should be close for our altitude and you could see if the float bowl position makes a diff. Two hitches: My center stud is a littler larger than original. I didn't like it when mine blew out @ 7000 grand and smacked my hood! OW! Also has dual fuel inlets. You'll need a y fitting or dual fuel line. Let me know. JS Quote Link to comment Share on other sites More sharing options...
Rob Posted June 10, 2000 Author Share Posted June 10, 2000 Thanks a ton for all the replies. I will not be getting a Demon. I'm a sucker for great looking stuff but not this time! Just replied to your email John. Wow what a generous guy! I am thinking that there's no reason that a double pumper won't be an upgrade, so maybe its not required to trouble you so much. BTW, let me know when you need that alignment tool. I have a hoist too if you need that! I have looked at and drooled over the 4150 pro. However, they have no choke. I like being able to fire up my Z any time of the year. The air density is highest in the Winter after all. A guy in a rod shop told me you don't need a choke with a 4 corner idle system. Is this true? I'm thinking that the only way to get away with having no choke is to set the idle extremely rich. It's my understanding that rich mixtures are the reason most FI motors go much further between rebuilds than carbureted motors. Once again, any inputs on this will be appreciated. Have a great weekend. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted June 10, 2000 Share Posted June 10, 2000 I know you have decided against the Demen, but I'll relay this anyway, unless any of you guys has a BG dealer close by, don't waste your time on a BG carb. You have to custom order the rebuild kits, as well as all the other things I mentioned before... I will probably sell this thing down the road when I swap to EFI. I also found out that it realy isn't BGs fault.. Seems that Holley has sued both BG and EAD for using Holley Cores for their units, not paying holley for the rights... Seems that now BG and AED will be designing their own carb bases once the cores they have in stock are gone. Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
John Scott Posted June 10, 2000 Share Posted June 10, 2000 Rob I wouldn't mess up my jetting over a cold start issue. It would be over rich the rest of the time. Most of my projects have had choke-less carbs. A few minutes at idle and it will be on its way. I know your Z is snug in the garage in the winter...isn't it? Holley's regular carbs still come with chokes, even if they are manual. No rocket science, but they work. You could always save your elect. choked carb for the winter months....Or add a supercharger! They'll start year 'round! JS Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted June 12, 2000 Share Posted June 12, 2000 I've got a 4150 2pumper with the choke horn milled (OK, hack sawed) off. Three pump shots, and away I go. Of course, I wouldn't recommend jumping on it until it's warmed up for at least five minutes... unless there is a power valve anti-backfire check valve installed. Most new Holley's come with this from the showroom floor. However, I'd double check for this item. Especially if there is no choke on the carb. -Andy Quote Link to comment Share on other sites More sharing options...
John Scott Posted June 13, 2000 Share Posted June 13, 2000 Come on Andrew! Its cooler to say milled JS Quote Link to comment Share on other sites More sharing options...
MYRON Posted June 14, 2000 Share Posted June 14, 2000 I have the hp4150 pro carb that has had some extra tweeking done and am very happy with it. I better be for 625.00 bones!!! It started life as a 750dp but it now has a 750 body with an 850 base plate and has been coated with some fancy slick stuff. it does not have a choke and it is a little rough until the temp comes up a little but the ease of changing jets and power valves is easy... I would suggest getting one.. Myron Quote Link to comment Share on other sites More sharing options...
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