thanks. so i am sub 110 but all within 10% and no blue smoke.
would it be safe to assume i need a valve job?
Not at all. Static compression readings reflect several engine conditions but the chance of having all the valves leaking "evenly" is less than miniscule.
Since the motor isn`t smoking that says the oil control ring and 2nd ring are still wiping oil off the liners adequately.
With your discription my suggestion is to check your engine`s cam timing.
If the cam timing is off it will likely reduce the static CR.
One of the "urban myths" scattered by many sources was the added power from advancing the intake camshaft and retarding the exhaust cam a couple of degrees.
This might help but only
at high RPM. In fact moving the cams in such a manner increases an already excessive amount of overlap killing low and mid-range torque/HP. The stock cams are not not going to reflect much power change at all due to their mild profiles.
Advancing cam timing needs to be clarified. Advancing the intake cam (clockwise) opens the valve earlier and retarding the exhaust (counter clockwise) closes the valve later. Both increasing overlap, reducing torque and reducing engine efficiency and reducing the static CR #s
you get when checking the engine with a guage.
To be clear these 1750 engines came with camshafts timed at various points LC wise depending on whether Euro carbed models, or USA versions with variable intake timing. If it was a spica car it had the vvt unit and the timing was to be at 114 int (100 when advanced above 1700 RPM) and 102 exh.
Alfa issued a TSB changing weber carb`d versions to 104 / 104 in the `70s.
The Euro 1750 used a larger lift version of their standard lobe design, and LCs were set at 99.5/99.5.. The drivability of these cams improved as well when reset to 104/104.
If your car has Carbs now, set the cams to 104/104 LCs and recheck the CR. Should be a bit higher and drive much better.
If it still suffers the Spica curse, set the cam timing on the exh side to 104 and make sure the intake side is not less than 114. If it`s a bit outside the 114 mark (cam mark to the intake side of the cap mark) that won`t hurt either.
If there is leakage issues the only way to determine where the compression is going is with a leak down test.