Technical Tapping noise is driving me nuts !!

That's a damned clever idea!

 

I run Rhoads lifters and so does my dad, they sound like a mechanical cam when warm. You hear all 16, not one or two. Try adding some heavy oil, 20-50, it will keep them from bleeding down so fast, even hot, if it goes quite, it a good bet they are installed. You can also tell with heavy oil if the idle quality to to $hit. If once warmed up it won't idle like before, then you Rhoads lifters.

Adjusting them is like a standard lifter with 0+1/4 turn, but you have to go very slow and watch the top of the lifter for movement from the pushrod. Since the oil bleeds off, setting zero lash is by sight only, or if you have a light touch, you can spin the pushrod till you feel zero lash. You can set them with it running, but you have to have a good ear to tell when you get it right.

A true sign of Rhoads lifters is high vacuum at idle. If it pulls hard off idle with a radical cam, is also a good sign you have them. The bigger the cam, the more they "rattle". My little 250 inline six has a bigger then stock cam, and with Rhodes lifters, it still has 20" of vacuum at idle and is really smooth, with out them, the transmission mounted shifter about shook it self to death.

Joe

 

It does sound like a wrist pin to me. Again, since this is fairly close to the top end, it can be mistaken for a valve train noise. It does have a very hollow quality to it.

I looked at a slant-6 years ago that had a similar knock noise. Wound up being a rod bearing on one cylinder. Ran very nicely too, just knocked like hell. This was a motor that sat for a few years until someone woke it up.

 

Tapping noise?

I chased a noisy tappet for a month on a 355 I built and knew for a fact that I had a lifter bore right on the outer limits of being in spec. I was seriously thinking about tearing it down and bushing the lifter bores. Then one day I went to check my tranny fluid and felt hot air blowing on me. Replaced a blown header gasket and never looked back.

The reason I mention it is that you just replaced your open headers with a complete exhaust. Think about it.

 

how about removing a valve cover and with it running can you push on a rocker one at a time with a screwdriver and see if the noise changes.

 

porknbeaner, I have thought about this and agree it's a possibility. A cheap and easy place to start!

 

Exhaust leaks will also leave a greyish ash where they occur. The greasier the motor, the easier they are to see.

 

I had a rhythmic ticking from a 327 and it turned out to be a busted fuel pump lever spring.

Also had a knocking sound from the front end of a 389 Pontiac and that one turned out to be loose bolts on damper pulley.
Mike T - Prescott AZ

 

Well So Far..........
Pulled the header on the drivers side and the exhaust man didn't change the gaskets. Center gasket had separated. Cleaned things up and installed new gaskets. Tapping is still there but it sounds different! Can't wait to change out the other side.
It may not get rid of the tapping but it needed new gaskets anyway!
Now the 90° elbow from the fueline into the Edelbrock is leaking all over the manifold! It's always something isn't it?
Joe

 

Backside of old center gasket!
The paper was stuck to the head, I did not peel it apart!

 

warped manifolds

 

I don't think anything is warped, he pulled loose the headers for some fabrication and didn't replace the gaskets.

 

I contacted Jack at Rhodes lifters and sent my video.
This was his reply!

 

The gasket theory makes sense, in that the noise started right after installing the full exhaust system. You could bolt on some cast iron ram horns with a short make shift pipe and turbo mufflers to see if it is indeed an exhaust issue. Fresh gaskets with your manifolds may get the same results. Good Luck!

 

I'm going to finish up the right side tomorrow after work and see what it sounds like then!

 

Keep us up to date on it.

 

Stopped by my local speed shop and told them about changing the header gaskets and told them what I used and they said "That won't work!"
So now I'm taking home a new set of gaskets!
I still don't think it will get rid of the tap, but who knows? At least the headers will be installed correctly!

 

I had a set of headers one time on a SBF that leaked with every gasket I tried until I went with the laminated aluminum ones. They were the only ones that wouldn't burn out in a few days or leak when first installed.

