Lifter noise

How much lifter noise is acceptable in a recently rebuilt 340? The engine was done to stock specs. First I had a lifter clicking on the left side, they replaced an alleged "short " pushrod and the noise stopped. Couple months later a lifter on the right side side starts making noise. All the lifters are replaced with no improvement. Builder suggests I get some of thse "thick" aluminum valve covers instead of the stamped steel ones. I think the cam was damaged during break in. Now there are multiple clicking lifters. I,ve had other engines with hydraulic lifters and no noise at all. Should there be no valve train noise at all? Thats what I think.

ya hydrallics should be quiet, so I agree, somethings wrong....

Thanks for the reply, I knew I had a problem, just wanted some confirmation. Been 30 years since I rebuilt an engine so I wanted a second opinion.

Check the rocker shaft orientation. They have notches in the ends. The notches go DOWN towards the head. One on the passenger side should have the notch down and to the REAR and the driver's side should be down and to the front. If they are not located properly, the rockers, shafts valve tips and springs will not see oil and all wear prematurely.

Thanks, will do.

mcgowang said:

How much lifter noise is acceptable in a recently rebuilt 340? The engine was done to stock specs. First I had a lifter clicking on the left side, they replaced an alleged "short " pushrod and the noise stopped. Couple months later a lifter on the right side side starts making noise. All the lifters are replaced with no improvement. Builder suggests I get some of thse "thick" aluminum valve covers instead of the stamped steel ones. I think the cam was damaged during break in. Now there are multiple clicking lifters. I,ve had other engines with hydraulic lifters and no noise at all. Should there be no valve train noise at all? Thats what I think.

Click to expand...

What's the Cam & Spec's....??????

Rickster

It's a Melling stock 340 cam, 429/444 lift. Talked to the machine shop today and we're goin to pull the engine and replace the cam if needed.

mcgowang said:

It's a Melling stock 340 cam, 429/444 lift. Talked to the machine shop today and we're goin to pull the engine and replace the cam if needed.

Click to expand...

I don't think your cam is the problem. There are other things that you should check first.

If you are going to pull the engine, I would go through it and make sure all of the oil galley plugs are there. I had a 340 that was rebuilt and the machine shop left out two of the oil galley plugs. After the fourth engine pull, I finally found the missing ones were the two behind the camshaft thrust plate. Nobody thinks to remove that and check for those. I always double check to make sure the oil galley plugs are in.

Also check to make sure none of your oil galley passages are blocked. An old wire coat hanger is good for this (remove the polished parts first so as not to scratch/damage the polished surfaces). The oil goes from the main bearings, throught the main bearing bulkheads to the camshaft, then up throught the head deck, through the head and then up to the rocker arms.

Pull the crank and make sure that all of the top bearing shells have the oil hole and that the holes are lined up with the ones in the block. Stick the wire coat hanger in all of the main bearing bulk head holes and make sure it is clear through to the camshaft bearings. Make sure that the camshaft bearings are properly installed and that the oil holes are lined up. They should not be more than 50% overlapped. If the coat hanger goes up to the camshaft tunnel, then you should be ok. Next check the oil passages to the head the same way. Stick the coat hanger through from the head face to the cam tunnel and make sure that the coat hanger goes through without any obstruction. Then check the holes on the head from the block face and make sure that the coat hanger goes through to the elongated holes on the rocker shaft without obstruction. When sticking the coat hanger through the camshaft holes, be careful and gentle so you don't scratch the cam bearings. I would say to make sure that all of the cam bearing holes are properly aligned and that the cam bearings do not block or overlap the holes. This is what feeds oil to the lifters. Then follow/trace the holes up through the head and to the rocker shaft holes.

Take your time and make sure that you check every oil passage hole that you can, and all of your galley plugs.

Good luck and let us know what you find.

Thanks again, engine won't be pulled unless no other option. I'll be taking your notes with me. This shop has been in business since 1960, so I'm hopeful it will get fixed.