liquidzorch

Hello, I have a 93 honda civic with a d15b7 engine. ever since i bought it about 8 months ago it has always had blue smoke come out of exhaust only at high rpms (about 4000rmps). About a week ago I went on the highway and after about 170 miles a water hose busted and the car heated up, the head gasket blew, anyway I got the car back home on tow truck, I didnt even try to start it, I put the new head gasket on, checked the head, and changed the valve stems. Now I have it running good again but when I put everything back together i broke the oil breather hose that connects to the intake manifold. It runs well without it, I just clogged the intake manifold side with plastic so no air gets in. I bought the hose and when I connect it to the pcv valve and turn on the car the rpms go way up, it seems like the oil breather has a hole or something where air can get by. My first question is: is it ok to run without it connected? what I have read is that that pcv valve is there to let out any extra air in the crank case, so I would guess that it doesnt need to be connected.

And one other question, its what is bothering me the most. The car only sometimes smokes at low rpms now, but it is only sometimes. Yesturday I drove awhile and no smoke out, only at high rpms like I said before. And today I drove the same amount and half way to my destination it started smoking even at idle (700 rpms). I tried to see if there was anything different that I do when it smokes but I do the same drive, the same roads. What can cause the car to smoke at low rpms only sometimes?

I cant check compression since I am in a town where nobody has good tools. I know that my smoking problem at high rpms is indeed the piston rings, but why does it smoke only sometimes at low rpms? any help would be great. thank you.