Nailhead Lifter Noise

**mottrodder** · 03-07-2006, 04:43 PM

I'll defer your questions about having the proper pushrods and rockers, and what the oil passages should look like to others who have more knowledge and experience than I do. My questions to you are, Have you checked to make sure the tapping noise is coming from the valve train? Have you used a screw driver, heater hose, or stethoscope to isolate the noise? I have heard of fuel pumps tapping and the valve train being blamed. Since you have "been into" the valve train and the noise still exists, I would at least check elsewhere before doing more valve train work. Have the heads had a valve job? Grinding the valves and seats, resurfacing the heads or block, using a different thickness head gasket can affect lifter preload and cause a problem. Lifter noise can be caused from both too much or too little clearance. Posting your findings will be appreciated. Good luck

**64RIV** · 03-24-2006, 06:41 PM

Conroy,
Are you making any headway with your tapping problem?
I was following your thread as I have a similar problem with my 425.
I posted my attempts to remedy my problem back in Sept of last year. I also went down your path of cleaning and flushing all the guck out of all the nooks and crannies. Nothing worked, tapping was still there. The tapping was annoying but other than that, the car ran great. I finally bit the bullet as suggested and pulled the heads for a rebuild. But once the heads were off I still didn't see anything obvious. Took the heads to the machine shop and the machinist said the valve stem and guide were a little worn but didn't think that it was bad enough to cause the tapping. He couldn't see anything else wrong. Since I was this far into it I told him to go ahead with the rebuild anyway. Bought a complete set of gaskets and decided that since I had the engine torn down to this extent I may as well pull the oil pan and clean it out while waiting for the heads to be done. The pan had a thick layer of sludge on the bottom and buried under the sludge I found pieces of broken piston. I climbed under with a flashlight and found that the piston skirt was broken off the piston of the tapping cylinder. All along I was convinced it was a valve tapping problem. I'm still not sure why this would cause the noise I heard or what would even cause it to break off in the first place. I'm just a novice mechanic myself. Maybe someone else can chime in and explain. But my guess on the noise is that with the reduced piston height, the piston has more of a tendency to **** in the cylinder on combustion and smack the cylinder wall? Maybe the cylinder is worn to the extent that this smacking fatigued the piston and broke the skirt off in the first place?

The next day I climbed back under and took a closer look and found yet another piston with ~3/8" crack but it was still intact. At this point I don't think I have any choice but to get a complete rebuild $$$. Hopefully this is not your problem but figure I would pass it on just in case. You may want to seriously consider looking in the pan. I hate to think what could have happened if I didn't and just slapped the heads back on fat dumb and happy.

Best of luck

Jim

**conroy** · 03-29-2006, 06:19 PM

Jim, thanks for your suggestions. Although I have not resumed working on my engine, I am hopeful to take a few days off next week to take advantage of the nice weather. Was your tapping noise constant or did it fluctuate and come and go? I hope mine is not a piston problem. I am hopeful that I find the problem when I remove the valley cover and check out the lifters. So far I have done a lot of cleaning of the valve train without knowing if it is making any difference. It certainly needed cleaning. I have decided to remove the oil pan and clean it along with the pick-up screen. It only makes sense to do that. I am anxious to get started. Cruise nights are fast approaching and I am looking forward to doing some short trips to area cruise-ins without that annoying tapping. I will let everyone know my progress as I go.

**64RIV** · 04-01-2006, 07:44 PM

Conroy,

The tapping was always there but was most noticeable at idle. Under load, it was barely detectable.

I just pulled the engine and dropped it off for a rebuild last week. Hopefully will have everything back together and ready to go in 3-4 weeks. Looking forward to cruisin as well.

Take care.

Jim

**conroy** · 04-17-2006, 11:56 AM

Looking at my first post this certainly seems like a long road. I took the week off starting today. The weather has been pretty nice so I can work on the car with the garage door open. Since my last post I have finished cleaning up the valves and springs. While I had the springs removed I installed valve stem seals on the intakes. I removed the valley cover and have removed half of the lifters. One lifter that was in the area where I detected the most lifter noise was substantially more worn than the others. The cam must have really been pounding it. All of the lifters were full of crud. I don't really know how there was any oil flow into the lifters. There are so many other things you find to fix along the way. I removed the water outlet to replace the thermostat. Naturally both bolts twisted off. I have them drilled and tapped and ready to put back. Even though I thought I had been checking the condition of hoses, I found a couple of accidents waiting to happen. So, I removed all of the heater, radiator, and fuel hoses for replacement. I am cleaning everything within reach to repaint the visible part of the engine, brackets, accessories, etc. I have been taking lots of photos along the way. For a novice, I sometimes stand back and say, "My God, what have I gotten into". But I'll take it one step at a time, and I will get there.

