15-01-2021, 06:35 PM
I believe a standard A7 pump is 1" bore and if it's in good condition there is no reason to overbore it, assuming a standard engine lubrication set-up. If your engine is pressure fed the pump configuration will depend to some extent on how it is set up.
As Paul says, it is not the diameter but the offset or eccentricity which increases output. Merely increasing bore diameter will only remove wear. My engine runs fine with a 20 thou increase in offset - but that's my engine and may not read across to front feed arrangements.
As Paul says, it is not the diameter but the offset or eccentricity which increases output. Merely increasing bore diameter will only remove wear. My engine runs fine with a 20 thou increase in offset - but that's my engine and may not read across to front feed arrangements.