Re: no compression

Posted by Fish'n Jim On 2014/5/29 21:20:10

I thought about this some more and think the "old gas" is a symptom not a cause. If your gas is sitting around in the tank long enough to get "old", then you're not exercising your motor car enough.
There were studies done decades ago, that most of the wear in the internal combustion motors occurs during start-up, when the parts are turning but the oil pump hasn't established flow. Essentially a short run without oil. The longer it sits between starts the more the oil drains out of the system to the pan. That slow flow out can leave deposits behind. This is a known problem on race engines and they turn them without firing until the oil pressure comes up after builds. Tolerances are tighter here. They came up with break in oil and lubes now to minimize this.
If you're not starting your engine every week/daily then probably may want to think about disconnecting the coil wire and turning over with the starter until the oil circulates/pressure comes up. Might be hard on the old 6V starter, so don't over do it. Let the starter cool down before cranking again with the coil connected. And don't rev the engine "cold". Let it warm up before revving, if at all. They don't recommend idle warm ups anymore so a slight increase over idle is better than a large one.
Change the oil, at least yearly instead of based on mileage, if you don't drive enough to get to oil change in one year. It still degrades once the engine has fired. Combustion products go into the oil and the oil additives only last so long.
Depending on the type and age of motor you have, other maintenance might be called for.
Solid lifter motors need to have the valves adjusted properly too, because if they're loose/tight, it damages the valve train. If the motor wasn't completely rebuilt, there's likely sludge and deposits in the valves, oil pasages, etc, so inspection might be necessary also. They used leaded gas and that liked to build up crud on the valve stems. Some of these motors don't have oil filters and that's makes it even worse.