I WAS RECOMENDED TO GET THE HOLLEY DOUBLE PUMPER Is that a good choice!??.
#1
I WAS RECOMENDED TO GET THE HOLLEY DOUBLE PUMPER Is that a good choice!??.
Hello an thanks for your time,i have a 455,400 trans,mild cam and will be going with 3.55 rear . i was told to go with a 650 double pumper.
i will be going with edelbrock rpm.i was told to start. with 650 so i wont over gas .so if i need more gas i can jet it.
so what do you think will be the best carb.
i will be going with edelbrock rpm.i was told to start. with 650 so i wont over gas .so if i need more gas i can jet it.
so what do you think will be the best carb.
#2
I think a Q-Jet would be a better choice. Here is a link to SMI I have one of their carbs on my 403 and it works very well for the street and at the strip with a 150 shot of nitrous.
http://www.smicarburetor.com/product...D2/9/sfID3/100
http://www.smicarburetor.com/product...D2/9/sfID3/100
#3
Hello an thanks for your time,i have a 455,400 trans,mild cam and will be going with 3.55 rear . i was told to go with a 650 double pumper.
i will be going with edelbrock rpm.i was told to start. with 650 so i wont over gas .so if i need more gas i can jet it.
so what do you think will be the best carb.
i will be going with edelbrock rpm.i was told to start. with 650 so i wont over gas .so if i need more gas i can jet it.
so what do you think will be the best carb.
Tim
#4
You didn't give a whole lot of information on the rest of your combo so I am going to assume it to be a basic 455 with stock heads and a very mild cam that will be going into your 4 door in your avitar and will just be cruised around on the street. If so I would not suggest a double pumper carb of any size for that application. I would either run a Q-jet or a Holley model 3310 which is a 750cfm vacuum secondary.
#5
Ive been running a Holley 750DP for 25 uears and I love it. I had it on a 455 G head solid lifter mild cam 9:1 comp 3.31 gears. when the secondaries open up it just screams. If you're looking to roast you're tires and do donuts you'll be very disappointed with a vacuum sec.
Last edited by Beob; March 24th, 2014 at 11:12 AM.
#7
#8
If not worried about gas mileage I'd go with the Holley 750DP. You'll be very happy if you add an intake and a spacer down the road. I'm running an 850 DP on a 461 and almost flinch when the secondary open up.
#10
That's why they make the vacuum secondary sytem tuneable. For the record I have a 850 DP on my '65 but I think it is a bit more radical than what the OP has and it spends a fair amount of time at the dragstrip.
#12
I agree as well if everything is gonna be mostly stock why sacrifice gas mileage if you have nothing to back it up with. I mean go dp if you are gonna go with upgrades in other areas but don't waste time and money both now and later on gas for something that won't add much power I hope I stated that right lol
#13
One of my buddies has one of these on his '79 Camaro, and it seems like it's a pain to get tuned right. Maybe it's just his lack of experience and trying it "trial-and-error" on his own, but the thing stalls out in revere and seems to dump WAY too much, trying to flood the engine.
#15
Ok,so many different options,my 455 has stock heads,bored over 40,mild cam.will be getting edelbrock rpm air gap intake upgrade. probably going with 3.55 gears .i have g heads,the moter comes from a 71 delta 88.
i like the holley avenger 4150 750manual. i never even herd of vacume.i plan on driving the car daily .i do like decent gas milage.so I'm just not shure what carb is the right one.
i like the holley avenger 4150 750manual. i never even herd of vacume.i plan on driving the car daily .i do like decent gas milage.so I'm just not shure what carb is the right one.
#16
QUOTE=chadman;673441]You didn't give a whole lot of information on the rest of your combo so I am going to assume it to be a basic 455 with stock heads and a very mild cam that will be going into your 4 door in your avitar and will just be cruised around on the street. If so I would not suggest a double pumper carb of any size for that application. I would either run a Q-jet or a Holley model 3310 which is a 750cfm vacuum secondary.[/QUOTE]
Ok,so many different options,my 455 has stock heads,bored over 40,mild cam.will be getting edelbrock rpm air gap intake upgrade. probably going with 3.55 gears .i have g heads,the moter comes from a 71 delta 88.
i like the holley avenger 4150 750manual. i never even herd of vacume.i plan on driving the car daily .i do like decent gas milage.so I'm just not shure what carb is the right one.
