Valve stem tip tap?

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Jun 13, 2024
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I've read through a lot on valve train. It's still fairly new to me. I have a HO 302 non roller. It has had a slight tap since I put the motor in the car. I ended up changing out lifters and no change. I dug into it some more today, swapped out pushrods. And rockers and it still taps. Would it be safe to say that the valve stem is too worn? They are non adjustable rockers.

I did notice with the engine running as I slacked off the mounting bolt, and started snugging it up, it would stop tapping for a few seconds then tap again. I could go a bit tighter it would stop tapping as I am turning the bolt. Then start tapping again.

Listening with a live of hose the tap is on the valve stem if that makes any difference.

Thank you
 
Is there a way to confirm it isn't a lobe on the cam? I forgot to mention as far as piling goes there's certainly no shortage. Definitely equal to the rest of them.

I don't mind changing the lifter. But if I could confirm it wasn't an issue that lies deeper I'd feel better about taking it apart again.

Thanks
 
Yep, no adjustment. I do have other lifters in the garage new. I really thought I changed that one last year. But I guess it's not impossible for it to be bad out of the box. I tried pushing down on the lifter but it didn't seem to want to collapse any.
Probably need to shim one or two rockers....
 
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Did you break the cam in when the engine was first started? This is done so the lifters wear to the cam. If not and you wiped out a cam lobe then new lifters won't do :poo:
 
When you go to replace the lifters, you can visually check the lobes.


I did notice with the engine running as I slacked off the mounting bolt, and started snugging it up, it would stop tapping for a few seconds then tap again. I could go a bit tighter it would stop tapping as I am turning the bolt. Then start tapping again.

This portion suggests a lifter problem to me.

If you had the wrong length pushrods, the whole thing would sound like a sewing machine.

Probably need to shim one or two rockers....
This too.
 
Did you break the cam in when the engine was first started? This is done so the lifters wear to the cam. If not and you wiped out a cam lobe then new lifters won't do :poo:
When I originally put this engine in it sat in a garage for a number of years. I know the previous owner and it always ran strong. Then I got it, found a foxbody with no running gear in it and used this engine. When I noticed the tap I put a new lifter and push rod in. Heard it tapping late last summer and well, it's spring so I'm going to figure out how bad of an issue it is.
 
When you go to replace the lifters, you can visually check the lobes.




This portion suggests a lifter problem to me.

If you had the wrong length pushrods, the whole thing would sound like a sewing machine.


This too.
That's why put that detail in there as in was very noticeable and consistent as I repeated it over a few times to make sure it was quiet for a few seconds.
 
I ordered the rods based on what that engine called for. I just went out to the garage and grabbed a new lifter and I'm going to check part numbers. Also today I tried the original pushrod that I removed last year with no change
So you didn't measure what pushrod length you needed??
 
Ahh, dog.... Pop the lifter out, look at the bottom of the lifter, shiny smooth surface with a slight cup, and I mean slight, if excess wear, galling, or pitting toss it, look down the lifter bore (if you can) same with the cam lobe, flat tappet cams (non-roller) the lifter spins on the cam, why the bottom of the lifter is cupped (concave). Engineers :doh:
Go figure. How many lifter/cam lobes did they wipeout before they figured that out??? Anyway you get the idea show some pics of the lifter and cam lobe (if you can)
 
I've read through a lot on valve train. It's still fairly new to me. I have a HO 302 non roller. It has had a slight tap since I put the motor in the car. I ended up changing out lifters and no change. I dug into it some more today, swapped out pushrods. And rockers and it still taps. Would it be safe to say that the valve stem is too worn? They are non adjustable rockers.

I did notice with the engine running as I slacked off the mounting bolt, and started snugging it up, it would stop tapping for a few seconds then tap again. I could go a bit tighter it would stop tapping as I am turning the bolt. Then start tapping again.

Listening with a live of hose the tap is on the valve stem if that makes any difference.

Thank you
Are these rocker shafts held with studs or bolts ? As I have had studs move and bolts stretch? Also for my old 4.99 they sell pushrods by the thousandths. I have the pushrod that you adjust then pull and measure when correct. Hey just guessing here , my 95 5.0 has roller cam and adj. rockers .
 
So I decided to swap 302's. That will give me some time to remove the intake and look at the cam. I had a 302 I could put in. That part is done, and it's running, but the engine I used I believe has a standard rotation pump and I THINK the HO I removed had reverse rotation. Is there a way to easily solve this? The motor I used had a v belt setup and the removed motor is not. I can't wrap my head around this. Thoughts?

Thanks
 
After removal of both pumps I came to the conclusion that I can run the water pump that was on the engine with that tap. The orientation of the water pump holes are the same. My question now is does any of the bolts pass through water passages or am I good there?

Thank you