Calderone

What's up guys , im back on the road but in the problem road !
If you remember last of my threads i was seeking some serious noise
coming from valves,cyl #8 area specifically.
I went ahead and installed a set of fresh Comp Cams roller lifters.
It didn't cure the noise but i wanted to use brand new lifters anyway.
i put brand new oil and its coming very strong from the roller rockers.
I swapped the roller rockers and pushrods and problem is still on Cyl #8 !
We adjusted valves with max accuracy so i discard anything about valve adjustment.

We found something new today : if i disconnect injector #8 ..the ticking goes away !
if i connect it again, the ticking comes again ! I dont think its an injector problem.

But i do think that maybe its a exhaust gasket leak around the flange on cyl #8 !

I know some of you told me about it and i did the test at night,but i didnt see any light or fire coming out of the headers.

What i think is strange is that the noise its not constant, you will notice it betterwhen the camera is not so near (3:08 minute 3:43 minute), its not like "slap slap slap slap slap slap slap slap slap"

its like more like "slap slap slap ---- ------ slap slap slapslap slap slap --- slap ----- slap slap ----"

If its not an exhaust leak and its an internal problem , i already made my mind and will make a big change on this subject , i might get a violent reaction at the engine and maybe i will swap block , crank and pistons ...not sure i dont have the money but i will work hard to do it !

383vett

If the noise goes away when the injector connector to #8 is disconnected, it sounds like the exhaust gasket to me. You won't always see a flame around the flange with a leak. Loosen the manifold and pull the gasket out and see what it looks like. It shouldn't take too long. That will give you your answer. I don't know if you have headers, but look for a pinhole on the underside where the primary meets the flange.

Calderone

Hi 383,that's exactly what im going to do tomorrow
i have 64448 Hedmans , a month ago i retightened because
they were real loose because the gasket somehow got thinner !
I will take off the gasket tomorrow and take a pic of it !
Thanks !



Cuisinartvette and Jim told me this in the past , but the new lifters sounds really smooth !
the drivers side sounds like heaven ! Now i have to check this damn gasket !

Thanks !

blackbear bob

Sounds like exhaust leak. Don't forget to check for a loose spark plug.
Bob

Calderone

I pulled them all to rotate the engine and put them with extreme care
and tightened very well, thanks !

383vett

After a fresh motor is run for a couple of times, the exhaust gasket will imprint where the flange is pressing against it (depending on the gasket type). This will make the bolts loose. They all need to be tightened. Check the other bank after you get this resolved. Good luck.

Churchkey

Old school method:

Cotton in one ear, a piece of hose in the other ear. With the engine running move the hose around to pinpoint the noise.

IMHO: Your rockers sound like they are out of adjustment. Solid lifter engines are quieter than yours is. The mic in the video may be overly sensitive & accentuating the noise, don't know.

For hydraulic lifters:

Suggest setting the lash with the engine running. Back off the adjuster until you hear the rocker clicking then tighten slowly until the noise from that rocker stops. At this point tighten the adjuster 1/4 turn. The engine should miss for a few revs then smooth out. Repeat in 1/4 turn steps until the adjuster has been tightened one full turn. Be sure the engine smoothes out after the final turn. Shut the motor off & tighten the poly lock. Repeat 15 more times.

SWAG: If the rockers are still noisy you may have the wrong length pushrods, need push rod guide plates or have rockers for 7/16 studs on 3/8 studs, have 10 degree retainers with incorrect keepers. Also check that the roller tip is contacting the valve stem & never touches the spring retainer as you turn the engine over by hand & cycle through the valve action. I have seen incorrect retainers for a particular valve stem length which allows the rocker to ride on the retainer.

Suggest finding the problem before driving the vehicle. Dropping a valve during high revs gets real ugly & real expensive real quick. Been there, done that at least a half dozen times.

Good luck.

GREGGPENN

That hose method works pretty good for finding air/exh leaks!

