well i finally got everything done almost as far as breaking it in goes...but everytime i start it after about 5 seconds i start hearing this big knock sound next to the front on the right side of the motor. now are you supposed to use the plastic bushing for the intermediate shaft on the oil pump if you use on of those solid steel types? i didnt use one so im wondering if that might be the problem. i held the fuel pump pushrod up with a bolt through the front on that hole to keep the rod from snapping on the fuel pump. then i used a smaller bolt so it wouldnt rub. anyone ever have this problem? i checked the valve covers to make sure they werent hitting - they checked out ok. any suggestions on what could cause that sound? a crushed lifter maybe?

 

Don't kno what it is. But it doesn't sound good. I will at least give you a push to the top..

 

Did you check and recheck all rods, mains and cylinder clearances when rebuilding? If it is coming from the front of the engine it wouldn't be the oil pump shaft making the noise. It is at the rear.

 

Try and listen using a long wood dowel or screw driver to isolate noise location...probe top of valve covers,then work down block.....you can try the fuel pump as well...

Rich

 

The metal rod that actuates the fuel pump can cause a knock. I had a new fuel pump that had a spring issue that caused a "knock", don't remember the details. I finally installed an electric fuel pump over 10/15 years ago. Also, make sure the bolt you used to retain the rod is not making contact..

 

A few years ago my 70 GMC 1500 did the same thing. I thought I had a major problem. I swapped out the fuel rod and it's been sweet ever since. I have no idea what was "wrong" with the original pump rod.
Good Luck...........44B

 

I hope it isnt dollars knocking to get out of your wallet. Hope its simple.

 

I had my ignition timed wrong with the new vibration damper I used. It was a couple of degrees after TDC and the engine produced a knock as if it had detonation.

It this is at idle, I would not suspect detonation, but check every surrounding item and then start dissassembling to get to the bottom of it.

 

well i tried listening underneath when it was idling and it sounds like its coming from somewhere in the oilpan, its a pretty low big knock...if that makes sense. im not sure if the pitch of a fuel pump pushrod would compare to this. but i guess replacing the the pump pushrod would be a lot less costly and save me a crapload of time.....now would you notice a difference in power or engine response if u had a loose rod cap or spun bearing?

 

Its real easy to drop the oil pan and pull some bearing caps. I would just do it. Good news or bad, its worth it to find the knock.

 

mine has a rather large cam in it and my knock turned out to be a flywheel that was a little loose. Do you have the knock under power or just sitting, out of gear?

 

Does it sound like a hammer hitting metal if it does don't run the engine pull the oil pan and inspect the rod bearings sounds like you may have a rod knocking once you hear this sound you will never ever forget it because it is the sound of alot of hard work.

 

You asked about the oil pump drive- if you have a steel collar, you don't need the nylon one- it's one or the other, with steel being preferred.

How's your oil pressure? Low, normal, what?

drop the pan and have a look if you can't isolate it to the fuel pump. Take the pump off, let it hang and start it. There will be enough gas in the carb to run for a couple of minutes.

 

ttt

 

It happens under idle out of gear * the sound* - cant i cut the exhaust that runs under the pan, fix the rod bearing (if it is that) and have the shop weld the pipe back on? i think first ill try the fuel pump and then if that fails ill cut eh pipe off and check the bearing caps....its more pronounced under the car then above it, but you also have the ground reflecting the sound, so im sorta confused

the oil pressure is perfect, 60 psi all the time, never waivers.

and i still am getting a little bit of smoke out the pipes, but i have CP rings, i forgot who makes them...i just know it starts with an H. ive been told the rings take longer to seat with those and forged pistons. is this true?

 

The oil smoke in the exhaust should go away- give the rings time to seat.

No reason you can't cut the pipe- there are some band clamps out there that will get you to the muffler shop.

Does your knock follow engine speed?

 

Did you re-use original oil pan? I had an aftermarket pan interfere with my non-stroker crank on a rebuild once.