Who runs a Mighty Demon 850 annlar

Posted By: PorkyPig

Who runs a Mighty Demon 850 annlar - 02/06/09 10:59 PM

A buddy picked up new BG Mighty Demon 850 annulr carb from a speed shop closing up. Who uses this carb on a 440 street car and how does it run? They may still have another for about $400 it could be a decent by.

Posted By: Cab_Burge

Re: Who runs a Mighty Demon 850 annlar - 02/06/09 11:45 PM

I dyno tested one on 9secondPhils 418 C.I. W2 motor versus a Speed Demon 850 with downleg boosters on back to back test, the Mighty Demon made less power and torque than the Speed Demon did. I also tested a Holley 1050 Dominator using a adapter and that made the most power and torque of any of the three carbs. See if that shop has a Speed demon 850 with downleg boosters and get it or a King Demon or a Holley 1000 HP with downleg boosters or a Holley 950HP or a Holley 1050 dominator, if you can get one at a good price

Posted By: cudabunch

Re: Who runs a Mighty Demon 850 annlar - 02/06/09 11:54 PM

Quote:

I dyno tested one on 9secondPhils 418 C.I. W2 motor versus a Speed Demon 850 with downleg boosters on back to back test, the Mighty Demon made less power and torque than the Speed Demon did. I also tested a Holley 1050 Dominator using a adapter and that made the most power and torque of any of the three carbs. See if that shop has a Speed demon 850 with downleg boosters and get it or a King Demon or a Holley 1000 HP with downleg boosters or a Holley 950HP or a Holley 1050 dominator, if you can get one at a good price

i have the Speed demon also sitting on a 505 chevy motor.The 950 Holley is a way better carb than the Speed Demon.

Posted By: runya

Re: Who runs a Mighty Demon 850 annlar - 02/07/09 12:04 AM

Seems the holleys always out perform the BG carbs, why is that, they look like they would would be a great carb, or is it a "looks can be deceiving" thing going on.

Posted By: Cab_Burge

Re: Who runs a Mighty Demon 850 annlar - 02/07/09 12:12 AM

Quote:

Seems the holleys always out perform the BG carbs, why is that, they look like they would would be a great carb, or is it a "looks can be deceiving" thing going on.

The Speed Demons I have had and used(two of the first 500 built) out perform the Holley 850 I had back then. I had the 850 Speed Demon and a Holley 950 HP flowed by Pettis performance and the Speed Demon out flowed and out ran the Holley 950 HP

I have since heard that BGs quality control went to crap later on so maybe there are some good Speed Demons and some bad ones

I really like my Holley six pak carbs also and the Holley list #9375 non HP 1050 Dominators on race motors

BTW, I am known to be different, and I'm proud of it

Posted By: amixon

Re: Who runs a Mighty Demon 850 annlar - 02/07/09 09:27 AM

Quote:

A buddy picked up new BG Mighty Demon 850 annular carb from a speed shop closing up. Who uses this carb on a 440 street car and how does it run?

I ran an Mighty Demon annular carb on my street 440(.040,stoke stroke, Indy SR's, .650ish Roller, Indy Dual Plane, and 10.5 CR) and in my heavy car the throttle response was amazing, not to mention I got that cam to idle about 850 rpm with it. To say the least, I like my BG stuff

(pumps maybe a different story

)

Anyway, 400 is a good deal on any new carb with Billet metering and base plates, even if you do have to rebuild it to check the Quality Control (or lack there of) of a company.

Anyone remember when Holley had a bad rash of metering blocks that had casting flash and junk inside of them? It happens to the best and the oldest companies out there...

I think if you go into a situation thinking some (one, thing, product) will fail or is worst than you have had-then it will be!

Posted By: Exit1965

Re: Who runs a Mighty Demon 850 annlar - 02/07/09 12:45 PM

I have that carb on a 440 street car. If I'm not mistaken, the CFM label varies on it, and they are best classified by butterfly size. Mine is called an 825 CFM by some, 800 by others, not sure if 850 is the same or not.

