I’ve just refitted the heads on my rebuilt jubilee engine and I’m only getting about 35psi compression on each cylinder. Stripped & cleaned all parts, honed bores & fitted new std pistons & rings as bores showed very little wear.
I haven’t yet refitted the idler timing gear and there are clearances under all the tappets.
Any ideas where I should start looking first?
Similar thread on the singles section M50 compression.
Most answers will be similar - WOT, crank speed, temperature etc,etc.
Fwiw, 35psi is very low and sounds like a closed throttle figure.
Your closed throttle comments have enabled me to realise what an idiot I’m being -
no timing idler = inlet valves closed = low compression!!
Dunce hat please!
What should the psi compression be on these engines.
According to the engine data sheet I have, attached it’s a compression ratio of 8.75:1 which works out to be about 128psi.
once I get a chance to assemble the timing gears properly and then check my compression I’ll update the thread with the results!