Do I have a Holley Double Pumper???
08-13-2002, 10:49 PM
#1
Racer
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What kind of Holleydo I have???
My Holley has a rectangular shapeon the fromt and back of the carb. On the back it says Holley.
[Modified by 68350hp, 9:51 PM 8/13/2002]
[Modified by 68350hp, 9:51 PM 8/13/2002]
08-13-2002, 11:09 PM
#2
Re: What kind of Holleydo I have??? (68350hp)
The accelerator pump is mounted on the bottom of the float bowl.
They look like this:
If you have one on the rear float bowl then you have a double pumper.
They look like this:
If you have one on the rear float bowl then you have a double pumper.
08-13-2002, 11:22 PM
#3
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Re: What kind of Holleydo I have??? (Pete79L82)
The accelerator pump is mounted on the bottom of the float bowl.
They look like this:
If you have one on the rear float bowl then you have a double pumper.
They look like this:
If you have one on the rear float bowl then you have a double pumper.
08-14-2002, 11:23 AM
#4
Le Mans Master
Re: What kind of Holleydo I have??? (68350hp)
My Holley has a rectangular shapeon the fromt and back of the carb. On the back it says Holley.
[Modified by 68350hp, 9:51 PM 8/13/2002]
[Modified by 68350hp, 9:51 PM 8/13/2002]
But seriously, if you have a vacuum actuator mounted on the passenger side of the carb...... then the answer is no - the top of this actuator looks like this:
[Modified by fauxrs, 7:23 AM 8/14/2002]
08-14-2002, 11:28 AM
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Re: What kind of Holleydo I have??? (Aaron-74)
The accelerator pump is mounted on the bottom of the float bowl.
They look like this:
If you have one on the rear float bowl then you have a double pumper.
A double pumper will have one of these on the from bowl AND the back bowl.
They look like this:
If you have one on the rear float bowl then you have a double pumper.
A double pumper will have one of these on the from bowl AND the back bowl.
08-16-2002, 02:51 PM
#6
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Re: What kind of Holleydo I have??? (Fevre)
The Holley I just had replaced is a double pumper (80777); however, I don't really know what that means. Other than it has twin accelerator pumps! When would you want a double pumper? What're the benefits/disadvantages? Etc., etc.
Thx.
Thx.
08-16-2002, 02:58 PM
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Re: What kind of Holleydo I have??? (jpelle)
It's was designed as a race carb but of course us street nuts got a hold of it. If you have a stout engine, the mech sec and extra shot of fuel help build horsepower fast. Empties your tank fast too. I think the main dis is that it is harder to tune than a vac sec and if it is too big for your engine it will make it run like crap. That being said if you choose the right one and tune it properly, hold on when you punch it. I have had a 750 dp on 2 engines and could never get it to run right. I think it was too big for the first engine and I had clogging problems with the second. I am going to rebuild it and try it one more time.
08-16-2002, 03:27 PM
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Re: What kind of Holleydo I have??? (Fevre)
Hmm... Well, that makes sense, since my mechanic recommend we replace it for two reasons: it needed to be rebuilt, and it was too big for the engine. He replaced it with the Holley Street Avenger (80670).
Oh, that reminds me... The Holley site says the vac sec is adjustable for street, perf, or economy... Anyone know how to do this?
Oh, that reminds me... The Holley site says the vac sec is adjustable for street, perf, or economy... Anyone know how to do this?
08-16-2002, 03:32 PM
#9
Safety Car
Re: What kind of Holleydo I have??? (jpelle)
By changing the springs in the vacuum secondary actuator. You remove the cover and pop in a new spring...lighter for earlier opening and heavier for later opening. You'll likely find that you need the lightest secondary spring on a light car such as a Corvette. It would appear that you don't really know that much about tuning so I would advise you not to fiddle with the thing too much.
