by Joe Curry
If you have removed any of the emissions equipment (particularly the air pump) from a Spitfire 1500 engine and it blows oil out various places, like the dipstick tube, it is quite possible that the problem is being caused by excessive crankcase pressure. Early Spitfire engines were engineered with an open breathing system. With emissions legislation, the systems were closed and the emissions equipment was used in part to help relieve the crankcase pressure. If local emissions requirements dictate that the equipment not be removed or disabled, all parts must be brought up to working condition.
Under certain conditions, it may be legal to remove the emissions equipment. One such case is using a 1500 engine in an older car that does not require emissions equipment. The pieces can be removed but to prevent oil from being blown out of the engine, the breathing system must be opened.
The system can be opened as follows:
If the car has an electric fuel pump, the port on the block makes a great place to mount a blow-by relief port. Fabricate a cover plate with a pipe the same size as the one on the valve cover. Connect a hose to this pipe and bend it upward to the top of the valve cover and then downward into a vented catch bottle. Pressure being built up in the crankcase will be vented into the catch bottle trapping any oil that is carried with it. Most oil escaping the block will be trapped in the hose and run back down into the oil pan.
If the hose from the valve cover has been disconnected from the carburetor, relief valve or carbon canister (as applicable), it can be tied into the catch tank using a "T" fitting as used on some variations of this engine. The carbon canister makes an excellent catch tank if it is no longer being used in its intended configuration.