Model A Ford oil change?

I'm sorry to hear about your loss, so I really hope I can help. I'm not a Model A expert, but I do know a little about oil. As a rule, older cars used heavier weight oil. Modern cars can get away with 5w-20 or less, but older cars more like 30-50 weight oil. The critical time is when you first start the engine. If the oil is too thin and has all run into the pan, the upper engine will be starved of oil. It needs to be thick so enough stays at the top. The other factor multi-grade vs single-grade oil. Multi-grade oil wasn't used much until after WWII, so your car was designed for a single weight. 10w-30 means the oil is about 10 weight when cold and 30w when hot. This makes staring a cold engine much easier than if it were straight 30w. Since you only use the car in the summer, you could use a single-grade oil just fine. I think the original oil was about 40w, so I would shoot for that.

The other factor to consider is additives. Almost all modern oil has detergents that will remove sludge from parts of the engine. Old oil did not have detergents and you had to worry about sludge all the time, hence the 3000 mi or less oil change advice (5000+ is plenty for modern cars/oil). If your dad used oil without detergents (less likely, but possible), adding oil with detergents will suddenly release all the deposits and you can get blocked oil passages, so tread carefully.

You also have to worry about ZDDP (Zinc dialkyldithiophosphates). Old oil had lots of ZDDP because it is such a great lubricant. However, it slowly wrecks catalytic converters on new cars, so modern oil has much less. Using modern oil with low ZDDP can slowly damage the engine, so make sure you choose an oil with a decent concentration of ZDDP (say >1500 ppm). Sometimes this isn't possible so you have to buy a third-party additive package which will boost the ZDDP levels.

This is why you have to drop the pan if you don't know: http://www.youtube.com/watch?v=jbqW6uHpASM If you are careful, you should be able to reuse the same gasket. If it leaks afterwards, then you will obviously need a new one.

Read this: http://www.rockymountainmodelaclub.org/Tech_Articl...

Good Summary at bottom: http://www.markhaywardismyhero.com/2008/11/18/what...

Special oil for classic cars (http://www.classiccarmotoroil.com/) multi-grade though, but has great ZDDP levels and extra additives for storage. A little pricey.

Ford Model A Engine Oil

First my condolences on your loss. My dad would probably know, too. But... I would recommend that that you find a Model A club. Car clubs are great sources of information and members help each other. Even if there isn't one in your area there are national clubs and with the web today, they are almost as good. Good Luck!