C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

choosing the right carb

Thread Tools
 
Search this Thread
 
Old 11-18-2015, 02:09 PM
  #21  
ddawson
Le Mans Master
 
ddawson's Avatar
 
Member Since: Mar 2001
Location: Lincoln, CA
Posts: 5,650
Received 598 Likes on 485 Posts

Default

With the L88 hood at least you have intake options. I used the Repo LS6 to fit under the stock hood. You may able to use an Air Gap.
The following users liked this post:
1970-Stingray (11-18-2015)
Old 11-18-2015, 02:11 PM
  #22  
AkitaCJ75
Heel & Toe
 
AkitaCJ75's Avatar
 
Member Since: Feb 2015
Posts: 21
Likes: 0
Received 4 Likes on 4 Posts
Default Oh boy!!

Originally Posted by 1970-Stingray
Hello folks

any way, there is this one thing if you guys can help me with it
i was thinking about buying a new holly carburetor
Any recommendation which holly i should get? + the intake that will go with it the best

Congrats. You know that saying opinions are like ***holes. Well opinions are carburetors are not because everybody has two or three That aside I agree with some other comments here that you should evaluate what you get don't be real eager to replace it. I know tinkering with it is what's fun.. well tinkering with what it's got could be a start as generally the mfg carb set up was probably pretty good for that engine. Now the stock 69 bb came with a 750 cm qjet I believe and I'm a lover of qjets. Properly set up and working qjet will perform as well as anything you'll put on it and won't waste fuel. But they do take a lot of study time to understand them but not that much more than your Holley,Quickfuels etc. If you want to try a Holley style, I see no reason why a vacuum secondary system can't be dialed in and lot less work dialing it in vs a mechanical. If somebody isn't running a high rpm race engine I don't recommend over 750 or manual secondaries. It's not necessary, waste fuel, and more work to dial in. But have fun with whatever you choose. Might find once you get the car money might be better spent elsewhere or it has bigger priorities.
The following users liked this post:
1970-Stingray (11-18-2015)
Old 11-18-2015, 07:41 PM
  #23  
1970-Stingray
Intermediate
Thread Starter
 
1970-Stingray's Avatar
 
Member Since: Nov 2015
Posts: 34
Received 0 Likes on 0 Posts
Default

Originally Posted by ddawson
With the L88 hood at least you have intake options. I used the Repo LS6 to fit under the stock hood. You may able to use an Air Gap.
talking about airgap i am a fan of those..


Originally Posted by AkitaCJ75
Congrats. You know that saying opinions are like ***holes. Well opinions are carburetors are not because everybody has two or three That aside I agree with some other comments here that you should evaluate what you get don't be real eager to replace it. I know tinkering with it is what's fun.. well tinkering with what it's got could be a start as generally the mfg carb set up was probably pretty good for that engine. Now the stock 69 bb came with a 750 cm qjet I believe and I'm a lover of qjets. Properly set up and working qjet will perform as well as anything you'll put on it and won't waste fuel. But they do take a lot of study time to understand them but not that much more than your Holley,Quickfuels etc. If you want to try a Holley style, I see no reason why a vacuum secondary system can't be dialed in and lot less work dialing it in vs a mechanical. If somebody isn't running a high rpm race engine I don't recommend over 750 or manual secondaries. It's not necessary, waste fuel, and more work to dial in. But have fun with whatever you choose. Might find once you get the car money might be better spent elsewhere or it has bigger priorities.
best comment haha
you know it man , can never get tiered of "tinkering" haha
i'm not planning high RPM that's true. But if the double pumper would work fine I see no problem with getting it.
the car arrives tomorrow and I'll see what happens then



Originally Posted by cuisinartvette
He could probably get away with a vacuum secondary on it esp with those gears;(not sure Id call the car light)plenty of performance cars came with vac secondarys back then.... Personally I like a double pumper on stick cars...actually most hot rods period. Personal choice

toobroketoretire just cant catch a break...he says DP you guys tear him up, VS same thing. Wow
now you and Jebbysan told me that for the 4 speed, a double pumper is recommended. well that sounds good i might go with a double pumper this time.
even though there is this guy who told me the that with the gears ratio that i have on the 4 speed , vac secondary is recommended.
ratio is 3.08


Originally Posted by Alwyn678
On my car I have had a Demon 750 a Holley 650 and currently an Edelbrock 600. The Edelbrock is by Far my favorite carburetor hands down. Could be how it "fits" with my complete Set-up
how would compare the demon with the 650 ?

