TartsHouseOfMuscle
New Member
How did the street demon work out ? I’m thinking about ordering one of the 625 cfm street demons for a mild built sbc 350
Street Demon or Edelbrock AVS2 or ?
- Thread starter Magnum87
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They worked great for me, pretty much just bolt on and go, I had to adjust the idle screw down about a 1/8 of a turn.
750 demon works well on my 340 , never a problem hot or cold
Why run that junk on the street? Either run so much better and you can just forget about carb issues.
stroked340
Well-Known Member
Junk would be the garbage Edelbroke and the Demons are trash right out of the box.If you KNOW how to tune Holley like carbs are the best out there!!
I know how to tune that junk. Never on the street. You could not give me a Holley.
The Carter/Edelbrock cam have an off idle lean stumble that can be very difficult to tune out. I know very well how to work on them and tune them (they're simple carbs). I've tried the avs and regular carbs and had the same thing. Anyhow other than that they're pretty good.
The street Demon seems like a good carb, pretty much a modern thermoquad. Know a few people that run them and they love them. Definitely get the resin bowl.
I have fitted two SD carbs, a 600 a 750. The 600 worked well, the 750 always had a flat spot. Owner rang Holley from Oz, unable to fix. All the usual things tried, bigger jets, air valve etc. He put his QJ back on, problem fixed.
I would never use one, they are poorly made & a cheap copy of the TQ.
I would never use one, they are poorly made & a cheap copy of the TQ.
thesiren74
Well-Known Member
So we put one on my dad's 360 5yrs ago and we have never touched it.
MidnightSwinger
Well-Known Member
I love my 750 on the 383.
750 WORKS great on my 340 3 years and counting started up no problem yestrday
thesiren74
Well-Known Member
You know that the demon has proven itself why would anyone ever want the edelbrock carb that's prone to heat soak and fuel evaporation.
340sFastback
Well-Known Member
Usually off idle stumble that hard to tune out is caused by Transfer Slots over exposed.
340sFastback
Well-Known Member
When I ran stock 340 I had a Holley 600 on there for years that I bought new. Fooled around with jets, accelerator pump cams, vacuum springs ect. Got it to run really good. Then when that carb got old and tired went with a 650 Edelbrock AVS. Had to put bigger accelerator pump nozzle and fool around with jets/rods a lot but got that running good as well. The Edelbrock I liked cause it had the original carb look to it and it ran really good once dialed in. I think Holleys get a bad rep cause ppl buy old ragged out used Holleys and not able to get them to run right.
As far as Edelbrock getting heat soaked yes that an issue but if intake cross overs are blocked and you run that Edlebrock gasket thats made to insulate from heat its manageable.
As far as Edelbrock getting heat soaked yes that an issue but if intake cross overs are blocked and you run that Edlebrock gasket thats made to insulate from heat its manageable.
MopaR&D
Nerd Member
I've been running a 750 Street Demon on the 360 in my Duster since about 2018 iirc. That engine has a 222/226* @.050" cam which has moderate idle vacuum, I think if I had anything over about 230* I'd run a Holley instead. Edelbrocks and Street Demons are great but they just don't work well with bigger-cammed engines that don't pull much idle vacuum. Mostly the design and lack of tune-ability of the idle circuit, accelerator pump and power enrichment don't lend themselves well to "hotter" engines. I love mine, kind of a pain to do "coarse" jetting adjustments as you have to remove the entire carb and take it apart to get to the jets but once the tune is set where I want it I don't have to touch it throughout the year. Only time I've had to make big changes is when I moved from 5000+ feet elevation in Colorado down to near sea level in Georgia. Back in CO it would start right up and be ready to drive in 2-3 minutes or less even when it was 20 degrees outside and between summer and winter all I'd have to do was tweak the idle mixture and speed just a hair and adjust the choke a bit.
It goes back to the decades-old debate; Edelbrock/Carter carbs are nice for milder street engines as they hold a tune better and are more forgiving but Holleys can be tweaked more to dial them in for higher-performance engines. Doesn't mean Holleys also don't work on mild street engines but they generally aren't as much of a bolt-on-and-go, set-and-forget carburetor.
It goes back to the decades-old debate; Edelbrock/Carter carbs are nice for milder street engines as they hold a tune better and are more forgiving but Holleys can be tweaked more to dial them in for higher-performance engines. Doesn't mean Holleys also don't work on mild street engines but they generally aren't as much of a bolt-on-and-go, set-and-forget carburetor.
Yup, Ran a Street Demon 750 on a 410 w/Isky 280 Mega but on a 106 LSA (instead of the 108) Saw 14 in/hg in park, idled fine (yes, choppy, but consistent) and had a nice strong consistent chop with about 11 in/hg in gear. Stroker, dual plane intake, EQ Magnum heads with 1.92 intake valve, ports favoring velocity etc. Combo has an impact. Throttle response was outstanding. It’s a great street carb that can be run on the strip to a point. but it’s no Holley when it come to tune ability or ease as mentioned. I’d buy one again if I had a need, they’re nice and certainly not a cheap copy of a Thermoquad. 
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Coming back to this, I got my Ford 400 finally swapped in my truck and I stepped up 2 jet sizes and down two metering rod sizes and it's spot on so far. Runs just as good as with the 351. Better since I have a lot more motor.
IMO it's a damn good Thermoquad copy. Anybody that cannot see the resemblance needs to be selling pencils in a cup on the street corner.Yup, Ran a Street Demon 750 on a 410 w/Isky 280 Mega but on a 106 LSA (instead of the 108) Saw 14 in/hg in park, idled fine (yes, choppy, but consistent) and had a nice strong consistent chop with about 11 in/hg in gear. Stroker, dual plane intake, EQ Magnum heads with 1.92 intake valve, ports favoring velocity etc. Combo has an impact. Throttle response was outstanding. It’s a great street carb that can be run on the strip to a point. but it’s no Holley when it come to tune ability or ease as mentioned. I’d buy one again if I had a need, they’re nice and certainly not a cheap copy of a Thermoquad.
furrystump
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Just to be clear, the AVS has the spring loaded air door. The “afb” version has the counter weights. Both of the Eddy’s use the AFB base with the slots for counter weight shaft. I run a 800 AVS, and it is WAY out of its comfort zone, but still working. It really needs a secondary transition system like the carter AFB. The small port that the counter weighted butterflies pass by. Add that the AVS spring is pretty fragile…..and you get lean spot on secondary opening. Also the secondary emulsion tube necks down at the bottom. Again, mine is way out of its comfort zone.
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I started with a new Holley in the 70's. I could tune it just fine. Tried everything and had it dialed in good enough for a "64" Barracuda with 273 to match the power to weight ratio of "68" 383 Road Runner. I just can't stand "having" to work on stuff, let alone fuel leaks, backfires, and burning your car to the ground. But when you get a really good, carb the Holley is nowhere close. No reason for me to ever run a Holley along with all the extra "tuning" parts. And for the record, I run original Carter carbs that are usually 50 to 60 years old with a 100,000 + miles on them. Just clean them up, put a kit in them, make your adjustments, forget about the carb, and enjoy your car. I get more power with better mpg with my used Carters than any Holley I tried.
thesiren74
Well-Known Member
If you haven't tried a Holley since the 70's your opinion is not valid of anything built in the last 10-15 years.
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