I got something for yall, I was talking to my friend and he said I should run 60 weight dino oil in my 351w, its drinking oil, and causing problems it never did, I put full synthetic 10w-30 in it, its just been giving me problems since I did a upper piston rebuild. Would I blow my oil pump out? It gets in the low 20s upper teens in the winter here, I am worried if my engine would be starved of oil if it was super cold out or just wanna implode, I have always put in factory oil in most of my vehicles. Any help is appreciated thanks guys!

 

I also lapped my valves, but I don't think I did it right, he also suggested marvels mystery oil to help my upper cylinders since I lapped them wrong, thought I would also pitch that.

 

20w50 conventional would be the thickest I would use during the summer. 10w40 in the winter. Too thick of oil will twist the oil pump driveshaft like a candy cane and snap it.

 

Per Ford Technical Bulletin, 5W20 is the revised weight from previous recommended Ford 10W30. Heaver oil is only masking your problem which you can do but it should be repaired properly. Just depends on your long term outlook for the truck.

 

the most i would run is 15-40. my experience with synthetic is engines not designed for it use it. go back to regular old oil and the engine stops leaking burning oil.

 

Yeah I don't want to turn the rod into a piece of licorice. I have been looking at my oil pressure and its right of the N or normal it was higher in the winter, I would imagine its because its warmer here. I just need it to not consume a quart every 100 miles, which is what its been doing.

 

What is an upper piston rebuild?

Lapping valves incorrectly would not cause the engine to suck oil, it may not run right, but not suck oil.

As for what oil to use, I use a full synthetic oil, 10w/60. I guess the Ford engineers would prove I am an idiot. Never had a problem in over 15 years. I used to run 15w50 full synthetic before that. In other words, for over 25 years, it's been using the wrong oil and synthetic to boot. Never had a problem. I also change it out every 5k.

 

I pretty much rebuilt everything except the pistons and crankshaft, but it was mainly everything that was above the pistons, I imagine there is a term for it. Thats weird, the engine runs really good, I should do a leakdown test. I would love to use that viscosity of oil, I am just worried of my pump shaft snapping, I did rebuild the oil pump, it looked good, maybe it will be fine running that thick.

 

Stick with 10-30 for that old 351
That 60w is for aircraft?
Don't use that ever
I would stay away from the thinner oils, like the bulletins recommend
That is a fuel consumption thing, not a motor longevity thing
All manufacturers now recommend thinner oils in all their previous powerplants
Like I said it is a fuel mileage thing, same as the low tire monitor system
They care not that you might have a flat, they are concerned with excess fuel use

 

10W60 is used on BMW Motorsport engines [factory spec road cars]. 15W50 was factory filled on the McLaren SLR.

I use my truck for towing. It's a Kenne-Bell supercharged 5.8L [351W]. I am really old school and I could really care less about getting that extra .1 mpg towing my 5th wheel. For some reason, in my head, I want to know the oil film is a bit thicker on the low rpm towing that I do. It makes me feel comfortable and in life, that is all I am trying to make happy. My wife gets the benefit that we are not broken down on the side of the road.

Could a thinner oil work? Probably, but I do not want to find out. I know what works for me. BTW, I never drive it when the outside temps are below 40F. I do not think I would be using it if it was below 0F. I think my bigger problem is why would I be there if it was that cold.

I'm posting my information as proof that it does work for one person on the earth. It also has since I have purchased it in 1997. Facts are better than opinions. Like all decisions in life, picking the oil you want is your choice. The only right decision is what the factory recommends. The problem is, oils have improved substantially over the years so what was good back then is not the best you can do now.

I think TPMS's are great. I also believe they were mandated not for fuel economy, but for SUV crashes. It really would not matter, they have perfected that system so it's reliable now. The first few years were terrible.

 

I really appreciate the input guys looks like I might switch it up when I get some extra cash. Thank yall for your time!

 

Agreed on thinner oils for engine. No thanks.