Demon Carb questions?
Thread Starter
Melting Slicks
Joined: Apr 1999
Posts: 3,264
Likes: 3
From: Toms River NJ
Demon Carb questions?
I know some of the stuff I want, and they are mechanical secondaries and 750cfm. I dont know if I should get the Speed demon or spring for the mighty demon...
My motor is a zz4 with the hotcam (duration at .050 is 218/228 and lift is 525/525)
I definitely need the milled choke tower of the mighty or I will have to do it myself on the speed demon cause of the drop base filter setup I want to use. If I just hold the carb upside down and dremel off the choke tower, will this be safe or will it possible get metal into the carb?
In any case, which would be better for my motor. FYI, I have no need for a choke. Some guy on ebay has them going to $400 including shipping and a fuel line. Just thinking about getting one.
Thanks
Chris
My motor is a zz4 with the hotcam (duration at .050 is 218/228 and lift is 525/525)
I definitely need the milled choke tower of the mighty or I will have to do it myself on the speed demon cause of the drop base filter setup I want to use. If I just hold the carb upside down and dremel off the choke tower, will this be safe or will it possible get metal into the carb?
In any case, which would be better for my motor. FYI, I have no need for a choke. Some guy on ebay has them going to $400 including shipping and a fuel line. Just thinking about getting one.
Thanks
Chris
Drifting
Joined: Jul 2002
Posts: 1,855
Likes: 0
From: Cocoa Beach FL
Re: Demon Carb questions? (74VETTE)
I am running the "Crate" Demon 650 which is the one they supposedly built specifically for the ZZ4 motor. It runs great and I love it! It has vac. secondaries and elec. choke. I've been told that the Spoeed Demon 650 flows as much or more than a Holley 750.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Demon Carb questions? (Mystery Machine)
I ran my 750 speed demon on a couple of my hot 355 motors. It's really better suited to 383+ ci I would opt for a 650 mech secondary carb or a vacuum sec 750 cfm
I use a dropped base open K&N 3X14 filter now and never had to even think about machining off the choke tower. I think that You might run into air direction problems if the air filter top is to close to the top of the carb. Machined off choke towers is a racers attempt in gaining additional cfm. Holley carb shops claim that their 850 duoble pumpers flow 930 cfm
I use a dropped base open K&N 3X14 filter now and never had to even think about machining off the choke tower. I think that You might run into air direction problems if the air filter top is to close to the top of the carb. Machined off choke towers is a racers attempt in gaining additional cfm. Holley carb shops claim that their 850 duoble pumpers flow 930 cfm
Melting Slicks
Joined: Aug 2001
Posts: 2,043
Likes: 1
From: Elkhorn WI
Re: Demon Carb questions? (Sigforty)
I also have the ZZ4 Demon.....650, I would also recommend for you application. I needed a spacer for my application to clear some vac line connections to the intake, you might also. Where as the Edel/Holly is a fat round carb the Demon is sleek, skiny, but longer...
read LARS write up on the Demons....they tested all of them on diff engines.
:cheers:
read LARS write up on the Demons....they tested all of them on diff engines.
:cheers:
Drifting
Joined: Jun 2001
Posts: 1,809
Likes: 0
Re: Demon Carb questions? (gkull)
gkull; got a couple of questions for you
1) 650 mech secondary carb or a vacuum sec 750 cfm; which would you recommend for stop light to stop light driving?
2) dropped base open K&N 3X14 filter; is this the one were the top is a air filter too?
1) 650 mech secondary carb or a vacuum sec 750 cfm; which would you recommend for stop light to stop light driving?
2) dropped base open K&N 3X14 filter; is this the one were the top is a air filter too?
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Demon Carb questions? (Tominator)
I don't have the K&N filtered top. IMO Your only going to flow so many cfm and a 3X14 has enough surface square inches that I don't see a restriction problem.
I believe that any carb can be mastered. Mech secondary carbs are more for the person that loves to tinker. Even for 1/4 mile drag racing I think that Vacuum seconds will make any car more consistant. I ran VS carbs for years. Go with a 750 VS :flag
I believe that any carb can be mastered. Mech secondary carbs are more for the person that loves to tinker. Even for 1/4 mile drag racing I think that Vacuum seconds will make any car more consistant. I ran VS carbs for years. Go with a 750 VS :flag
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Drifting
Joined: Jun 2001
Posts: 1,809
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Re: Demon Carb questions? (gkull)
gkull; thanks for the input, your word is usually gold around here. IF you had the K&N top filter that would mean me and a bunch of others would have to get it to.
It's kind of like the movie "Fast and Furious" the guy at parts store says "When Vin Desal (spell) races he's gold, the others guys pour in to buy all the same stuff" [not that I will admit to ever watching the movie or being one of the first ones in line to buy it at the store :skep: I think someone most have told me about that part of the movie :rolleyes:]
It's kind of like the movie "Fast and Furious" the guy at parts store says "When Vin Desal (spell) races he's gold, the others guys pour in to buy all the same stuff" [not that I will admit to ever watching the movie or being one of the first ones in line to buy it at the store :skep: I think someone most have told me about that part of the movie :rolleyes:]
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Demon Carb questions? (Tominator)
Tominator - The top filter is a great idea. I always used the tall four barrel velocity stacks on my tunnel rams. Your straightening the air flow to the venturi area. Without a cowl hood the air cleaner top is into the fiber hood insulation on most vets. It would also be sucking the hottest air.
even a 650 VS carb would work on 355 ci and under 6500 rpm.
The only reason a mech second can make more power on a dyno run is because the pistons are not working against high manifold vacuum in the low to mid rpms. When a VS carbs secondaries open they are again on equal ground. So peak power should be the same.
Is this a compliment? :eek: your word is usually gold around here.
even a 650 VS carb would work on 355 ci and under 6500 rpm.
The only reason a mech second can make more power on a dyno run is because the pistons are not working against high manifold vacuum in the low to mid rpms. When a VS carbs secondaries open they are again on equal ground. So peak power should be the same.
Is this a compliment? :eek: your word is usually gold around here.
Le Mans Master
Joined: Dec 2000
Posts: 5,245
Likes: 25
From: Blue Ridge Georgia
Re: Demon Carb questions? (gkull)
The 650 Speed Demon with Vac Sec's is the item to buy. I have it on my vette and on my 383 in my 73 Z-28. I was told that it gives 10 more HP than a 750 Holley.
Drifting
Joined: Jun 2001
Posts: 1,809
Likes: 0
Re: Demon Carb questions? (gkull)
gkull; yes it was a compliment, your knowledge/experince are great, I can't express all that I have learned from your post on the forum. You rank up there with LARS. Better stop don't want your head to swell so much you can't fit in your car. :D
Thread Starter
Melting Slicks
Joined: Apr 1999
Posts: 3,264
Likes: 3
From: Toms River NJ
Re: Demon Carb questions? (Tominator)
thanks for all the replies guys....I rarely use my car for street driving and do mostly racing....so considering that, y'all think the 650 would be better than the 750?
Race Director
Joined: Feb 2000
Posts: 12,431
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From: CT
Re: Demon Carb questions? (74VETTE)
thanks for all the replies guys....I rarely use my car for street driving and do mostly racing....so considering that, y'all think the 650 would be better than the 750?
I hear that most people are way over carbed and they leave alot on the table. I think i may be one of them too, so there is only one way to find out :smash:
