Exhaust issues
Thread Starter
Cruising
Joined: Jun 2014
Posts: 14
Likes: 0
From: pa
Exhaust issues
Hello all. Has anyone experienced a popping sound in the exhaust? My car has Hooker side pipes. Currently, my 68 has a popping sound only in the right side exhaust. I can hear it in 1st and 2nd gear when I let off the gas and at high rpm. Any suggestions? Thanks in advance.
Race Director
Joined: Mar 2017
Posts: 11,949
Likes: 4,507
From: Virginia
Does the sound go away if you step on the clutch, or put it in neutral? I had the same symptoms with my 4-speed when I added Hooker sidepipes. What fixed it for me was to double-check the Lars-style ignition tune with some carb adjustments.
Specifically:
Specifically:
- Do the Lars tune correctly (I had accidentally moved the vac advance hose to ported vacuum, meaning ignition timing was an extra 12 degrees retarded at idle. Vac advance hose should be connected to manifold vacuum, and vac advance limited to 10-12 degrees total).
- Adjust the idle mixture screws on the carb.
- You may need to re-jet your carb, too (I haven't done this yet).
Thread Starter
Cruising
Joined: Jun 2014
Posts: 14
Likes: 0
From: pa
I had no idea.
Does the sound go away if you step on the clutch, or put it in neutral? I had the same symptoms with my 4-speed when I added Hooker sidepipes. What fixed it for me was to double-check the Lars-style ignition tune with some carb adjustments.
Specifically:
Specifically:
- Do the Lars tune correctly (I had accidentally moved the vac advance hose to ported vacuum, meaning ignition timing was an extra 12 degrees retarded at idle. Vac advance hose should be connected to manifold vacuum, and vac advance limited to 10-12 degrees total).
- Adjust the idle mixture screws on the carb.
- You may need to re-jet your carb, too (I haven't done this yet).
Thank you very much. The popping does go way when I push in the clutch or in neutral. My technical skills are not great but I will do my due diligence and figure it out. You’ve given me a place to start. Thank you.
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
Popping through the exhaust suggests to me that you have combustible mixture getting into the exhaust. That means it's not burning in the cylinder for some reason. Might be as simple as a fouled plug, or a lean mixture.
