300 Inline 6 Oil Recommendation

Messages
16
I guess I will revisit for an oil recommendation for my truck now, after getting the 427w oil squared away. I have a 1983 Ford F-100 with a 300 Inline 6. The engine was rebuilt last year, just a mostly standard rebuild, .030" overbore, .010/.010" on the crank, mild Comp 268 hydraulic flat tappet cam kit, new valves, freshened heads, stainless LT header, Offenhauser 4bbl, Edelbrock 500cfm carb. Since I got it back and broken in properly with Lucas 30w oil, I have barely driven the truck. I need to change the Lucas oil out for some everyday stuff because it looks like the old gal will be towing my car trailer and Mustang to the local AutoCross about an hour away next week and then to Tulsa, OK (about a 6-hour trip) the following week for the track event there.

Since it is a 3-speed C6 automatic (also rebuilt last year along with the engine) with no overdrive and a 3.55 rear gear, the RPMs stay a little higher than I would like while cruising down the interstate. Usually sits right at about 3000 RPM at 65ish.

I do not know the bearing clearances on this one, but they should be close to factory. The factory recommendation was, I think, 5W-30. For these longer trips, do you folks think I will be ok with the 5W-30 or should I go with a good 5W-40 for a little more temperature resistance? Are the rumors about flat tappet cams with synthetic oils ("synthetic oils are too slick for flat tappet cams, they don't allow the lifter to rotate properly") true? Is there a need for extra ZDDP in quality synthetic oil? Should I just switch back to the Rotella 15W-40 I was using before?

Already have the Motorcraft FL-1A filter for this one.

Thanks in advance!
 
Messages
5,618
Location
Ohio
I use a conventional 10w-30 in my 1987 F150- 4.9 engine. My manual specifies 10w-30 or 10w-40 for temperatures above zero. Those engines did not have high tension valve springs so it is easy on the oil and you shouldn't need any extra ZDDP.

I have a 4spd manual shift with 3.55 rear end. I also rev about 3k at 65mph.
 
Messages
18,142
Location
Upper Midwest
I do not know the bearing clearances on this one, but they should be close to factory. The factory recommendation was, I think, 5W-30. For these longer trips, do you folks think I will be ok with the 5W-30 or should I go with a good 5W-40 for a little more temperature resistance? Are the rumors about flat tappet cams with synthetic oils ("synthetic oils are too slick for flat tappet cams, they don't allow the lifter to rotate properly") true? Is there a need for extra ZDDP in quality synthetic oil? Should I just switch back to the Rotella 15W-40 I was using before?
No.

Any decent brand of oil in any grade you mention is fine.
 

GimpyHSHS

Thread starter
Messages
16
I use a conventional 10w-30 in my 1987 F150- 4.9 engine. My manual specifies 10w-30 or 10w-40 for temperatures above zero. Those engines did not have high tension valve springs so it is easy on the oil and you shouldn't need any extra ZDDP.

I have a 4spd manual shift with 3.55 rear end. I also rev about 3k at 65mph.

How long have you had the truck/how many miles are on it? Have you had any issues with running the engine that high for extended periods of time? I'd probably be ok running a little lower speed if I had to, but I do want to get there eventually lol.
 
Messages
1,927
Location
South Carolina
You'll want more ZDDP for the aftermarket flat tappet cam.

Driven GP-1 15w-40 would be a good choice as it's pretty much designed for this application. That said, High Performance Lubricants HDEO 5w-40 is superior in most every way and about the same price. Both contain 1000+ ppm Zn and P with the later containing a lot more moly and detergents.

The myth that synthetic oils can't be used with flat tappet cams is just that... a myth. There's no truth to it whatsoever.
 
Messages
1,396
Location
Pacific Northwest
When you say you've hardly driven it since the engine rebuild, what does that mean? Have you driven it long enough to fully break in the engine? I wouldn't tow with it unless you've put a few thousand miles on it first.
 
Messages
102
I guess I will revisit for an oil recommendation for my truck now, after getting the 427w oil squared away. I have a 1983 Ford F-100 with a 300 Inline 6. The engine was rebuilt last year, just a mostly standard rebuild, .030" overbore, .010/.010" on the crank, mild Comp 268 hydraulic flat tappet cam kit, new valves, freshened heads, stainless LT header, Offenhauser 4bbl, Edelbrock 500cfm carb. Since I got it back and broken in properly with Lucas 30w oil, I have barely driven the truck. I need to change the Lucas oil out for some everyday stuff because it looks like the old gal will be towing my car trailer and Mustang to the local AutoCross about an hour away next week and then to Tulsa, OK (about a 6-hour trip) the following week for the track event there.

Since it is a 3-speed C6 automatic (also rebuilt last year along with the engine) with no overdrive and a 3.55 rear gear, the RPMs stay a little higher than I would like while cruising down the interstate. Usually sits right at about 3000 RPM at 65ish.

I do not know the bearing clearances on this one, but they should be close to factory. The factory recommendation was, I think, 5W-30. For these longer trips, do you folks think I will be ok with the 5W-30 or should I go with a good 5W-40 for a little more temperature resistance? Are the rumors about flat tappet cams with synthetic oils ("synthetic oils are too slick for flat tappet cams, they don't allow the lifter to rotate properly") true? Is there a need for extra ZDDP in quality synthetic oil? Should I just switch back to the Rotella 15W-40 I was using before?

Already have the Motorcraft FL-1A filter for this one.

Thanks in advance!
shear resistant for the highway revs

 

GimpyHSHS

Thread starter
Messages
16
When you say you've hardly driven it since the engine rebuild, what does that mean? Have you driven it long enough to fully break in the engine? I wouldn't tow with it unless you've put a few thousand miles on it first.

I have probably driven it about 500 miles since the 30 minute camshaft break in. Mainly around town and things. It certainly isn't ideal. I will probably drive it some this weekend and to and from work every day next week. It still needs some things done to it. I would like to get the new rear leaf springs on before the long trip at least. Needs a new power steering pump, mine works perfectly, but is leaking through the body of the pump. And I would definitely appreciate getting the new AC system filled before driving it much...

I am also not too sure on the bumper-mounted hitch. The plan was to put a receiver and 2" hitch on it last year, but I got sidetracked working on the Mustang and never did it. I have towed a lot of cars on a bumper mount hitch (my dad owns a used car lot and most of the hauling I ever did was with a bumper mount hitch on various trucks off the lot), but I would certainly prefer a receiver style.
 
Messages
5,618
Location
Ohio
How long have you had the truck/how many miles are on it? Have you had any issues with running the engine that high for extended periods of time? I'd probably be ok running a little lower speed if I had to, but I do want to get there eventually lol.
These engines are bullet proof. If there's oil and coolant in it, you can't hurt them. 3000 rpm in nothing, my redline is about 5500. I never came close to that. I have read that people have accrued 300-500k miles on them, running them harder than I do.
My father bought the truck new in 1987, I bought it from him in 1997 when he bought a new Ranger. I have 105k miles on it. I never had to open up the engine and use about one quart of oil in 5000 miles which is when I do an oil/filter change. My father would run the oil for 3k and then change it.
 
Messages
1,048
Location
Daytona Beach
I had one in a 1980 F150, and it ran about 100,000 before trade in. No issues.
My friend had one that wore out the timing gear at 300,000 miles (plastic teeth) so replaced that, sold it to another friend that put another 200,000 on it, no rebuild!
I think they used this engine in UPS trucks at one time. No guess on how many miles THEY would put on them!

What I'd like to know is this: Did all that work and money improve the power much? I always wanted more power when I had mine.
 
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