Originally Posted by Jebbysan
3310 is an excellent choice.....best bang for the buck out there...
But as others have said....why do you need a new one?

And as far as annular boosters go....one only sees big gains on a low vacuum motor with bad signal.....

Holley will not recommend a Vac Sec for a stick....but it still works very well if the secondary spring is lightened up to account for the fast increase in RPM under a load in first gear.

I have heard a LOT of good things about Quick Fuel....but have never tried one.....they are kinda pricy...but all tuner carbs are.
If cost is no object....go with Patrick at Pro Systems.....

This is my opinion...based on years of screwing around...and your results may vary!

Jebby
Interesting, so holley recommend mechanical secondary.
thanks man thats why i post this thread to get more infos and decide what i should get

btw screwing around gives you a good experience.. sometimes you f*** things up but at least we will learn haha

Originally Posted by The13Bats
I too have been guilty of making a reply to quickly after not fully reading what the poster actually said, I am far more careful that that and do rear all posts...

So when you get past the cats telling you keep what you have and etc

The main thing you need is a bit more info as in which heads you have will make a difference, oval port or rectangle port, very different creatures made for different RPM power bands.

As far as pulling the old carb just to save it I would have to say that in and of itself is a waste of $$$ you are modding the car anyway having the old carb in a box will only soothe a purist would be buyer so much.
well thats not the only reason
i don't like it haha
for the money , i bought the car for a good price less than what was in my mind , so i kinda have money that i thought it was going to be spend on buying the car
Old 11-19-2015, 07:56 AM
  #24  
cv67
Team Owner
 
cv67's Avatar
 
Member Since: Oct 2004
Location: altered state
Posts: 81,242
Received 3,043 Likes on 2,602 Posts
St. Jude Donor '05

Default

If youre set on getting the holley dp try and find one similar to the hp series that had adjustable IAB etc in the top. If it gets cammed up that can solve the stinky idle syndrome.

holleyperformance on ebay sells returns/blems super cheap just picked up 2 intakes last week from them that woulda run me over $700 at Summit, spent less than $350

Last edited by cv67; 11-19-2015 at 07:57 AM.
The following users liked this post:
1970-Stingray (11-19-2015)
Old 11-19-2015, 08:37 PM
  #25  
1970-Stingray
Intermediate
Thread Starter
 
1970-Stingray's Avatar
 
Member Since: Nov 2015
Posts: 34
Received 0 Likes on 0 Posts
Default

Originally Posted by cuisinartvette
If youre set on getting the holley dp try and find one similar to the hp series that had adjustable IAB etc in the top. If it gets cammed up that can solve the stinky idle syndrome.

holleyperformance on ebay sells returns/blems super cheap just picked up 2 intakes last week from them that woulda run me over $700 at Summit, spent less than $350
yes i found one that has those idle air bleed on top
thank you for reminding me of that

750 CFM ULTRA DOUBLE PUMPER CARBURETOR
Electric Choke Mechanical Secondaries
PART# 0-76750BL

i think i'm getting this one


now for the Intake manifold

should i go with the single plane or dual plane

my buddy told me to go with the dual plane for a street car.

any opinions on that?

https://www.holley.com/products/inta...lds/parts/8019
i was looking at this one
Old 11-19-2015, 08:58 PM
  #26  
Jebbysan
Dr. Detroit
Support Corvetteforum!
 
Jebbysan's Avatar
 
Member Since: Mar 2012
Location: New Braunfels Texas
Posts: 9,963
Received 3,892 Likes on 2,564 Posts

Default

Originally Posted by 1970-Stingray
yes i found one that has those idle air bleed on top
thank you for reminding me of that

750 CFM ULTRA DOUBLE PUMPER CARBURETOR
Electric Choke Mechanical Secondaries
PART# 0-76750BL

i think i'm getting this one


now for the Intake manifold

should i go with the single plane or dual plane

my buddy told me to go with the dual plane for a street car.

any opinions on that?

https://www.holley.com/products/inta...lds/parts/8019
i was looking at this one
That is a great choice and very similar to the Original L-88 intake....
Performer RPM is a second choice.....

Jebby
Old 11-20-2015, 01:04 AM
  #27  
bluedawg
Safety Car
 
bluedawg's Avatar
 
Member Since: Jan 2009
Location: anchorage ak
Posts: 3,736
Received 55 Likes on 53 Posts
Default

Originally Posted by flyeri
750 will work but Holley will not reccomend a vacuum secondary with our light cars and manual transmission. Call them
Holley ultra 950 hp double pumper flows 830 cfm. Oh and as cuisenartvette said the corvette is not a light as far as sports cars go.

