Technical Tapping noise is driving me nuts !!

I have listened to this in person, and it is definitely top end. It's something in the valve train, somewhere. I keep think the foreboding, which is a cam lobe going flat, but the engine is an older build that sat for years being assembled in the mid to late eighties, and has a fairly radical cam.

Made me think about the 15 minutes of fame that Rhoads Lifters held back then, and how they were built to purposely bleed hydraulic pressure off at idle to tame heavy cams for street use. As well as it's running other wise, and knowing the era of the build, that's still where I'm putting my money... For now.

 

Could defiantly be cam related,but is the car running poorly? HRP

 

HRP, The truck runs great! Engine runs smooth off idle, no miss, pulls strong. Tap quiets down after warmup but doesn't go away!
☆need louvers!, I did some research on the Rhodes lifters and found they do tap at idle but the problem is I think I am only hearing one......shouldn't I be hearing sixteen ?

 

Could it be a wrist pin rattle? HRP

I had a strong running 327 in my 40 sedan and on firing it up it had a loud knock but quieted down after warmup,but it didn't go away.

I drove it for several years like that but eventually tore the engine down and discovered a bad wrist pin this is when we figured out my problem. HRP

 

Joe, when I was listening, I heard it all across the top end rather than isolated to one section of it. That's what made me think of the Rhoads lifters, especially after you told me the era of the engine build. If it truly was isolated to one or two cylinders, then I would go back to my original thought of a lobe flattening out, although the cam I pulled from the Plymouth years ago was impressively flat all across, considering it was a well over .500 lift cam when new.

 

That certainly is a loud noise ! I can't believe you couldn't hear it even with open headers . I'm with the rest about looking for it with a hose to the ear or a hose-type stethoscope . Sounds like upper-end to me .

 

My pal Dave experienced a cam problem were the lobs were damaged due to the lifters and in his case the engine ran like crap. HRP

 

I keep thinking about not hearing it with the open headers and the noise appearing with the new exhaust. (?)
Could an exhaust header leak sound like it's coming from the top center?

 

I tend to agree with HRP but can't tell much from the video. Wife's 55 had a loud knock and would quiet some when warm. She drove it everyday like that for a few yrs. and ran it a Sears Pt regularly. When we redid it --it was a bad wrist pin/piston on #6=Hot 327 (L79) and ran very well even with the noise.

 

Funny (ironic) the bad wrist pin on my 327 was also # 6. HRP

 

Cam is ground from billet, would that make a difference?
Found the guy who ground it for Babe Erson Cams.
Steve Long of Steve Long Racing Cams.

 

Bent pushrod? BTW, is the dist gear made to go against your billet cam? Nice pickup!

 

Here is one similar:
A rod knock can be diagnosed by pulling the spark plug wires one by one and listening to the change in engine noise at each cylinder.
^
1. exhaust header gasket leak
2. rocker arm to valve retainer interference
3. lifter loose in its bore
4. center camshaft bearing worn-gone-damaged
5. excessive crankshaft end play
6. excessive cam walk
7. fuel pump knock (travels through the cam)
8. crank hitting the windage tray
9. crank hitting the dipstick tube
10. crank hitting the side of the oil pan (bent)

 

Ricks Garage...Love the Video !

 

Yes the billet cam drives the distributor.

 

quick way to find a exhaust leak to eliminate that as noise is feed some ATF into the carb and look for smoke in places other than the tailpipe plus it will knock carbon off valves which can cause a knocking noise. all the advice given is solid and should net good results!

 

That's no tappet, its piston speed, wrist pin??

 

I had a similar noise in a hipo 289, ran like a sob. Pulled it apart and found a cracked piston skirt. . Hope you find it before it really makes a mess of something.

 

I keep thinking about not hearing it with the open headers and the noise appearing with the new exhaust. (?)
Could an exhaust header leak sound like it's coming from the top center?
Any ideas on this?
Sounds awful metalicie for an exhaust leak! (?)

 

Yes.

 

You might narrow things down a bit by pulling one spark plug wire at at time with the engine idling. Listen to hear if the of the noise changes or goes away. If things quiet down note which cylinder you have unplugged. This won't help much if it's a valvetrain noise, but it might lead you to a specific cylinder if it's something like a bearing knock or a cracked or collapsed piston skirt.

Also run the engine briefly with all the accessory belts removed, one at a time if there's two or more to eliminate things like a cracked pulley or fan blade. Try the same approach with the torque converter unbolted and pushed back as far as possible into the transmission pump. And take a good look inside the bellhousing for signs of any funny business going on in there.

 

Thanks for all the tips and things to look for! I will keep this post updated as I check off the list! For right now I'm going to say: "It has Rhodes Lifters! "

 

I had a guy with a SBC.... Knocking like that.... Terribly ... The noise did speed up and wasn't consistent. We checked for a cracked Flex plate, wrist pin noise, lifter noise-adjustment, rocker studs, had a billet cam, check for right distributor gear (bronze), it ended up being a front (chrome) cover seal.... Never seen or heard anything like that before. The hose or screw driver against your ear trick works.. Keep us posted...Good Luck!

 

I was faced with a similar situation. It wound up being a piece if the valve guide that broke off and embedded into the piston and was slapping against the head. Here's the thread, it a long read but somewhat interesting.
http://www.jalopyjournal.com/forum/...just-developed-ticking-knocking.928151/page-6


Posted using the Full Custom H.A.M.B. App!

 

I read that, Thanks!
Sounds like you went through Hell to find your engine problem!

 

Having heard this in person, I can tell you that it isn't as "heavy" as it sounds on the video. It sounds like a light staccato tapping like you would hear coming from a mechanical tappet cam. I am convinced that it's not bottom end stuff. I'm damn near convinced that it's some type of variable pump up type lifter, such as the afore mentioned Rhoads lifters. This is true Especially after the cam specs Joe was talking about. He has drained the oil out of it recently, and it showed no signs of metal wear, which kinda kills the tappets going flat deal too.

 

Yes, The mic on my smart phone really "enhances" the tapping sound and volume!

 

Expanding on need louvers? theory of the possibility of having Rhodes Lifters.
Does anyone have experience with Rhodes Lifters?
Is anyone presently running them?

 

If it were me I would probably be inclined to get into the engine and change out the cam and lifters once it was determined that it is not an exhaust leak.
Maybe you could get by with a lifter change however cam and lifters usually wear in together. ( I think )

 

Messy as it seems.. sprinkle liberal amounts of talcum powder around the header flanges while it's running, you'll find the smallest exhaust leak right away.