Finally fired up my winter build last weekend. Car is a 2008 z06. Motor is a brand new 363ci gen 4 aluminum block with trick flow 220 LS2 style heads, ls2 intake, johnson 2110 lifters, BTR stage 3 twin turbo cam etc. I fired it up and it builds up 60PSI oil pressure and the motor sounded very healthy. No tapping or noises, just like every other healthy LS i've ever had, so that was a releif. The car idled like crap though and sometimes wouldnt even stay running. I checked the log after I shut the car down and it seemed like I had ~85kPA MAP pressure at idle which seems very high and almost (to me) indicates a vacuum leak. I tripled checked all obvious areas and did not see any issues. Visually everything seems like it is sealed up just fine, including the brake booster connection on the back of the manifold.

Im still waiting for my tuner to get back to me with an updated tune, but while I wait im doing my due dilligence to ensure it is not a mechanical issue on my side.

Before the motor was installed i measured for pushrods and came up with 7.400 to zero lash. Johnson calls for .035" preload +/- .010. Pushrods were available in 7.425 or 7.450 but I went with the 7.450 since most people seemed to agree 0.050" is fine for the Johnson 2110 and also aluminum motors will expand more as they heat up which will reduce that number. I just doubled checked multiple cylinders on both banks last night and got similar numbers at 7.3875 up to 7.40625. If I add .035 to that smallest 7.3875 number I get right at 7.425. I am wondering if maybe I should have gone with the 7.425 pushrods, but Im looking for some opinions from you guys. The pushrod length cannot be drastically off as I seem to measure within .018" difference to zero lash MAX across the board. Like I said, just trying to do my due diligence and make sure Im not hanging a valve open or something. One other thing I noticed on some valves was when I tightened to 22ftlbs, the lifter seemed to not compress at all and the valve would open slightly. I am wondering if this is normal or not. Ive done a bunch of cam and valve spring swaps on LS motors before and can't say i've noticed that before. This is my first set of Johnson 2110s. I am positve the lifter was on the base circle during all of my checks.

One other thing I forgot to do was apply sealant to the intake rocker arm bolts. Not sure if this is the case on stock style LS1 heads, but the intake rocker bolt hole goes right through to the intake port on the head. I will be applying some sealant to all of those, but I am doubtful that would cause a major vacuum leak.

Again, mayne the tune just needs work and i'm being paranoid, but im doing my homework in the meantime. Thoughts welcome.

 

I've tightened more than a few LS rocker arms and I've never seen one open a valve if the lifter was on the base circle. I have no experience with Johnson lifters. I've always used stock or Caddy racing lifters. That just doesn't seem right though.

Edit....maybe throw in a set of stock length push rods and see if the problem disappears.

Edit (again)....just noticed you're dealing with an LS7. Don't know what stock length LS7 pushrods are, but meant try some 7.4". Surely you or someone around you has some laying around. If that cures it, you know the ones you're using now are too long.

 

I know I had to apply sealant when using Trickflow 225s.

 

Same. But this is my first time with these lifters. Some reading online says its normal and the valve will close after a few minutes after the lifter bleeds down.

Going to grab some later today. Also ordered some Tick 7.425 pushrods just in case.

 

One other thing I noticed on some valves was when I tightened to 22ftlbs, the lifter seemed to not compress at all and the valve would open slightly. I am wondering if this is normal or not. Ive done a bunch of cam and valve spring swaps on LS motors before and can't say i've noticed that before. This is my first set of Johnson 2110s. I am positve the lifter was on the base circle during all of my checks.

My 2116lsr did the same thing & it runs quiet & smooth (except for the mild cam chop) That being said I did custom P.R.sizing though Manton, we did 3 different size groups that were within .012" of each other. I would not feel comfortable with .050" preload, .045" yes. I would call Johnson's tech he's very helpful

 

Sealed up the intake rocker bolts tonight. Re-checked everything and fired the car up but without the MAF plugged in. Ran much better and MAP pressure was around 45kPA at idle, which I believe is more normal for a cam this size. Makes me lean more towards my running issue being tune related and not necessarily mechanical.

 

Sorry for reopening a dead thread but I am currently building a motor with a very similar set up (stage 3 twin turbo btr cam and some Johnson 2110R’s). Did you end up switching out the 7.450 for the 7.425 pushrods?