351 Cleveland popping and ticking sound

[jczar]

I need some help. I have a Ford 351 Cleveland. The problem that started my investigation was a popping and ticking sound out of the drivers side exhaust. The popping sound only occurs when I am at steady speed. It does not pop when accelerating or deceleration. I replaced the exhaust header gasket. I cleaned and sealed the exhaust slip pipes. I checked the following: timing @ 34 degrees, vacuum 17 to 18 Hg and holding steady. Checked to see the wires were correct to plugs. Adjusted the air/fuel mix. Checked distributor for cracks and burns. Checked rotor to #1 plug at TDC. Replaced spark plugs. Removed the valve cover and checked the rods. They do not appear bent (spun each one). Checking the compression it seems to have low compression. I squirted oil into #6 and compression came up 4 pounds. The engine starts and runs fine. Added Sea Foam to fuel thinking possible buildup around valves. No vibration, no smoke. Any ideas would be much appreciated.

Compression
#1 = 90 #5 = 92
#2 = 92 #6 = 70
#3 = 100 #7 = 92
#4 = 100 #8 = 90

[FWB]

Originally Posted by jczar

I need some help. I have a Ford 351 Cleveland. The problem that started my investigation was a popping and ticking sound out of the drivers side exhaust. The popping sound only occurs when I am at steady speed. It does not pop when accelerating or deceleration. I replaced the exhaust header gasket. I cleaned and sealed the exhaust slip pipes. I checked the following: timing @ 34 degrees, vacuum 17 to 18 Hg and holding steady. Checked to see the wires were correct to plugs. Adjusted the air/fuel mix. Checked distributor for cracks and burns. Checked rotor to #1 plug at TDC. Replaced spark plugs. Removed the valve cover and checked the rods. They do not appear bent (spun each one). Checking the compression it seems to have low compression. I squirted oil into #6 and compression came up 4 pounds. The engine starts and runs fine. Added Sea Foam to fuel thinking possible buildup around valves. No vibration, no smoke. Any ideas would be much appreciated.

Compression
#1 = 90 #5 = 92
#2 = 92 #6 = 70
#3 = 100 #7 = 92
#4 = 100 #8 = 90

seems as though #6 is your problem child......with all the things you have checked........broken valve spring? bent valve? cracked piston.....and or ring..

start diggin',
was the motor sitting? just buy the car? happened after a spirited drive?
a little background may give you some more responses

[505stang]

run a leakdown test on the motor, if you here air coming out of exhaust pipe, it is exhaust valve related, air coming out of carb, it is intake valve related, air in radiator it is usually a head gasket #6 is low and this test should help

[Turbonut48]

Yes, give it a leak down test.
505 forgot to mention air from crankcase means rings or piston problems.

The Nut