300ex engine knocking

[scott58976]

ok i got a problem i dont know if it is a big problem or not though.....i just put together my engine andi fired it up to break it in and it sounds awsome except for a very load knocking noise. i have no idea what it is and my pipe got hot really fast like i didnt even run it for 30 seconds and it was too hot to even touch really quick.....and the knocking noise is coming right where the valves are... the only thing i can think of is that when i put the stock head gasket on i had it bored .080 over so it stuck over the edges a lil could the piston be hitting that metal gasket??? PLease help me! thanks alot

[Cody_300ex]

Where is it coming from? Put the piston in backwards?

[scott58976]

it sounds like it is coming from where the valves are and it has a real ping too it if u listen really closly

[scott58976]

i put the piston in with arrow facing to the front of the engine

[olschoolATC]

Make sure that the Oil filter is in correctly. Putting it in backward will cause NO OIL to get to the top end. It is actually a common mistake, I'm told.

[scott58976]

no the oil filter is in right......what else could it be??

[WildWestRacing]

Sounds like your valve lash may be incorrect or the rocker arm shaft could be worn and causing the noise. If the engine didnt make this noise before you rebuilt it then I would have to go with the valve lash assuming everything else is installed correctly.


Bill

[scott58976]

whats a valve lash?

[james7734]

Valve lash is the clearance between your valves and the rocker arms. Otherwise known as valve adjustment. If it is off you will get a loud tapping from the top end of your motor. You can do it yourself, there is an article on this web site on how to do it. Stock setting for a 300ex is .004 of an inch. If you do not want to do it, you can have your dealer do it. When I had my dealer quote me, they quoted me $55 for one adjustment. So, I did what every self respecting builder does, I did it myself. It is like a 20 minute job and you can do it with the motor in or out of the frame. Anyway, let me know how you make out.

[scott58976]

oh yeah i already ajusted them and it still made that noise so then i ajusted the rocker arms to set right up against the springs so it wouldnt ave any gap between and it still had the loud knocking noise

[ltl666devil]

make sure it timed right cause if its one tooth off it will make ure vavles hit the top of the piston. i had that problem

[Cody_300ex]

Aftermarket cam?