LA 318 engine knocks straight after an overhaul

[Kaitsu]

It´s me again with my freshly rebuilt 318. Engine does everything alright, but over the engine sound, I clearly hear that there´s this metallic noise coming from somewhere inside the engine. I used a screwdriver to listen for an echo and I traced the sound to left rocker cover. The sound reminds me of a fan hitting a metal pipe, like "ping"

Engine has new timing set, cam, lifters, rocker shafts and rockers and new exhaust valves. Intake valves were not replaces, neither were the push rods. The crankshaft was polished and all bearings, but not upper connecting rod bearings. Pistons are original but re- ringed. Cylinders are re- honed.

Hope I could provide enough information for someone to lend me their thoughts.

 

[bremereric]

Don't run it. I would disassemble it and look for something you missed.

 

[Kaitsu]

I removed the valve cover and noticed that rocker arm shaft was not assembled correctly, the oil holes were pointing up. I re- assembled and started, everything works fine cold but when the engine is warm, the same type of metal- to metal ping continues on idle. Straight after I depress the throttle pedal, even barely, the noise goes away and returns few seconds after revving. Could this be some kind of dirt in the lifter? I´m using Kendall 10- w40 GT-1 motor oil.

 

[bremereric]

A ping is way different than a ticking lifter.

 

[kkritsilas]

Some people can describe the same noise as a tick, others a ping, others as a ting, etc. Kaitsu's first language is not English, either, so describing noises is going to be even more of a difficulty.

His original description said knock. By that, most people would automatically assume a bearing issue (rod or main, or maybe piston slap or even pre-ignition/detonation). Reading the description, it isn't knock at all, in the normally understood sense. Similarly, his description of a "ping" may be a lifter tick (or for that matter, maybe not). From his description of the symptoms, though, sounds like a lifter ticking to me, but just an opinion.

 

[Jack Meoff]

Post a video of it.

 

[9secRR]

anything hitting valve cover? is there baffles in the valve covers? rockers could be touching?

 

[Kaitsu]

I now have solved the problem: I got wrong instructions for assembling the rockers to the rocker shaft: mine were assembled as all the knuckles pointing forward on both banks. I red the service shop manual for guidance and it had a picture on the page that told me to assemble the most front rocker knuckle forward, 2nd rocker knuckle pointing rear and so on. Reassembled and no knocks, pings or tacks of any kind. Now, only transmission shift issue and carb dialing left...

 

[bremereric]

Sometimes the manual solves the headaches.

 

[80 Lebaron Coupe]

I now have solved the problem: I got wrong instructions for assembling the rockers to the rocker shaft: mine were assembled as all the knuckles pointing forward on both banks. I red the service shop manual for guidance and it had a picture on the page that told me to assemble the most front rocker knuckle forward, 2nd rocker knuckle pointing rear and so on. Reassembled and no knocks, pings or tacks of any kind. Now, only transmission shift issue and carb dialing left...

Yes there are Left and right rocker arms on both sides.
Each cylinder has a Left & Right.
I assume all you left rockers were on one side,
and all your right rockers were on the other side.
Glad to hear it all fixed now.