65SSZO6

iTrader: (4)

Built a 04 LQ4 with 317 heads and the 04 ZO6 cam.Originally I went with Trick Flow .080 7.350 long push rods,but when the engine is hot it sounds like I am getting valve train noise coming down from 2500-3000 RPM.Like the push rod is bouncing up and down between the lifter and rocker tip?

I kept the original 7.40 factory push rods from the engine.I put the 7.40 push rods on the left side of the engine and kept the 7.35s on the right side.I think it is quieter and oil pressure is higher? Also I realized the injectors are louder than any valve train noise I am getting.

When I built the engine,I colored the valve stem tip turned the engine over a few times and the wear pattern on the stem was high.Replaced the 7.40s with the TF 7.350s and the pattern was perfect dead center 1/3 of the valve stem tip.

Heads were milled .004 or .005

Any recommendations? My thoughts are someone has to have built this combo before?

Shawn MacAnanny

iTrader: (12)

Really the best way to check is to use an adjustable pushrod length checker. I am running .100 preload on the stock lifters. I thought that the z06 cam used a larger base circle for some reason which meant the ls6 pushrods were longer.

XtraCajunSS

iTrader: (2)

You should not be using shorter than stock pushrods with your setup unless your heads are extensively milled or altered in some way. With stock non-adjustable rockers, pushrod length is used to set lifter preload, nothing more. The base circle on an LS6 cam would be smaller due to the increased lift offered by that cam. If anything, you'd need a little longer pushrod. The 7.4's should solve your noise problem.

Shane

Shawn MacAnanny

iTrader: (12)

Well thats typical for all bigger cams but for some reason i though the base circle was bigger to reduce pushrod length for higher sustained RPMs. I'm not sure where i heard that from though.

sparkwirez06

iTrader: (18)

The base circle on the zo6 cam is .050 smaller, requires a longer pushrod.
http://www.ls1howto.com/index.php?article=21 this post may help you.

Shawn MacAnanny

iTrader: (12)

Oh i believe you just for some reason i always thought the Z06 cam was backwards from the rest of the cams. I had an 01 but never checked the base circle on the cam.