I've had only good results with these on small blocks, price is right too - http://www.summitracing.com/parts/sum-m08600vs/overview/
Your Demon carb is a Barry grant carb, is it not? That would make it akin to Holley architecture. Has someone possibly put a power valve in the rear metering block on this carb? Especially one with larger number opening point such as say 8.0 or so? If it is vacuum secondary, do you have the lightest spring in the vacuum chamber? Does the metering plate have replaceable jets on that carb? A 600 cfm vacuum secondary carb should be just about dead on for a 302 with a couple bits of rump rump stuff on it. I fall firmly in the camp of out of the box and just run it, AFB (Edlebrock) if ya want razor sharp response and you know a bit about tuning, Holley.
FWIW, I've been doing this for fifty years and back in the day, I could read plug and tailpipe color with the best of them. Today's fuels make this really, really difficult; now I will never, ever try to set up another carb without a wideband O2 sensor and digital readout. When someone says: it's because he is searching in a dark room for a black cat which might not even be in there. With the O2 sensor, the air/fuel ratio is what it is without any guesses or misunderstanding of WTFIRGO. Easy to say, difficult to do. That's why rather than teaching kids in school mathematics, they just give 'em calculators and computers. I gave myself the O2 sensor and am much happier than I was back when I was flunking calculus. jack vines
Gotta have a wideband fuel mix reader to set them perfect, no doubt. Still amazes me all the bigger better carb stories, a little research will show the proper cfm needed, but good luck!
Jack - the "ABC's of carburetion" - (A)lways (B)uy (C)arter And I concur with the O2 sensor and wideband; but it also helps to do the math FIRST and start with a carb that will be reasonably correct in airflow for the engine. Math is the hotrodders's second best friend (a money tree is first). Jon.
I have a Carter Competition Series 9635SA 625CFM on my 302 SBF mild cam and 289 Hi-Po heads,RPM intake works fine with no mods.Many Ford guys swear by the Motorcraft/Autolite 4100 Carbs used on late 60's Mustangs,Summit has this to offer:http://www.summitracing.com/parts/sum-m08600vs kind of the best of both worlds with a similar design of the 4100 and with upgrades, you can use Holley parts for tuning.Several forums have had good reviews on them,in most cases also a side benefit 2-3 more MPG over the 1406 Edelbrocks they replaced.DVD guide comes with it too.
Quadrajet....great mileage, and when those two giganic rear barrels open....no nicer sound...!! I have had one on my vette now since 84 without touching it....30 years...and when I call for it....its there. Just custom built one for my 283 thats now being completed in my 49 Fleetline.
I am one of those "Ford guys". I had a Mustang with a 289 built to factory HiPo specs. It had a Holley 650 double-pumper on it, I had to adjust and play with it all the time. I finally yanked it and put on an Autolite 4100, best thing I ever did. I never had to touch the carb again, and it started better and ran smoother. It may not have had the same "balls to wall" punch as the Holley (because I went a smaller CFM), but I'll take the reliability aspect any day. Autolite carbs are all I'll ever run.
I'm running a summit 750 on my Elcamino- no problems in 2 years. Been down the Holley 1850 road, lotsa fun, lotsa tinkering. Q-jets are great if you spend the time (or money) to set one up right for your combo-good mileage though. AFB's and Edelbrocks have problems with fuel pressure and need regulators, even the carter fuel pump designed for them blew past the needle and seat. Otherwise, trouble free. Rochester 2gs (x3) are fuel pressure sensitive but are a kick in the pants when running right. The old Holley economaster gives great low end, but not really hot rod material.(I am toying with the idea of dual economasters though). Rochester 4 jets don't make any power, good for resto or low horsepower dual quads. Strombergs work well on single carb inline engines, never run one on a v8 though. My .02 worth based on what I have done over the years. guess Ishoulda read the title, disregard the 2 barrel comments
ive run about every carb you can think of in 40 yrs.run holleys when they were king on the street.bought bunches of them because they flooded.lol not really ,just to much carb for the engines is what it always was. I now run mostly edelbrocks because I like the shiney looks and they remind me of the older carters.which were easy to work on.so were the holleys but its still back to the shiney looks. ive found that any carb that's the right size and tuned to run on a certain engine is good as the other.they both get the fuel where it needs to be,up to me to see it gets the right amount of the fuel there.now out of the box runnin ive had much better luck with edelbrock but then I mess with it too....
