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View Full Version : 750 demon double pumper VS. Holley 750 Double Pumper



s4dustin
10-17-2007, 06:02 PM
i have the chance to buy a brand new in the box demon 750 Double pumper for 300 bucks or a used holley 750 double pumper for 175 bucks......

one of my buddies who is way more mechanical than i am says demon are crap.....

I dont know anyone who has used a demon..so do i go new demon or used and rebuild holley....

West Texas Z
10-17-2007, 06:10 PM
I've never tried Demon ever but they look freaking awesome. I have the Holly 750 and LOVE IT. Cant go wrong there for the price. I say go for the Holley.

Dont get me wrong, I would love to try the Demon, but like I said, HOLLEY OWNS.

Adam's 55 Chevy
10-17-2007, 07:43 PM
If you buy a demon spend a day stripping it to remove all the swarf inside.

West Texas Z
10-17-2007, 07:46 PM
whats swarf?

z28orshoot
10-17-2007, 09:26 PM
i like the demons. out of the 6 demon carbs that i have bought, only one had any problems IE" shavings in thee bowl. HOWEVER i disassemble any new part to check for that reason. a quick blow out with air and carb cleaner and no propblems at all.

demon had a run of QI problems. ther ewere shaving left in bowls, metering blocks and other areas. i believe they have fixed the problem now. this was a few years ago. had a bad rap since.

i like demons for the billet parts and non pourous metering blocks and baseplates. they take all the same little parts, tunning is the same.
to me i like the way the demon looks but the choice is up to you.

acadian
10-18-2007, 03:44 PM
bought a brand NEW demon jr from summit 3 years ago, ran like crap
till i found lot of porosity problems in the front fuel bowl near the needle and seat o-ring (flooded my intake on the first try). looked awesome but in polite term a piece of **** with WAY too sloppy linkage, stuck choke and the primarys were mechanically pulling the secondary plate( on a vaccum secondary !!!!) due to burrs on the secondary linkage slot...

bought a holley avenger , top notch out of the box with minor adjustment.

learned my lesson very well , i fixed all the trouble till i found the unrepairable porosity in the front fuel bow, could have bought a new bowl but instead decided to not spend another peny on the thing.(i was really mad at them for manufacturing such a crappy product+waisting at least 10 hours on the thing)
Lost roughly 300$ to learn...

but i must concede, they look awesome but that's it...

+STILL WONDERING WHY SUMMIT IS NO LONGER A SUPPORTING VENDOR FOR DEMON CARBURATOR...
MUST BE SOMETHING TO DO WITH COMPLAINT I GUESS...

Z- man
10-18-2007, 04:16 PM
Simply put, go with the original, Holley. Not a dolled up copy-cat with a bad reputation.

MonzaRacer
10-23-2007, 04:00 PM
Trully, Holley all the way.

s4dustin
11-05-2007, 04:45 PM
well, if you see the above post...came across a brand new proform 750 racing carb never used for 275. get it wed. see how that works.....

Adam's 55 Chevy
11-05-2007, 08:56 PM
whats swarf?

bits of metal left from the cutting and milling of the carb. The cleaners at demon only come in twice a week so you have a 60% chance of getting it left inside.

LS6 Tommy
11-08-2007, 12:51 PM
My best friend worked for Barry. All the carbs he does for his customers are Holleys. Need I say more?

Tommy

MonzaRacer
12-07-2007, 10:28 PM
bARRY GOT SUED BY hOLLEY FOR MODIFIYING HOLLEYS AND CALLING THEM bARRY gRANT CARBS DO HE MADE HIS OWN AND CHANGED JUST ENOUGH TO STAY OUT OF COURT.They got big enough they had to throw everything out the door and I was informed that at first they wetbenched every carb but when averyone wanted one they started to only doing every so many. Well those got proper service on assembly and ran, most were simply assmebled and slapped in box.
Thier are several of the BG guys on here but while they stand up for carb problems there are still toms of bad carbs that require a vibratory cleaner and many hours ficxing QC problems.
Just fixed a brand new one from FACTORY as it rplaced another of the QC problem issed ones, supposedly cane directly hand built off the line,,,uh huh took out a table spoon full of crap out of vibratory cleaner.
Proforms good stuff. Never had an issue just wish they would build a 750 vac sec base plate, got several but all with broke bases.
Good luck.

Shawn MacAnanny
01-24-2008, 04:52 AM
I had a demon 650? i think it was a couple years ago, Had all sorts of trouble tuning it. Looking back on it now im pretty sure all my problems were from the electric fuel pump i had. They do look awesome though.

kmcanally
01-24-2008, 11:11 AM
I have had good luck with my Quick Fuel carb...replaced a Demon

willieboy240
01-24-2008, 11:46 AM
go with a NEW holley. dont be cheap when it comes to carbs. :twothumbs

hotrodf1
02-26-2008, 10:41 AM
I struggled with my Demon for a couple months and had to use a Wideband to get it dialed in even close. This was after I bought the carb that BG tech specifically recommended for me, which was the 750 Mighty. I had to drill / tap 8 passages in each metering block to be able to set the holes to the correct diameter. The tune on the stock MIghty, is really rich at mid range, and then leans out to very dangerous 16:1 at high RPM. I actually thought the O2 sensor was lying at first!!! :eek:

I won't make that mistake again. I will say it works great now, and I learned a ton os usable info. BUt what a pain. Hope you *love* carb tuning if you decide on the Demon.

fun2gofast
08-04-2008, 06:52 PM
When I bought a new demon for my malibu it not only had shavings in it but also the idle circuit was not drilled all the way through. After that it ran well, probably will not buy another.