I am soon buying a new carb for my bb chevy.
my question is about a choke free style.
I have only owned Holley carbs in the past. Due to some air cleaner and hood clearance issues I want the Mighty Demon. this style is chokeless which i need because it has no air horn or choke horn sticking up above the venturies. This will allow me to gain clearance between the carb and air cleaner lid (i can only use a 2 inch air filter).
My point being what is it like running a carb with no choke on a street car?
Will there be any starting trouble?
Just would like to here from those who run this style carb.
The car will be only driven in warm temp's but i want to start it and run it in the garage during winter months (Michigan winter month's).


Thanks much!
Bill C.

Holleys HP series carbs do not have a choke either. You might have to baby it for a while to keep it running,but where there's a will, there's a way. I installed a Mallory Hyfire ign. box on mine and cold start problems went away,I'm running the HP950. Havent tried it in the dead of winter yet,but sure made a difference.

I just put an 850 Mighty Demon on mine (see signature), replacing an 850cfm 4150 Holley. The Holley didn't have a choke either and I drive the car year round. Now I won't even try to compare my winters to yours, but I have driven regularly at and below freezing (regularly, like 3 days every 5 yrs). It's not that the car is going to be hard to start, it'll start easy, just give it a couple of pumps, the inherent problem is keeping it running. You won't be able to start it and then run back in the house to get your coffee while it warms up. You pretty much have to be present for it to warm up.
As for the Demon, everything that you heard will apply, and nothing that think will apply. The Demon almost asks to be tuned before it ever touches the manifold. I pulled the bowls prior to installation as to know what jets and power valve I was starting with. I was surprised to find 88's front and rear, I had run 72/85 in my 4150 for more than 13 yrs. The carb ran good, crisp in the middle, alot on top. A week or so in my idle fell out, my plugs were pretty black. In the literature it'll ask whether your intended idle is 1000 rpm or over, my take on this, if you intend anywhere near 1000, set your rear throttle plates equal to the fronts (exposing the slot) and therefore involving more idle mixture relevance to the rear screws. If you have a 700 idle, keep them closed, either way your not supposed to bring the idle up with the idle speed adj. rather to use the "idle eze". Easier said than done. I found that it is necessary to use the idle speed, but keep track of turns, adj mix, back idle speed off, increase rpm with idle eze. Note: idle eze doesn't react like you expect, to me, it seems that somehow it's gotta be messin' up what I just did.
That said, it seems to be O.K., 80/88, but I think since I am running it square (all 4 idle mix), I may try 84/84 0r 86/86 or 84/86. I like to smell like gas all the time. I'm curious as to your Demon experience. Lotsa luck
Rowdy

Bill,

If you've already got a Holley carb and want to use it, you could replace the carb body with one on the Proform units...they have no choke horn.

I have looked at the hp series Holley, but the 850 cfm says it is calibrated for ford Winston cup and has no notched floats.
Swapping the body with the proform carb wont work cause my carb is in really poor shape, not much to salvage as it is the original 1970.
Rowdy, you did not sound really pumped about the Demon? I am no carb God so if it takes a lot of tinkering maybe i wont like it huh?
What about the Edelbrock thunder avs series anyone? Does their secondary compare to a holley mechanical secondary? I really like machanical over vac's.
Edelbrock claims their carb's are just as responsive.

keep the feedback coming both for demon or edelbrock....It helps.
thanks everyone

The Demon almost asks to be tuned before it ever touches the manifold... I'm curious as to your Demon experience.


With all do respect, I've got to disagree 100%!
I can't stress enough...call Barry Grant, talk to one of the techs and get a carb recommendation.
I did! :thumbsup:
Absolutely the best carb I've ever owned. After asking specific questions about MY application/setup, the tech recommended a King Demon RS 995.
After purchase...right out of the box, all I've ever done is idle and mixture settings. Runs like fuel injection...hot or cold. Plugs look great, too.