Last edited by bluedawg; 11-20-2015 at 01:15 AM.
Old 11-20-2015, 11:14 AM
  #28  
TheSkunkWorks
Le Mans Master
 
TheSkunkWorks's Avatar
 
Member Since: Apr 2007
Location: Graceland in a Not Correctly Restored Stingray
Posts: 7,353
Received 68 Likes on 50 Posts

Default

IMCO a 750 VS belongs on a mild 350 SBC auto. I personally wouldn't put anything smaller than an 830 DP on a stout BBC 4-speed C3, as I've successfully run as large as 1050 Dom (progressive 2nds) on a moderate street 427. YMMV
Old 11-20-2015, 11:34 AM
  #29  
pauldana
Race Director
Support Corvetteforum!
 
pauldana's Avatar
 
Member Since: May 2003
Location: California
Posts: 10,679
Received 396 Likes on 306 Posts

Default

Originally Posted by MotorHead
Wow you jump in every question as soon as posted, I didn't know Google and Wikipedia were that fast. Your name should be toomuchonlinegivingbadadvicetoretire.
:rof l:



Formula for carburetor/throttle-body CFM:
Cubic inch of motor multiplied by max RPM, divided by 3454

454 X 6500?? /3453= 855cfm
The following users liked this post:
4 speed (11-21-2015)
Old 11-20-2015, 12:43 PM
  #30  
toobroketoretire
Melting Slicks
 
toobroketoretire's Avatar
 
Member Since: Apr 2009
Location: Great Plains Iowa
Posts: 2,632
Likes: 0
Received 114 Likes on 108 Posts
Default

Originally Posted by pauldana
:rof l:



Formula for carburetor/throttle-body CFM:
Cubic inch of motor multiplied by max RPM, divided by 3454

454 X 6500?? /3453= 855cfm

But after you figure in a reasonable 85% volumetric efficiency you'd end up with only 726 cfm.
Old 11-20-2015, 12:56 PM
  #31  
gkull
Team Owner
 
gkull's Avatar
 
Member Since: Apr 1999
Location: Reno Nevada
Posts: 21,747
Received 1,329 Likes on 1,057 Posts

Default

I personally have a Demon 825 cfm that has been professionally bench flowed and then tested on dyno test mule motor of @ equal HP.

I believe in chokeless double pumpers with bowl sight glasses and 4 corner A/F ratio adjusters on a intake manifold that matches the head port size. Single planes require less cfm than a dual plane intake. I think that the Holley hp series come close out of the box as do quick fuel and proform carbs.......

Everything you said about the motor tends to say that it is just a low budget rebiuld. 427 heads mean nothing because they made low powered 427's that came in family station wagons and the 390 hp vette. 10/10 crank indicates that it has a crappy cast crank that was blemished from ware requiring machining. Smart people throw them away and install an internally balanced forged crank. 9.75 C/R is fluff for just some cheap cast piston with stock rods.
Old 11-20-2015, 01:16 PM
  #32  
pauldana
Race Director
Support Corvetteforum!
 
pauldana's Avatar
 
Member Since: May 2003
Location: California
Posts: 10,679
Received 396 Likes on 306 Posts

Default

Originally Posted by MotorHead
Wow you jump in every question as soon as posted, I didn't know Google and Wikipedia were that fast. Your name should be toomuchonlinegivingbadadvicetoretire.
Originally Posted by gkull
I personally have a Demon 825 cfm that has been professionally bench flowed and then tested on dyno test mule motor of @ equal HP.

I believe in chokeless double pumpers with bowl sight glasses and 4 corner A/F ratio adjusters on a intake manifold that matches the head port size. Single planes require less cfm than a dual plane intake. I think that the Holley hp series come close out of the box as do quick fuel and proform carbs.......

Everything you said about the motor tends to say that it is just a low budget rebiuld. 427 heads mean nothing because they made low powered 427's that came in family station wagons and the 390 hp vette. 10/10 crank indicates that it has a crappy cast crank that was blemished from ware requiring machining. Smart people throw them away and install an internally balanced forged crank. 9.75 C/R is fluff for just some cheap cast piston with stock rods.

