MG Car Repair: 77 mg midget alt. problem and oil pressure problem, high crankcase pressure, compression gauge

Question
Hi
I have a 1977 mg midget w/ 1500 eng. and webber carb. also, an aftermarket electronic ignition kit.
Before I put another alternator in is there anything that might be blowing out the electronics in the alternators.
The one i had in there for about a year(it was used) just stopped charging. I just put a rebuilt a guy had in his garage and it did not charge, I think I just got a bad rebuilt alt. but hate to put another one in if there's some thing wrong that would blow it out.
Also, I think I may have an oil pressure problem, If I drive more than a couple of miles oil starts to leak on the engine and the car stalls out. I feel like the oil is being forced out through the valve cover area, It as though there is to much pressure built up in the engine and no where for it to go. Could I have a bad oil pump or clogged screen or maybe some kind of clogged passages in the block?
Thanks
John

Answer
Hi John,
You can check the wiring easy enough, there should be just two wires going to the alternator. A large brown wire that is hot all the time and a smaller wire that goes to the Ignition light. Also check to be sure the polarity of the battery is correct. That is about all you need to do to check the wiring.

As for the oil leaks, you need to run a compression test, "Dry" and a "Wet" compression test. Be sure you hold the throttle open and let it turn over at least 4 or 5 revolutions on each cylinder. Then put about 3 or 4 squirts of engine oil in the plug hole and run another test. This is called the "Wet" test. The "Wet" test will be higher than the "Dry" test but it should not be more than 10% to 15% higher. Yours will probably be much higher than 15% higher on the "Wet" test. Which is a sign that you have a piston ring problem causing the high crankcase pressure. The oil pump has nothing to do with it. The oil pump only applies oil pressure to the bearing not the gaskets.

If you don't have a compression gauge, they are not expensive and can be bought at most auto parts stores and even at Wall Mart.
Let me know what the readings you get.
Howard