No disrespect taken here, as a matter of fact, I have high expectations for my Demon. In no way was I trying to disuade Proex's decision, odd as it sounds, even kinda ease him into. Sometimes this stuff isn't in your mind in a type format, especially when your skimmin' other threads lookin' for your own answers. I intended to talk to Demon prior to purchase, doubt that I would have sprung the extra two bills for the race( hindsight 20/20), but I made spontaneous online Jeg's order. My Holley got the blame for some erratic behavior. The next day, before the Demon arrived, I discovered a broken adv. spring. The Demon is now an expensive experiment. Oh well.
If hood clearance is at a premium, a tape measure might prove more important than any of this.
I emailed BG Tech and await a response to my jet question.

With all do respect to all of the fine gentlemen who have responded thus far.......I will inject my 1 1/2 cents worth........Like was already said if you have the patience to sit in your car and enjoy it while it warms up then a chokeless carb will be fine......I know because i've had them.....in your application use a 750 HP Holley vac secondary carb.......they're about 500 big ones but well worth it...............now go out and by it and e-mail me the compliments telling me what a genius I am later.........

Jo, I have looked at the hp holley series. I'm pretty sure i need more than a 750 cfm i am pulling around 500 HP on a 468 bb. Again the 850? cfm HP is said to be calibrated for winston cup racing and don't have notched floats.

Still would like to hear more feedback from those of you that are using chokeless carbs on street drivers.

Thanks everyone
Bill C.

Jo, I have looked at the hp holley series. I'm pretty sure i need more than a 750 cfm i am pulling around 500 HP on a 468 bb. Again the 850? cfm HP is said to be calibrated for winston cup racing and don't have notched floats.

Still would like to hear more feedback from those of you that are using chokeless carbs on street drivers.

Thanks everyone
Bill C.
The 750 will be great for street driving because the carb is small enough to give great response and still give acceptable performance on the street.however ,theres a big difference between the 3310,4779 and HP stuff ,I'm talking HP stuff here...use the 750 with vac secondaries.they are race calibrated but the small ones are very good even on the street ........however,if there is an 850 version that is comparable on features then .....try it, but from my own experience use the 750.....

I've ran chokeless carbs for several years (here in TX) with no problems whatsoever. I'm running a BG Speed Demon right now. I had a local carb guru mill the choke horn and make some other mods. Ran great on the dyno, will report back when I get it on the road.

I am running a Speed Demon on my 396 and I actually removed teh electric choke because I didn't need it anyway. I left it on summer settings year round so no sense in have extra wires and the ugly black choke control and plate if you don't need it. You will have to feather it for a couple minutes, but you'll be surprised how well it idles after she warms up for a minute or two. If your like me your gonna baby sit anyway. I'm still learning to tune carbs so like you I was a little reluctant, but its really no big deal once you get into it. My carb ran fine right out of the box, just getting fusy with it now, you may notice the thread I started about the idle. It really is a great carb, and it out performs the Holley I had on the engine by a mile. Well 1/4 mile, Ha!

Oldskool67

I started out with a speed demon 750 w/elec choke and after some tuning on the dyno I called the guys at Barry Grant and they helped me choose the Mighty Demon 650 for my 383. It ran great "right out of the box". I just bolted it up and fired it off. I put the car back on the dyno and GAINED 25 MORE Hp than with the 750. I did end up increasing the jet size 2 sizes in front and rear to correct a slight lean problem. I have had it on for about a month now and it runs great in hot (95-100) and cold (45-50). I do have to stay in the car for a few to warm it up... but that doesn't bother me.

Just my Two Cents....

Steve

love my mighty 650
shane

I just went to a 670CFM vac sec. on my 408BBC. Dropped down from an 870CFM vac sec. Throttle response with the smaller carb is nothing short of incredible. The fuel seems to mist into the venturi's as opposed to squirting in - most likely I assume this is because of the increased air velocity. JMHO, but I tend to like smaller carbs on street cars, sized so that I can take complete advantage of the carb's capacity rather than going larger and having lazy throttle response.