Anyone Running A Holley 650 Dp?

86lxhatch · Aug 15, 2012

I am thinking about getting one, but I have some questions...

1) do the cars start up okay without having a choke?

2) do they offer them with chokes?

3) which is better, manual or electric, if that is an option...

4) can you run power brakes off of the carb, or does the vacuum have to come from the intake manifold?

Boosted92LX · Aug 15, 2012

I ran one on a 351 in the early 90's without a choke and it did fine. Keep in mind I'm in Texas and it doesn't freeze here often. Not for very long anyways. It did come with a manual choke, but I sawed the horn off and smoothed it for better flow. As for the brakes, I don't think it matters really as long as you have vacuum.

CarMichael Angelo · Aug 15, 2012

A true Holley 650 DP,.. list# 4777 will come w/ a manual choke. It will have a large vacuum port at the rear of the carb in the base plate for the power brakes. An electric choke will be easier to deal with, and you can get it as an option on another mfg's carb (i.e. Quickfuel). What ever you do, dont be an Allen and saw the choke horn off of the carb.

Boosted92LX · Aug 16, 2012

Yeah.. its much smarter tospend 200 bucks on a carb body with no horn to drag race with when you've got a machine shop to modify the old one for free...

CarMichael Angelo · Aug 16, 2012

SSeater said:
Yeah.. its much smarter tospend 200 bucks on a carb body with no horn to drag race with when you've got a machine shop to modify the old one for free...

Aww C'mon! Milling the choke horn off of a standard Holley, does not make it the same as a race carb that was originally Cast that way, w/ all four bore throats smoothed and blended.

Now I'm no aerodynamic physicist, but which one would you think will flow closer to advertised CFM?

Boosted92LX · Aug 16, 2012

You win Mike.

For the record i dont do work as chitty as the top pic.

srtthis · Aug 16, 2012

quickfuel FTW!

85_SS_302_Coupe · Aug 16, 2012

Mike you crack me up sometimes. Use your head man....air has to move up and over that choke horn. Remove that huge wall that air has to go around, and flow is made easier. No, it won't flow as well as a proper no choke main body, but it will flow better nonetheless. It's especially useful when you have to run a drop-base breather that puts the breather lid closer down on top of the carb, like the stock Fox duel snorkel does. There might be a half inch or so of clearance between the choke horn and the breather lid...but if you cut the choke off you gain an inch and a half of clearance, which is a lot less restriction for air to move through. It's a worthwhile mod if you don't NEED a choke, and you're too cheap to buy a proper main body. As far as how smooth the air goes into the venturies...it's not any less smooth than it was before the choke was sawed off is it? It's exactly the same thing, just shorter and less of an obstacle for air to travel over.

I ran a 650dp for years, ran awesome. I dynoed my 347 with the same carb i ran on my stock long block 302. The guy who tuned it was going on and on about how the duel plane intake i was running would only let me rev to 5500, and how the breather was gonna choke it out and on and on. Then it spun the rollers and he couldn't believe that it had just made more rwhp than another EFI 347 he had recently dynoed that had fancy aluminum heads on it. Then we took the breather off to see if it was choking power, and the A/F was all over the place and it put down LESS power. He said "whatever you do don't ever run another breather but this one".

When i got the cash, i stepped up to a Pro Systems custom built carb with a fancy NASCAR main body. I haven't been back to the dyno but between the carb and a Vic Jr. intake swap the car pulls way harder. I'm suspecting the gains are mostly from the intake swap though.

My old Holley

My new fancy pants Pro Systems 780

Oh, and i've started both of these carbs in the dead of winter...two pumps on the pedal, fires up first crank. Sure, it doesn't idle on it's own and you have to sit and goose it for a couple minutes to keep it running, but after two minutes or so it idles fine and once it warms up it runs like any other carbed car in the winter. If you WANT to run a choke, i'd suggest an electric over a manual choke. I got the manual because i didn't want to fool with wiring the electric, and i never used it so i took it off. I even spent the cash on a manual choke cable...waste of time. Just go electric and be done with it, or nothing at all.

ratio411 · Aug 16, 2012

A DP Holley will run fine on the street with or without a choke.
If you want seamless cold running in a cold climate, an electric choke is your best bet.
You can leave it manual and never hook it up, or remove it totally, that is up to you if you don't feel you need a choke.

