ddpsnake
Well-Known Member
remember gents, every engine wants what it wants,no matter what, i do not pay attention to stock specs, sure its a good starting point, but.
HOLLEY CARB TUNING HELP
- Thread starter Landon
- Start date
66Satellite47
Well-Known Member
I agree, for the most part the stock Holley is close. It appears the OP should start there. It sure needs more shooter than a 21. Didn't know they made that small. Smallest I've seen is 25. Working the shooter size & cams will cure the flat spot. Jet tuning may be worth a little something too.
Landon
Active Member
I have some size 18 nozzles! The 31/32 nozzles were a big help over the 21/21 setup. I might drop a couple sizes on my main jets.
Canadian1968
Well-Known Member
Don't worry about having a passenger. That should not be part of your tuning process .
You have already realized that the bigger squirter is helping which was a no brainer like most people have said . At least that's in the right direction . But I think it's safe to say that your main jets are to big as well. On the primary at least.
But instead of jumping all overy the place start right back at the basics .
If your ignition timing is where you want it. Hook up a vaccum gauge to the bottom port at the front of the carb (manifold vaccum ) . adjust your idle mixture screws to get your highest vaccum. Next check your accel pump adjustment , make sure there is 0 play but no pre load. At the slightest touch it should activate your pump (squirter ). Take the car for a drive , nice easy accel from a stop, cruising , do some moderate accel off cruise ( fron 30 mph to 60 maybe ?) as well as from a dead stop. This will help diagnose the first 3 circuits of the carb (idle, cruise and accel/power)
Carb works on different circuits depending on the throttle input when they all work together you will swear it's fuel injected ?
walk before you run !
You have already realized that the bigger squirter is helping which was a no brainer like most people have said . At least that's in the right direction . But I think it's safe to say that your main jets are to big as well. On the primary at least.
But instead of jumping all overy the place start right back at the basics .
If your ignition timing is where you want it. Hook up a vaccum gauge to the bottom port at the front of the carb (manifold vaccum ) . adjust your idle mixture screws to get your highest vaccum. Next check your accel pump adjustment , make sure there is 0 play but no pre load. At the slightest touch it should activate your pump (squirter ). Take the car for a drive , nice easy accel from a stop, cruising , do some moderate accel off cruise ( fron 30 mph to 60 maybe ?) as well as from a dead stop. This will help diagnose the first 3 circuits of the carb (idle, cruise and accel/power)
Carb works on different circuits depending on the throttle input when they all work together you will swear it's fuel injected ?
walk before you run !
Landon
Active Member
should I go up to a higher # power valve on the primary like a 8.5 or 9.5 due to my high vacuum reading?
what about smaller secondary main jets and adding a power valve instead of the factory plug?
66Satellite47
Well-Known Member
Which list number is your carb? A higher number power valve could help fuel economy. Didn't think think the power valve plug in the secondary was stock. You could try 8.5 or even 10.5 & see how they work.
Canadian1968
Well-Known Member
Do the basic adjustments first . Then drive it .
When you roll on the power for accel test your vaccum will start to drop. Its correlation between throttle input and when your engine vaccum reaches the rating of the power valve. Are they in the right spot? If power valve is to low the closer to WOT you will need before it opens and you may notice a flat spot in power band. If it's to high it will open to soon and just dump in waste fuel that will make you run very rich.
You can check your plugs to see what they look like. My bet is they are fouled pretty bad from the 78 jets you have in the.primary .
When you roll on the power for accel test your vaccum will start to drop. Its correlation between throttle input and when your engine vaccum reaches the rating of the power valve. Are they in the right spot? If power valve is to low the closer to WOT you will need before it opens and you may notice a flat spot in power band. If it's to high it will open to soon and just dump in waste fuel that will make you run very rich.
You can check your plugs to see what they look like. My bet is they are fouled pretty bad from the 78 jets you have in the.primary .
Similar threads
