HELP!!! 347 owners GET IN HERE

[twolo4u2c2]

OK.....Its been 1000 miles since my 347 install and I do have come questions about how this things sounds running. It has NO rod knock ...BUT. Its does have a slight noise that sound like a valve tap but just a tad lower in tone and towards the top end. The kicker is its only present when at part throttle with a load on the motor. I can rev it up to 5000 sitting still with no noise what so ever. Put a load on it(hearing intake turbulance) and the noise is there.. There is no metal in the oil. Looked at the oil under a play microscope( justa a big magnafying glass)very clean.. no shavings. My question is Could this be a lifter? I'v also herd of piston slap in the cylinder due to the high rod ratio in 347's. or is this normal?

 

[twolo4u2c2]

Anyone?

 

[srothfuss]

When do you hear the noise? Under acceleration or decel? How noticable is it in the cabin? Is it on 1 side of the engine or in the middle?

 

[twolo4u2c2]

I only hear it under accel. And it quiets down some when warm. I really only hear it when my conv top is down. But now that I know what to listed for I hear it all the time now.....i'm thinking lifter. My new ones werent here when I put it together to I took the original apart cleaned and reinstalled them. Might have been a bad idea. oh and the motor is stone quiet at idle.

 

[srothfuss]

Does it sound like a sticky injector..?

I am going to say that it isn't the lifter because you would hear a 'bad' lifter when the engine is cold also.

 

[twolo4u2c2]

mabey i said it wrong......Its loud under accel when cold.......and quiets down some but I can still hear it when its warm. I dont know what a sticker injector sounds like. It also increases with engine speed. I think I have a lost cause till something goes. SORRY...im fustrated.

 

[srothfuss]

It's OK to be mad... All that work and so close to perfection, but still not there... I know the feeling (not with this car yet)

A sticky injector will sould like valve tap, but the noise would only be evident when the motor is warm. It would also change with the RPM but it typically doesn't get louder.

Before we jump right to blaming the lifter... Have you tried listening to the engine with a broom stick? Take a old broom handle, cut it to ~18." You can use this 'tool' to amplify noise in your engine to help you pin point your problem...

 

[twolo4u2c2]

That will be hard. It only makes this noise when under load. Almost like a ping but constant and changes with engine speed. Sittin still at idle it so quiet besides the exhaust you would thing its not running. Thats why its so hard to find. :damnit: :damnit:

Im gona go underneith and make sure its not and exhaust leak make sure everything is tight. I just went out in the garage and started it up. on a quick blip of the throttle it seems loader on the driver side valve cover. I took a long extention and put it to my ear and its loader that the driver side. than the pass side. but unless I get a load on it it doesent make that sound. mabey an intake leak once the suction really get rollin. could that be it? I duno...Ill llok at it closer after carlise spring swap meet this weekend. Ill keep you posted......thanks for your help.