08-16-2002, 03:37 PM
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Re: What kind of Holleydo I have??? (gerry72)
But Jerry, that's how you learn!
jpelle
If you can, pick you mech's brain and/or see if he will let you watch him tune it. Also do what I never used to, read the directions. If you really want to dive in, get a few books on engine rebuilding and performance upgrading. Remember what is written is not law but will give you a better understanding of how your engine works.
jpelle
If you can, pick you mech's brain and/or see if he will let you watch him tune it. Also do what I never used to, read the directions. If you really want to dive in, get a few books on engine rebuilding and performance upgrading. Remember what is written is not law but will give you a better understanding of how your engine works.
08-16-2002, 03:38 PM
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Re: What kind of Holleydo I have??? (gerry72)
Yeah, I know squat about carbs. But this is how I learn. I thought it must be the springs.
Anyhoo, I don't plan on doing much to my 'vette at all, for now, 'cept some interior work. But it's good to know something of what I'm talking about when I pay someone to tune my car for me!!
Thx.
Anyhoo, I don't plan on doing much to my 'vette at all, for now, 'cept some interior work. But it's good to know something of what I'm talking about when I pay someone to tune my car for me!!
Thx.
08-16-2002, 03:41 PM
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Re: What kind of Holleydo I have??? (jpelle)
Yeah, I know squat about carbs. But this is how I learn. I thought it must be the springs.
Anyhoo, I don't plan on doing much to my 'vette at all, for now, 'cept some interior work. But it's good to know something of what I'm talking about when I pay someone to tune my car for me!!
Thx.
Anyhoo, I don't plan on doing much to my 'vette at all, for now, 'cept some interior work. But it's good to know something of what I'm talking about when I pay someone to tune my car for me!!
Thx.
08-16-2002, 03:48 PM
#13
Safety Car
Re: What kind of Holleydo I have??? (Fevre)
But Jerry, that's how you learn!
....
....
My caution was more that until you learn how a carburetor works and how you tune it, I wouldn't break out the wrenches and screwdrivers just yet.
08-16-2002, 03:54 PM
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Re: What kind of Holleydo I have??? (gerry72)
But Jerry, that's how you learn!
....
No doubt, but as Mark Twain wrote: "Experience may be the best teacher, but it ain't necessarily the cheapest."
My caution was more that until you learn how a carburetor works and how you tune it, I wouldn't break out the wrenches and screwdrivers just yet.
....
No doubt, but as Mark Twain wrote: "Experience may be the best teacher, but it ain't necessarily the cheapest."
My caution was more that until you learn how a carburetor works and how you tune it, I wouldn't break out the wrenches and screwdrivers just yet.
BTW Quoting Twain and turning wrenches, you a true renaissance man.
:cheers:
08-21-2002, 04:45 PM
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Re: What kind of Holleydo I have??? (jpelle)
OK, I did a little bit of research and found out that the info my mech gave me appears to be wrong -- which is really annoying since that's the info I used when deciding to get a new carb.
He told my that my old carb was a double pumper (true) without a choke (true) and that at 750 cfm (false) it was too big for my LT-1 (probably true?). Oh, and it needed to be rebuilt (???). So, he went out and got the Street Avenger 670cfm for me.
Now I find out that the old carb (part # 80777) is actually a 650cfm double pumper with mechanical choke (not connected). I don't think this was the original carb (although the LT-1s did have a 4150, which the 80777 is), but I don't know for sure. Can anyone tell me the part number of the original LT-1 carb?
So, which carb is "better" -- the 80777 or the new Street Avenger (80670)?
He told my that my old carb was a double pumper (true) without a choke (true) and that at 750 cfm (false) it was too big for my LT-1 (probably true?). Oh, and it needed to be rebuilt (???). So, he went out and got the Street Avenger 670cfm for me.
Now I find out that the old carb (part # 80777) is actually a 650cfm double pumper with mechanical choke (not connected). I don't think this was the original carb (although the LT-1s did have a 4150, which the 80777 is), but I don't know for sure. Can anyone tell me the part number of the original LT-1 carb?
So, which carb is "better" -- the 80777 or the new Street Avenger (80670)?
