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-   -   Does this engine sound healthy? (https://67-72chevytrucks.com/vboard/showthread.php?t=843817)

guyryan100 04-16-2023 08:16 PM

Does this engine sound healthy?
 
Take a listen here:
https://youtube.com/shorts/sxIUvKSwWdM

This is a standard 350 crate engine. It's warmed up and idling at 850 RPMs. Timing is advanced to 34 at 2500 PRMs. There is wind noise into the camera when I go to the driver side, but you can get the gist of the engine sound from the first half of the video.

The engine sounds loud to me, not from the exhaust but from up front. Does this sound like it should, do you think?

Ryan

RustyPile 04-16-2023 08:43 PM

Re: Does this engine sound healthy?
 
That irregular clicking noise sounds like leaking header gaskets.. How's the oil pressure. If the "clicks were more rhythmical , I'd think the valve lifters need adjusting..

Steeveedee 04-16-2023 09:29 PM

Re: Does this engine sound healthy?
 
Leaking headers for sure (and maybe some metallic clinking of rockers?). Fixing the gaskets would be first.

72SB 04-16-2023 09:31 PM

Re: Does this engine sound healthy?
 
Assuming you have oil pressure....

Sounds like lifter noise but #2 the ash color at header/head sounds like exhaust leak there.

Use a long piece of heater hose run along header flange listening to other end of hose. You will hear a leak if there is one

Might want to check/do a valve lash

guyryan100 04-16-2023 10:29 PM

Re: Does this engine sound healthy?
 
Thanks all, oil pressure is steady at 50. I do have new gaskets, will change those out first.

Getter-Done 04-16-2023 10:55 PM

Re: Does this engine sound healthy?
 
A stethoscope would narrow down your noise.

Start with valve covers then oil pan and don't rule out the fuel pump.

Link to stethoscope: https://www.amazon.com/Lisle-52750-S...1699849&sr=8-3

Warrens69GMC 04-17-2023 12:40 AM

Re: Does this engine sound healthy?
 
Sounds like my 350 before I had the valves adjusted

Grumpy old man 04-17-2023 10:09 AM

Re: Does this engine sound healthy?
 
What oil are you using in it ? Sounds like valve noise to me . :chevy:

guyryan100 04-22-2023 04:29 PM

Re: Does this engine sound healthy?
 
Oil is 10W30 with about 50 miles on it, Valvoline brand I think. 50 psi of oil pressure.

I took one valve cover off and there is tons of lash on the #8 intake valve. I did not rotate the engine into any particular position.

I believe:
* This rod should never be loose regardless of position, and
* I can tighten this one down to zero lash, turn the engine over, tighten again if its loose, and ultimately add 1/2 - 3/4 turn to put it under load all without knowing the cam position or needing to put the engine in any particular position.

If that's true, I'll tighten it down per all the valve adjustment videos I've been watching.

The other rods on this side are all tight and tunable except #8 exhaust and #2 intake, both of which are tighter such that they cannot be turned.

Here is a video which also shows what oil I have on the rockers after taking the cover off.


Does all this sound right?

72SB 04-22-2023 04:39 PM

Re: Does this engine sound healthy?
 
is your motor a flat tappet or full hydraulic cam motor?

If the former, are you using a high zinc content oil?

I assume you know how to lash/adjust valves. You need to be on the base circle of cam for the particular valve you are lashing.

assuming your valves were lashed correctly and one gets as lose as the one in video, the lifter could be collapsed

If you have a flat tappet cam motor and did not use high zinc content oil then you wiped a cam lobe(s)

MySons68C20 04-22-2023 04:59 PM

Re: Does this engine sound healthy?
 
Judging by the rocker stud thread exposure which should be close to the same it looks like a flat lobe to me.....cut open the oil filter and check for metal.
If it is just out of adjustment it could be a loose rocker stud nut backing out.

guyryan100 04-22-2023 05:14 PM

Re: Does this engine sound healthy?
 
Its a basic crate motor circa 2003, my understanding is it would be unlikely not to have hydraulic lifters in that year?

Grumpy old man 04-22-2023 05:19 PM

Re: Does this engine sound healthy?
 
Is this the same crate motor installed 20 years ago ? How many miles ?

guyryan100 04-22-2023 05:20 PM

Re: Does this engine sound healthy?
 
Yes it is, has about 550 miles on it.

GSP7 04-22-2023 05:21 PM

Re: Does this engine sound healthy?
 
No


.

Grumpy old man 04-22-2023 05:49 PM

Re: Does this engine sound healthy?
 
How long have you run it before you took the first video ? whens the last time you've run it before ? up to operating temp ? :smoke:

Before I'd start tearing into it / adjusting anything I'd do an oil change and cut open the filter , check for metal , Your in Ga so using an oil like Castrol classic 20/50 Is my preference and a Wix filter . I would'nt run it until thats done .

guyryan100 04-22-2023 05:55 PM

Re: Does this engine sound healthy?
 
