Demon carbs???
 

Anyone running a Demon 850 carb? Are they still made by Grant? Are parts (jets) etc interchangable with Holley.
Any good bad or indifferent opnions? I'd prefer to get a Holley HP4150 but they dont seem to list a 850, only a 830

Thanks

Dan

I run an 825 Demon Race carb on top of my Whipple. Yes it does use Holley jets, etc. I love it and it has worked flawlessly for two seasons now. Personally, I wonder if there is much difference between an 830 and an 850? I bought the Demon mostly because they build it at the factory to specifically be used in a blower application. It has totally different metering blocks and air bleeds from a regular carb. It saved me time from having to mess with it. I got baseline info from Whipple and tested mixture for 3 hours and it was dialed in.

Dan:

Demon carbs are made right in America by Barry Grant Inc. (unlike some other carburetors) All of your tuning parts (Jets, PV, Sqtrs, Bowl & Metering Block Gaskets etc.) will interchange with Holley, Moroso, or most other manufactures. Based on the design the Demons will atomize the fuel more efficently, giving you better throttle response, TQ, and HP. If you're comparine vs. a Holley HP (non marine carb) the Mighty Demon is a much better choice. You get a better quality product for less money. I'd be happy to answer any questions you have, give me a call at the office (706) 864-8544 ext. 125

Doug

While we are on the topic, can anyone tell me if the length of Demon carbs is different than the Holleys? Does the different looking fuel bowl stick out as far as the little nub on the Holley fuel bowl?

Dan what are you running on your 540? an 800? I might be interested in it...if you upgrade that is. I have two 850's on my 454's way to much for me.

Tomcat
Overall lenth the Demons are about .200" longer than a Holley. If you have any other questions please feel free to give me a call at the office (706) 864-8544 ext. 125

Doug

Don
Have a Holley hp4150 950 on my motor now. Seems to run good but the ports show its running too rich. It dynoed ok but I think overall I would be better with an 850.

Bigwavez
The 830 was built and calibrated to run on ford small block nascar motors, and Ive been told the are not good on marine motors by Teague

Rumrunner
Ill call you tommorow

Thanks guys

Dan

I'm running the Speed Demon 750's on my 454/400 Cyclones, they have worked perfect so far plus they do look cool.....Fred

Fred did you switch them over or were they on when you bought the boat? if you bought them what did you pay for them?
Don

Thanks for the info RumRunner.

Rumrunner
Thanks for the help...didnt know you were at BG. I'll been in touch once I decide what I'm gonna do

Dan

Dyno, the previous owner had just had them and the intakes put on along with $9,800 into the rebuilds, the engines only had 15 hours on them when I bought the boat.....Fred

Fred do you know wich carb it is????if you look at summit there are several different ones....

DanB, If I remember correctly a while back, Teague Marine used to like running the 830's at one time---hey they worked for me. Remember what Tom Earhart said; in the 20 or so years he's been dynoing engines, he never saw a carb follow/meter/respond as well as what they did on my engines. And they ran well in my boat too!
I (like you) think you'd be better off with a smaller carb than your 950cfm for your 509" engine too!

If you go to a thread called "New carb size on .030" over 454" in the Technical Q & A section you will see some posts of mine comparing the 830 with the 950 on one of my 540's last spring---certainly not that you need me to tell you, but I think you're on the right track. :D

Mark

Mark
After getting the scoop from Teague and Grant, I think I'll go with a proven combination. Them guys are the pros, and sure know more about carbs and the history then I do.
Thanks anyway
Dan

Dyno, mine are the Speed Demons, there are also the Road Demon, Race Demon, King Demon......Fred

Thanks Fred! There are so many different ones I was soooooo confused! you impressed with them? Did you have holleys on the 30?

Been running 2 X 775 RS race demons for 3 seasons. They nailed the set-up out of the box, only thing I had to do was fatten it up 2 jets all the way around. Make sure the base plate screws are lock tite'd (mine wern't) and check the boosters once a season to be sure they are staying tight.

RumRunner,

I have Demons on a pair of na 540s. I looked at your web site where it defines the the carb numbers, but where can I find the numbers on the carbs?

I found a DR 56 on top, which I assume are 1000 Race Demons and I found 175 on the throtle plates, which I guess are 1.75" and the venturis are silver.

I would like to give you a call sometime about my setup because of a bog down problem when accerating 1800 - 2000 rpm. I really have to baby it to get on plane and both carbs do the same. The carbs were set up on a dyno for proper egts. My builder usually makes carbs a little rich on the top end.

What info do you need from me if I where to call your office?

Thanks,
rbtnt

rbtnt

If the carbs are completely silver they are 1000 Drag Race Race Demons (p/n 2563010DR), if they are Gold with silver Venturi sleeve they are 1050 RS Drag Race Demons (p/n 3593010DR)
As far as info get a list of your engine specs (size, comp, cam info, heads,intake, ect) and driveline (drive, gear ratio, prop, ect) and where you're having the problem, and if you've done any tuning or notice any time the problem is better or worse and I can fix you right up.
I'll be in the office Thurs, Fri, & Mon, I'll be doing some dyno work at Reher & Morrison next Tues, & Wed, but will be back next Thurs, & Fri. Just give me a call (706) 864-8544 Ext. 125 If you get my voice mail just give me a number I can reach you at and I'll get back to you.

Happy New Year

Doug

rbtnt;
I had a 1050 dominator that did the same thing around 2000 rpm on a 502. The carb got LEAN, the only way I could make it go away was to go with fatter jets. Which of course left the dreaded "black transom" Changing air bleeds, etc. did not help.

Dyno, yes I did have Holleys on the 30' that I bought from DanL (RIP) they were 700cfm's off a 800sc, they worked great, bolted them on right out of the box and only set the idles!...The Speed Demons on the 40' are 750's, they were 15 hrs old when I got the boat and have worked great, are you changing yours or ?....I don't know if you would notice any diff. between the two or not other than the Demons are a little more cosmetically smooth.....Fred

jdnca1 - Thanks for the info. An engine builder I talked thinks the angle of the boat at that rpm might be causing the primary bowl to overflow with fuel. We tried squirting with the pumps and didn't help any. I don't have a problem when the engines are cold, so it seems to be a too rich problem.

RumRunner - I need to round all the info up before I call. It will take a few weeks. Thanks.

Fred the 850's on my boat are a little big, but dont think I'll change them, might need bigger later!

understanding what everyone's been saying...

I am running the Holly 830 w/ a built 454 procharged set-up. I have two option, move into another carb (the Demon) or call Nickerson and have them set it up. Teague doesn't want to touch my set-up because of the procharger (not much experience w/ centrifical blowers)... What to do???

My problem is a sever stumble off the line. I was told the fuel might be it - change everything out to 1/2" lines and added the aeromotive fuel pump, increased jets - lowered them, power valves, squirters, etc. I'm done and need some experience...

Go with the demons or with a true carb guy (Nickerson or someone else)?????

FeverMike:

Unless you're making other changes, or you're having carburetor problems you're most likely not going to see much difference just changing the carb on your HP500.

DanB.: If you want to sell your HP950 carb to buy an 850, I may be interested in it for my street/race car. The 750 isn't cutting it.

Cheitman
Check your PM box
Thanks
Dan