Engine knock

[B-Mann]

Hey guys just looking for some experienced imput. My 72 Cutlass has a 350 Rocket with a 4 bbl edelberock carb, It had a bad miss and i changed all the plugs wires and dist cap and rotor, that helped the miss but I now hear a slight knock while ildling and if you rev it up obviously the knock gets worse. Just wondering if I should pull the engine or is there something else i should check first? Hopefully this won't be an exspensive fix. Thanks again guys i'm new to all of this i have always had a newer car and I look to you guys and friends for advise but I want to learn.

[Yellowstatue]

If the knock sounds like it is down deep in the engine it could be a rod, but if is a softer tick it might be a lifter...does it come from one side of the engine or the other...remove the rocker cover from the noisy side and push or pull on the rocker arm when it is idling and see if it is a lifter...if so then removal of the intake is required to change lifter...better to change all 16 at once or it could be a damaged rocker arm in which case change the damaged one, inspect the others and drive away

[ricdiculus]

Here's a neat little trick for ya. Take a long socket wrench extension, place one end against the oil pan and the other against your ear. Think stethascope, (think i wish i could spell!) You will be amazed at how usefull this can be. next try placing it on the valve cover roughly over each rocker assembly. If you have any internals making any noise, you'll find it ( as i guess you relize, the engine should be running for these tests ) By the way, You have checked your timming right? If its too advanced it can cause some serious knocking.

[B-Mann]

My dad actually used a hose and did that he heard the loudest coming from the bottom on the drivers side of the engine. How easy is it to replace the rods and does that require pulling the engine. i know this all probally sounds funny but like I said i'm trying to learn. Thanks

[B-Mann]

Also my car didn't have an dust cover over the flywheel and I now have bought one but need to know what size bolts to get to install. Does anyone have this info? Thanks again.

[ricdiculus]

Well if you've got a bottom end knock, the right way to fix it would be to pull the engine. You may have got lucky and caught it befor it damaged the crank, but if not you will need to get it turned most likley. If any of the journals on the crank have been scored the will destroy a new bearing quickly if you dont get it turned.(use a lathe to return the journal surfaces to new condition.) That being said, I've seen a buddy of mine pull the oil pan of a chevy 350, use a little emery cloth to polish up the journal with the bad rod bearing, install a fresh bearing, and drove it for another 5000 miles before he sold it, still running. All this was done while the engine was still in a van. The problem with this fix is that you have no control over the journals size. which means, the new bearing may now be a little lose scince some material was removed from the crank, but not enough to use a undersized bearing. when the crank is turned, not only do you get a fresh surface for the bearing to ride on, but enough material has been removed to goto a resized bearing, usually 0.010 under, so that you maintain proper clearance between the bearing and the crank.

[Yellowstatue]

Originally Posted by B-Mann

Also my car didn't have an dust cover over the flywheel and I now have bought one but need to know what size bolts to get to install. Does anyone have this info? Thanks again.

The bolts for that flywheel cover are 1/4 X 20 X 1/2 inch long, I have seen some people use 1/4 inch sheet metal screws there...try one of each in the hole to see which screws in more easily...