I think George here has it nailed down! this^^^^^
Old 11-20-2015, 02:37 PM
  #33  
toobroketoretire
Melting Slicks
 
toobroketoretire's Avatar
 
Member Since: Apr 2009
Location: Great Plains Iowa
Posts: 2,632
Likes: 0
Received 114 Likes on 108 Posts
Default

Gosh, for weekend hobbyists you guys are really smart. The engineering departments of the big three really needed guys like you to guide them.
Old 11-20-2015, 09:29 PM
  #34  
Les
Race Director
 
Les's Avatar
 
Member Since: Dec 1999
Location: Sierra Foothills CA
Posts: 10,831
Received 961 Likes on 571 Posts

Default

Originally Posted by toobroketoretire
Gosh, for weekend hobbyists you guys are really smart. The engineering departments of the big three really needed guys like you to guide them.
Does somebody need a cookie?
The following users liked this post:
SH-60B (11-21-2015)
Old 11-20-2015, 10:03 PM
  #35  
toobroketoretire
Melting Slicks
 
toobroketoretire's Avatar
 
Member Since: Apr 2009
Location: Great Plains Iowa
Posts: 2,632
Likes: 0
Received 114 Likes on 108 Posts
Default

Like it or not mechanical secondary carburetors and short-runner single plane intake manifolds are intended for track racing where engine speeds remain high. Which is why none of the "big three" American automobile manufacturers ever used them. Its torque that gets a car in motion and its torque that keeps it in motion and its the weekend warriors who are determined to kill that torque in any way they can.
Old 11-20-2015, 10:10 PM
  #36  
pauldana
Race Director
Support Corvetteforum!
 
pauldana's Avatar
 
Member Since: May 2003
Location: California
Posts: 10,679
Received 396 Likes on 306 Posts

Default

Originally Posted by Les
Does somebody need a cookie?
hard not to bite
Old 11-21-2015, 12:10 AM
  #37  
1970-Stingray
Intermediate
Thread Starter
 
1970-Stingray's Avatar
 
Member Since: Nov 2015
Posts: 34
Received 0 Likes on 0 Posts
Default

Thank you everybody for all the information you provide


So i made my mind i'm going with the double pumper and dual plane intake

WEIAND STEALTH INTAKE - CHEVY BIG BLOCK V8
PART# 8019
https://www.holley.com/products/inta...lds/parts/8019

750 ULTRA DOUBLE PUMPER
Electric Choke
PART# 0-76750BL
https://www.holley.com/products/fuel...arts/0-76750BL

again thanks , a lot of good infos in here

Get notified of new replies

To choosing the right carb

Old 11-21-2015, 07:22 AM
  #38  
fishslayer143
Drifting
 
fishslayer143's Avatar
 
Member Since: Aug 2009
Location: new iberia la
Posts: 1,346
Received 156 Likes on 143 Posts

Default

Originally Posted by ddawson
I talked to Lars and Quick fuel. Went with a 830 SS.

Very happy with the results.
Lars is a smart guy..and Quickfuel is an EXCELLENT carb.. had a QF SS 750 DP on my stroker for 6 years now.. In my opinion, there is no equal to QF
Old 11-21-2015, 03:38 PM
  #39  
Les
Race Director
 
Les's Avatar
 
Member Since: Dec 1999
Location: Sierra Foothills CA
Posts: 10,831
Received 961 Likes on 571 Posts

Default

Originally Posted by pauldana
hard not to bite

Originally Posted by 1970-Stingray
Thank you everybody for all the information you provide


So i made my mind i'm going with the double pumper and dual plane intake

WEIAND STEALTH INTAKE - CHEVY BIG BLOCK V8
PART# 8019
https://www.holley.com/products/inta...lds/parts/8019

750 ULTRA DOUBLE PUMPER
Electric Choke
PART# 0-76750BL
https://www.holley.com/products/fuel...arts/0-76750BL

again thanks , a lot of good infos in here
That should be a nice combo for you. Enjoy!
Originally Posted by fishslayer143
Lars is a smart guy..and Quickfuel is an EXCELLENT carb.. had a QF SS 750 DP on my stroker for 6 years now.. In my opinion, there is no equal to QF
I really like the quality of their carbs and rebuild kits. After seeing the quality of the gaskets on a friend's Quickfuel carb I now only use their rebuild kits.
Old 11-21-2015, 04:26 PM
  #40  
toobroketoretire
Melting Slicks
 
toobroketoretire's Avatar
 
Member Since: Apr 2009
Location: Great Plains Iowa
Posts: 2,632
Likes: 0
Received 114 Likes on 108 Posts
Default

When you finally realize you bought the wrong style of carburetor Holley will be more than happy to sell you the right style for another $550 (plus shipping). Its your money so you can waste it in any way you wish.


Quick Reply: choosing the right carb



All times are GMT -4. The time now is 11:06 AM.