Ok,so many different options,my 455 has stock heads,bored over 40,mild cam.will be getting edelbrock rpm air gap intake upgrade. probably going with 3.55 gears .i have g heads,the moter comes from a 71 delta 88.
i like the holley avenger 4150 750manual. i never even herd of vacume.i plan on driving the car daily .i do like decent gas milage.so I'm just not shure what carb is the right one.
#17
Sound like too much carb to me. I would stay with vacuum secondary single pump on a manifold like that. Too many folks over-carb. I'd look at a Holley 650 street avenger. Also, look for a book by David Vizard on tuning Holley carbs. Lots of great info on carb selection and tuning. If you're not into carbs, a 1406 Edelbrock might be a good choice.
Tim
Tim
#19
You'll get the best of both with a properly set up QJ on that car. I run a 750 vac secondary Holley on my 455 no problems.And break the tires loose at 25mph in drive.Gas milage is so so....until I get on it. QJ gives you decent mpg and performance on what you have.My 400 with a mild rebuild has a QJ and runs just fine.
Last edited by drjr56; March 24th, 2014 at 03:52 PM.
#20
Vacuum secondary bog
The vacuum secondary will never bog out if adjusted correctly. It provides smooth power delivery when transitioning from 2 to 4 barrels. Excellent design for the street, especially with an auto and tight converter.
A 650, really! The cubic inch/volumetric efficiency and rpm band would dictate a need for a 750 if you plan to see power up to 5500. IMO.
Too much carb is bad, I agree... Don't discount a well built quadrajet.
A 650, really! The cubic inch/volumetric efficiency and rpm band would dictate a need for a 750 if you plan to see power up to 5500. IMO.
Too much carb is bad, I agree... Don't discount a well built quadrajet.
#21
Even by Holley's standards it's recommended you use a vac secondary 750cfm carb. You can play with their recommendations yourself below.
http://holley.com/applications/Carbu...bSelection.asp
http://holley.com/applications/Carbu...bSelection.asp
#22
You probably heard that from someone who doesn't know how to properly adjust the vacuum secondary operation. As dmullin posted, when properly set up there is a smooth transition with no bogging. Lots of us with vacuum secondary carbs can attest to that.
#25
Even by Holley's standards it's recommended you use a vac secondary 750cfm carb. You can play with their recommendations yourself below.
http://holley.com/applications/Carbu...bSelection.asp
http://holley.com/applications/Carbu...bSelection.asp
#28
Sound like too much carb to me. I would stay with vacuum secondary single pump on a manifold like that. Too many folks over-carb. I'd look at a Holley 650 street avenger. Also, look for a book by David Vizard on tuning Holley carbs. Lots of great info on carb selection and tuning. If you're not into carbs, a 1406 Edelbrock might be a good choice.
Tim
Tim
#29
The avenger was my firsts choice.even though i will be driving the car i plan on doung a head upgrade and start playing at the track, i want speed but still keep it street .the guy that will be working on the car is highly respected and builds race cars. he told me the double pumper is what I'm looking for so I'm stuck between the avenger an the dp.
my head is spinning .
my head is spinning .
#30
I deleted your other thread as a duplicate. Your not going to get different answers.
Your engine size is a 455 and your rpm should be 5000. Mild build, street use, pay attn. to the notes about the DP vs vac secondary.
http://holley.com/applications/Carbu...bSelection.asp
Your engine size is a 455 and your rpm should be 5000. Mild build, street use, pay attn. to the notes about the DP vs vac secondary.
http://holley.com/applications/Carbu...bSelection.asp
#31
Ok,I'm new to all this stuff so i know nothing about rpms.so what is your openion on the dp vs.vac secondary .and i take it that u are saying the 455 rpms are 5000 or that the goal is 5000 rpms?.
