What kind of oil can the oil pump in an early 240 take? Right now I have 20W-50 in it and it runs fine. Was thinking about 60 weight, but I think that is a little heavy.

 

id just use 10 or 15 most. i run 10W30 in my 78 300 6

 

60 weight seems a little heavy. I think it may qualify as grease (just kidding, I don't know when grease starts, but I know 85 is grease).
I've used straight 30 in the summer for extra protection. Usually the straight grades like 30 are non-detergent and someone told me once,always use an oil with detergent.

 

For your engine, I would stick to ao 5-30, 10-30 or 15 weight oil. Don't go much above that, or you could actually be doing more harm to your engine than good. Also, using a heavy oil like that causes your engine parts to have more internal drag, thus reducing power and fuel mileage. While it may not be very noticable, it is true. Also, using a heavier oil than recommended can can cause sludge build up, especially if you only run your truck for a few miles at a time. This is because the engine never gets a chance to warm up properly, which means that the oil doesn't warm up properly. This lowers the viscosity of the oil since it never gets a chance to warm up and become more viscous. This combined with the possible water vapor in the engine causes the oil to sludge on the heads other areas of the engine. Finally, using a heavy oil like you are can starve certain engine components from getting the proper oiling, this reducing the life of these components (this mainly applies to head components). This is also because the oil is not viscous enough to get through the oil passageways properly. Think of it this way, its like the difference between how well water will drain through a funnel, as compared to how well cold mollasses will drain through a funnel. Hope this helps out a little.

 

Hoyt is correct. Also, there is a posibility of breaking the drive gear for the oil pump/distributer.

 

Well, I guess it partly depends on what you are trying to accomplish. I spoke to two highly respected mechanics in my area and discussed my situation and desire to reduce smoking. They said in very old vehichles with high mileage, they have used gear oil, which is 85wt. Both of them said this independently. Two different shops, completely unrelated. I decided to go with straight 40 wt for the hot Florida climate (96 degrees today). During the colder season I might drop to straight 30.

 

[updated:LAST EDITED ON 09-May-02 AT 10:31 AM (EST)]I can't imagine using a straight weight oil for anything. Oops. I do have one application... in oil bath air cleaners. That's it. I don't even use that in my lawnmower. 10w30 or 10w40 is what I've been running in my '70 240 since I bought it in '79.

I'd use 50 or 60 weight to get it to the junkyard if the bearings were completely shot. Else, that tar is way to viscous. Takes forever to pump up there. Thicker isn't better. What the manufacturer specifies is best...they designed those engines with a given viscosity of oil in mind.

 

When it comes to engines with 214,000 miles on it, i will go with my mechanics recommendation, b/c i think he is right. Sure, the manufacturer recommends a 10/30 or something like that, but it's for normal circumstances. As the engine becomes as worn as mine with 214k miles, the thicker oil improves oil pressure and reduces the amount seeping into and around the pistons causing smoking.