Rob WS6

iTrader: (16)

After putting in the ASA cam and deciding I wanted something more boost friendly and less lopey, I took it out in favor of an LS6 cam. Purchased brand new from Summit along with Trick Flow 7.425 pushrods to account for the .050" smaller base circle. Everything is all installed and running well, but Im noticing some valvetrain noise, ticking if you will. Its not really present at idle, I only really notice it when Im driving next to things the sound can bounce off of, but its definitely there.

Whats considered acceptable as far as LSx valvetrain noise? Its more of a high pitched tap, almost header leak sounding, but concerning none the less.

This is on a stock LQ4 that has never been opened up, around 115k miles. New LS6 cam and springs, stock rockers, Trick Flow 7.425 pushrods.

A.R. Shale Targa

iTrader: (2)

You might have too much preload on the lifters as the factory uses 7.385 pushrods with valves that are .0236 taller.

Rob WS6

iTrader: (16)

I don't have the taller LS6 valves. Just stock 317 heads.

I mic'd the base of each cam and the LS6 cam, according to my calipers, is .059 smaller than stock... cut in half, that's roughly .030 longer pushrod that Id need. The ones I bought are .025, so I should actually have .005 less preload than I did with the stock cam/pushrods, correct?

A.R. Shale Targa

iTrader: (2)

As I mentioned the factory pushrods are a bit under 7.4 so yours would be .040 longer. Also the LS6 valves being almost .024 longer is effectively only about .015 on the PR side after you factor the rocker ratio. To get the same preloaded that the LS6 has would be 7.385 + .015.

Always2Slow

iTrader: (8)

Always measure pushrod length don't assume.

Rob WS6

iTrader: (16)

I have a length checker, just didn't think I would need to use it. I'll pull a rocker tonight and use it, see what I come up with. Basically you're saying I could have .015 too much preload?

Rob WS6

iTrader: (16)

Well, you were right. After checking with the length checker, it wants a 7.405-.410 pushrod, so 7.4 it is. Right now it looks like I have about .080 preload, probably a bit much for my high mileage lifters. Thanks all, lesson learned. Measure before you buy... even if everything is stock!

Always2Slow

iTrader: (8)

Good to hear you got everything sorted.

Rob WS6

iTrader: (16)

Got em all swapped out in an hour and took it for a ride, feels great, definitely quieter now, back to the way it was.

This is why I love LS engines... 1 hour to change the pushrods start to finish, no valve lash to dick with like on an old SBC. Hell I did the 2nd cam swap in 4 hours flat and that was with a trip to Lowes for a couple longer bolts for my balancer puller.