#32
some one said what are your rpms what?
I'm not understanding what people mean about rpms. I have a 455 and need the right carb,so when someone. sais u need 5000 rpms. is that the goal rpms that i need with the carb or is that what the 455 produces?.
o yea stop giggling I'm new to this.lol
o yea stop giggling I'm new to this.lol
Last edited by 4door!cutlass; March 24th, 2014 at 09:00 PM.
#34
The reply was this:Your engine size is a 455 and your rpm should be 5000. Mild build, street use, pay attn. to the notes about the DP vs vac secondary.
So I'm asking what does he mean,your rpm should be 5000.
So I'm asking what does he mean,your rpm should be 5000.
#35
My two cents:
1) QJet
2) Holley vacuum secondary or an Edelbrock
You mention you're going with an Air Gap manifold. That's tall and will require AC bracket modifications to fit if you have AC. It's also rated for 1500-6500 RPM which you're never going to see with your set-up. If that is the Cutlass in your sig that you're putting all this into then I'll bet it's too tall with that manifold and will require cutting the hood. You need a nice low rise dual plane and a new mechanic or at least stop taking his advice. Stick with the QJet and stock for now.
1) QJet
2) Holley vacuum secondary or an Edelbrock
You mention you're going with an Air Gap manifold. That's tall and will require AC bracket modifications to fit if you have AC. It's also rated for 1500-6500 RPM which you're never going to see with your set-up. If that is the Cutlass in your sig that you're putting all this into then I'll bet it's too tall with that manifold and will require cutting the hood. You need a nice low rise dual plane and a new mechanic or at least stop taking his advice. Stick with the QJet and stock for now.
#38
The rpms (revolutions per minute) you need from your engine will depend upon what you want it to do.
If you want horsepower for screaming down a drag strip you will want lots more rpm than if you want stump pulling torque for towing a heavy trailer.
So what are you going to use the engine for?, bear In mind the higher the rpms tou want the more strain there is on moving parts, particularly pistons and rods. To build a 455 Olds engine to run at 5000 rpm for any length of time will be expensive, either because to build one to handle it will require strengthened quality parts, or because the engine won't last long if you leave it as standard.
The carb you require is also dependant on what cam you use, compression ratio, exhaust system and other factors.
Let us know what modifications your engine has and what you want to use it for and you will find plenty of well informed help and advice here from people who have lots of experience building engines successfully.
Roger.
If you want horsepower for screaming down a drag strip you will want lots more rpm than if you want stump pulling torque for towing a heavy trailer.
So what are you going to use the engine for?, bear In mind the higher the rpms tou want the more strain there is on moving parts, particularly pistons and rods. To build a 455 Olds engine to run at 5000 rpm for any length of time will be expensive, either because to build one to handle it will require strengthened quality parts, or because the engine won't last long if you leave it as standard.
The carb you require is also dependant on what cam you use, compression ratio, exhaust system and other factors.
Let us know what modifications your engine has and what you want to use it for and you will find plenty of well informed help and advice here from people who have lots of experience building engines successfully.
Roger.
#40
My two cents:
1) QJet
2) Holley vacuum secondary or an Edelbrock
You mention you're going with an Air Gap manifold. That's tall and will require AC bracket modifications to fit if you have AC. It's also rated for 1500-6500 RPM which you're never going to see with your set-up. If that is the Cutlass in your sig that you're putting all this into then I'll bet it's too tall with that manifold and will require cutting the hood. You need a nice low rise dual plane and a new mechanic or at least stop taking his advice. Stick with the QJet and stock for now.
1) QJet
2) Holley vacuum secondary or an Edelbrock
You mention you're going with an Air Gap manifold. That's tall and will require AC bracket modifications to fit if you have AC. It's also rated for 1500-6500 RPM which you're never going to see with your set-up. If that is the Cutlass in your sig that you're putting all this into then I'll bet it's too tall with that manifold and will require cutting the hood. You need a nice low rise dual plane and a new mechanic or at least stop taking his advice. Stick with the QJet and stock for now.