[hwiibob26]

Acquired a cheap 72 caprice 402 with what assumef was a collapsed lifter, tappin/knockin in valve train

Replaced cam and lifter set, broke rocker arm stud, wore out timing set

Got everything back together fired ready to break in cam and same noise

Going to readjust valve tommorrow, pour some tranny fluid down the carb maybe carbon build up

Any other ideas i really dont want to pull the engine for rebuild

In short HELP!!!!!

[68NovaSS]

Double posting isn't allowed and really won't get a quicker response, I've deleted your previous duplicate thread.

[454C10]

If the cam had a flat lobe or if there was a concaved lifter, then the bearings are most likely bad also.

I would start by pulling the heads. Maybe a valve seat has come loose. A compression test should be able to locate the guilty cylinder.

What cam did you put it?

[BOBCRMAN@aol.com]

A badly spun rod bearing will let the piston hit the head and sound like an upper engine noise.

[F-BIRD'88]

Pouring trans fluid down the carb will not cure anything. Its just a waste of a quart of trans fluid.
When a cam fails in a BBC you must inspect the lifter bores for burrs. These burrs must be removed or the
new lifter will not rotate freely and the cam lobe and lifter face will soon fail again.
The problem that cause the rocker arm stud to break must be addressed. This never happens for no reason
on a BBC.

[hcompton]

To clean carbon from the engine use gm top end engine cleaner or water in a fine mist spray bottle or even a squirt gun but never poor anything into the carb that include and even especially gas.

Never herd of trans fluid in the carb in the oil yeah it works about as good as marvel to clean crap out of the engine but still not recommended.

Is it a knock or a tap. A knock it needs to come apart and with a tap ot might need to come apart. Is it a tapping sound like the valves. Exhuast manifolds and cracked heads or headers can make some streange sounds.

Also check the flexplate before you pull the motor. They do break and sound like a rod knock.