Is this noise normal?

[digadam]

Hi there all,
I’ve slowly been getting things improved on the Mach 1. It has 351c 4 V.  I recently had brand new custom headers and exhaust installed, new push rods and gauge plates. It has a solid cam and solid lifters and my mechanic assures me he has the lash set correctly and that this “sewing machine “ sound is normal. He’s a bit deaf though.  What do you think? Is the tapping sound normal?  Thanks. Adam

https://youtu.be/p1-7N4FDf1o

[1969_Mach1]

Before chasing valvetrain noise it sounds like you have a bad exhaust leak or loose spark plug.  If it's an exhaust leak it sounds like it's from one or two ports at the cylinder head(s).  If you don't have a mechanics stethoscope get a length of vacuum hose or fuel hose.  Hold one end to your ear and move the other end around each exhaust port and anywhere exhaust can possibly leak.  Also check around the intake manifold at the gasket area about in the middle on each side because there is an exhaust crossover passage in that area.  You will probably find an exhaust leak somewhere.  Then it's a matter of fixing it.  I've had good luck with Mr. Gasket exhaust header gaskets but Remflex header gaskets are supposed to be about the best available.  https://www.summitracing.com/search/bran...-cleveland

[digadam]

Before chasing valvetrain noise it sounds like you have a bad exhaust leak or loose spark plug.  If it's an exhaust leak it sounds like it's from one or two ports at the cylinder head(s).  If you don't have a mechanics stethoscope get a length of vacuum hose or fuel hose.  Hold one end to your ear and move the other end around each exhaust port and anywhere exhaust can possibly leak.  Also check around the intake manifold at the gasket area about in the middle on each side because there is an exhaust crossover passage in that area.  You will probably find an exhaust leak somewhere.  Then it's a matter of fixing it.  I've had good luck with Mr. Gasket exhaust header gaskets but Remflex header gaskets are supposed to be about the best available.  https://www.summitracing.com/search/bran...-cleveland

Thanks for that. I was ruling out exhaust leak because only the week before I had an exhaust shop put on completely new custom made headers and I assumed that would be ok. The previous headers leaked bad.

[JTS71 Mach1]

Yeah I agree with 69 Mach1, it most definitely sounds like you have one, if not a couple exhaust leaks. Those must be addressed first, as already stated. There's no way to tell if you have valve train noise, with all that extra noise going on. Good gaskets, and maybe some locking header bolts like Stage 8. Should cure the exhaust leaks. Good Luck, and let us know if that helps??? 

JTS

[digadam]

Yeah I agree with 69 Mach1, it most definitely sounds like you have one, if not a couple exhaust leaks. Those must be addressed first, as already stated. There's no way to tell if you have valve train noise, with all that extra noise going on. Good gaskets, and maybe some locking header bolts like Stage 8. Should cure the exhaust leaks. Good Luck, and let us know if that helps??? 

JTS

Thanks very much. I’ll be taking it straight back to the exhaust shop this week. Not happy. Only just had a brand new custom header system put on a week ago. You’d think he’d do it right for the price I paid.

[JTS71 Mach1]

You know, I was thinking about what you posted. The fact that you had "custom headers" built. It could be that the header flange, the part that bolts to the head, has warped from the welding process, and is causing poor sealing against the head. I was thinking of this because I just completed a set of custom headers for my "Jacobra". Do a search for Jacobra, and you'll find the thread, and you'll see what I'm talking about, I wanted to attach them to the engine to weld them but I found that near impossible, they're pretty rough looking but functional. I 'am sure the
flange probably warped due to the welding, so I will take them to my friend Joe at the machine shop, and have the flange planed flat, to remove any warpage. Just might be what you'll need to do??? Hope it helps. 

JTS

[1969_Mach1]

I'm surprised whoever did that exhaust work let you pick it up like that.  After it's fixed keep in mind the gaskets will relax a bit so the header bolts will need to be snugged up a couple of times.  If you don't follow up doing that, more exhaust leaks sometimes occur.  After that, once in a while, two or three times a year quickly go over them to make certain they are all tight.

The stage 8 locking bolts JTS mentioned are supposed to work good to stop bolts from backing out.  I've never tried them.  I've had good luck with Mr. Gasket header bolt lock washers.  You usually need about 1/4" longer header bolts when using the lock washers as they are very thick.


FYI, if you have a situation where you cannot get a socket or the box end of a wrench on a header bolt, ARP makes header bolts with reduced hex or 12 pt. head sizes to work around that problem.

[Steven Harris]

I hope that by now you have been able to get that exhaust leak fixed and are well pleased with the true sound of your motor and exhaust.

I also noticed that you do not have your vacuum advanced hooked up.  You will need to address that so that the motor runs as it should.

[digadam]

I hope that by now you have been able to get that exhaust leak fixed and are well pleased with the true sound of your motor and exhaust.

I also noticed that you do not have your vacuum advanced hooked up.  You will need to address that so that the motor runs as it should.

Hi everyone. Thanks so far. A quick update. Went back to the exhaust shop. Definitely not leak. So I dropped into an old school mechanic around the corner and he will look at it properly in a couple of weeks as he is too busy this week but he thinks it’s rear passenger side lifter or rocker. Will let you know in a couple of weeks. I’m not much of a mechanic and never lifted valve covers myself so probably should just the experts to do it.

Btw what is the vacuum advance?

[1969_Mach1]

From the video it sounded more like an exhaust leak.  But I guess that's not what it was.  If you find a valve adjustment extremely loose for no apparent reason, what kind of oil are you using?  It should be something with a high zinc (ZDDP) content for cars with flat tappet cams.  With the wrong oil, I have seen a few times a cam lobe or lifter get worn down and ruined.