I have been trying to get my 72 in roadworthy condition since i recently took it out of storage where it sat for 7 years. added headers and 2.5" exh. and have replaced a lot of the ignition (still got the orig points-type dist.) i'd been trying to tune it, and decided that with the new exh it was running lean. rebuilt the qjet, bumped up the primary jet area by ~10% still having trouble with timing - i have to set initial at least 16* - 18* for it to idle smoothly. then started getting an engine surge at idle. regular, and it caused the trans to surge as well (when in drive at a stop.) decided it ws a vacuum leak. found the/a leak at the EGR block-off plate on my Edelbrock 350 performer intake. the guy I bought it from had ground down the casting presumably to fit a different carb on another car and it caused a leak between the cast and plate. i used JB weld to build up the casting and made a new block off plate out of 3/16" aluminum stock. cleaning the casting up i shoved small squares of cloth into the EGR ports to keep bits of debris from going into the engine. the day was getting late/dark and it started to rain. so by the time i finished the new block off plate, i just needed to bolt it on with a new gasket and see if that solved my surge problem. i was excited and tired and put the plate on - fired it up and waited to see how i did with the leak when i realized i hadn't taken out the cloth bits...oops . the fore/push side bit was still there, but the aft/pull side had been sucked away. what should I do? at this point i really can't afford to pull the intake off. where does that EGR port lead to - back to the intake plenum? is it possible for the cloth to pass through the engine like a kidney stone? or do i have my excuse to rebuild the engine?

oh, and here's a pic of the block off plate. i know, amateurish, but it was the first time ive ever done any engraving...

 

Computer ate my first attempt to reply...

Bottom line: You'll never know for sure whether it's still hanging around in your manifold, or one of your bowls, diverting airflow and affecting mixture to one cylinder.

You've got to take the manifold off to check all the ports and blow through the runners with compressed air, or you'll always be wondering.

- Eric

 

If the side that was OK is what goes to the heads, then the cloth is in the manifold passage that leads under the plenum. A hole goes from that passage into the plenum under the carb. Check hole size vs. size of the cloth--it probably didn't get into the plenum, then a runner, then an intake port. You could put a plug into the hole in the floor of the plenum. Some intakes/car brands used a steel fitting threaded into the manifold iron, others a simple cast hole.

 

Eric is probably right, but I might spend a little more time trying to fnd it first. Maybe a shop vac could suck it back towards the EGR port. Removing the carb is a pretty easy option too. Small flashlight, stiff wire a with hook bent on the end and hemostat clamps are good tools for digging around in tight spaces, you might get lucky.

 

I suppose I should make clear that my point is not so much that he HAS to take off the manifold, as it is that that's the only way he'll KNOW it's out, and not be constantly wondering if it's still in there.

It'd drive me nuts.

Also, while he's in there, he might as well...



- Eric

 

Tiny mirror and good flashlight, or one of those flexible inspection cameras? Those cams are getting pretty cheap - Harbor freight had em for 70 bucks before...

 

Thanks for the replies guys. Ill pull the carb and look for it. So if I understand you correctly the port from the EGR goes under the intake plenum where there is another port for the returning gasses join the A/F mix? Hopefully the wad of cloth got stopped at that point.