Morris Minor Owners Club

I have the engine breathing setup with open pipe in tappet side cover, non vented filler cap and rocker cover pipe into breather tube on side of carb. Engine idles fine.
Can someone confirm if the following should be happening or is there some impending doom looming.
1. If I remove oil filler cap then revs drop off.
2. If I remove the cap and put my hand over it I'm feeling a blow out of the rocker cover.
Does this sound right or am I starting to worry too much?

That 'blow' with hand over is not great - suggests to me that the cam follower cover and/or rocker cover breathers are blocked. Take them off and rod them through! And is the air filter plastered with thick oily mess..... When you rev up with cap off -is there a 'plume' of smoke/fume?

OK, testing a bit limited at the moment due to being at work. This is what I have managed.
1.With cap off a good few revs doesn't produce any smoke.
2.Rocker to carb pipe is clear, can blow through that. Air filter OK as pipe feeds into side of carb. It is a bit oily though.
3. Tested suck/blow with filler cap a bit better with a sheet of paper in case my club hands couldn't feel properly.
4. Sheet of paper completely over cap hole stays in place so there must be suck. If I move it to leave a slight gap you can feel a slight blow up to 2/3 inches away, sheet starts to jump about and idle drops.
5. With cap on and finger blocking open end of pipe on cam follower cover then revs drop. Same effect as taking off filler cap but to a lesser extent i.e. revs don't drop so much.

Doesn't sound as bad as first thought then but just not sure of the change from suck to blow when the rocker cap 'seal' is broken. Any thoughts? Hopefully better than the ones when I walked back into the office looking like I had black lipstick on.

Hahahah - it sounds pretty much exactly as it should be then! And the connection to the carb is MUCH better than to the filter.

Phew, that's a relief. It was the changing from blow to suck when the cap is removed that I didn't understand.
I have always used a carb with the intake to save the airfilter....
Thanks for your confirmation Mr BMC.
Just need to get this bl#@dy lipstick off now....