Anyways now that I have taken care of terrible quality (#65 jets installed in the secondaries when #88 were specd; several metal slivers not loose but present in carb; unfinished drilling of holes in metering block) I am happy with it. It was the only carb I could get to work with my car and idle properly in gear and out. At least, it made it easy since it has that idle eze screw in it. On other carbs I tried (not that they were customized for this motor) when the carb was idling at 900 and I put it in gear it would drop to ~600 and start to croak. I tried drilling butterflies but that didn't seem to help. The demon was made for lumpy cams and makes it easy.

Just make sure you pull that thing apart, check for metal, look in holes, and CHECK THE JETS. I pulled mine apart when I got it, found those slivers and unfinished holes, but I didn't think that they would put horribly undersized jets in the secondaries. Check everything.

Posted By: emarine01

Re: Who runs a Mighty Demon 850 annlar - 02/07/09 02:37 PM

the BG guys say the 850 mighty will flow 1000 cfm out of the box , not too shure about the annular , kinda big boosters , I think they would cut down air flow , anyway we have both a 850 annular & holley 9375 1050 annular for our small block , I like the holley better but cant tell much of a diff in ET , I think its all in the tune up

Posted By: Hemi Allstate

Re: Who runs a Mighty Demon 850 annlar - 02/07/09 03:01 PM

I don't have any experience with the Mighty Demon, but I do have a 950 anular Race Demon that was on my 472 Hemi when it was dynoed. The dyno opperator didn't like seeing the Demon carb at all. By the end of the session the Demon had out performed the shops custom built 1000 cfm Holley, that usually gives the best performance on the dyno! There was a few chips in the needle and seat that were removed. None any where else.
My

Mark

Attached picture 5007309-Henryintake004.jpg

Posted By: 9 Sec Phill

Re: Who runs a Mighty Demon 850 annlar - 02/07/09 03:50 PM

As Cab posted, we tried three differant carbs on the 416 but there was only 1 HP differance between them, not enough to worry about in my eyes. At the track I tryed a 950 hp and loss .5 in et from the 850 demon I ran. I also tried two carb spacers, 1" and 2". the 2" killed the et, dropped from 7.0 to 7.5, the 1" dropped it to 7.3. This is on a indy W2 intake with an 850 mighty demon....Phill

Posted By: PorkyPig

Re: Who runs a Mighty Demon 850 annlar - 02/07/09 04:50 PM

Quote:

unfinished drilling of holes in metering block

Which ones???

Posted By: Exit1965

Re: Who runs a Mighty Demon 850 annlar - 02/08/09 07:46 PM

They were the ones that went through to the same passage as the air/fuel mixture screws. The passages were perpendicular to eachother, so the holes I am talking about were supposed to go far enough in to penetrate the a/f mixture passage, but when I looked in them, there was only a small hole there but I could see the angle of the drill. It just was not drilled through completely.

Posted By: dave571

Re: Who runs a Mighty Demon 850 annlar - 02/08/09 08:33 PM

Personally I think an 850 mighty is a little big for a street 440.

It'll work, but FWIW I replaced a 750 mighty demon that worked really well on my 440, with a 950 hp holley worked by bigs, and saw no improvement in et or mph.

I'm not slamming Big's with that statement at all, I'm just saying that any properly set up carb will work, and you only need as much CFM as it'll use. Any more just hurts throttle response, especially on a street car.

Posted By: Cab_Burge

Re: Who runs a Mighty Demon 850 annlar - 02/09/09 01:45 AM

Quote:

It'll work, but FWIW I replaced a 750 mighty demon that worked really well on my 440, with a 950 hp holley worked by bigs, and saw no improvement in et or mph.

I'm just saying that any properly set up carb will work, and you only need as much CFM as it'll use.

I have seen the the opposite of your findings on a strip car,446 C.I., 906 heads with a TM7 intake. started the year with a Holley 600 CFM double pumper and switch carbs throughout the year to a 700 D.P., 750 D.P. 950HP and then switch intakes to a Mopar M1 4500 intake and a 1050 Dominator, that car went faster everytime I made the carb bigger

Sorry for high jacking this thread, not intentional, just trying to add to this in a positive manner