454 clacking
 

I just reinstalled my two freshly rebuilt 454's into my boat primed both motors and started them. The one sounds fine and oil pressure is ok.

The other motor is reading 54 lbs of pressure on a mechanical oil pressure gauge when spinning the pump with a drill and shaft. But when I start the motor its making a clacking noise. I shut the motor down fairly quickly when i heard this noise. Did I not let it run long enough or should I be looking else where? I'm an outboard guy just getting into these v-8 motors

Thank you in advance
Ray

sounds like a loose rocker arm. A friend had a 502 rebuilt recently and had a horrible clacking that sounded like all the rockers were loose. Upon teardown, we found the builder had mistakenly put 454 head gaskets in the 502 causing the sealing rings to contact the pistons.

I had both motors done at the exact same time and by the same person. I would assume (i know thats a dangerous word) that if one motor was wrong the other would be also.

If you want to take it apart, pull teh valve covers and check the lash on the rocker arms. Then prime the oil pump with a drill and make sure all the push rods are getting oil through them to the rocker arms.

Have you contacted the engine builder???? I would do that first.

You need to use the proper tool to prime the oil pump. Do them both and see what pressures you get. If they're uneven, you know where to look. It takes little effort to check the rocker clearance. Beyond that, there are many possibilities. The best advice I can think of is to have the builder looking at it. If you destroy one searching for the problem, he'll tell you to pound salt- I would.

What kind of camshafts are in these engines?

If flat tappet it may have wiped a lobe.....but hopefully not....

Also, one of the lifters may just need to pump up... Before starting it again pull the valve covers and check the lash on all the rocker arms.

Who is the builder?

If you are priming the engines with a basic "stick in the drill" type then you are just getting oil to the crank mains and probably not getting any oil yet to the lifters.....did you see any oil coming out on top of the rocker arms during your priming? When i prime a motor i use an old gutted distributor......it seals the passages properly so oil can run the full course through the engine.........i'm suspecting that either you have a loose rocker arm or the lifters dont have oil in them yet...or worse case a collapsed lifer somewhere....