The OP only has about 100 miles on this rebuild. It would seem very odd that the oil filter, he indicated was a Bosch, which is an ISO certified oil filter, would become clogged.
A 22 engine sitting for 3 or 4 weeks will not have enough oil left in the filter to make a diddly difference – and if anyone can show me otherwise I’ll be waiting right here for the proof.
Even if the “anti-drainback valve”, which is not leak proof, did keep the filter full of oil after the engine is turned off, the amount of oil in the filter will not make ANY measurable difference in oil pressure or flow after the oil pumps turns and begins to suck oil from the oil pan.
The amount of oil in the oil filter at start up has virtually no measurable effect on the failure of timing chain, tensioner, or guides.
That’s just my worthless opinion.
Gnarls.
