It's not vapor-lock / part 2

Ok then - Like most everyone stated, it's definitely not vapor-lock...

I got my new Powermaster starter today & as soon as I fired it up the problem was still there, cold engine & all.

Spending a little more time with it I can again, best describe the sound as quick little popping noises coming up through the carb as I rev the motor. I don't hear them at idle - only as a give it gas. Also, they don't seem to be back-fires - just a strange popping sound that progresses in frequency with the rpm's...

I tried advancing & retarding the timing and that didn't change anything.

I also cut the zip-ties & separated the plug-wires as recommended by a previous poster.

The ignition system is pretty much brand-new so I'm sort of at a loss here with what could be causing this.

Also new is the carb, intake, cam, lifters, rebuilt heads.

For those who didn't read my first thread I was basically cruising at a steady 3000rpm when out of the blue, all of a sudden the carb just started popping, it's more obvious as you apply more throttle.

Any help would be GREATLY appreciated...

D.Hearne said:

Try spraying carb cleaner all around the intake as it's running to see if you may have a vacuum leak.

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Just tried spraying WD-40 around base of carb & around where the intake mates to the heads & block - nothing...

I measured the vacuum & the guage read around 7" @ idle. The needles shaking a little but I figure that probably has more to do with the cam.

iskwezm
are the floeats sticking and dropping too much gas???

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I checked the float level & they seem ok - I remove the check plug with the fuel pump on & gas just barely dribbles out when gently rocking the car.

I'm starting to think it's not a carb problem. Upon listening closer it sounds like the sound is actually coming from inside the drivers side valve cover... ( damn )

UPDATE*

Well I just removed the drivers side valve cover & found the #5 Cylinders exhaust valve rocker to be completely loose. WTF!

At least I now know what the noise was.

When I set the lash I tripple checked EVERYTHING - How in the world could this have happened? Is it possable something could have been damaged as a result of driving it like this?

Thanks...

351carlo said:

Unfortunately, yes. It is possible to wipe the cam. I wouldn't run the motor any longer until you check this out. Easiest way is to pull the intake and check out your lifters.

After wiping my first cam, I routinely check my lifters for abnormal wear. These days you just never know what's gonna happen.

7" @ idle for that motor is too low. You should be up in the 12-14" range minimum.

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Man - Don't tell me that, I don't want to pull my intake again... ( LOL )

Far as vacuum goes I figured with the cam that I have 7" would be normal?

Here's my advertised cam specs: It's a Crower solid lifter - Part#15313

Intake: Duration: 274* Lift: .541
Exhaust: Duration: 288* Lift: .528

I'm using rocker arms with a 1.6 ratio