383 hp lifter noise

[DP78]

Hi everyone and its been awhile since I have asked any questions. I have been researching on here to find out what could be the issue on my 1970 383 HP with lifter noise, but have not seen any threads that talk about details into the rocker shaft assembly. Its a stock rebuilt 383 with the stock 906 heads and lifter set up. I took off the valve cover (drivers side) and notice play between rocker arms and could slide them back and fourth a little bit, depending on which valves are opened and closed.. Are they suppose to be able to move or are the spacers that go in between them worn. Its pumping oil on all of them and it runs just sounds like a tapping noise. Any ideas that I could do?

 

[khryslerkid]

It's normal to be able to slide the rocker sideways on the shaft if there's no load.

As far as lifter noise, there might be a collapsed one that's not pumping up. You have to bump the engine around, watching for each individual rocker making it to the top of the stroke. Then see if there is excessive play. Could be a bent pushrod causing it too.

Does it run with a miss? Does the engine have alot of mileage on it?

 

[ODZKing]

Back in the 70's there was always some lifter noise in the V8's after many years. Oil got gunky and thick and sometimes made the lifter not come up all the way.
Our solution back then was transmission fluid. It is very high detergent and in most cases would free the lifter after running a while. I am not suggesting you change the oil and put in 5 quarts of fresh tranny fluid, but a few ounces will do.
In the 90's I had a Lebaron GTC that got noisy after 100,000 miles. I had a mechanic friend suggest using "Restore". It happened to be a 4 cyl turbo and it did quiet right down. (Don't get the 8 cylinder one and use half ... someone suggested that!)
I have used it in my 67 - 383 and it does INDEED quiet the engine noise. Fresh oil change and a can of restore.
My 2 cents.

 

[clazar]

If it's nothing noticeable, maybe some bad gas. I thought I had a bad lifter. But it was I needed some better octane for engine ping.

Chuck

 

[DP78]

I do not hear the engine missing, maybe I'll double check to make sure the exhaust is not leaking around the manifolds. I will check out a few of those things and report back, thanks.

 

[Dennis H]

Mine had two bent rods after an oil pressure loss episode. Replaced them, got quietER. Still a little rotating mass sound. Rythmic but not a knock or tap. Hard to describe. Gets quiet after FULL warm up. Good oil pressure and no consumption. I'm gonna drive it. Amsoil 10-40.

 

[monaco66coupe]

use oil that doesn't have a fast drain back feature, and use Lucas #10036 as an additive. I Use Rotella 15-40 or Mobil diesel oil. That noise will go away. Modern oils suck, as they aren't designed to lubricate older engines. So, Lifters tick due to poor pump-up qualities of modern engine oil.

 

[miller]

Just a couple things to consider...

First would be using a 'good' set of tappets, so no excessive bleed-down. That would creat a gap from part to part.
The overall build of the motor, meaning cutting the heads or block, how much it was cut, and the thickness of the head gasket used. Keep in mind the head surface to crank centerline is a given measurement. If changed, adjustments must be made to get correct clearances.

If your sure the motor is 'stock', with no major changes to the head surface to crank centerline, the valvetrain should fall into place, assuming the right parts are used.

Use cylinder #1, for example, at TDC compression stroke. That would put both #1 tappets on the base circle of the cam. There should NOT be any up and down play for the two pushrods. You should be able to easily spin the pushrods, that show there's no excessive pressure. Of course, you've got to remember tappets work off of oil pressure, but even without, there should not be play at the pushrods.

Can't find it right now, but...correctly set up, when the tappet is sitting on the cam's base circle, the plunger in the tappet should be pushed down, via the pushrod, a minimum of .010"...max .050. That measurement is from the top of the plunger to the retainer clip, or wire.
That makes a zero 'lash' at the rocker arms...no up and down play.

If you do have play, 'something' is wrong.

- - - Updated - - -

Here's a one size fits all for hydraulic tappets.

This one shows .020 to .060.

 

[DP78]

Well my problem ended up being an exhaust leak. Thanks for all the replies and info guys.:hello2:

 

[Dennis H]

What? Good to hear but it was never metnioned that it got quiet at full warm up. Did it?

 

[DP78]

No just had some lose manifold studs to tighten up and the noise reduced significantly. I was able to find it by listening through a tube around the lifters and exhaust to determine where the noise was coming from and that is how I found the leak. Thanks Again

 

[Dennis H]

Got it. Good deal. I use a set of those mechanics stethoscopes.