 

I would start with checking the exhaust for leaks before you start tearing the whole car apart chasing it. You said it became noticeable after your new exhaust was installed. That has to be a clue. An exhaust leak can definitely sound like a tick of some sort. Unfortunately I cant listen to the noise on my work computer, but I had a noise on the right side of my engine that was driving me nuts, I pulled the Valve covers & found nothing, so I went through and retightened all the bolts on my exhaust and it went away. You could probably even spray some soapy water or cleaner around the junctions & gaskets while the exhaust is cold and look for bubbles when its running.

 

The clue here is the new exhaust system. I'll bet that a baffle has broken loose and the exhaust pulses are rattling it. Had the same problem a few years back and it took a lot of detective work to find it.

 

I had a similar sound coming out of an engine I built and got a hell of a deal on some used roller rockers and latter found out why. The bearing trunions were bad on a couple of the rockers and drove me crazy. Replaced with some comp roller tipped rockers and quiet as a mouse.lol. As had another motor that the flex plate bolts had worked loose and did that sound like crap. Thought the whole bottom end had come lose. Doug

 

Replaced the header gaskets with FelPro #1444 performance header gaskets last night. It sounds better but didn't get rid of the tapping. So I'll keep looking for the tapping source. I'm not going to tear into it until I've ruled out the easier stuff to check.
Going to buy my own stethoscope at Harbor Freight so I can spend some time listening and don't have to keep borrowing one!

 

Just chased my tail for days on something like this. Rattle, mostly on the passenger side. Pulled the cover and found three push rods with light scuffing from sharp edges on the guide plates, easy! Deburr guide plates and flip push rods, still taps. Turned it over with the starter and one valve is ticking loudly every time the spring compresses. Pull the spring and find too short a damper catching on the guide, think I got it this time, nope.

Does it worse as RPM increases so now suspect oil starvation. Try another distributor since it intersects oil to lifters on passenger side and still ticks. Finally buy a stethoscope and narrow it down to at least three, all exhaust valves. Pull the spring on the worst one and find a sloppy guide on the fresh from the machine shop heads!!! Only just broke the cam in. At least I know what's up now and can stop doubting my self.

 

Bought a used Chevy daully 454 that had a weird noise as rpms went up. My buddy heard it as he rode his gold wing next to me on the freeway. Ran great though. Pulled motor down. put it on the eng stand and heard a clink clink clink noise as we rotated the motor on an eng stand. easy find piston skirt lying in oil pan. put in a new bullet and off we went.yruhot

 

get the stethascope set up and remove that amplified thingie on the end and just use the clear tubing. Run it around the header flamge and it will tell you big time in a hurry if they are leaking. infact run it all over the place. Same therory and the garden hose but you look like a Dr. instead.lol.Also if you got the vavle cover off slide the tube down into the lifter galley while running. you'll be amazed at what you hear. Also down around the fuel pump area. A cheap thing to try. How about a broken baffle in a muffler or I was gona say a heat riser but you got headers if I remember correctly.yruhot.

 

Looks like you have a cable dipstick? I had a flatty that all of a sudden started knocking LOUDLY that I was ready to yank the top apart, and right before when it was running I pulled the dip stick to check oil and sure enough it was bent a bit and smacking the crank if put in backwards...stupid engine

 

I'm still looking! I replaced the header gaskets, all tight there.
I have been listening with the stethoscope and I'm hearing the tapping best down both sides of the intake manifold where it meets the heads. Sounds like solid lifters. I know that it has hydraulic lifters, I adjusted them! I talked to Jack Rhodes of Rhodes Lifters and sent him my videos. He believes it may have Rhoads Lifters.
So for now I'm going to go with that theory and just keep a close ear on it !!
Joe

 

I finally decided to replace my gaskets with copper,more expensive but they don't burn out as bad. HRP

 

I would love to be able to find copper header gaskets for my Y Block. Can't seem to locate any however.

 

Sold the truck, engine turned out to be junk!

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