What should an engine sound like?

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1967 'cuda said:
I think that everyone is hesitant to assure you that there's nothing wrong. No one wants to have said it's OK and then find out that you dropped a valve or something like that later. I seriously thought it might have been a bit noisy but not to the point that I'd be panicking. But I've known guys that were amazing at picking up on problem noises that I couldn't. An inspection of your oil and a look under those valve covers would give you more re-assurance.

If you've got a stethoscope (or at least a 3 foot length of garden hose) you could listen more closely along the lengths of each valve cover. I would think that the sound should be pretty consistent all around and if you were to find a spot that was a lot noisier then maybe have more reason for concern.
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That's understandable, its hard to diagnose something over the computer anyways. The oil looked pretty good considering its a new motor. I am going to pull the valve covers off today and see how everything looks. For all I know the rockers are hitting something on the valve covers. That's not something I really checked, probably should have since I have roller rockers installed. Those M/T valve covers don't seem terribly tall anyways.

I will take something to take a listen, but from listening before I haven't been able to pinpoint a loud spot, its consistent on both sides.
 
Also to add it only makes that noise when it idles, once the RPM's go up I cant hear anything, don't know if that means anything. That would rule out lifters I would assume? I remember this old camaro that had a collapsed lifter, had an audible tic throughout the rpm range that increased with the revs.
 
I would think that rocker arm to valve cover clearance problems would not go away with more RPM, and more likely make more noise. Maybe your lash is set a little loose.
 
That's true. I will still take them off to take a look at everything though.

I originally set the valves with a 1/2 turn after zero lash. But I thought that was standard. With my rocker arms it said to turn to zero lash and go one full turn, just seemed like alot to me. But that could potentially be whats causing my issue.
 
You stated you are using roller rockers with hyd lifters. That means they are adjustable. There are many theories on correct lifter preload. You may be a little loose. Most people set them by fully bottoming them then backing off to get the least noise and best performance.
I have seen some brand lifters with 1/4" plunger travel.
 
69MOPE said:
You stated you are using roller rockers with hyd lifters. That means they are adjustable. There are many theories on correct lifter preload. You may be a little loose. Most people set them by fully bottoming them then backing off to get the least noise and best performance.
I have seen some brand lifters with 1/4" plunger travel.
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Yes I am. And that is possible, I could try tightening them up and see if the noise decreases. Is it recommended to adjust them again after cam break in? or are they usually good to do if done correctly in the first place?

And I am using comp cams lifters, not too sure what the plunger travel on them is though.
 
So I took the valve covers off, and one of the intake rocker arms was slightly loose, so at first I thought I was in the early stages of wiping my cam. I put a sharpie mark on all the pushrods to see if they were spinning, they all are, mind you some faster than others, but they all spin. Does that mean my cam is good?

And the rocker arms aren't contacting the valve covers.
 
I can only speak from personal experiences. I've built less than twenty motors throughout my life and have only seen a few cams go bad (they were on other people's motors). The lifters I'd seen were scored pretty deep to where the bottoms were cupped and they could not spin.
 
I think I heard the noise in your video. Does not sound like bottom end at all; at first it sounded to me like a loose fuel pump lever or pushrod on the pump cam. But if it is on the driver's side, that seems all wrong. Does the same sound show up by the fuel pump with a stethescope (or whatever you use for that listening)?

The next similar sound would be something tapping the underside of the valve cover.

I could not tell you what a bad roller rocker sounds like.....but a bad/funky rocker would be my next candidate for that sound. Have you checked for all rockers to be tight on the shats? All shaft bolts tight? I'd re-check all of that and for a loose adjustment. I have not had a hydraulic adjustment 'go bad' but I have re-adjusted them and found that they were not quite right the first time. Sometimes you can think you are on the heel of the lobe but not really be quite there.

And, yes, you cannot diagnose sounds well over the internet!
 
That noise showed up on both sides, I just happened to only show that side, and it very well could be the fuel pump, I've been getting wonky fuel pressure, but I just suspected that it was the gauge that was faulty, I will listen to the fuel pump to see if I can hear anything there.

So when I adjusted the valves I went 90 degrees toget to top dead center on each cylinder, and adjusted both valves at the same time, not as accurate, I will re-adjust them all by adjusting the intake when exhaust is opening and vise versa. Because I have a few that are slightly loose, and once was worse than the others. After adjusting the one it got lots quieter, the noise is there, but it's uniform on both sides. I just don't think I adjusted them right in the first place not that there is something wrong (I hope lol)

Cam is fine....I think, all the pushrods are spinning around pretty good. Is there a certain speed they should spin at? And is it bad they they spin both ways randomly? Or am I good as long as they are spinning?
 
My recollection is that mine did not all rotate the same direction.
 
Okay so I should be good there then.

So I adjusted all the valves, and then started it up, is a lot quieter. I mustn't have adjusted them right the first time, well it's all good now! Before I could hear it fairly easily, now I have to completely put my ear on the valve cover and I can only hear slight valve train noise, and it's the same on both sides.

I'm happy this is all figured out! And it was no big deal. Now I just have to fix my belt squeal! Lol
 
DartVadar said:
Okay so I should be good there then.

So I adjusted all the valves, and then started it up, is a lot quieter. I mustn't have adjusted them right the first time, well it's all good now! Before I could hear it fairly easily, now I have to completely put my ear on the valve cover and I can only hear slight valve train noise, and it's the same on both sides.

I'm happy this is all figured out! And it was no big deal. Now I just have to fix my belt squeal! Lol
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Rather safe than sorry. ;-) I'm practically a total moron compared to some of the guys on this site. They've sure saved my behind a lot. It's the main reason I decided to become a gold member. Good luck with her.
 
1967 'cuda said:
Rather safe than sorry. ;-) I'm practically a total moron compared to some of the guys on this site. They've sure saved my behind a lot. It's the main reason I decided to become a gold member. Good luck with her.
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Exactly! I just hope It is all fine! Seems to be. And I've been saved multiple times as well, don't know what I ever would have done without this site.

But about the pushrods spinning. As long as they spin that indicates that there isn't a flat cam lobe? They all are but some change direction randomly.
 
DartVadar said:
Exactly! I just hope It is all fine! Seems to be. And I've been saved multiple times as well, don't know what I ever would have done without this site.

But about the pushrods spinning. As long as they spin that indicates that there isn't a flat cam lobe? They all are but some change direction randomly.
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Although I've never intensely watched mine, My recollection is that their behavior was similar.
 
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