The biggest drawback to a DP is the fuel economy... there is none.

A double pumper also works even LESS effieciently when the car has an auto trans.

My 302 with 4 speed and 4.11 gears in a 2800# car got 5 mpg with a 700 DP.

Unless the carb is free and you don't drive the car much, you will SAVE money by purchasing a new 570 Street Avenger vacuum secondary with electric choke.

You never made it real clear what you are doing with the car, so it's hard to pin down one good idea.

ratio411 · Aug 16, 2012

85_SS_302_Coupe said:
Mike you crack me up sometimes. Use your head man....air has to move up and over that choke horn. Remove that huge wall that air has to go around, and flow is made easier. No, it won't flow as well as a proper no choke main body, but it will flow better nonetheless. It's especially useful when you have to run a drop-base breather that puts the breather lid closer down on top of the carb, like the stock Fox duel snorkel does. There might be a half inch or so of clearance between the choke horn and the breather lid...but if you cut the choke off you gain an inch and a half of clearance, which is a lot less restriction for air to move through. It's a worthwhile mod if you don't NEED a choke, and you're too cheap to buy a proper main body. As far as how smooth the air goes into the venturies...it's not any less smooth than it was before the choke was sawed off is it? It's exactly the same thing, just shorter and less of an obstacle for air to travel over.

I ran a 650dp for years, ran awesome. I dynoed my 347 with the same carb i ran on my stock long block 302. The guy who tuned it was going on and on about how the duel plane intake i was running would only let me rev to 5500, and how the breather was gonna choke it out and on and on. Then it spun the rollers and he couldn't believe that it had just made more rwhp than another EFI 347 he had recently dynoed that had fancy aluminum heads on it. Then we took the breather off to see if it was choking power, and the A/F was all over the place and it put down LESS power. He said "whatever you do don't ever run another breather but this one".

When i got the cash, i stepped up to a Pro Systems custom built carb with a fancy NASCAR main body. I haven't been back to the dyno but between the carb and a Vic Jr. intake swap the car pulls way harder. I'm suspecting the gains are mostly from the intake swap though.

My old Holley

My new fancy pants Pro Systems 780

Oh, and i've started both of these carbs in the dead of winter...two pumps on the pedal, fires up first crank. Sure, it doesn't idle on it's own and you have to sit and goose it for a couple minutes to keep it running, but after two minutes or so it idles fine and once it warms up it runs like any other carbed car in the winter. If you WANT to run a choke, i'd suggest an electric over a manual choke. I got the manual because i didn't want to fool with wiring the electric, and i never used it so i took it off. I even spent the cash on a manual choke cable...waste of time. Just go electric and be done with it, or nothing at all.

Yeah, carbs (generally speaking) always make more power than EFI.
The biggest draw to EFI is reliability and economy. Some say throttle response, but that isn't true if you know how to properly tune a Holley.

I see where your dyno guy was coming from on the dual plane intake.
Those intakes are way overrated.
I ran a single plane on the street with awesome low end power and crisp response, but everyone was telling me how a swap to an agressive dual plane was going to do so much more for me, so I bought a Performer RPM. No other changes, and I lost power and response everywhere. I put a 2" open spacer on it (couldn't fit air cleaner), and gained back some performance, but it never fully came back until I put my single plane back on. I am talking about a MILD single plane, not a Vic Jr or larger mind you.

IMO most 5.0 carb'd guys are leaving much power on the table if they are running a dual plane. These short stroke engines have to rev to make power, so why mismatch the intake?

Edit: That reminds me...
To the OP, a double pumper also does not like dual plane intakes, just like they don't much like auto trannys. It'll work with dual planes or autos, but it's not optimum. Just like a vacuum Holley doesn't work as well as a DP with single plane or manual tranny.

