Valvetrain noise after cam swap

[Superdave]

you did put assembly lube on the cam for the install right?

pushrods are all in the right spots?

the 99 lower chain sprocket is a press fit, are you sure it's installed all the way in?

oh yah, and you CAN use the new guide with the old chain but you'd have to shave off about 1/8" of the rubber. Smells great

[IsaacHayes]

Yeah the only thing other than lifters I can think of is if the push rods are way too short and there is no load on the rocker/etc when the valve is closed but a lot of space for the push rod to bounce up and down.

Are the pushrods in the right places? :P

Did you use the pre 99 chain guide too? You can't use the new guide on the old chain/sprockets.

[geldartb]

checked all the lifters they all seemed fine and filled up with oil when we test primed the engine. it definately had good oil pressure.

they are stock rockers.

cam is timed right i used the printout from the all data subscription i have and did everything the way the picture was.

its definately coming from the middle of the engine. it stays with the rpm's as the engine rev's.

3400-95-Modified was the other guy there with me, he was mostly monitoring the engine with me.

the pushrods are the one that ben makes with the cam from the store here so they were all custom measured by him.

[powerdoctor]

Have you checked your lifter pre load? or clearances?

What kind of rockers?

You may have to take some off your rocker pedistals.

Turn the engine over till you lifter is bottomed out or on the back side of the cam.
Is the rocker loose at this point?

What clearence if any do you have?

Are you sure the cam is timed right ?, just asking here.

I usually like about .004/ .006 preload on the lifters.
Some say .006/ .008

This is valvetrain noise and not spark knock right?

[geldartb]

ok so i bought the cam and the pushrods and spring the whole nine yards, tore into the engine replaced the old parts with the new ones i had put it back together and it sounds like i swapped a duramax diesel in there instead.

heres what went in
99 3400 chain and sprockets.
1357 grind with pushrods from the store here
comp cams springs from the store here

now it made the noise the first time when we started it up, yeah ok its been sitting for three months the oil drained out of the lifter. you figure a couple of minutes it would go away nope it didnt still sounded like i swapped a duramax in there.


fast forward 2 weeks later i started by taking the valve covers off to see if anything was hitting or looked wrong. the only thing that was looked off was one of the spring ate away a little peice of metal from the head where it wasnt ground down from the factory.

later that day my helper Jon showed up and looked over checked a few things couldnt find anything out of the ordinary so we took the lim off checked the lifters found a few that hadnt oiled up yet. ok so the only thing i had with me was the cordless impact so we hooked up some extentions so we could check oil flow, did that and had good oil presure while doing so and all the lifters filled up so you would think problem solved nope after putting it back together still ounded like a duramax diesel.

the cordless impact spins freeload at 1650 and impact and 2600 so it should have been putting out near full idle oil pressure which it was doing a pretty good job at.

im at a loss here on what the problem could be. i mean the lifters are getting oil and the engine has oil pressure about 40-50 at 1200rpm.

any suggestions would be helpful. next are to replace all the lifters with new ones and if that doesnt work it gets pushed out back and burnt.

fyi the engine and lifters only have about 7300 miles on them and this thing ran fine before taking it apart. i find it kinda funny that the lifters failed or whatever while the engine wasnt running and out of the car.

sorry about the long novel