C2 oil consumption

[Joep F.]

Board members,

What is according to your opinion an acceptable oil consumption of a '65 327?
I added about 1 liter after 700 miles driving, is that ok? My oil pressure is allright.

Thanks, Joep

[Mike McKown]

My opinion is

if the car leaves an embarrassing trail or cloud of smoke behind it, it's time to fix it. You're probably borderline there.

If you drive the car very little, that's the approach I would take. It could run many years this way. If you expect to drive it a lot, maybe you should go ahead and fix it.

I'd guess the majority of 327's when new used about a quart of oil every 2000 miles based on what I saw as a gas pump jockey back in that day. Many used more, some less.

[Roy B.]

Re: C2 oil consumption

Not to worry

[Gerard F.]

Re: C2 oil consumption

Joep,

My 67 327/300 with 61000 miles, uses a quart per 1000. No blue smoke so I'm not worrying about it. Just switched over to 15W40 C1-4 for diesel engines, to see if that makes any difference.

Jerry Fuccillo
#42179

[Duke W.]

Re: C2 oil consumption

Oil viscosity range rarely has much effect on oil consumption though many claim otherwise.

The mileage and repair history (if known) on the subject 40 year old engine might be helpful, along with which engine option the car has and any known modifications, in offering a diagnosis. A quart every 700 is "high", but oil consumption in and of itself is basically a nuissance. A "hot" spark plug equivalent to AC45 will usually prevent severe plug fouling at this level of oil consumption.

If compression and leakdown numbers are okay, a new set of valve O-rings (OE type valve seals) will often mitigate oil consumption, but many heads that have been overhauled may use different than OE seals. During this procedure valve guide wear can be checked and, if necessary, the heads removed for overhaul. This then allows a bore wear check, and you go from there as necessary.

Duke

[Joep F.]

Re: C2 oil consumption

Thanks all for your replies.
The block of the engine is from a Corvette 250HP from 1965 (the car itself is 1964). The manifolds, exhaust and carburetor from the 365HP. The type of heads I didnt check yet. Do the 365 HP manifolds fit on all of the head types, or only at the ones with the higher compression?
As its a kind of reconfigured engine, I guess she has been overhauled one day. Though my service history goes till 1984 and doesnt tell about an engine overhaul.

Furthermore she doesn't smoke really.

I'll check out the heads. Can valve seals be replaced without head removing?

Thanks,
Joep

[Joe L.]

Re: C2 oil consumption

Joep------

The 62-65 SHP exhaust manifolds which were 2-1/2" outlet size will bolt up to just about any PRODUCTION small block cylinder head. They can be and were regularly adapted to all sorts of small blocks that did not originally use them. They were so popular that GM continued to sell them until very recently. All are now discontinued, though.

The valve seals can be replaced without removal of the cylinder heads. All you need is an air compressor and spark plug fitting (to hold up the valves) and a lever-type valve spring compressor tool. The fitting and spring compressor tool are very inexpensive.

[Joep F.]

Re: C2 oil consumption

Joe,

Thanks for the info.
Does the same count for the inlet manifold? So the only way to tell what kinds of heads are installed are to see if it has mechanical or hydraulic adjustable valve lifters?

Joep

[John H.]

Re: C2 oil consumption

Joep -

If you remove the valve covers, you'll see the casting number and casting date code on each cylinder head; that will identify what they are, although it won't necessarily tell you the valve sizes. If you post the casting number and date code, we can tell you the original usage.