Why does the motor stumble after each 1/4 turn? And, why keep going to one full turn? Many performance and factory mechanics like 1/4-1/2 turn.

AGENT 86

Take a lit cigarette and move the cherry end around the circumference of the port. If there is a leak, the smoke will be disturbed and the cherry may glow harder.
Old smokers trick

Churchkey

Each 1/4 turn of the adjustment nut will crack the valve open & cause a momentary loss of compression on that cylinder until the lifter bleeds down & allows the valve to reseat.

Opinions vary on the amount of rocker adjustment. 1/4 turn on a 3/8 x 24 thread rocker stud = .010 movement of the rocker arm & may not locate the push rod cup deep enough in the lifter to compensate for thermal expansion of the components leading to noisy rockers when the engine is hot. Rocker adjustments should always be made when the engine is fully warmed.

I am also a factory trained wrench & I happen to like 1 full turn for hydraulic lifters on a stock application.

For a performance application with hydraulic lifters I lash the rockers at .002 clearance hot.

Cheers

hooked073

just me but I always liked the 1/2 to 3/4 turn. Closer to 3/4, seems much less then that they have a tendency to tap some and float out eaiser

mike100

I always preferred 2/3rds to 3/4's of a turn lifter preload.

I also agree with the 'old-school' method of a long rubber vacuum line in your ear and the other end will probe around the manifold seal. Any puff of air will be a very noticeable noise in your ear. Try blowing on it to test that out.

obviously there is a chance something is broken inside. a busted ring land or a bad bearing makes a LOT of noise and you'd know it by now if that was it. A flattening cam lobe will put a lot of metal in the oil and start missing...can't really think of any other scenario. well, maybe a lot of piston skirt clearance- that usually knocks when cold, but ok when warm.

You could just drive it a few hundred kilometer until something fails- sometimes that is the most cost effective diagnostic you can do- wait for the problem to get bad.

GREGGPENN

Hmmmm....one full turn vs .002" less than zero lash? Wow, that's quite a difference! I asked because I also have a thread posted here about rocker noise, adjustment, and valvetrain noise (using a unique combo of components).

Since you're posting such a big difference between rocker adjustments for performance and stock applications, why did you advise Sammy (OP) to use one full turn with his performance heads and roller rockers?

tpi 421 vette

You have a blown header gasket. Put a Felpro #1404 in it, and that will solve your problems.

cv67

Its easier to tear the motor apart


Keep us posted Calderone

Churchkey

It was a suggestion to try & solve a problem not advice.

I do not know or keep track of what whiz bang combos everyone runs, don't care.

cv67

Why would you want to use lash on a HR , these dont function like a solid would, the lifter has to have some preload to keep from self destructing and seriving the purpose in a way it was designed for.

Calderone

Hi guys, i decided to get things solved today and went with a couple of friends (we weren't sure ,its very very confusing because i did have a lifter problem on cyl#8 (it was very very noisy)) Jerry inmediately said , its a blown headER gasket , so i proceed to take the gasket off and that was it ! it was cut and in very bad shape, i have no time to buy a gasket from USA so i bought a sheet of Asbestos (has a inner metal layer) and cut it to match the original gasket. Work wonders !!! the new lifters are really smooth and im very happy with it. So i have to say Thanks to everyone here , as always ! and this week the Vigilante Converter is going in !!! Im planning to install the new Master Cyl , DRM Spring and Brake shoes i have laying here because this Saturday 11 will be my first time at the track , i will video it and post it here , wish me luck guys !!!

Now if you are wondering how does the track look like , here's a couple of videos :
Oh ..its actually 1/8 mile , i wonder how my car will perform in the 1/8 !!!

Sat 11 :



Sunday 12 i will be here :

tpi 421 vette

Your car will probably run alot better with the header leak fixed. The header leak allowed air into the exhaust system creating a false lean condition the computer would be seeing. So it would start dumping fuel making it pig rich. And this will make it run like a pig.

cv67

Try and get a head gasket on there right away that stuff you used will cause some damage when it fails.