Garry_W_C5_1999

I am in the middle of assembly and measurements for my LS3 (C5 but posting here as it is a C6 style motor). The upgrade includes custom cam, new lifters (2116LSR), new trunion's, springs, etc. All is installed and I am measuring for pushrod length with 7702 comp cams tool. The measurements I am getting are longer than the stock 7.4" pushrods. One thing that is confusing me is that I only expected to see a difference related to preload since the things are similar. But I am seeing a bigger number. What gives? Does my new Cam have a smaller base circle? Are the 2116LSR's shorter? I want to understand what is going on before I go any further. Perhaps someone has measured a 2116 and has a chart to share like the one at the bottom?

lazerlemonta

Plunger sits deeper in the lifter at zero lash..... .093 (.035 preload) travel in these compared to stock lifters .200 (.080 - .120 preload)

xBoostx

Un-sure if is your first src but even for the benefit of other readers who may venture in as well here's some...

When measuring push rod length be sure to keep the oil transfer hole in the rocker adjuster lined up with the oil channel in the rocker body generally (about two turns out) that will live adjusting range as well, when the oil transfer hole is fully lined up (meaning open with out restriction) then proced to measure push rod length with a dial caliper.

As a rule I measure front and rear on both side after the valve is fully and properly adjusted (with the piston @ top dead center on the compression stroke for every valve lash you check) keeping mearuments in writing then take an average for the correct lenght, I hope this can help, David.

93Polo

I have not used the 2116s. I have 2110s and I came in under 7.4 but my heads are also decked, so you can't really use my setup as reference. I am running a CamMotion cam.

I don't trust the turns method to be accurate as my checker turned very easily. I checked mine by getting it close then wrapping the checker in tape to keep it from moving. Once the checker was at the correct length, it was measured using some calipers purchased from Harbor Freight
https://www.harborfreight.com/8-in-d...per-63712.html

See post 11 here when ordering pushrods and discussing length:
https://ls1tech.com/forums/generatio...-pushrods.html

Katech has a good video posted on the topic, and Vettenuts has also started an informative topic. Vettenuts also makes a convincing argument for running the largest diameter pushrods you can fit.

Tooley and Summit both sell house brand 11/32" pushrods if you don't want to spring for Mantons.

Garry_W_C5_1999

Thanks for the input. I did more measurements last night. I am confident I have the correct pushrod measurements. I am just trying to verify the logic behind why. I measured and called and found out the new cam base circle is smaller. I measure the old pushrods and they are shy of 7.4". I called Johnson but the guy I got connected to was not able to give me any clear measurements (surprising to me) other than they are shorter (roller to cup), he was vague and spoke of significant variations which did not seem right. Below is my latest numbers and it feels a lot like the lifters must be approx. 0.190 shorter. I wish I could get an accurate measurement on 2116LSR roller tip to rod cup. The heads are all bolted down with new gaskets so I don't want to tear open for peace of mind. This is my first experience with this level of adjustment so I missed an opportunity to measure the new lifters before install.

FTI. Engine was stock GMPP LS3 525hp. Head not milled and No Valve job during this install. Pistons 0.010 out of the hole.

93Polo

Sounds like you're on the right path to me but I am not an expert.

https://ls1tech.com/forums/generatio...-question.html
https://ls1tech.com/forums/generatio...ation-ls3.html


If you have questions Manton and Brian Tooley have been easy to deal with but you may want to call Johnson again.