Eldebrock Carb tune-up advice.
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Le Mans Master
Joined: Jan 2001
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From: San Diego CA
Eldebrock Carb tune-up advice.
Okay got the answers for the timing http://forums.corvetteforum.com/zerothread?id=690115 so now the carb question:
Carb is Eldebrock Model #1400, 650 mech. secondary. I no longer have my vacuum guages but rule of thumb. With car warmed up, 700 RPM, off choke, turn clockwise on either left or right bank idle circuit needle till CAR DROPS IN SPEED, STOP, then open back up 2 turns counter clockwise. Do same to other bank.
This sound about right for getting in the ballpark?
Carb is Eldebrock Model #1400, 650 mech. secondary. I no longer have my vacuum guages but rule of thumb. With car warmed up, 700 RPM, off choke, turn clockwise on either left or right bank idle circuit needle till CAR DROPS IN SPEED, STOP, then open back up 2 turns counter clockwise. Do same to other bank.
This sound about right for getting in the ballpark?
Melting Slicks
Joined: Oct 2002
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Re: Eldebrock Carb tune-up advice. (Cali,68,L-79)
Hey dave, here is all the info you would ever need for that carb http://edelbrock.com/automotive/index.html :thumbs:
Thread Starter
Le Mans Master
Joined: Jan 2001
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From: San Diego CA
Re: Eldebrock Carb tune-up advice. (battsup)
Thanks for the info. Send them e-mail on their tech line. Typically these are no brainer carbs and the above decription should get me as close as possible without using vacuum guages.
thanks,
David
thanks,
David
Melting Slicks
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Re: Eldebrock Carb tune-up advice. (Cali,68,L-79)
Yeah, that method should get you close. I use the vacuum gauge. I twist until I get the highest possible vacuum. Then I back down the idle speed a notch. You can fine tune even beyond that. But I don't.
If gas fumes get heavy, and your eyes start to water, you know you have it too rich. :crazy:
If gas fumes get heavy, and your eyes start to water, you know you have it too rich. :crazy:
Drifting
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From: FRANKLIN GA
Re: Eldebrock Carb tune-up advice. (Cali,68,L-79)
Cali this is the way I did mine as per the instruction manual that came with the carb.
back out (open) a jet the motor rpm will rise when it stops rising stop backing and screw in until the rpm's start to drop slightly I think it was 100-200 rpm's
do the same with the other jet
you may have to adjust the idle set screw a couple of times if it starts to idle too high I did on mine.
This setting lets it run slightly on the rich side but it works perfectly on mine. Mine will start to ping if I run it on the leaner side.
Hope it helps
back out (open) a jet the motor rpm will rise when it stops rising stop backing and screw in until the rpm's start to drop slightly I think it was 100-200 rpm's
do the same with the other jet
you may have to adjust the idle set screw a couple of times if it starts to idle too high I did on mine.
This setting lets it run slightly on the rich side but it works perfectly on mine. Mine will start to ping if I run it on the leaner side.
Hope it helps
Thread Starter
Le Mans Master
Joined: Jan 2001
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From: San Diego CA
Re: Eldebrock Carb tune-up advice. (Vetterodder)
No such animal. An Edelbrock 1400 is a 600 cfm vacuum secondary carb.
600 cfm, square-flange, electric choke #1406*
Recommended for most Performer applications. Calibrated 2% leaner than #1405. Includes both timed and full vacuum ports for ignition advance. All Edelbrock carbs come with an Owners Manual. Comes with the following metering jets, rods and springs: Metering Jets: Primary .098, Secondary .095; Metering Rods: .075 x .047.
I was told these are all mech secondaries??? :confused:
Team Owner
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Re: Eldebrock Carb tune-up advice. (Cali,68,L-79)
I can't imagine running a 650 VS on a L-79, but anyway without a vacuum gauge or even for that matter with a VG. Your tachometer and ears tell you how it's running.
With the motor up to operating temp. Turn each of your mix screws 3 turns out from the lightly seated point. Disconnect the vacuum advance and plug it. to the carb. Set the idle speed to a couple hundred above your normal idle. IN your case 900 rpm.
Start turning both screws in equal amounts in 1/4 turn increments. you should hear the idle smooth out and speed up as you turn your mixture screws in. check the tach and keep turning it back down to 900 rpm after it increases.
If the carbs A/F ratio is near what it should be at some point between 2 & 1 turns out your motor should have the best sound and highest rpm.
Reconnect everything and turn it down to the desired speed.
[Modified by gkull, 10:05 AM 11/14/2003]
[Modified by gkull, 10:46 AM 11/14/2003]
With the motor up to operating temp. Turn each of your mix screws 3 turns out from the lightly seated point. Disconnect the vacuum advance and plug it. to the carb. Set the idle speed to a couple hundred above your normal idle. IN your case 900 rpm.
Start turning both screws in equal amounts in 1/4 turn increments. you should hear the idle smooth out and speed up as you turn your mixture screws in. check the tach and keep turning it back down to 900 rpm after it increases.
If the carbs A/F ratio is near what it should be at some point between 2 & 1 turns out your motor should have the best sound and highest rpm.
Reconnect everything and turn it down to the desired speed.
