So I have a b18c1 bottom end with supertech high compression pistons and forged rods, put together with a b16 head with aftermarket intake valves, crower titanium dual springs and retainers, with skunk2 pro series cams and aem adjustable gears.

The motor was running a little rough and making some valve chatter.. turns out the timing was off (crank was lined up with the middle line of three marks on the pulley rather than the single mark to the right) and some of the rockers were loose, some tight.

I adjusted the valves and then realized the timing was off and corrected the timing. Now the motor has a hellacious rattle/knock sound when I crank it up. I've disconnected the distributor and turned the motor over and no abnormal sounds, tried pull the plugs and rolling it over and nothing..

I cant imagine it all of a sudden spun a bearing because it was fine and all I did was adjust valves and fix timing.

Any ideas?

 

Is the engine seized? Do you mean you pulled the plugs and tried turning the engine over by hand?

Sounds like the timing may still be off. Pull the belt off and re do the timing belt, then set the valve lash again, it takes allot of practice to adjust the valves properly. The valves could of got tight and can make a knocking sound! Make sure your setting the lash per Skunk2's settings for Pro 1 cams. Rotate the engine with no spark plugs by hand after to make sure the engine rotates smoothly.

 

It cranks and runs, it just makes a knocking sound similar to a rod knock, but I have checked every way I can to determine a spun bearing and it doesn't seem like thats it.. it rolls over by hand with a socket wrench smooth. I fired it up last night and pulled the plug wires 1 by 1 and no change in sound other than the motor dieing down a little each disconnected wire, except Cylinder 3 is apparently not firing.

 

Drain the oil and check for metallic debris that should tell you if a bearing has spun. Did you have the cylinders bored and use oversized pistons? Are you using Pro 1's? Did you have the engine degreed for the cams you installed?

 

Check the valve lash