FD3/64 gas turbine run up in semi scale Rc Heinkel He 162

Run up checking my self build FD3/64 to 7psi with mods as below.

alloy open top compressor wheel.
Mark Drake designed combustor with curved vaporizer sticks.
Turbine wheel as per book but cut at an angle to reduce see through, wider blades also main turbine angle 37 degrees tip angle reduced by 2-4 degrees.
m/c from solid alloy front not spun as book,with nylon close fitting to compressor blades.
3% oil in fuel with a restricter fitted to send 3-5% fuel oil to bearings oil fed to front of front bearing air feed from front no air hole in middle of bearing tube.
3 normal size bearings fitted ,one at front two at turbine end.
Run up was to 7 psi case pressure at about 4.30 min max pressure is 7.5 psi which should be about 85k
Only 5c temp on the day and the pump was rattly/slack clearance making the engine run rough you can see the pressure gauge needle bounce and engine shake.