what carb for my 383
#21
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You don't have much in the way of advice here. Edelbrocks like yours are rich out of the box and made for bigger ci motors. VS carbs can be much bigger and not suffer drivability problems. Because they are an on demand CFM. The secondary's don't open unless the vacuum rises.
Your second saving grace is your dual plane having a split plenum. So each side only sees @ 400CFM max
So your size is fine. I ran Edelbrock on my vette for 10 years. You just need to learn how they work. First off I would read the manual about how to drop the idle and cruise AF ratio 6%. Then you can fine tune it by doing the math of flow area of the jet minus the area of the rod. Use online calculators for area. They sell the spring kit so you can change how fast your rods react.
They are a wonderful carb.
You can pm me with question or here in posts.
Your stall is way to low
Your second saving grace is your dual plane having a split plenum. So each side only sees @ 400CFM max
So your size is fine. I ran Edelbrock on my vette for 10 years. You just need to learn how they work. First off I would read the manual about how to drop the idle and cruise AF ratio 6%. Then you can fine tune it by doing the math of flow area of the jet minus the area of the rod. Use online calculators for area. They sell the spring kit so you can change how fast your rods react.
They are a wonderful carb.
You can pm me with question or here in posts.
Your stall is way to low
#22
Team Owner
Remove the tail shaft ujoint
Remove the speedo cable off the side of the tranny
Remove the TV cable
Support the engine on the rear of the oil pan with one floor jack
Support the tranny at the balance point near the front of its pan.
I cut two 6X8 inch pieces of plywood to protect the pans from denting
Unbolt the tranny from the rear cross member and the cross member from the car frame and move it out of the way.
Lower the tranny and rear of the motor to give you room to get the bell housing bolts out of the block.
Many years ago I modded my cross-M to let the exhaust pass under. So I wouldn't have to screw with the exhaust ever time I pulled the tranny. I used 3500 and 3800 stall efficient converters and a 4.11 rear end
http://www.corvetteforum.net/c3/gkull/
#23
Safety Car
You don't have much in the way of advice here. Edelbrocks like yours are rich out of the box and made for bigger ci motors. VS carbs can be much bigger and not suffer drivability problems. Because they are an on demand CFM. The secondary's don't open unless the vacuum rises.
Your second saving grace is your dual plane having a split plenum. So each side only sees @ 400CFM max
So your size is fine. I ran Edelbrock on my vette for 10 years. You just need to learn how they work. First off I would read the manual about how to drop the idle and cruise AF ratio 6%. Then you can fine tune it by doing the math of flow area of the jet minus the area of the rod. Use online calculators for area. They sell the spring kit so you can change how fast your rods react.
They are a wonderful carb.
You can pm me with question or here in posts.
Your stall is way to low
Your second saving grace is your dual plane having a split plenum. So each side only sees @ 400CFM max
So your size is fine. I ran Edelbrock on my vette for 10 years. You just need to learn how they work. First off I would read the manual about how to drop the idle and cruise AF ratio 6%. Then you can fine tune it by doing the math of flow area of the jet minus the area of the rod. Use online calculators for area. They sell the spring kit so you can change how fast your rods react.
They are a wonderful carb.
You can pm me with question or here in posts.
Your stall is way to low
Not sure how mild your 883 is but I think if you don't plan of driving over 5,500rpm you'all get a more responsive, reliable running engine if you stick with something in the 700-750 cfm range.
Its true the Holley 750 DPmay have the best WOT power but I bet for everyday driving the smaller Carb would behave a lot better
Edit went back and read op's specs and changed recommendations.
Last edited by augiedoggy; 05-13-2013 at 08:43 AM.
#24
Team Owner
http://www.edelbrock.com/automotive_...erformer.shtml
#25
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Brrrrrrrr...... Scotty we reached 64 today, then it rained, how can you say brrrrrr, at least it aint -20*f, my girl doesnt do good in the rain, so if traction in the rain is a concern, dont go double pumper, now then if you can stand adrenaline coursing through you viens and have traction issues on dry pavement the double pumper is your drug.....
Gkull, the OP is using a Performer RPM Airgap, I believe, and it has a pretty good sized chunk of the divider cut out. Do you think that this will have a major effect on carb choice?
Here is something else to think about:
http://www.summitracing.com/parts/su...50vs/overview/
Scott
#26
Team Owner
Gkull, the OP is using a Performer RPM Airgap, I believe, and it has a pretty good sized chunk of the divider cut out. Do you think that this will have a major effect on carb choice?
