Bill Pilon

I have had my Vette for 37 years and drive it several thousand miles a year. You on the other hand rarely drive your top-flight Vette. The way I see it is you have a whole bunch of old slightly worn parts working in near perfect harmony with each other and I would not change a thing to break up that tune, I don't see this engine ever approaching the red line and I believe chances of a catastrophic failure are about nil, in fact I would worry more about the rebuild failing.

If it were mine, and I didn't drive it a lot more than you do, I would do nothing other that continue to clean and pamper it the way I expect you do, maybe put a little seal softner in the oil just on the chance it might do what is advertises it will do.

My Vette is kind of like an old recip engine in an airplane if it don't leak and smoke a little I got reason to worry. Many years ago when I started flying the rule of thumb was as long as the oil outlasts the gas you were good to go.

Bill

Gavin65

This information is spot on, start with a simple compression check, it will tell you what direction to go in, If it were me I would replace the old gaskets, and the valve seals, than go out and enjoy the ride.

solidaxel

Have the engine compartment cleaned then evaluate the worst leak and fix one at a time.......... you said you have a lift!

karkrafter

You've get a ton of fellas telling you to replace the valve seals...but you do realize there are no actual 'valve seals' on 1966 Chevrolet Corvette engine. There are oil deflectors.. valve stem 'o' rings that do absolutely ZERO to seal a valve stem.

Your oil burning issue is the rings...it's always the rings. Futz around with the seals all you want and it won't change anything.

Now you can pull the heads, machine the valve guide bosses for an umbrella type 'valve seals' But what the hell, while your there, replace the valves and valve guides because if you ARE losing oil in the heads that is where it's happening..

Like I said..leave it all alone....

MikeM

Don't get yourself all worked up now. You're correct in saying they are not valve seals, but they are oil seals and they prevent oil off the rocker arm from running down through the keepers/retainers and oozing on down the stem through the guide and in to the intake. They just don't seal the guides and weren't intended to.

When they get old, hot and cracked they definitely will cause oil consumption and smoking on start up.

Do you think the General spent the money on them for nothing?

Now, if you want to put seals on, then yes, they will do a better job of controlling the oil that runs down the valve stem.

karkrafter

I didn't realize I was sounding 'worked up' I'll do my best to control my crazy ideas...Buuuuuut, I don't believe you have a true understanding of what the o - rings do...at least as far as what I was taught.

Think about this...You shut the engine off...gravity pulls all the oil in the engine to the oil pan including the oil that was on the rockers valve stem etc..as the engine sits, do you think those o rings, when the are brand new and soft and do all that they could possible do, keep even one single solitary drop of oil from passing over the top of them on its way to the bottom of the engine?

Those o rings are there to deflect oil while the engine is running, to sling excess off and the valve goes up and down [very fast].

Oil that gets into a cylinder thru the heads when the engine is not running is caused by either a restriction in the oil drains causing the oil to 'pool' around the valve guides or the valve to valve guide clearance. [Of course that not taking into consideration a bad intake manifold gasket or a crack in the head itself.]

Replacement of the o rings will do absolutely NOTHING to keep oil running down the valve out of the cylinder when not running.

MikeM

This is another way of saying what I said above except for one thing. It will keep oil from running down through the keepers and retainers and down the valve stem when the engine is off.

But you didn't answer my question of why GM put the O rings on there to start with if they were totally ineffective. I agree, not the best idea but if you want to know what they do, just leave them off your next rebuild and see how much oil it uses. Even with new guides and valves.

karkrafter

Wow, ok I'll say it again..


They are there to sling oil off while the engine is RUNNING, keep oil from bathing the tops of the valve guides.


They have NO purpose on an engine that is static [not running] It was not their purpose when they new, and that is not their purpose now.


I never said were totally ineffective. But they have NOTHING to do with oil control on a NON running engine and will not stop one scintilla of oil from running down the guides while the engine is NOT running.


Not running...it would make no difference if they are new, old and cracked [like me] or not even there. Without the momentum of the valve going up and down, they will have no effect. Now an umbrella seal is a different story...