**Groundhog180** · 04-17-2006, 05:38 PM

Hi Conroy,It is good to see you have resumed work.I wanted to tell you what was found on my motor to prevent you from the same mis-fortune.
The machinist ground the exhaust seats good on the drivers side head.On the passenger head,he shorted me 2-3/32 on the exhaust seats,He did not apparantly bother to check his work!
I got spec's for the "free height" measurement from a machinist that is well known around here.This is from the spring seat(springs removed) to the top of the stem,valve closed.For a 1958 head it is 1.970-2.000.Being under means either the spring retainer is hitting the top of the guide or the inner spring binds.Once that lifter pumps up,the pushrod and rocker are history.
If you end up getting your heads redone,get someone good and double check his work afterward.
I have another head to put on until the day this one can get straightened out.I too learned alot.I'll let you know again when it is running.
Looking forward to following your story.I wish you well.

Lee Gathers

**32-67S** · 05-08-2006, 02:47 AM

Originally Posted by 64RIV

Conroy,

The tapping was always there but was most noticeable at idle. Under load, it was barely detectable.

I just pulled the engine and dropped it off for a rebuild last week. Hopefully will have everything back together and ready to go in 3-4 weeks. Looking forward to cruisin as well.

Take care.

Jim

Jim, do you have a cost to rebuild the complete engine? I have just purchased a 425 LX to go in my Riviera GS (that currently has a LT engine in it) and was wondering what you spent or expect to spend. Any body else have a comment regarding rebuild cost? I know it varies depending on parts reused, engine bored or not, crank turned or not, new pistons etc., I am assuming a valve job etc. I know what a Corvette small block recently cost me and it was an arm, a leg and half my rear end !

Thanks in advance for the input,

Chuck Nixon

**64RIV** · 05-10-2006, 06:41 PM

Chuck

I was a bit over optimistic about my estimate to complete. Still not done so I can't give you a final cost yet. But to this point I have ~$500 labor and ~$600 parts. One thing I found out is that the parts for this engine are expensive relative to others, and not easy to come by. Will give you a final cost when I am done. FWIW eBay has rebuild kits from Maddog starting from ~$900 to $+++. Got a gasket set from them. Price seemed reasonable.

Best of luck,
Jim

**64RIV** · 06-04-2006, 04:59 PM

Ok, as promised here is the final (I hope) cost. ~$1800

New:
Pistons (40 over)
Rings
Lifters
Oil pump
Valves
Springs
Gaskets
Main bearings (expensive)

Cam
Cam bearings
Rod bearings
Cam sprocket
Timing chain
Balance
Hot tank
Valve guides/replacement
Water pump housing stripped bolt holes, helicoils
???...

Break down ~ $1100 Parts, $700 Labor

More than I originally expected, $$$$$$$, but now its new.
whew

**conroy** · 06-07-2006, 07:43 PM

Jim, I appreciate having an idea on a total rebuild too. Getting back to the original thread, I have finished disassembling all of the accessories from my engine. I have degreased it and have one coat of primer and one coat of POR engine paint on it. I am painting it in place, getting at all the visible nooks and crannies. Just before I put the valley pan back on for painting, I will install new lifters and push rods. I have two sets of valve springs to remove yet, to clean up and install valve stem seals on. I still need to lift the engine to remove the oil pan to check the pickup screen and clean the pan before I paint it and reinstall with a new gasket. I still have not gotten an answer on what steps I need to take to lift the engine for pan removal. Can you help me? I have posted this question here and on the ROA message board, with no detailed response. I know the center link on the tie rod has to go, and the engine and tranny mounts have to be unbolted. What about exhaust or any other thing before I bolt an engine lift onto the intake manifold mounting holes?