Here is something else to think about:
http://www.summitracing.com/parts/su...50vs/overview/
Scott
Here is something else to think about:
http://www.summitracing.com/parts/su...50vs/overview/
Scott
Really what is 750 cfm vs 800 you would only maybe have a minor difference in primary throttle bore diameter.
I also only had single plane intakes on 355ci with my 750 Edelbrock carb. I probably put 70,000 miles on it in 10 years and 100 upon 100's of runs down the drag strip. It was just a learning curve to figure out.
To the poster do you have the 1711 carb or the thunder AVS?
#27
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The key is vacuum secondary and how small the plenum and runner volume is.
Really what is 750 cfm vs 800 you would only maybe have a minor difference in primary throttle bore diameter.
I also only had single plane intakes on 355ci with my 750 Edelbrock carb. I probably put 70,000 miles on it in 10 years and 100 upon 100's of runs down the drag strip. It was just a learning curve to figure out.
To the poster do you have the 1711 carb or the thunder AVS?
Really what is 750 cfm vs 800 you would only maybe have a minor difference in primary throttle bore diameter.
I also only had single plane intakes on 355ci with my 750 Edelbrock carb. I probably put 70,000 miles on it in 10 years and 100 upon 100's of runs down the drag strip. It was just a learning curve to figure out.
To the poster do you have the 1711 carb or the thunder AVS?
#28
Team Owner
#29
Drifting
Everybody wants theirs to be the biggest, most hairy-chested thing on the planet...then overlook the obvious.
A 650 Double Pump is a very solid carb for a 350 or 383 engine, volumetrically. You'll give up a very tiny amount beyond 6,000 RPM, but if your engine can't run up there, you're not giving up a thing.
Also, the Annular Boosters give even more 'spunk' to the low end because of the better atomization. If you go with a 4-corner idle circuit, there is great control and LOOOTS of low end bite when you need it.
I chose a QuickFuel 650 DP Annular Booster carb and it is an awesome piece.
A 650 Double Pump is a very solid carb for a 350 or 383 engine, volumetrically. You'll give up a very tiny amount beyond 6,000 RPM, but if your engine can't run up there, you're not giving up a thing.
Also, the Annular Boosters give even more 'spunk' to the low end because of the better atomization. If you go with a 4-corner idle circuit, there is great control and LOOOTS of low end bite when you need it.
I chose a QuickFuel 650 DP Annular Booster carb and it is an awesome piece.
#30
Melting Slicks
yes it does, not smart enough to give the technical reasons why. my 69 300hp running a spreadbore with th400 trans which I presume has a low stall, hesitated all the time. fix was changing the plastic cam for the accel pump. hurray for the holley platform and it adjustability and every speed shop carries parts.
#31
Team Owner
Everybody wants theirs to be the biggest, most hairy-chested thing on the planet...then overlook the obvious.
A 650 Double Pump is a very solid carb for a 350 or 383 engine, volumetrically. You'll give up a very tiny amount beyond 6,000 RPM, but if your engine can't run up there, you're not giving up a thing.
Also, the Annular Boosters give even more 'spunk' to the low end because of the better atomization. If you go with a 4-corner idle circuit, there is great control and LOOOTS of low end bite when you need it.
I chose a QuickFuel 650 DP Annular Booster carb and it is an awesome piece.
A 650 Double Pump is a very solid carb for a 350 or 383 engine, volumetrically. You'll give up a very tiny amount beyond 6,000 RPM, but if your engine can't run up there, you're not giving up a thing.
Also, the Annular Boosters give even more 'spunk' to the low end because of the better atomization. If you go with a 4-corner idle circuit, there is great control and LOOOTS of low end bite when you need it.
I chose a QuickFuel 650 DP Annular Booster carb and it is an awesome piece.
The true answer though is to get the existing 800 working the best it can
#32
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Yes, I do have a Vacuum gage and a back timing light, and I have a jet and rod kit...
My Tri-Y headers are due in on Friday, So I will need to install them and the Pypes system, and mod the connection to the headers, then I can start to tune the carb to the new set-up.....
Since I work 2nd shift, I'm kinda limited to only the weekend
By the way, my name is Lee
#33
Team Owner
Us guys with the nice front ends have to stick together.
Right off the bat. I think from what you said you have a hot h-flat edl cam and heads. Your max timing should end being less than 36 degrees @3200 rpm. So set your timing at 3500 rpm to 36 with the vacuum advance disconnected. Where idle falls it falls unless you recurve your dizzy to limit the max mechanical.
