Hello, I just finished a frame swap on my 1971 Corvette. This is my first Corvette restoration. I am 18 and finished the full complete chassis rebuild including engine and trans. As I am coming to a close and getting ready to start driving the vette I have been hearing a popping sound coming from the right exhaust pipe. At first thought it was timing or a loose plug wire. But with further digging I ended up replacing the points, loosening and tightening the valves on that side of the engine and adjusting the carb even putting on a different Q-Jet and the same issue is happening. I decided to take out the plugs on that side (not easy when the car has A/C). And as I was pulling some of the plugs they were very loosely put into the block. That worried me so I checked the compression to make sure that the valves weren't damaged and they all had good compression. I am stumped. The only thing that I could think of that might be the issue is the full chambered exhaust. But I really don't think that is the issue. I really don't want to pull the head but if it needs to be done I guess I have to. Any help or suggestions on what to do next would be appreciated.

Lukas


Below is some pictures of the build

 

If you have the heat riser - check to see if it's open.

I would double check the wires to see if one is crossed.

Darken the room and spray a little mist of water on the wires - look for arcing. I use an old Windex bottle.

Last summer I had a bad plug , new - right out of the box , I used a multi meter to check and one plug was open.

These are the easy ones to try.

 

Will check tomorrow.

Thanks,
Lukas

 

Looking at your picture I noticed the vac line on your distributor is before the bracket. I know GM made this adjustment in the AIM. So on my SB 69 I had to adjust it behind the orange bracket and move my plug wires over one. Not sure if that was still the case in 71.I'll check my pictures!

RVZIO


Vac line to distributor is behind bracket

71 Not sure it looks pretty even with bracket but line ran behind bracket.

 

Have you pulled one wire at a time to see if the engine rpm changes? Also try disconnecting the vacuum advance and see if it goes away. Do you know how much advance you have and what it is when its all in? When you had the plugs out did you see what the tips looked like. Where they oily, brown, tan or white and how far down the insulator did the color reach?

Great job on the build so far!!!

 

1 cylinder misfire. Plugs on that side need to checked for fouling. You may find one of them is worse than the rest. The spark plug wire can be burned and short circuiting to the exhaust or elsewhere. Check inside distributor terminals if you cant find it in the plug/wire. That is where I would start.