I'm not talking big leaks, but the 'marking your spot' kinda leak. I've been told a few times that 'they all leak a bit' surely that's not right. If put together properly shouldn't they be oil tight?
Ok, so they shouldn't, but do just when I bought my van it had a 'recon' engine but leaked oil, the vendor said "they do leak a bit" then at the weekend it was at a vw specialist and when my youngest son pointed at the oil drip on the floor the mechanic said " yep, reminds you to put oil in" It's difficult to see exactly where but appears to be at the split in the case. Would I be trying to achieve the impossible in building an oil tight engine?
depends where the leak is and if you can stop it. Mine leaked from the distributor mount because someone didn't put the right seal in, put a new seal in and now no leak.
I think most engines will leave a spot or two on the floor but shouldn't be much more than that.
Rear mains oil seal is a really common leakage point, as is pushrod tubes and valve covers. Mine drips a bit, valve covers mainly, tho' the sump drain bolt drips a bit as well. I'll fix it, one day...
Generally they all seem to sweat a bit , but I did once own a '66 Karmann Ghia for 7 years and it never shed a drop in all that time (nothing) -so it
is possible.