I just got done with a rebuild for my 06 LSJ. New crank bearings, connecting rod bearings. The block and head decked. Cylinders bored to fit 86.5mm (recommended to bore by machinist).


I started the engine after priming the oil system. I then primed the fuel system. Once it started it would die. Started again and held at 1-1.5k rpms. Checked for codes. Had a P0300 code. Checked the interceptor gauge for misfires. Cylinder 3 and 4. Pulled plugs and checked compression. Cylinders 1-3 have 170-173psi while #4 has 0psi.


i have not pulled the valve cover yet nor done a leak down test. Once I had seen that I decided to be done for the day with it after dealing with a few issues along the way. I will update with what I find from it.


block has 150k miles and the head is a B207R head with 50k miles. All LSJ parts minus the head.

 

You can have 0psi in a cylinder if the valves are hanging open. Maybe take off the valve cover and see if you have anything hanging up in there. Do you have stock cams?

 

I am still running stock cams. I have yet to pull the valve cover off it yet. I’ve just put inconel valves in the exhaust and nitrate on the intake. New rocker arms, and 82# springs.

 

Did you lap the valves when you installed them?