The hotter your cam the more initial you need. so if at 850-900 rpm idle it is 12+ great more like 18 is even better.
From the Edl. online charts do the rod and jet change to 12% less on cruise and 6% less on the full power. I'm just doing a wild *** guess
because you are 2300 miles away. If idle is gas smelling exhaust. Your have the idle screws.... engine hot vacuum gauge on the full vac port adjust your screws to max vac. like 1 turn from lightly closed is where you should end up. To get the idle correct A/F you might need to drill a .125 hole in the primary throttle blades just like all Holley carbs
I ended up making tapered rods like a Quadra jet. Edl rods are stepped and have an abrupt fuel curve AF change.
Right off the bat. I think from what you said you have a hot h-flat edl cam and heads. Your max timing should end being less than 36 degrees @3200 rpm. So set your timing at 3500 rpm to 36 with the vacuum advance disconnected. Where idle falls it falls unless you recurve your dizzy to limit the max mechanical.
The hotter your cam the more initial you need. so if at 850-900 rpm idle it is 12+ great more like 18 is even better.
From the Edl. online charts do the rod and jet change to 12% less on cruise and 6% less on the full power. I'm just doing a wild *** guess
because you are 2300 miles away. If idle is gas smelling exhaust. Your have the idle screws.... engine hot vacuum gauge on the full vac port adjust your screws to max vac. like 1 turn from lightly closed is where you should end up. To get the idle correct A/F you might need to drill a .125 hole in the primary throttle blades just like all Holley carbs
I ended up making tapered rods like a Quadra jet. Edl rods are stepped and have an abrupt fuel curve AF change.
Last edited by gkull; 05-14-2013 at 09:36 AM.
#34
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Us guys with the nice front ends have to stick together.
Right off the bat. I think from what you said you have a hot h-flat edl cam and heads. Your max timing should end being less than 36 degrees @3200 rpm. So set your timing at 3500 rpm to 36 with the vacuum advance disconnected. Where idle falls it falls unless you recurve your dizzy to limit the max mechanical.
The hotter your cam the more initial you need. so if at 850-900 rpm idle it is 12+ great more like 18 is even better.
From the Edl. online charts do the rod and jet change to 12% less on cruise and 6% less on the full power. I'm just doing a wild *** guess
because you are 2300 miles away. If idle is gas smelling exhaust. Your have the idle screws.... engine hot vacuum gauge on the full vac port adjust your screws to max vac. like 1 turn from lightly closed is where you should end up. right at idle needs a .125 hole drilled in the primary throttle blades just like all Holley carbs
I ended up making tapered rods like a Quadra jet. Edl rods are stepped and have an abrupt fuel curve AF change.
Right off the bat. I think from what you said you have a hot h-flat edl cam and heads. Your max timing should end being less than 36 degrees @3200 rpm. So set your timing at 3500 rpm to 36 with the vacuum advance disconnected. Where idle falls it falls unless you recurve your dizzy to limit the max mechanical.
The hotter your cam the more initial you need. so if at 850-900 rpm idle it is 12+ great more like 18 is even better.
From the Edl. online charts do the rod and jet change to 12% less on cruise and 6% less on the full power. I'm just doing a wild *** guess
because you are 2300 miles away. If idle is gas smelling exhaust. Your have the idle screws.... engine hot vacuum gauge on the full vac port adjust your screws to max vac. like 1 turn from lightly closed is where you should end up. right at idle needs a .125 hole drilled in the primary throttle blades just like all Holley carbs
I ended up making tapered rods like a Quadra jet. Edl rods are stepped and have an abrupt fuel curve AF change.
#35
Team Owner
#36
Drifting
I certainly am not the expert on the subject, but if a carb is oversized, does locking down the jets and idle circuit to not allow as much fuel "fix" the issue? My limited understanding says that this is true TO A DEGREE...adjustments...but if there is fundamentally too much 'carb' there, then you can't strike the stoichiometric balance between air and fuel. You'll always be chasing a rich condition.
All this comes from a person that had a Holley 750 on his LT-1 engine and it ALWAYS seemed sopping wet. Plugs were always black...pistons were black when I pulled them out...easy to flood. It was this experience that pushed me toward the 650 when I decided to 're-fuel' the car.
I'm not trying to fight back. I don't have the answers. But I am trying to speak to the other side of the coin that perhaps a Holley-based 750 isn't the answer to EVERYTHING...