[Modified by gkull, 10:05 AM 11/14/2003]
[Modified by gkull, 10:46 AM 11/14/2003]
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Racer
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From: Spartanburg SC
Re: Eldebrock Carb tune-up advice. (Cali,68,L-79)
That's the same carb I have, but I don't know much about it. I'm pretty sure mine could use a tune up too though, I've always had problems with it idleing too high (1100 rpm) or too low (500 rpm)
Thread Starter
Le Mans Master
Joined: Jan 2001
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From: San Diego CA
Re: Eldebrock Carb tune-up advice. (gkull)
Gkull, my comments in bold
With the motor up to operating temp. Turn each of your mix screws 3 turns out from the lightly seated point. seated to mean almost all gas closed off correct? righty tighty(CLOCKWISE) lefty loosey(COUNTER CLOCKWISE) or reverse on this carb :confused: Disconnect the vacuum advance and plug it. to the carb. Set the idle speed to a couple hundred above your normal idle. IN your case 900 rpm.
Reconnect everything and turn it down to the desired speed. what is pupose of disconnecting vac. adv. and bringing up idle to 900 RPM then just reconnecting and droping to 700 RPM with no adjustment??
Start turning both screws in equal amounts in 1/4 turn increments. CLOCKWISE OR COUNTER CLOCKWISE you should hear the idle smooth out and speed up as you turn your mixture screws in. turn mixture screws in decreasing gas flow or turning out increasing gas flow??, because above we have them barely off their seats so turning in would completly stop gas flow unless the screws are turn clockwise (in) to increase gas flow. check the tach and keep turning it back down to 900 rpm after it increases.
If the carbs A/F ratio is near what it should be at some point between 2 & 1 turns out your motor should have the best sound and highest rpm.
With the motor up to operating temp. Turn each of your mix screws 3 turns out from the lightly seated point. seated to mean almost all gas closed off correct? righty tighty(CLOCKWISE) lefty loosey(COUNTER CLOCKWISE) or reverse on this carb :confused: Disconnect the vacuum advance and plug it. to the carb. Set the idle speed to a couple hundred above your normal idle. IN your case 900 rpm.
Reconnect everything and turn it down to the desired speed. what is pupose of disconnecting vac. adv. and bringing up idle to 900 RPM then just reconnecting and droping to 700 RPM with no adjustment??
Start turning both screws in equal amounts in 1/4 turn increments. CLOCKWISE OR COUNTER CLOCKWISE you should hear the idle smooth out and speed up as you turn your mixture screws in. turn mixture screws in decreasing gas flow or turning out increasing gas flow??, because above we have them barely off their seats so turning in would completly stop gas flow unless the screws are turn clockwise (in) to increase gas flow. check the tach and keep turning it back down to 900 rpm after it increases.
If the carbs A/F ratio is near what it should be at some point between 2 & 1 turns out your motor should have the best sound and highest rpm.
Team Owner
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Re: Eldebrock Carb tune-up advice. (Cali,68,L-79)
On the edelbrock web site or your manual it has a picture of what everything is. the two larger spring held screws on the front. clock wise shuts them. don't turn it in hard because you can damage the seats.
I screwed up - I went back and edited to add the last line and I had a phone call in the middle of typing and didn't see in the little window that I wasn't at the end before sending it back off
[Modified by gkull, 10:47 AM 11/14/2003]
I screwed up - I went back and edited to add the last line and I had a phone call in the middle of typing and didn't see in the little window that I wasn't at the end before sending it back off
[Modified by gkull, 10:47 AM 11/14/2003]
Team Owner
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From: Reno Nevada
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Re: Eldebrock Carb tune-up advice. (Cali,68,L-79)
So anyway your three turns out CCW and the 900 rpm help smooth the idle. Where changes made have a more noticble effect.
i turn mine up to 1100 because it's so hard to hear over the motor noises. But my normal in "N" idle is kind of rumpy at 900 rpm.
i turn mine up to 1100 because it's so hard to hear over the motor noises. But my normal in "N" idle is kind of rumpy at 900 rpm.
Thread Starter
Le Mans Master
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From: San Diego CA
Re: Eldebrock Carb tune-up advice. (gkull)
Okay last question so start 3 turns off of fully closed (lightly seated), RPM increase is necessitated due to lack of fuel. Start turning both screws in equal amounts in 1/4 turn increments which increases gas flow and raising RPM. I'll hear the idle smooth out and speed up as I turn the 2 mixture screws out (CCW). At some point RPM will no longer increase as screws are backed out (CCW). At this point screw in, (CW) both screws to gain a 100 RPM decrease and then reset curb idle to 700 RPM and I'm ready to
:auto:
[Modified by Cali,68,L-79, 1:03 PM 11/14/2003]
:auto:
[Modified by Cali,68,L-79, 1:03 PM 11/14/2003]
Team Owner
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From: Reno Nevada
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Re: Eldebrock Carb tune-up advice. (Cali,68,L-79)
Let's just say that out of the box the 1406 correct idle A/F ratio should probably fall into the 1-2 turns out range on a fresh motor that has perfect electrical tune.
The 900 rpm gets the motor in a better running area. 3 turns out might make a motor shake - cough and wease because it's so rich. You don't want to be adjusting on something that is always dying on you. So the higher rpm can handle being way out of carb tune and it's still low enough that the ignition advance isn't kicking in and causing it to idle smoother.
3 turns out should be way rich - as you turn the screws in CW the mixture leans out and idles smoother. AS you pass the peak point it's going to loose rpm and get a ratty idle again. So back up to the best setting.
The 900 rpm gets the motor in a better running area. 3 turns out might make a motor shake - cough and wease because it's so rich. You don't want to be adjusting on something that is always dying on you. So the higher rpm can handle being way out of carb tune and it's still low enough that the ignition advance isn't kicking in and causing it to idle smoother.
3 turns out should be way rich - as you turn the screws in CW the mixture leans out and idles smoother. AS you pass the peak point it's going to loose rpm and get a ratty idle again. So back up to the best setting.
