I adjusted the valves 1 full turn and they still make noise when I first start it in the morning. After the engine warms a little they stop making noise.

It seems like the noise is louder from underneath the van tho.

?????????????

 

1 full turn may be too much, the valves may hang open a bit. It is a tapping sound, right?

 

yup

 

I think it may be an exhuast leak somewhere. I started the van without the engine cover and it was all quiet. You can't hear it real well up top, but the ticking is definatly loud as hell underneath.

So I took an old rag and stuffed my hand over the tailpipe and I could hear the exhaust hissing up front by the manifolds. I wonder why it started doing this now and not before?

 

1 turn is alittle much when I adjust mine I only go 1/4 turn after they quit tapping

 

what did you just adjust it 1 turn ofter you could not rotate the push rods or untill they stopped making noise??? I did the first a 1 was just a little too mucj
much
235* plus it runs funny
180 stat fixed that tho.

 

I started at 1/4 turn. Then because of whatever noise it is that I'm hearing I did another 1/4, then another 1/4. Then I realized that I had 1 full turn on them and something was still making noise.

So I re-did the whole thing tonight. This time I put them at 1/2 turn and drove around trying to figure out what is making all the racket. It all sounded normal with the engine cover off. Like I said in my previous post, I think it's the exhaust.

 

AstroCaptain do you happen to be using Comp's Extreme Energy series line of cams?

They tend to make a little more noise than usual. If so, you may just be hearing a "normal" noise.

 

Nope. I have the GMPP "383 truck" cam. 196/206 @ .050" .431/.451.

 

Exhaust leaks are more of a clicking sound than a tapping sound, is it your header or collector gaskets?

 

Roger that. Both XE cams made the noise in one of the LT1s and it drove me freakkin' NUTS until I realized it was just a ramp thing and I got used to it. Once it's warmed it goes away unless the RPMs get really low - and that's with 45 PSI of oil pressure still.

 

Glad I read this thread for when I install a XE cam, I probably never would have figured it out.

 

For the record.....my XE is a little noisier when cold. Once it warms up it sound JUST a TAD calmer than a solid flat-tappet....

Ahh well, i am switching to solid anyways. (i love how they rev )

Astro....you may indeed have a minor exhaust leak. They really drive me crazy.

 

How to tell it's an exhaust leak (foolproof).......

If it gets LOUDER the more more load you put on the motor, it's an exhaust leak. If it stays about the same regardless of engine load, it's something mechanical (like a valve tap).

1 full turn down is NOT too much. Stock spec is actually between 1 and 1.5 turns down from zero lash on most motors. Many hot rodders keep it very close to zero lash in case they float the valves the lifter won't pump up very far and there will be less chance of bending a valve against the top of the piston.

If you had them adjusted down too far you would know it, beleive me. If you hang just ONE valve open it'll have a dead miss. If you hang TWO open, it'll idle like a top feul car.

 

COOL, i think i am gonna go tighten down on 2 of my valves.....LOL

 

Thanks to all for your replies. I, myself, have never had to deal with adjusting valves so trouble shooting valve noises is something I've never dealt with.

I found it was a manifold collector leak! DOH! I did redo all the vlaves to 1/2 turn like I said. It seemed unanimous that 1 turn was too much. It was the exhaust leak that I thought was valve tap.

This morning I got under the van on the DRIVERS side and put my hand on the "collector". I could feel exhaust coming out of it. I guess I tweaked the pipe or something when I had it off (never fit quite right to begin with).

One last question. Do I need to change my oil right away? I know roller cams don't need all that break-in crap at start-up so should I change the oil soon? I was gonna change it soon(<500 miles), but how soon?

again...thanks all for putting up with my nagging

 

Captain,

What I have done in the past on roller-cammed engines is to start and run in the engine for about 5 hours of operation, then dump the oil. Maybe I'm not as careful as some, but regardless how hard I try I always seem to accumulate "junk" in the oil on a fresh start. Little bits of gasket fiber, tiny pieces of extra bearing metal, paint chips, ring facing, fresh iron particles, whatever, seem to find their way into the oil. The pickup screen should protect the pump from larger particles and the filter should protect the engine from the smaller particles, but cutting open the first filter usually reveals some of this "junk". If the filter gets fairly saturated with debris it can go into bypass and allow unfiltered oil to circulate.

During the initial run in, a little sustained middle-RPM cruise running, and a few hard accelleration runs to seat and lap the bearing shells and lap the rings into the cylinder bores will probably generate a few more particles.

After the 5-hour run in, the next 500 are for engine break in running with moderate-throttle operation to lap in the crank and rod bearings and polish up the bores completely. Keep your foot out of it for this period, then change the oil and have at it. This is a good time to go to synthetic.