460 is a huge oil burner

[pacem]

this 460 engine has 45K mis on it but burns oil badly, 1 qt in about 700 miles. I hear this is common for 460s. Any suggestions? It doesn't seem to vary with different oils.

I plan to use Chevron Delo 400 15w-45 with a bit of Mobil 1 5w30.

 

[Bdiddy]

Why not just go for straight Delo?
HDEO oils have excellent performance in all areas except very cold weather, IMO. No need to mess with
mixes.

Have you ran any of the HDEOs in this vehicle before? I find that they can do wonders as far as leakage/consumption is concerned. If you're lucky you may not need anything else.

 

[Motorbike]

quote:

---

Originally posted by pacem:
this 460 engine has 45K mis on it but burns oil badly, 1 qt in about 700 miles. I hear this is common for 460s. Any suggestions? It doesn't seem to vary with different oils.

---

Some of the 460's and 6.9's suffering from oil consumption are from the lack of concentricity of the valve guide ID and the OD of the guide chimney which is often a cause of premature seal failure .

Some engines may be off as much as .030 from the factory so I hear .

It can be reworked by centering the guide and remachining the guide boss.... with the heads off though

If the engine pings it will destabilize the piston ring pack and burn more oil... I'd make certain it does not ping .

Is this the truck that see's only occasional use ?

PS . Those 460 can burn a little oil and live a very long life

 

[pacem]

yeah, the mileage is so bad with these big blocks, under 10mpg when towing, and not higher than 11 when not, that I rarely drive it.

It does run wonderfully however. No pings, smoke, lack of power or anything.

 

[pscholte]

If Motorbike's suggestion is not the problem, then I think a straight 40 wt in the summer and a 15W40 in the winter might be a good approach. Your VA climate should accomodate that easily.

 

[pacem]

are there any problems with using a straight-weight, like slow pressure build-up at starts?

 

[pscholte]

I don't believe there are any pressure build up problems; it is wise to let an oil that thick warm up a bit before you get on the engine hard and of course, get it out before the temps get to or below freezing.

 

[Gene K]

quote:

---

Originally posted by pacem:
yeah, the mileage is so bad with these big blocks, under 10mpg when towing, and not higher than 11 when not, that I rarely drive it.

It does run wonderfully however. No pings, smoke, lack of power or anything.

---

F350 4x4
460 7.5L EFI
5-Spd Manual
4.10 Gears
35" Tires

16 MPG Highway
11 MPG City

No Oil Use

Gene

 

[pscholte]

quote:

---

Originally posted by Gene K:
F350 4x4
460 7.5L EFI
5-Spd Manual
4.10 Gears
35" Tires

16 MPG Highway
11 MPG City

No Oil Use

Gene

---

show off!

 

[TallPaul]

quote:

---

Originally posted by pacem:
yeah, the mileage is so bad with these big blocks, under 10mpg when towing, and not higher than 11 when not, that I rarely drive it.

---

I have a 460 in a motorhome (27' cutaway van, 1990) that weighs about 10,000 - 11,000 pounds (comparable to towing). I get between 7.5 and 8 MPG!

Oil usage, though, is an apparently moderate 1 quart per 3000 miles.

 

[pacem]

I heard that oil usage is contingent upon RPMs with this motor. I have a 3-speed auto transmission and at highway speeds, I am turning pretty high rpms. 3,000 at 57mph in fact.

I wish I had a 5-speed manual, because that would really keep my rpms down, enable better mileage, save the engine, etc.

I hear that 11mpg is the norm for 3-speed auto, while the newer overdrive transmission and especially manuals add a few mpg.

 

[OffOrWFO]

What year is the truck? I assume it is an older non EFI if it has a C-6 behind it. Sounds like you also have 4.10:1 gears. I had a 1985 truck with a 460 in it with 4.10 gears. Burned a Qt in 800 miles since it was new. Never changed in the 140K that I had it. Still ran great and when it was sold in 1999. Rear gears were changed at 95K to 3.50:1. = 75MPH @ 3000 Rpm. Mileage and oil consumption didn't change at all but I also ran it faster with the taller gears. Don't worry about the oil burning as it will not effect the life of the engine. The oil burning didn't seam to be from the valve guides as there was never any smoke on shifts and sudden lifts after hard runs.
Fuel mileage was 7-10 towing and 11-12 unloaded.
My truck also benifited greatly from a straight up/non retarded timing gear and chain. The original nylon/plastic gears didn't wear very well and should be changed at 100k. They also retard themselves quickly as they wear. Add that to the factory emmisson driven retarding and it leaves room for a substantial 20-30hp increase plus better fuel mileage

 

[pacem]

It's an 89 but the engine is newer. Yes, I have C6/4.10 in it but it's too low. I would change to 3.55 except that I decided I need a manual transmission instead.

It doesn't smoke in any color in any circumstances.

Thanks for the tip on timing chain.