new car with carburetor questions, I'm terrible with them (Page 2/3)
weaselbeak OCT 21, 12:14 AM
"Apparently most carb issues are due to incorrect timing settings."


You should not even LOOK at the carb until you know all the electrics are right.
rogergarrison OCT 22, 01:30 PM
Generally, I find most mixture screws should be open about 2 full turns , give or take. If you run it too lean, you will burn valves. I still say 10-12* advance is enough for street car. Choke setting is easy. When the engine is warmed to operating temp, just adjust it to where it is just barely all the way open, then closed will be where it should. If it isnt all the way closed at that setting when its cold overnite, replace the choke coil. You can also just convert it to a manual cable so you have full control. Thats very easy too, they make a $10 kit for that.
weaselbeak OCT 22, 06:09 PM
The choke pull-off setting is very important. Do a google search on how to set it, as I am a single finger typist and it would take me all night to try and explain it. Look for explanations with pics. It's easy to do, once you understand the concept.
GreenPlatypus OCT 22, 06:18 PM
Retarded the timing a bit. Seems like a happy medium around 13-14 degrees at idle. At 2500 rpm it is around 32-32. really need to get a better vacuum gauge and a air/fuel gauge. fuel pressure is at 5.5 psi. turned the air mix scres out about 3/4 turn, idle is back to a touch rich. choke appears to work like it should. it fully opens and closes. runs and drives good until you hit 35-40% throttle. then all hell breaks loose. it stops accelerating, bogs down and will stall if you don't get out of it. oh yeah, transmission slips too. this car is a piece of

Let me rant for a bit With fuel injection that works why the **** would anyone want to run a carburetor? Oh yeah, I HATE camaros, wish i could just scrap this thing. i do not know why she keeps wasting money on them. they are getting progressively worse. may just tell my wife she will have to have someone else tune it. But then I am paying for it

I may try to block the secondaries from opening and see if that is an issue. they may be opening too soon. then try a few stages richer then leaner on the squirters. doubt that will make a difference, but i'll see when i get that far. will check the floats when I get a bit more time.

[This message has been edited by GreenPlatypus (edited 10-23-2012).]

rogergarrison OCT 23, 05:07 PM

quote
Originally posted by GreenPlatypus:

Retarded the timing a bit. Seems like a happy medium around 13-14 degrees at idle. At 2500 rpm it is around 32-32. really need to get a better vacuum gauge and a air/fuel gauge. fuel pressure is at 5.5 psi. turned the air mix scres out about 3/4 turn, idle is back to a touch rich. choke appears to work like it should. it fully opens and closes. runs and drives good until you hit 35-40% throttle. then all hell breaks loose. it stops accelerating, bogs down and will stall if you don't get out of it. oh yeah, transmission slips too. this car is a piece of

Let me rant for a bit With fuel injection that works why the **** would anyone want to run a carburetor? Oh yeah, I HATE camaros, wish i could just scrap this thing. i do not know why she keeps wasting money on them. they are getting progressively worse. may just tell my wife she will have to have someone else tune it. But then I am paying for it

I may try to block the secondaries from opening and see if that is an issue. they may be opening too soon. then try a few stages richer then leaner on the squirters. doubt that will make a difference, but i'll see when i get that far. will check the floats when I get a bit more time.




Are you using the right vacuum port ? It could be the secondaries are opening too soon. You might just have too big a carb. Given a choice, Ill take a carb over FI anytime. I put my last 2 carbs on my V8 FIero and the Super Bee. Both were set almost perfect right out of the box. I never had to touch them again. The SB runs perfect and I havent touched the carb for years now. Before the engine swap, the original 318 had the original 2 bbl carb on it and ran great after 40 years. It got about 17 mpg and its a huge car. The 413 still gets about 15 mpg on the highway. You couldnt pay me to switch it to an aftermarket FI system. Ill give you FI generally gives better gas mileage, but I dont care myself. My Astro V6 with FI only gets 16 mpg, same as my Mercedes 450 SL V8 (Bosch FI).
GreenPlatypus OCT 25, 10:19 AM

quote
Originally posted by rogergarrison:


Are you using the right vacuum port ? It could be the secondaries are opening too soon. You might just have too big a carb. Given a choice, Ill take a carb over FI anytime. I put my last 2 carbs on my V8 FIero and the Super Bee. Both were set almost perfect right out of the box. I never had to touch them again. The SB runs perfect and I havent touched the carb for years now. Before the engine swap, the original 318 had the original 2 bbl carb on it and ran great after 40 years. It got about 17 mpg and its a huge car. The 413 still gets about 15 mpg on the highway. You couldnt pay me to switch it to an aftermarket FI system. Ill give you FI generally gives better gas mileage, but I dont care myself. My Astro V6 with FI only gets 16 mpg, same as my Mercedes 450 SL V8 (Bosch FI).



