OIL CONSUMPTION/FRUSTRATED

[BYGDDY]

Hey guys, in a nutshell, 350, mild rebuild done app 15000m ago, 268 cam, supposed to be forged pistons, stock crank and rods, i bought it a month or so ago, the previous owner had warned me that it uses a bit of oil and he was certain it was valve seals.....i get it home and drive it app 1000m over a month and its down at least 3ltrs of oil!!! On start up there is zero smoke, driving around town, zero smoke, but at high rpm, 4500-6000rpm it has some minor smoke, i swaped intakes and carbs, in that process i left the pcv out and just had breathers installed, that then caused the dipstick to push out and spray oil all over my headers....alot!!! so back went the pcv valve, and no more exsessive crank case pressure...but still using a significant amout of oil....i thought intake gaskets, but then realized it was doing the same thing before i did the swap, it runs fantastic, has 35psi oil pressure at idle hot, and 50+ cruising....i had plans to go with good heads, more cam, etc etc, but now have those plans on hold thinking the rings are pooched....any ideas or input??? Thanks
Dave

 

[bowtie81]

Sounds like too much crankcase pressure, and some bad rings. I had roughly the same thing before no smoke at start up nothing driving around but it used up oil cause the rings were shot.

 

[BYGDDY]

Sounds like too much crankcase pressure, and some bad rings. I had roughly the same thing before no smoke at start up nothing driving around but it used up oil cause the rings were shot.

Yah thats where i was leaning as well, im wondering how much butchery "budget based" i can get by with, like dropping the pan, pulling the rods and slugs, and self honing, new rings, reinstall, and see what happens......?

 

[tiedyemike8]

You'll have to pull the heads and look at the cylinders to find out. If they are scored, honing and new rings wont help.

 

[BYGDDY]

You'll have to pull the heads and look at the cylinders to find out. If they are scored, honing and new rings wont help.

Yah, im thinking a fine winter project, for now, it runs good, like real good lol, so drive, add oil, repeat!

 

[Hotrodrobert]

What is the oil level in the crankcase? I had a SBC that used lots of oil and found out the dipstick was about 1" too short so it had too much oil in the pan. It would use a quart in about 200 miles. When the volume of oil was checked and the stick recalibrated, the oil consumption stopped.

 

[BYGDDY]

What is the oil level in the crankcase? I had a SBC that used lots of oil and found out the dipstick was about 1" too short so it had too much oil in the pan. It would use a quart in about 200 miles. When the volume of oil was checked and the stick recalibrated, the oil consumption stopped.

Yah, i wondered that as well, but 5ltrs is rightish, and it doesnt stop using oil, 200miles and down a quart, yet had a buddy follow me couple weekends ago and pounded it mercilessly, (see my broken 7.5 thread lol) and he said nothing visable, on accel, around 5800 he says just a hint of smoke, small small puff as i shift, but that was it, on decel, nothin.....so frig i have no idea, well, some idea actually lol, pulled the plugs, oh man, i have no idea how this thing runs at all, they are totalled, caked with chunks of everything, oil, shiny stuff, but mostly oil, brutal......so new plugs going in and i guess i will just keep changing em till i do the motor this winter.....sigh.....