zulatr

Last winter I had my valve guides replaced and did a cam and springs “while I was in there”. I installed a Pat G recommended Cam Motion cam with EPS lobes, spec’d as 226/244 .639”/.639” 116 LSA +4* advance. I also installed (again Pat G recommended) BTR 660 dual valve springs with Ti retainers which were installed at 1.780 height/155# of seat pressure. After doing the push rod measurements I stayed with the stock 7.800 rods. I installed a Vararam at the same time. Engine is otherwise stock with factory exhaust manifolds breathing into the later Z06/ZR1 NPP mufflers. After a couple of rounds of Pat’s remote tuning the car runs great, very drivable and really rips when you put your foot in it. I have not had it dyno’d, though probably will after I do LT’s, possibly this winter.

The question is, how much more valve train noise should I expect with this combination over the stock cam? I’m running steeper cam profiles with heavier springs. On my LS6 the engine shop said expect more depending on the cam, which I never ended up doing. It’s getting cold so I’m driving with the windows up now, and the valve train noise is pretty noticeable, more than before the cam change. It’s loud enough that my wife asked what the “ticking” was. Listening to the engine hot with the hood up it seems to be pretty uniform bank to bank. Oil has maybe 3000 miles on it and is clear. I’m going to doing my end of season change and will cut open the filter at that time. I’ll try do get a decent video of the sound, but nothing I’ve taken so far has been of any value.

Anyone running something like this combination have any experience?
Thoughts?

Pitufina

LS engines valve train is noisy to begin with, and once you add a cam, stiffer springs, etc the noise is just going to get worse. Once you install headers the noise becomes even more noticeable due to the resonance on the thin walls of the headers. If you removed the fuel rail covers, then that's another reason why the noise is noticeable. Mine has a cam and headers and it is much noisier than stock. The fuel rail covers and intake cover if your ls7 even has one which I don't even remember...do a job job at keeping the noise down.

JaimeVrod

I haven't changed my cam yet, but I agree long tube headers do contribute to louder valve train noise. The easy solution is to get a blower and the blower whine will drown out some of the valve train noise.

JetstreamGS

Nature of the beast. My cammed LS3 sounds like a sewing machine.

tblu92

There is one issue you need to consider with a nosier valve train-----
The new added noise is often mis interpreted as KNOCK by your knock sensors--consequently timing will be removed from you tune even though you may not hear any detonation---Other mods such as thinner walled LT headers can also create this "false knock"----A tuner can realize whether you in fact have real or false knock from added engine noise-----False knock CAN be corrected with tuning via HP or EFILIVE