Before the first video it had run about a minute. Since that first video I've only moved it out of the garage and back in once, and have not started it in several days. The second video was from this afternoon and I did not run the engine at all today or in the few days prior.

guyryan100 04-22-2023 05:56 PM

Re: Does this engine sound healthy?
 
... and its gone on a lot of 20 minute errands in the days before the first video including highway speeds.

guyryan100 04-22-2023 07:41 PM

Re: Does this engine sound healthy?
 
The amount of lash was about 1/8", and must have been on the low part of the cam because the exhaust valve for cyl 8 was open.

I just rotated the engine one click, and the rod came up and opened the intake valve. I don't know if it opened it fully but I just mean it put the rod under a load. All the other rods are still tight. I rotated it a bit more and it closed that valve and the same rod is loose.

I will check the oil, I guess if I took off the intake I could get a good view of the lifter.

guyryan100 04-22-2023 07:54 PM

Re: Does this engine sound healthy?
 
Using Allen wrenches as a poor man's feeler gauge, the amount of lash is 7/64", or about 0.11".

And I believe the rocker stud for this valve is a bit higher than the others. Its hard to photograph but when I put a straight edge across the top of the rockers, the gap between the straight edge and the top of the stud is definitely less on this rocker.

Getter-Done 04-22-2023 09:53 PM

Re: Does this engine sound healthy?
 
Quote:

Originally Posted by guyryan100 (Post 9198599)
Using Allen wrenches as a poor man's feeler gauge, the amount of lash is 7/64", or about 0.11".

And I believe the rocker stud for this valve is a bit higher than the others. Its hard to photograph but when I put a straight edge across the top of the rockers, the gap between the straight edge and the top of the stud is definitely less on this rocker.

From this info.

It sounds like the Press in stud has back-out.

Screw in studs are an Option.

Take your time and find the Exact issue.

Ironangel 04-24-2023 11:21 AM

Re: Does this engine sound healthy?
 
Use the EOIC (Exhaust Opening, Intake Closing) to adjust the valves. When the exhaust valve begins opening, adjust the intake valve lash. (zero lash plus 1/2 turn of the nut) When the intake valve is closing, adjust the exhaust valve, same method. follow the EOIC method all the way through the firing order. I find this other 90 degree method easier a faster, Find TDC on your balancer, using the TDC line or timing mark on the balancer as 12 oclock, rotate the motor 90 degrees and mark the balancer, rotate another 1/4 turn (90 degrees) and make another mark. Rotate another 1/4 turn and mark the balancer for four equal spaced marks representing 90 degrees of the crank. At TDC you can adjust both valves on #1 cylinder. Rotate another 1/4 turn and adjust both cylinder 8 valves. Another 1/4 turn and adjust both #4 valves, you'll rotate the crank twice to complete the firing order. Dont use the spin method on the push rods, your looking for the point where the rod no longer moves up and down, thats zero lash. Add 1/2 turn and your golden! The valves/lifters must be on the base circle of the cam to adjust them correctly. When the intake closes at TDC both the intake and the exhaust valves are closed and on the base circle for the power stroke. Then the exhaust valve will open and by then you have rotated the crank 1/4 turn and should be on the next set of valves in the firing order. 18436572 Most new balancers have the 90 degree lines already on them, the older balancers need to be marked...Hope this makes sense to you...;) PS. I heard rockers clicking in the video, the second video showed a loose lash that was likely missed during the initial valve setting. Look for flec in the oil and check the tops of the studs with the straight edge, a high stud is a problem...

68 P.O.S. 04-24-2023 12:29 PM

Re: Does this engine sound healthy?
 
This is my favorite method: https://www.youtube.com/watch?v=5EGlb_VpTAw

guyryan100 04-25-2023 07:55 PM

Re: Does this engine sound healthy?
 
I took 2 rockers off today to get exact measurements.

The problem valve's rocker stud is indeed pulled out 1/8" which is the same amount as the excess lash.

I know I could remove the head, remove the stud, and tap for a screw in stud.

Or I could just put it back together and see if it gets worse.

Or I could carefully hammer the stud back down and then put it back together and monitor.

I don't really want to take the head out and am not going to risk tapping it myself, am I taking a big risk if I take my chances? I also thought about drilling a pin through it to hold the stud in place after I hammer it back down.

Steeveedee 04-25-2023 08:56 PM

Re: Does this engine sound healthy?
 
Do not hammer the stud back down, that will not work. And don't take the head off. Do you have any metal-working experience? I've done this many times, but I've been working with metal and machinery for decades. Hopefully there is someone close to you that posts here and can do this simple repair.


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