Thanks for the advise guys took a better look at this today

Struggled to see abything with transducer even when restricting intake

Have got some waveforms I'll post up incase some of the more experienced ones can spot something on it for fortune reference.

But did a normal compression test.
dry test
Cyl 1 140
Cyl 3 200
Cyl 5 205

Cyl 2 200
Cyl 4 200
Cyl 6 190
Wet test

Cyl 1 170
Cyl 3 220
Cyl 5 205

Cyl 2 210
Cyl 4 210
Cyl 6 210

I set number 1 cyl to tdc compression.
I haven't got a leak down tester so put smoke machine In. In hope to simulate something similar

I had smoke coming out of number 5 plug hole
Cyl 5 being on exhaust stroke.

This suggested to me burnt exhaust valves.

Anyone else think different?

So it's left on ramp partially stripped stripped ready for head to come off on Monday at some point