Valvetrain noise after cam swap

[3400-95-Modified]

shouldnt what sound deeper?

Brendan set your idle in the IAC section for like 980 or higher, mine is at like 910 to get it to idle, anything lower and your just asking for it to surge like that.

Then you can do more checks without having to hold the damn gas pedal.

[IsaacHayes]

I just realized my sub level on my speakers was turned all the way down. LOL that's why the engine note sounded "off". hahaha That can't be knock, it does sound like valve train or the worlds nosiest injectors!!

[powerdoctor]

When did shaving the pedistals become old school?

how do you compensate for smaller base circle cams?
buy new "shaved" or "lengthened" pushrods .... for a couple thou's slop ? ... come on.

That noise is slop in the valvetrain.

either the cams lobe diameter "under the curve" is too small for the pushrods or something.

Prime example of why I hate non adjustable valvetrain.

[geldartb]

the camera sucks for picking up audio. and its pointed towards the front of the car so its not gonna catch the loudness from the back. it sounds different in person. the camera isnt the best thing to pic up audio it is a picture camera afterall.

jon if you want you can pull the lifters you got.
that was the stock idle i never had a chance to change it to anything other than stock.

heres one pre cam same pipes the cameras about a couple feet back from the car.

http://s60.photobucket.com/albums/h5/95blackz26/Videos/?action=view&current=Grandam.flv

those are series 1 3800 supercharged 30lb injectors. i thought about the injectors but thats still way too damn loud for injectors.

the only other injectors i got are the series 3 3800 sc ones which are shorter than normal and even with my custom bent brackets it still didnt like them.

well considering all the measuring and stuff was done by ben here, i honestly dont think that its wrong length pushrods. i trust ben on that one.

[powerdoctor]

Those are those new "noisy" injectors.. garaunteed to grab some show points ....

[geldartb]

eh heres a pic of the beast. this is how its been for the last few months. i kinda diggin the no hood thing.
definately miss driving it but dont miss the cop attention it got. oh yeah and the amount of gas it consumed.
dont mind the steelies i put crappy tires on it seen as how it wasnt gonna be driven.

[3400-95-Modified]

You compensate for smaller base circle cams by extending your pushrod for the difference in the base circle... which is what he did by buying new pushrods from Bens store matched to his cam. SAME way I did mine. If you grind material on a pedestal then you change geometry and change where the tip rides on the valve stem, those are two things you don't want to do since the geometry is already correct and the rocker tip is already in the right location.

[geldartb]

yeah were not grinding shit off the head or anything else.
its either swap lifters and if that doesnt solve the problem then drive it out back and burn it well after i put insurance on it.

[powerdoctor]

Well that does not sound "correct" to me or any one else so far.

If those pushrods were engineered for a new cam and for new lifters and new rockers with new valve stems and tips, and anything is worn, you are screwed into buying new stuff huh?

Damn those non adjustable valvetrains

And you will never feel nor see any destruction from a few thou off geometry.

I bet from the factory the "geometry" varies from rocker to rocker because they are stamped and not machined or blueprinted, they are pushed down the line and kicked out the door to the showroom floor...


I'm a poet and didn't know it ...

[geldartb]

there should be minimal wear at the most. the engine has 7300 miles give or take a few on it. and i didnt really drive it that much in the year the engine was in the car.

maybe about 8 trips down the 1/4.

the fact the the lifters or something went shitty baffles me since this thing ran fine and sounded normal no noise when it was parked 3 months before this.

maybe the little gremlin snuck in and had his way with my lifters who knows.

and it spun over fine for me before it went in the car. wasnt putting this thing back in the car until it was fine.

[bszopi]

How are roller fulcrum rockers stamped? I agree that they may vary slightly from rocker to rocker, and that they are probably not exactly 1.6 ratio from the factory, but I think they are close enough within tolerance to not cause excessive noise.

I think you've spent too much time with the iron heads and aare trying to apply the same principles to the newer engines, when that's not the case.

[IsaacHayes]

My ball/pivot 1.6 ratio are stamped, but I have no noise now that I have replaced the chain and guide. Only ticking you hear is the injectors! LOL never heard them before haha.

Once you swap some lifters we'll see what happens. I can't think of anything else to do at this point.

[geldartb]

neither can i its got the both of us baffled. theres nothing that showed any wear.

the only one spot where one spring ate a peice of the head that wasnt ground down from the factory stayed the head.

the different lifters better solve the problem or im gonna pull the cover over it and forget about the car all together. can you say trailblazer ss time.

[gpse3400]

Yeah that valvetrain noise is your cam profile. My old 3.2 GEN2 and my 3400 did that when I had a wild cam in them. 3100MPFI's engine sounds the same too. You're fine as far as that goes. You defiantely have a SHARP ramp of actuation of the valvetrain and that will cause that sound to happen. As long as your pushrod length and spring pressures are matched you are set. depending on your cam prfile some 60Degs will do this others will not. The noise is a byproduct and is not an issue but I figure you can negate the noise using solid rollers or a speced out custom hydraulic lifter. I never noticed any wear on the valvetrain and I had 30K+ on my last rebuild.

BTW I have the same black tool box with the red drawers.

[geldartb]

pushrods are the ones ben had custtom made to go with the cam and the springs are the comp cams 26986.

yeah the toolbox is empty i was using it as a table to set my other toolbox on. kinda out grew that one. just havent brought myself to throw it out yet hence why i have so much crap. i kinda miss that toolbox at least everything was organized.