Frankie the Fink

My original 63 had oil leaks at the rear main seal, valve covers and oil gauge metal tube where it entered the block. Also blew a nice cloud sometimes on startup. Fixed all of that and replaced valve seals and its all good now. Never cracked open the engine...

A few hundred dollars in repairs. If you do a leak down and compression test and all is well I wouldn't get into a major overhaul... I'm just sayin'...

My valve seals had degraded to the point of a 10 year old rubber band...

MikeM

This is our point of disagreement, I think. When the engine is off, the oil splashed on top of the retainer will be shed off to the side of the valve instead of running down the stem. If it isn't shed, it will run down the stem and into the intake stream. That's all I'm gonna' say. If you want to continue, go ahead.

ejboyd5

To those who have commented: Please read the original post. The owner has a top flight car the moves about 200 miles a year and has some minor oil leaks. He is not disposed to do any work himself and if the leaks were corrected he might drive it perhaps 100 more miles per year.
Not withstanding these facts, many of you would have him expend untold amounts of money and disturb an original top flight car, but to what avail? Any effort and money expended will not increase his use of the car and might be detrimental to its top fight status.
If ever the aphorism, "If it ain't broke, don't fix it," has application it is here. Wipe up the leaks, continue to drive it 200 miles a year and enjoy it for what it is, a top flight example that is not and will not be driven.

LouieM

I vote to fix the leaks. I've bought midyears the past that had plenty of oil leaks and I fixed them one by one. Opening up the engine could just be a big fat can of worms as "mission creep" takes over. Besides, not all rebuilds go perfectly. When my current 327 was redone it was great for a few weeks until the fuel pump lobe on the new Comp Cam decided it was tired of being a lobe and became a circle, thereby spreading metal shavings everywhere, so back out the engine came.

Pipe doctor

Ooookkkk. so I'm caught up...... Thank you everyone for all the input. YES. I sort of agree with the if it ain't broke method especially as I grow older. Seems to get something done right today ,unless you do it yourself ,is nearly impossible. I have high standards and GREAT EXPECTATIONS. With that being said I think I will start small and see if I can tackle the basic oil leaks. I mean I can see distinctly where they are coming from , the engine bay is very clean and there is not a lot of grease /oil underneath the engine either. I just don't want this to snowball into something more than I am comfortable doing myself. I am sure I will be back with questions as I go. Thanks agin ,clay

Nowhere Man

then find a new hobby. these engines leak a drop or two here and there. if it stops leaking that means out of fluid. sorry to be a downer but every single old car I ever looked at that gets driven leaks

karkrafter

Can you get the oil pan off a 327 while it's still in the car on a Corvette?

emdoller

I understand your desire to fix the leaks. I hate leaks. But given what you’ve said, I wouldn’t touch the car. Enjoy it and keep an eye on your coolant and oil levels which I doubt will become a major issue given your stated driving habits.

Ed

MikeM

Well, looks like it's unanimous!

Workin On 59

I think it is wise to go conservative on this and try to identify and remedy the leaks one by one.

One thing that you might want to consider is to get out and drive the car at least once a week during good weather. When I bought my 65 in 2012 it had been driven very little for years and most of the time sat parked in the previous owner's garage. It had leaks from the engine and powerglide. Soon after I got it and drove it regularly (but still only around 500-1,000 miles per year on average) the leaks have all but stopped as old dry seals now have fresh oil and tranny fluid on them and enhance their sealing performance.

Good luck and enjoy your car as this life is short and time flies by.

Doug

65tripleblack

Have to drop the center link first.

65tripleblack

I'll refer you to post #18 one more time, and since we live close to each other, I'll offer you my help as well. I agree that you'll probably never get your old engine to stay completely dry. Ask me how I know.

Some people here, notably John H use baby/talcum powder sprinkled over a freshly cleaned area to isolate the source of a leak. I have never tried it, but see how useful it can be. Others might chime in here about their experience with this. Good luck.

Joe