uidzer0_z28

Hey guys,

Last week I just finished swapping my 82 camaro's CFI setup to a carbed system. I replaced the system with an Edelbrock AirGap Intake, Edelbrock 600cfm non-egr carb, and a new mech. advance distributor. Everything seems to have gone just fine except it seems like I have lost a lot of low-end power like around idle-2500 rpm, when I am crusing at higher speeds I can step on it and really take off but if I am at idle and go to WOT I can't even chirp the tires, it seems to bog a little (sounds like it) and then slowly accelerates. I am not sure if the carb is tuned quite right but I got a vaccume guage and I tuned it to get the most vacume from both sides. (although I am not sure it is quite right, there is about 1 full turn in the mixture screws where it makes no difference in idle or vaccume readings)

Any help would be great!

Thanks,

Ben

jeffs82z28

What do you have your initial timing set at?
Do you have an advance curve kit in the distributor?
What primary jets are in the carb?

Those are the first Questions that need to be answered.

uidzer0_z28

I have the timing set at 6* btdc
I dont know what an advance curv kit is... sorry
The carb is stock

Hope this helps heh...

-Ben

jeffs82z28

First thing I would do is start bumping the initial timing up a couple degrees at a time and test driving. Don't go over 12* initial timing, or you may run into hard starting and high rpm spark knock.
The butt dyno will tell you if it is helping, but use a stop watch over a measured course, 1/4 mile drag strip is preferred.

An advance curve kit is used to change the timing curve as the engine rpm increases.
If you have an HEI distributor, the advance components are right under the rotor.
I would suggest you buy a book or two and learn about what the curve kit is, what, and how it does what it does, before playing with it.

I think you will see an improvement just by advancing the initial timing to 8 or 10* BTDC. (Before Top Dead Center)

Hope this helps.

uidzer0_z28

Ah, I see what you mean...
Well here is my problem, I have the HEI vacume advance distributor and I have it hooked up to the vacume port on the carb but I am a little weary to advance the timing anymore because dosn't the distributor do that when I increase the throttle, when I put a timing light to it and step on the gas I can watch the mark on the flywheel go very far beyond the timing tab torwards the passanger side. Should I still bring the timing to 8-10*btdc?

Thanks,

Ben

jeffs82z28

Ben,
Yes, the increase in timing is from the mechanical advance mechanism in the distributor.
The ignition timing will advance up to about 32-34*, depending on the rpm of the engine.

The vacuum advance is for increasing the timing under part throttle cruise.

If I remember correctly, the vacuum canister should be hooked up to a port on the base of the carb or manifold port so it gets a manifold vacuum signal. I've been using the computer controlled stuff for so long that I don't want to say with authority "Do This My Way" . Know what I mean?

There is a Tech article that talks about the vacuum advance distributors, it may help.

When you are setting the timing, are you dis-connecting the vacuum line at the distributor and plugging it with something?
You have to have the vacuum dis-connected while setting base (initial) timing.

evil t/a

Advance your timing to 12-14 .

RB83L69

Hmmm... let's see... you took off a FI system with 2-foot-long drinking-straw runners, and put on a near-race manifold with 4" runners designed for a larger motor. That would explain the soggy bottom end. I'm afraid it's just going to be that way with the combo you now have. The intake will prevent the thing from having the low end that it should, and the cam & maybe exhaust will keep it from having its full high end capablilites.

No amount of fiddling with the timing is goign to fix it, although you should of course adjut the timing to make the car run the best. I'd suggest not bothering with the light until after you have the car tuned up, then merely write the setting down for future reference.

There are 2 ports on those Carter carbs that you can use for vacuum advance. You need to hook the dist to the one that has no vacuum when it's at idle, but has vacuum when the throttle is opened part way.

There is a "governor" type of system in the dist that increases the advance with increasing RPM. If you are setting the timing, you need to keep the engine RPM below 700, to make sure it's not mechanically advancing. Reset it as you adjust if necessary.

SSC

Hey Man-nnn thats a "full race" setup.

Uidzer0,
Turn your A/F screws in all the way then back them both out 1 & 1/2 turn. Standard Eledcrap tunning on a SBC and it's funny because 99% of the time it will put you dead on as far as A/F mixture goes. Then take your vac guage and tie into manifold vaccum, with the car @ operating temp advance the distributor until you reach peak vaccum then back it off two inches of vacuum. This will help quite a bit if not fix your problems all togather. I would consider getting a manifold better suited for you setup either a stealth or a junk RPM.

uidzer0_z28

well,

I tuned the carb a little better and it is not quite so soggy anymore... and yes i know this is more of a race setup but that is what I plan to do with it in the future, right now I am just purchasing parts that are going to transfer over to a 350 block later on, you see I am in the navy so I only work on it when I can and it is more of a hobby than anything.

Thanks for all your help though!

Ben

evil t/a

Did you advance your timing?

uidzer0_z28

not yet but I am planning to do that tomorrow morning when I have time.