#37
Melting Slicks
In re-reading the original post, it appears he was throwing up the white flag as it relates to his current carb. Lars indicates that he has had minimal success with this particular carb and I think everyone agrees this is too much fuel for the engine. Seemed like he was planning on making a purchase.
I certainly am not the expert on the subject, but if a carb is oversized, does locking down the jets and idle circuit to not allow as much fuel "fix" the issue? My limited understanding says that this is true TO A DEGREE...adjustments...but if there is fundamentally too much 'carb' there, then you can't strike the stoichiometric balance between air and fuel. You'll always be chasing a rich condition.
All this comes from a person that had a Holley 750 on his LT-1 engine and it ALWAYS seemed sopping wet. Plugs were always black...pistons were black when I pulled them out...easy to flood. It was this experience that pushed me toward the 650 when I decided to 're-fuel' the car.
I'm not trying to fight back. I don't have the answers. But I am trying to speak to the other side of the coin that perhaps a Holley-based 750 isn't the answer to EVERYTHING...
I certainly am not the expert on the subject, but if a carb is oversized, does locking down the jets and idle circuit to not allow as much fuel "fix" the issue? My limited understanding says that this is true TO A DEGREE...adjustments...but if there is fundamentally too much 'carb' there, then you can't strike the stoichiometric balance between air and fuel. You'll always be chasing a rich condition.
All this comes from a person that had a Holley 750 on his LT-1 engine and it ALWAYS seemed sopping wet. Plugs were always black...pistons were black when I pulled them out...easy to flood. It was this experience that pushed me toward the 650 when I decided to 're-fuel' the car.
I'm not trying to fight back. I don't have the answers. But I am trying to speak to the other side of the coin that perhaps a Holley-based 750 isn't the answer to EVERYTHING...
George (gkull) is very experienced with tuning and giving good tech advise here. If the OP listens to him and follows his advise to a T, the car should run very well with the 800 Eddy.
#38
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In re-reading the original post, it appears he was throwing up the white flag as it relates to his current carb. Lars indicates that he has had minimal success with this particular carb and I think everyone agrees this is too much fuel for the engine. Seemed like he was planning on making a purchase.
I certainly am not the expert on the subject, but if a carb is oversized, does locking down the jets and idle circuit to not allow as much fuel "fix" the issue? My limited understanding says that this is true TO A DEGREE...adjustments...but if there is fundamentally too much 'carb' there, then you can't strike the stoichiometric balance between air and fuel. You'll always be chasing a rich condition.
All this comes from a person that had a Holley 750 on his LT-1 engine and it ALWAYS seemed sopping wet. Plugs were always black...pistons were black when I pulled them out...easy to flood. It was this experience that pushed me toward the 650 when I decided to 're-fuel' the car.
I'm not trying to fight back. I don't have the answers. But I am trying to speak to the other side of the coin that perhaps a Holley-based 750 isn't the answer to EVERYTHING...
I certainly am not the expert on the subject, but if a carb is oversized, does locking down the jets and idle circuit to not allow as much fuel "fix" the issue? My limited understanding says that this is true TO A DEGREE...adjustments...but if there is fundamentally too much 'carb' there, then you can't strike the stoichiometric balance between air and fuel. You'll always be chasing a rich condition.
All this comes from a person that had a Holley 750 on his LT-1 engine and it ALWAYS seemed sopping wet. Plugs were always black...pistons were black when I pulled them out...easy to flood. It was this experience that pushed me toward the 650 when I decided to 're-fuel' the car.
I'm not trying to fight back. I don't have the answers. But I am trying to speak to the other side of the coin that perhaps a Holley-based 750 isn't the answer to EVERYTHING...
#39
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Being too rich and having too big of a carb are two separate issues. A large carb can be jetted to run the correct afr's. What too large of a carb will do is bog when you step it all the way down even when jetted right.
George (gkull) is very experienced with tuning and giving good tech advise here. If the OP listens to him and follows his advise to a T, the car should run very well with the 800 Eddy.
George (gkull) is very experienced with tuning and giving good tech advise here. If the OP listens to him and follows his advise to a T, the car should run very well with the 800 Eddy.
#40
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I was wondering, do I keep the basic step up spring ( 5" ) or go to a different color, also do I keep the basic secondary jets for now, and with all the fooling around I have done with this over the years, I have forgotten which hole the pump arm rod was originally in, top, middle, bottom....Took the carb off last night, took the top off.. I think I need to do a good cleaning on this thing, it looks gunky inside and looks like it has black dirt inside....