crankcase compression and breathing problems

[niftyrodman]

I have learned something today and that is the design of the cam cover breather on the early motiors was designed to create vacuum as the vehicle travelled at a cruising speed, and Ive been corrected in relation to crank leaks that are more about the balance of air than excessive oil pressure. Well as I was driving down to Dover Tasmania, I was thinking about this dilemma and in my engine which is "new" in the reconditioned sense, while it is idling has quite a bit of air exiting the rocker cover breather outlet. Is it possible that this air flow would be reduced, when travelling, by the induction of the cam follower cover breather? Ive noticed a few drips of oil emanating from this down pipe, and have stopped that by inserting a vey small rectangular piece of the open stiffish sponge material,in behind the thumb shaped plate inside the cover. This stuff you can buy in a square, that is designed to fit in the air cleaner pocket of some 80s cars with pcv valve setups in breather situations. Anyway I, guess no matter how new an engine is there will always be a degree of blow by from compression.

[paul 300358]

I have a mini non vented rocker cove fitted with a vented oil filler cap, a standard mini tappet cover with the oil catch can built on which is connected to the vacuum pipe on a HIF38 carburettor. I have no oil leaks but 70lbs oil pressure at 30 mph hot or cold.

I did have to extend the catch can pipe as the can and the bottom hose end up in the same place.

[niftyrodman]

Yes well, theres no doubt that I have an overpressured crank case, and perhaps that is a lesser problem solved by 1 Use the fuel pump blank plate to add a crank breather with a catch, and 2 Improve the front seal wih the solid damper and the modified timing cover. I am grateful for the continuing helpful suggestions by all. As far as the oil pressure is concernred, there is no need in my view for a 70 psi pressure I now have a cold 60 psi and a hot 38, and I cant see any reason for any pressure higher.

[niftyrodman]

Yes well, theres no doubt that I have an overpressured crank case, and perhaps that is a lesser problem solved by 1 Use the fuel pump blank plate to add a crank breather with a catch, and 2 Improve the front seal wih the solid damper and the modified timing cover. I am grateful for the continuing helpful suggestions by all. As far as the oil pressure is concernred, there is no need in my view for a 70 psi pressure I now have a cold 60 psi and a hot 38, and I cant see any reason for any pressure higher.

[niftyrodman]

Thanks to Phil, I found a catch can with sight glass on line, and I will fit it on the suggested fuel pump cover plate. I bought a 1/4 BSP tapered tap yesterday to fit an air line fitting to the plate. A simple addition, that makes sense.