85_SS_302_Coupe · Aug 16, 2012

Well, for what it's worth i did still make pretty awesome numbers with a Stealth...if I had to run a duel plane, i'd run a Stealth over anything else.

CarMichael Angelo · Aug 16, 2012

85_SS_302_Coupe said:
Mike you crack me up sometimes. Use your head man....air has to move up and over that choke horn. Remove that huge wall that air has to go around, and flow is made easier. No, it won't flow as well as a proper no choke main body, but it will flow better nonetheless. It's especially useful when you have to run a drop-base breather that puts the breather lid closer down on top of the carb, like the stock Fox duel snorkel does. There might be a half inch or so of clearance between the choke horn and the breather lid...but if you cut the choke off you gain an inch and a half of clearance, which is a lot less restriction for air to move through. It's a worthwhile mod if you don't NEED a choke, and you're too cheap to buy a proper main body. As far as how smooth the air goes into the venturies...it's not any less smooth than it was before the choke was sawed off is it? It's exactly the same thing, just shorter and less of an obstacle for air to travel over.

I ran a 650dp for years, ran awesome. I dynoed my 347 with the same carb i ran on my stock long block 302. The guy who tuned it was going on and on about how the dual plane intake i was running would only let me rev to 5500, and how the breather was gonna choke it out and on and on. Then it spun the rollers and he couldn't believe that it had just made more rwhp than another EFI 347 he had recently dynoed that had fancy aluminum heads on it. Then we took the breather off to see if it was choking power, and the A/F was all over the place and it put down LESS power. He said "whatever you do don't ever run another breather but this one".

When i got the cash, i stepped up to a Pro Systems custom built carb with a fancy NASCAR main body. I haven't been back to the dyno but between the carb and a Vic Jr. intake swap the car pulls way harder. I'm suspecting the gains are mostly from the intake swap though.

Oh, and i've started both of these carbs in the dead of winter...two pumps on the pedal, fires up first crank. Sure, it doesn't idle on it's own and you have to sit and goose it for a couple minutes to keep it running, but after two minutes or so it idles fine and once it warms up it runs like any other carbed car in the winter. If you WANT to run a choke, i'd suggest an electric over a manual choke. I got the manual because i didn't want to fool with wiring the electric, and i never used it so i took it off. I even spent the cash on a manual choke cable...waste of time. Just go electric and be done with it, or nothing at all.

My point wasn't to try and say that the carb would run just as good if he kept the air horn on it, It was to say DO NOT mill that air horn off if the main purpose is a street driven car. The choke is more important than the extra XXX CFM that'll be gained from cutting the choke horn off.
AND,....if he intended to drag race (solely), and was starting from scratch,...might as well buy one of the multitudes of race prepped carbs that has the main body cast w/o the stupid choke horn in the first place.

As for the dual plane vs single plane, I'm also a staunch supporter of the Weiand Stealth. All other dual plane manifolds are GAY by comparison. I had one on a 460, and that "stock" engine w/ a flat tappet cam, and headers ran 7-OH in the 1/8th in my 1980 Fairmont.
Adding two N2O Powershot plates stacked (w/ pills set at 175) w/ a 3310 vacuum secondary carb, ran 6.40's all summer long several years ago in my "Dumb phase". If ever there was an intake manifold that shoulda NOT worked,...that one was it. But it ran great.

Right up until it spit a valve outta the cast iron head in the burnout box.

86lxhatch · Aug 16, 2012

okay, I live in e. tenn. and it doesn't get real cold here either. The car will be a road race style application, and will spend almost all of its time in the upper rpm range, except when I cruise on the weekends. The car is not a daily driver, and basically this is the setup as of now:

stock bottom end 306 with forged speed pro pistons(9.5:1)
t5 manual trans
gt40p iron heads
b303 cam
1.7 roller rockers(crane)
crane energizer beehive springs
msd 6al ignition
reman. motorcraft distributor with vacuum advance and steel gear
ford racing headers

I wanna order the edelbrock vic. jr. intake and run the Holley 4150 hp carb(650 cfm), but am concerned about vacuum for the brakes as the vic. jr. does not have a vacuum port on the manifold. Does this carb have the brake vacuum port on it? And will my brakes function as they should? I will be upgrading the brakes next when I do my 5 lug swap, but need them to function normally until I am ready for the next phase of the build...

