pcmhacking.net

So I figured it was time to do some proper measurements.

Quickly whipped off the drinkers side rocker cover (after removing the intake ducting and TB) and pulled out a push rod and measured.

Stock pushrods are 7.05" long. These are my stock worn push rods.... This is my push rod length checking tool set at zero lash. I know I can get a 6.95" replacement pushrod, that would give me .0265" pre-load. Need to figure out what these lifters want/like. Or what will suit LS7 lifters...

Looks like there is still some residual moisture in the crankcase. Engine has only really idled up to temp and I'm sure the oil hasn't even been fully heated through yet. Really need to get that hose for the PCV system fitted so it can do it's job.

Looks like a 7.0" pushrod will be ideal and give us 0.0765" pre-load which is a touch over the max recommended .075" pre-load for LS7 lifters and smack bang in the middle for stock lifters.

I run the Ls7 lifter at ~.015" preload. Because I like rpm

In-Tech wrote:I run the Ls7 lifter at ~.015" preload. Because I like rpm

No noise from the lifters like that?

Not a drop over stock
The majority of my cams are a .365" lobe too

On the LS blocks, at temp the heads and block expansion works out to ~.010" (or .25mm) which still leaves me .005 preload. .015-.025" preload cold are my numbers on a build.
On the LS with a .365" lobe I usually end up with a 7.350" pushrod. I know yours is a different combo, just mentioning because the factory LS pushrod is `7.400" and has tons of preload, it is because factory stuff tolerances is quite different from performance realities.

Good to know. Will keep that in mind for when the LS7 lifters go in.

Cheers

Plan is to check for shim stock tonight at my supplier and maybe we can cut our own shims to suit instead of getting pushrods at this time.

We run 0.060 on the vb with ls7 lifters

Managed to find some .020 shim stock. Now to turn it into something usable under the rockers guide plates.

Hopefully this solves my noisy lifter problems short term. I've also ordered a filter service kit for the trans, O2 exhaust bungs and step drill bit to make fitting said bungs easier.

A bugger it, it's a beautiful day outside (22° in the shade, clear blue skies). Why not go work on a car and get a tan/burn!

Quickly stripped out the rockers and started on a plan. Getting good at stripping out rockers, literally a 10 minute job now. Shim steel is close to the correct width to make a shim plate for 3 rockers in one. So the plan is to cut 4 strips of shim steel, 30mm wide, 135mm long, turn down a 5mm edge so the shim will sit in place on the rocker boss's on the heads without sliding away to make assembly easier and drill some holes to suit. I'll take it back to work tonight and see if the shim steel will cut using the shears at work and then drill some holes/fold the edge. All going well I'll have a proof of concept sorted tonight and then will only need to replicate it 3 more times this weekend.