Oil consumption

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tekslk

tekslk

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I have a la 360 rebuilt 1 year ago that uses excessive oil. ! qt to 200 miles, doesnt smoke alot, smells rich at idle, heads are 73 360 we took to macchine shop had them checked they put new springs and seals in them and said they were great. I did a compression check all cyl were 155 to 158, Runs and starts fine just uses oil. I have no intake vaccume leaks but could it be the intake internally? Any help or suggestions is greatly appreciated, Thanks.
 
Have you looked underneath to see if you can see if any oil is getting down there?

That much should be almost gushing from the engine. Is there a spot in the place where you park?
 
Car is bone dry underneath and not a drop of oil on my garage floor. Im still leaning toward intake but can this be?
 
If the car is running rich, you are washing the cylinders with fuel, the rings will never seat.......
Fix the carb, change the oil, most likely it is dilluted with gas.
 
tekslk said:
Car is bone dry underneath and not a drop of oil on my garage floor. Im still leaning toward intake but can this be?
Click to expand...

If it's not leaking, it's burning it. What do the plugs look like?

I really find it unlikely that the intake sealed so poorly that it's sucking that much oil.
 
How can the intake leak oil when it only seals ports and water jacket?
 
Plugs couldnt burn a nicer color I didnt mean it was rich just has the oil smell when you stand behind the exshaust. Everything is great other than the consumption, It will smoke at the bottom of the mountain when I first give it gas then it clears up.
 
Do a leak down check, testers are around $40.00.
Rings not seated or valve guides are shot, my first guess.
Also check your PCV system, you need at the very minimum pcv valve on one cover and a breather on the other.
Does your dipstick push up after a hard run?
 
I made a mistake of using metal OEM intake gaskets on an aluminum intake. It burned oil sometimes and didnt most of the time. What type of intake gaskets you use?
 
The 273 in my Valiant burns 2-2.5 quarts a week. No joke. But...it's 46 years old. lol

How's the crankcase pressure? Could be pushin it through the rings, valve seals and/or intake gaskets.
 
Do you have the crankcase ventilated? Breather on one VC and PCV on the other?
 
pcv valve good breather on other valve cover, minimal blow by, I used rock auto gaskets but cant really answer your question. What exacly is a leak down test.
 
tekslk said:
What exactly is a leak down test.
Click to expand...

See here, this is a pretty good video for explanation purposes. An old boy told me once if it smokes going uphill, rings, if it smokes going downhill, valve seals.

A quart every 200 is a lot.

[ame="http://www.youtube.com/watch?v=GvG22YMOzUI"]Automotive Cylinder Leak Down Test - YouTube[/ame]
 
If you hear air in the following:


  • Tailpipe - exhaust valve/seat, cylinder head gasket, cylinder head
  • Throttle body, intake, or air cleaner - intake valve/seat, cylinder head gasket, cylinder head
  • Radiator - cylinder head gasket, cylinder head
  • PCV, Breather, or other crankcase opening - piston rings, cylinder wall, piston, cylinder head gasket, cylinder head
  • Outside - spark plug, cylinder head gasket, cylinder head, DI fuel injector


I'm wondering if your rings haven't seated.
 
During a leakdown test is good time to look at the plugs too, to isolate what cylinder is burning oil the most. What type of cam and valvetrain do you have? I had a rebuilt engine that smoked like an train. Every cylinder. I thought it was the intake too. It turned out to be cam had a little too much lift and at max lift the spring retainer was just kissing the valve guide seals enough and allowing oil to be drawn in under vacuum.

Burning oil can only come from a few locations. Past the intake seal, past the rings, past the valve guides, or in rarer cases the head gasket that seals the oil plumbing to the head.
 
I'd do the leak down test first, then pull the intake and look down the port to the valve stem. IMO, the guides are probably part of the problem, and cylinder wall finish, or cleanliness when assembled might also be a problem. How many miles are on it?
 
Im getting a diffrent intake from a friend so I will be putting that on soon.
 
I have a crane cam 484 lift, double valve springs, The heads are 1973 360 heads with 188 valves. doesnt smoke driving normal
 
Do a leak down before you pull the intake. If your determinate to pull the intake. Take The Time to Inspect the Gasket CLOSELY! If it has been sucking oil up thru it, you will see it on the gasket as well as the intake port.

My guess is the valve guides are bad and the valve seal can control it as the valve is walking around and stretching the valve seal.

Your spark plugs should be showing which cyl are using oil. Post up some pic of them.
 
O and that video, of doing a leak down test........well he left out a vary important point!

THE CAM MUST BE POSITIONED SO THAT BOTH VALVES ARE CLOSE, OR, THE ROCKER ARMS ARE REMOVE SO THAT THEY CAN BE CLOSED!

His leaking exh valve could have been because the cam was holding it open and causing the false leak!
 
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