hi i just rebuilt my holley , an now there is vapors coming from the front vent tube . why is it doing this ? is the float set to low ?
when i set my floats should the car be runing , if so i am worry they may not get set right due to the fact the car has a big cam an wont idle lower than 1000 rpm . but runs better at 1100.
i need all the help i can get on tunning this carb an seting timing .
any info would be great thanks

 

In a situation like this, you MUST be using a vacuum gauge to know what is going on inside the CARB and manifold.

At 1100 RPM (which is WAY to high at idle), what is you're vacuum reading?

Double check for vacuum leaks (the easiest way to do this, is to spray some CARB cleaner (while the engine is running of course) around the manifold bolts and the CARB bolts.... if the engine revs up, there's you're leak. If it doesn't.... lets move on;

What are you're cam spec's? What's the advertised duration & lift? If you don't know, just gie me the part number....

The vent tube on the CARB, just exactly that.... it vents unused vapor. Just hook it back up to the vent canister, and if you ripped yours out already, get an aftermarket one (this helps tremendously with big cam street cars).

 

Advance the distributor slightly (counter clockwise), until you hear a slight pinging (with a load, you must be driving)...

Then, retard the distributor just enough until the pinging goes away (this is only determined with a load of course, as you must be driving.... and the pedal must be floored)...

Once the pinging goes away, it's timed! The idea is to advance it just enough to hear a slight pinging, then to retard it (clockwise) so that the spark knock is no longer prevalent when you floor it.

BTW.... you didn't touch you're rocker arms did you? They 'might' be too tight, but this is only if you took them off.

 

this is what i have been told about the eng its a 396 , compression is 12:1 cam is a custom grind isky 340 duration 580/580 lift . that alli know about the cam . has roller rockers but i havent touched them. heads are rectangle ports .
i rebuilt the carb cause it was runing rich . before i rebuilt it had a vacume reading of 4.5-5 in of vacume. i did adjust it a little but with out a vacume gauge. its not as rich as it used to be but still a little rich. i am not sure if it sould still be alittle rich but theres a lot done to the eng .
this is my first time having a eng this radical. so any info would be great
thanks chad

 

My ***... that's a radical cam! Are you setting this thing up for the track, or the street?

High compression means more horsepower, but for the street.... bring down that cam to a more streetable 230 Duration and 520/520 Lift (you'll be much more happier.... believe me).

 

yeah i know ,wasnt really what i wanted but was a deal i couldnt pass up. i am hoping it want be as bad as i think it will with the doug nash 5 speed . but i want to try runing it the way it is first.
after all its only a car that a toy / weekend car an that not even every weekend. yes that was right 340 duration 580/580 lift custom grind cam . so i am still open to help .
thanks