I like the Rochester Q-jet. Almost infinite adjustability, small primarys keeping airflow up, great signal through the primary venturies. Adjustable opening of the HUGE secondaries making a great carb. If you understand how they work, you'll be rewarded with smooth power and an ungodly sound when those secondaries are fully open.
I have had good luck with the Summit Racing "Steet/Strip" 600 cfm carb- I slapped it on my Ford 302 and did a small adjustment and been running great for the past 3 years I just got one for my '67 IH Scout 800 w a 345 IH Engine-
A Quadrajet on a FORD ! I catch flack from some folks about that "ugly" HEI on my SBF.Bottom line is use what you feel most comfortable with,over the counter Edelbrock/AFB parts and Holley parts are EZ to find not so with the Quadrajet which also has a lot more internal parts and is best left to the more experienced tuner.
I picked a 429 four speed Q-jet out of an "Any Carb, $10.00" box at a swap meet.....made good $$$ on that one.
Holley with vacuum secondaries ? You can get different diaphram springs, to calibrate the opening rate. 4TTRUK
Lots of great info here, thanks guys! Anyone tried an Edelbrock Thunder Series AVS? Based on the info in this thread, and the CFM calculator, i'm thinking i'll go with a 500CFM. Seems really small, but sometimes you gotta trust the math I guess.
500 Edelbrock. Bigger is not better, you are not running steady-state at WOT. Your primary concern is a carburetor that meters fuel/air best at PART throttle. Run a regulator at no more than 5.5psi. Set the float levels out of the box. I too only now tune with a wideband O2 sensor and gauge. You can still tune it old-school, too. Edelbrock has excellent documentation, and good tech people.
I guess you mean the 4350 here:http://www.drbob.tqhosting.com/tech/carb/4350_compared.html That thing is butt ugly Since the original poster does have a 302 it probably would not be a good fit,being a carb guy that knows his stuff what is your choice based on what he has?
Good point Jon!!!... After playing around with a Holley for so many years, I got good at dialing those carbs in for just about any aplication. Last one I did for a customer was a 750 cfm #3310-2 on a 454 in a Vette.. He was a very happy camper...
If you dont open up the secondaries on a holley 4 BBl carb on a regular basis and burn all the fuel out of it. The fuel gets stagnet and turns to varnish. the carter carbs use the same fuel bowl for the primaries & secondaries and dont have that problem.
You answered your own question. You said you ran the edelbrock till the shafts wore out and had trouble with the others. If you're comfortable with that run with it. They all have pros and cons. I'm a holley guy myself, but have run the others. Ken
NO, NOT the 4350! Ford used genuine Rochester quadrajets on the 429! Check out the part number that I posted. http://www.thecarburetorshop.com/7040286_1.jpg http://www.thecarburetorshop.com/7040286_2.jpg http://www.thecarburetorshop.com/7040286_3.jpg http://www.thecarburetorshop.com/7040286_4.jpg As to what I would use on a 302? Definitely different than anything posted so far, AND NOT A RECOMMENDATION FOR SOMEONE ELSE, but I would put two Carter AFB 9400's on my 302 (if I had a 302). For someone else, my earlier post about using the brand that one is most familiar with or wishes to become familiar with! If the 302 hasn't been overly modified, then stock Ford 302 manifold and carb would be an excellent choice. Jon.
Not if it is a 4 corner idle carb and besides, who doesn't open up the secondaries on a regular basis?
The Jalopy Journal
