66jack

I am new at this so bare with my and my explanation...

Not really sure if its the problem...but here is my diagnosis....

This engine has less than 500 miles on it....

This started last Saturday and I just dove into it this afternoon.

At idle NO CLATTER..at about 1500 rpm is when it starts and continues up into the higher range..."Most of the clatter on the Drivers side"

EXCELLENT OIL PRESSURE THROUGHOUT.

So i figured the valve lash need to be done again to get rid of clatter....

When i pulled the valve covers #1 IE were just a little loose...so i decided to run them all again, BOTH SIDES...

Put it all back together,fired it up and RATTLE IS STILL THERE....

One possible idea is that i used the 'old push rods' from the engine i pulled out of car...that engine had 15 thousand miles on it...the reason i pulled it is it was burning a lot of oil...

Could it be that some crap was lodged in push rod and came loose or a bent push rod or rods?

Any and all Suggestions/questions are welcome....

Kerrmudgeon

Just for a laugh check the inspection cover on the bellhousing. Don't laugh....it happened to me last summer. I was ready to tear the motor down until i found it got a little bent somehow and was hitting the flywheel and making a clatter.

DansYellow66

If it is quiet at idle I would be thinking something other that the lifters. They usually are noisiest at idle when oil pressure is the lowest. The inspection plate as suggested above is one possibility. Are you still running an operating heat riser valve on the passenger side exhaust? Engine belts worn, loose or pulleys out of alignment is a possibility.

MikeM

Forget the pushrods.

Jackfit

Hi Jack,

I had the same problem just after I got the engine back from the last rebuild. If you have had the rocker arms and nuts replaced, the nuts are a little taller then the orginal ones. I took off the valve cover and sure enough, I could see marks on cover where the nuts were tapping the cover.

Simple solution. You may have on a standard valve cover gasket. Remover and put on the thick one. They have it, just ask at Napa. The 1/8 or so of an inch made the difference. No tapping in 46,000 miles the last two years.

So, just take off a cover and look

Jack

rustylugnuts

You can also leave the valve cover on and use the poor man Stethoscope, a (long handled screw driver) putting the handle to your ear placing slotted end on cover, if the sound is deafening, your rockers are hitting your cover, if moderate I would say re-check your valve adjustments.

rustylugnuts

Frankie the Fink

Jack's observation is certainly worth checking out.

FelPro makes two thicknesses of SBC cork valve cover gaskets; I believe 5/32" and 7/32"; I ALWAYS use the thicker ones...

66jack

Morning all:::

I will check the FW cover plate later this AM

I have the thick felpro gaskets on

New factory style rocker nuts...



Why would this just 'ALL OF A SUDDEN START', if its the inspection plate?


Another question:

I am just out of curiosity going to pull the drivers side cover and inspect the rockers.

If #1 ie is loose again, what would be your suggestions/ideas as to the cause?

Kerrmudgeon

Best 3 bucks you'll ever spend.......

http://ca.search.yahoo.com/r/_ylt=A0...ope-41966.html

larrywalk

Could be a worn rocker nut which gradually backs off.

66jack

NEW NUTS

kerrmudgeon;

Bought that scope last year...

cv67

Mightbe your lifter bleeding down after shutting off may not have been out of adjustment.

Is it a HR cam? Quicker ramp? Do it while the cars running and drive it.

MikeM

If you're using the stamped steel valve covers and you put them on backwards, they will hit the rockers too.

You can also find the noisy rockers and rule out anything else by putting the heel of your hand on the valve spring end of the rocker and push down. If the noise goes away, that's the location of your noise.

If you find #1's loose again, you have the rocker nuts backing off as stated, stud pulling or something wearing down. Check the #1 studs for the number of exposed threads above the rocker nuts and see if anything looks different from the others.

Check the ball seat area of the rocker in question and see if you can find a crack opening up that lets the rocker flex when rpm goes up.

66jack

Like i said i am new to diagnosing....

WHAT IS HR AND QUICKER RAMP?

stock rockers

280 Comp Cam

The clatter/rattle is at higher RPM's at or above 1500...not at idle...

Dennis Beck

A loose or blown exhaust manifold gasket can sound like lifter noise. You have had the engine out and back in. Check your exhaust manifolds for a blown gasket or loose bolts. Just a thought.

Dennis

65tripleblack

Are you sure it's not detonation? The 280H is a mild cam and since we don't know what it replaced, it might have too much compression and/or spark advance.

tuxnharley

Right, but have you used/torqued them more than once? I know this is gonna sound crazy, but when I replaced the head gaskets on my ZZ4/350 last summer the rockers kept loosening up and making noise. After re torquing them a couple of times I asked a local Corvette shop about my problem, and was told the nuts are now made with a slight "crimp" (for lack of a better word) in the internal dimension to keep them locked - the first time they are used. Apparently they are not reusable, once and done only. So, I bought a new set, put them in, and no more problems!

Sounds crazy, don't know if it's ZZ4 specific or not (how could it be?) and I'm sure I'm gonna get a load of comments on this............ but, all I can say is - It fixed my problem!

66jack

These are Brand New first time use...

66jack

This is freshly rebuilt 327/11:1, 40 over forged piston 280 cam...

I reused the push rods, and rockers/*****, 'stamped steel'...new nuts...

tuxnharley

Sorry - your first post seemed to indicate that you had taken it apart and reused them...................