If the lifter is worn in straight lines, it's ALREADY toast.

But the spark plug thing, is NOT valve-train related.

Sounds like you have more than one issue.

 

If the lifter is worn in straight lines, it's ALREADY toast.

But the spark plug thing, is NOT valve-train related.

Sounds like you have more than one issue.

 

KREWAT ... I see how you got to 22k posts... just push the button twice!! ... heh.

If the noise goes away with the lack of spark.... it is not a lifter. Not a cam.

Sad to say, I'd bet it is in the reciprocating parts. The only way I know to find out is disassembly.
Can you describe the sound with more adjectives? Kronk Kronk or RAp RAp or Tic Tic or boom boom. Sharp or soft, higher pitched or lower.
When you installed / removed the lifters, were there any that were difficult? They should have slipped into the bore easily and not have any binding. Removal after years of service is a bit harder, as they tend to grow varnish or other deposits on the lifters below the travel area (cam lube splash deposits) that you have to work past to remove them.
Did you assemble the heads to the block or did the machinist? If you, did you happen to note the 'notch' position on the piston crown? They should all point the same way, otherwise the oil hole in the connecting rod will point at the wrong surface. At least the old engines has a squirt hole that lubed the cylinder wall {I think}, or maybe it was the cam... Been a LONG time.
tom

 

Rod knocks will quiet down most of the time when plug wire is removed but some can get louder..between 4cyl,I6 V6,ST-8 v8 my 2cents ez to pull pan on 4x4
orich

 

Years ago I had a 352 with a similer noise, it ended up being a badly worn exhaust valve guide. It only made a ticking noise when the plug wire was on , pull the wire no noise. Look for carbon buildup on the exhaust valvespring. One other thing would be a head gasket leaking compression to the outside , this will also make the same noise.

Just some thoughts------Hotwrench

 

The thought on the head gasket is a good one.

Do a compression check.

 

Have you hooked up a vacuum gauge?

 

I think I'm losing my mind........
There is a guy I work with who has been out of town. He is a very good mechanic, and he came back yesterday and gave a listen.
first off, he instantly said he thought it was not a rod knock or any knock for that matter, and he thought it was valvetrain related. he has personally dealt with rod issues in he past on various engines.
So I walk over and pull the #3 spark plug.......and it still does it!!!!!! I coulnd't believe it.!
So I pull the valve cover, and he claims it instantly got louder, further proving his valve train theroy. so with cardboard in place i fire it up and I notice that since replacing the lifters on #3, EVERY pushrod is now turning. everything looks great. Than I turn over the engine so #3 is at tdc. and I start pulling and pressing on the rocker shafts. the sound of the rocker springing back against the pedestal sounds alot like the noise. so I am able to slide both rockers off the valve, and to the side. THAN i notice that the top of#3 exhaust valve looks WAY more worn that the top of #3 intake valve. my co worker confirms this.
so than I'm thinking maybe there is a problem with the rocker shaft since they are off the old motor. so I swap rocker shafts from pass. to driver side to conduct a little experiment.
well both sides make the noise for about 20 seconds untill the drivers side stops, and I'm back to the normal pass. side racket....
I had to stop there. it was getting late.
but now it seems it is not the bottom end!!!!!!!!!
and one other thing, my co worker claims he could hear a miss in the engine that was timed with the noise??
sorry to give wrong symptoms before......I swear things are changing......

 

I have not hooked up a vaccum gauge. thats a great idea. I will do that today..

 

Hey, glad to hear it might not be bottom-end, that's good news.

 

New rocker shafts are cheap. If you have pits worn into the rocker arm tips, you should replace them. Not a lot of dough, and you run less risk of messing the valve stem tips up and you get better oil flow control as the groove cut into the rocker arm 'bushing' area will direct the flow properly and you tighten up the clearance insuring better flow to the 'last one down the line..'.


You are saying that the height of the tip of the valve stem measured from the top of the spring retainer washer is different on the #3 exhaust, aren't you?
If the valve stem height above the spring top is different, perhaps the wrong valve was installed. I have seen valves that are duplicate in every way except the height above the keepers, thus affecting the length of stem left exposed. Measure a few others...
tom

 

No, the height isn't different, just the wear, where the rocker contacts it. I am going to order some new shafts and rockers and see what happens. I can't imagine it could make that much noise, but hey, I'm willing to try anything now that I "think" I can leave the engine in the truck.......

 

so the vaccum is only 8 ? at 800 rpm with the engine warm. It is steady. now keep in mind I am at 9500 ft abouve sea level. but I went to turn the air fuel mixture screws and I was able to turn one all the way in and the other a half turn out before it affected idle......so i obviously have a leak somewhere.......I will get out the carb cleaner tomorrow.

 

duplicate post, delete at will.

 

Pull the plugs, look for oil fouling and lean-burn conditions.