Carb may be oversized, but can't be much, i think the calculator thing recommended a 600 cfm carb.

As far as i know, there is no adjustment for the secondaries, or doesn't appear to be any. I guess they have a "set from factory" and live with it ordeal, but I'll look into it. I "believe" the secondaries are opening too soon as well, or not enough fuel when they open. I can hold the secondaries shut and it is a little better, doesn't bog, hesitate, or stall, just has no power. Still think I need to fiddle with the timing a bit more, will do that when the new vacuum gauge and afr gauge get here. I'm tossing out the timing light and doing it my grandpa's way. Though he had a 5 gas analyzer and one of them big old engine diagnostic machines for tuning carbs and ignition, I'll use the afr gauge to attempt to mimic his stuff. I don;t think he ever used a timing light, just set it too engine vacuum. Every time he replaced a carb it just bolted on and worked out of the box. I don't know, maybe there is some tampered settings inside, it does have a "REMAN" stamp on it.

I am crapping on carbs because I am getting frustrated with the wife. She wants to drive the car, not nag me while I fiddle with it They do have there place and work very well, when they want too. I am just a child of fuel injection, and always had cars with fuel injection. Never really wanted to do the whole performance side of things. I just prefer they would have left the fuel injection on a car that came with fuel injection. I would never use an aftermarket fuel injection system on anything.

Wish my camera could take videos, I'd post it showing exactly what it is doing. Maybe time for a new camera.
rogergarrison OCT 28, 07:10 PM
Ive never had to mess with them, but if I remember, you can reposition the linkages to secondaries into one of a couple different holes/ or bend the linkages slightly to open later. On mine (again if Im remembering) the linkage to secondaries is mechanical. When the primaries open nearly all the way, it pushes the lever to open the secondaries. Im just going from old memories because mine have always worked perfect out of the box. You could test drive the car with the secondaries disconnected completely and see what it does. I did that to the SB when gas was over $4.50 a gallon a couple of years ago. The linkage just has a tiny 'key' clip that snaps in a groove...you need a small needlenose to pull it and reinstall it.

[This message has been edited by rogergarrison (edited 10-28-2012).]

GreenPlatypus NOV 02, 04:46 PM
Alright time for an update. Got my carb tune kit and did some swapping for a baseline. Reset the floats, they were close but I got them better. I put in .092 primary and .095 secondary jets, swapped the metering rods to run 1 stage richer on power and 1 stage leaner on cruise - again baseline so it will change. I also swapped in a 5inhg take up spring but will probably go a little more aggressive. also adjusted my accelerator pump to get the most fuel - but may need larger pump jets. And i tightened the secondary plate spring. kinda goofy but hey, it is a whole nother animal now It still has a quick bog under load, but it no longer stalls, and at idle it runs and revs up like a sbc should. Drives awesome till you punch it, it'll hesitate for a second then take off. Need to check the WOT fuel pressure now that I think about it. I need to retime my dizzy again, put it back to about 18-20 advance at idle, seems to liek that the best and redo some carb settings once I get my wideband. But I am getting closer!!!! And it needs a cat to get through inspection.

The reason for my troubles, it had 4 different holley, yes HOLLEY, primary and secondary jets, none where the same size. It had two different metering rods, and two different take up springs I know I should have checked first, but damn that is some poor assembly on Edelbrock's part.

Carbs are easier to understand once you tear them apart and put them together a couple times. Yay I am learning
weaselbeak NOV 02, 09:01 PM
"18-20 advance at idle,"

That's way too fast at idle, and will give you the bog problem you are experiencing. Back off to 8-12 degrees.
carnut122 NOV 03, 08:32 AM

quote
Originally posted by GreenPlatypus:

Let me rant for a bit With fuel injection that works why the **** would anyone want to run a carburetor?



I'm finishing up my 53 Ford F100 project. I decided to go with fuel injection. There are about 60 different wires running into the PCM that makes fuel injection happen. With a carb, you might have one wire? If I had installed a carb instead, I'd have been done months ago.