Posting in here because I know alot of guys with aftermarket Injection run this cam..got my car running and taking it in for my dyno tune on 21st. I know my new 280 XFI cam has a big lift .576 .571 and a fast ramp rate so my concern my be over nothing so here's my question. Is it normal for this cam/valve train to make some noise. it doesnt really sound like the ajustment is off and making alot of cladder. It more has a some what loud sewing machine sound to it? Anyone with this cam hearing that same noise and is it normal? My engine builder did the adjustments

 

I guess it all depends on how bad and what it really sounds like. My moms old sewing machine, I dont think any engine should sound like that.

I swapped out to comp full roller rockers at the same time (also noisy in themselves) and noticed more noise in the valvetrain. Not sure if the cam had anything to do with it. The valves are most certainly going to be making more noise from hitting the seat faster than usual though.

The only files I have recorded right now are these
http://home.earthlink.net/~chris.foster/GPNewTrans.wmv (open headers, sorry! )
http://home.earthlink.net/~friederikef/GPrev1.mpg (at 0:06, 0:18, 0:21, and 0:24 you can kinda hear the noise from the valves slamming shut)

 

What was the piston to valve clearance ?

This a retro or OE roller? If retro, what is the end play ?

-- Joe

 

its a retro.. My engine bulder did all the adjustments and I spoke to him this morning he said everything was fine after he had it on his dyno and I just put it in the car and have 0 miles in it. I'm also reading the noise im hearing might be my SVO injectors..anyway its going to the chassie dyno on wends so I'll have the guy there look it over b4 the dyno

 

I have 30# SVO's as well. I will see if I can get a decent recording of the various noises and post it and you can see if yours is the same or not.

 

You will have audible valve train noise versus a stock set up. The tie bars on the retro lifters add to any extra noise that the rockers or valves create during operation. I am running retro PBM/Morel lifters on my 87 GN with a Comp cam, and it is louder than it was before with an Edelbrock flat tappet cam. I have T&D adjustable rockers, too, and the motor does have a sewing machine clickety clickety sound from the valve train. Thanks, Rudy.

 

The only chatter I get is the lifters bleeding down after shutting the engine down for 5 minutes. I'm replacing them with LS7 lifters.

 

thanks guys...I'm starting to think my valve lash might be alittle off. I think the noise is like a light tap at RPMs lower then 1200RPMs..If I bring the RPMS higher the noise goes away. I can hear it strongest on the drivers side. Sound is strongest coming from under the lower intake in the # 3 and 5 cylinder area. Maybe a lifter..hoping adjusting the valves will clear it up