86lxhatch · Aug 16, 2012

Thanks for all the info. and tips!

86lxhatch · Aug 16, 2012

CarMichael Angelo · Aug 16, 2012

I already said that the carb has a brake vacuum port on its' base plate. Building a car that will spend "almost all of its' time in the upper RPM range" that will have to double duty as a weekend cruiser is an oximoron,........... but since there is nothing in either your existing list of mods, or your wish list that revolves around making all of its' power in the upper RPM band, I wouldn't worry about low vacuum when driving it on the street.

85_SS_302_Coupe · Aug 17, 2012

I have a pretty healthy cam...i don't have any vacuum issues even with a single plane intake. I wouldn't say my car is a track car because it sees the street about 98% of the time it's driven, but when i drive it i drive it hard and it sees 7k+ quite often. I drove it just as hard with the old Holley. In casual street driving I can't leave off an idle but that has more to do with the cam than the carb, i have to bring it up to about 2500rpm or so to keep it from bucking.

As for the vacuum ports...i've ran the brake booster off the base plate port without any issues. The only problem you might have is that you lose that port for your PCV valve. So, to get around this i drilled/tapped a hole in the back inside of one of the runners and i use that for the PCV valve.

ratio411 · Aug 18, 2012

Run a mild single plane intake.
You'll get the best of both worlds.
I suggest the "Torker 289".

85_SS_302_Coupe said:
Well, for what it's worth i did still make pretty awesome numbers with a Stealth...if I had to run a duel plane, i'd run a Stealth over anything else.

Yeah, IMO the Stealth is the way to go if you are going to run a dual plane.
The Edelbrock parts didn't impress me at all.
My neighbor runs a Stealth with a 570 and auto tranny in his 302 powered 56 pickup, and that impressed me when I drove it.

Boosted92LX · Aug 18, 2012

ratio411 said:
Run a mild single plane intake.
You'll get the best of both worlds.
I suggest the "Torker 289".

Eh, those old torker intakes seemed good back in the day, I had one. In fact, it's in a friend of mine's garage, next to a weiand. When you compare the port sizes between the two the torker is microscopic. To be fair, though, this is a torker II and not a 289..

Personally I think a super vic or a strip domiator are better choices.

85_SS_302_Coupe · Aug 18, 2012

I've ran a Victor Jr on a stock head/cam 302 and it didn't run as poorly as people said it would. It was a little lazy down low but it screamed like a SOB up top.

Anyone Running A Holley 650 Dp?

86lxhatch

Active Member

Boosted92LX

It's only an inch or two. What's the big deal?

CarMichael Angelo

my rearend will smell so minty fresh,

Boosted92LX

It's only an inch or two. What's the big deal?

CarMichael Angelo

my rearend will smell so minty fresh,

Boosted92LX

It's only an inch or two. What's the big deal?

srtthis

the guy doing it does every local racers rear end

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

ratio411

ratio411

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

CarMichael Angelo

my rearend will smell so minty fresh,

86lxhatch

Active Member

86lxhatch

Active Member

86lxhatch

Active Member

CarMichael Angelo

my rearend will smell so minty fresh,

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

ratio411

Boosted92LX

It's only an inch or two. What's the big deal?

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

Similar threads

Anyone Running A Holley 650 Dp?

Active Member

It's only an inch or two. What's the big deal?

my rearend will smell so minty fresh,

It's only an inch or two. What's the big deal?

my rearend will smell so minty fresh,

It's only an inch or two. What's the big deal?

the guy doing it does every local racers rear end

it sucks (I know) to be on the receiving end

it sucks (I know) to be on the receiving end

my rearend will smell so minty fresh,

Active Member

Active Member

Active Member

my rearend will smell so minty fresh,

it sucks (I know) to be on the receiving end

It's only an inch or two. What's the big deal?

it sucks (I know) to be on the receiving end

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