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Discussion Starter · #1 ·
My 62 194 6 cyl produces black sooty exhaust when first started and runs rough until warm then runs real smooth. I'm thinking worn valve stem seals allowing oil to run into combustion chamber when it sits over night or longer. If that's it I plan to replace seals with head still on engine using an air hold tool. Will this one work? https://www.amazon.com/Powerbuilt-648457-Valve-Holder-Hose/dp/B002IO0X26

It says it works for 14 mm and 18 mm spark plug holes?

I've never done this but it seems straight forward. Do I use stock stem seals? I've read a lot of posts about umbrella seals or something like that and I don't know what that is but then most of those are talking about after market and over sized valves etc.
 

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Valve seals

My 62 194 6 cyl produces black sooty exhaust when first started and runs rough until warm then runs real smooth. I'm thinking worn valve stem seals allowing oil to run into combustion chamber when it sits over night or longer. If that's it I plan to replace seals with head still on engine using an air hold tool. Will this one work? https://www.amazon.com/Powerbuilt-648457-Valve-Holder-Hose/dp/B002IO0X26

It says it works for 14 mm and 18 mm spark plug holes?

I've never done this but it seems straight forward. Do I use stock stem seals? I've read a lot of posts about umbrella seals or something like that and I don't know what that is but then most of those are talking about after market and over sized valves etc.


Pull the carb off & rebuild it with a kit---the choke is set too rich or the pulloff isn't working. Don't waste your time & $ on valve seals. As stated above black sooty exhaust is rich fuel---blue smoke is oil consumption.:)
 

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Discussion Starter · #4 ·
I've adjusted the carb according to the manual and utubes I've seen. Also when it warms up it runs really nice. I could be wrong about the color of the smoke. When the stock exhaust was on it the pipe pointed to the ground behind the left wheel. I would get a big black spot on the drive way but I never paid attention to the color of the smoke. Now the exhaust is cut off just past the muffler. I've been restoring it for several years and need to get an exhaust pipe put on it.

I don't mind rebuilding the carb but I don't have a great track record with that. I always seem to make them worse!
 

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Sounds like the choke is set too rich. If the valve seals were bad, you'd get that smoke at other times when you drove and oil is up in the valve train. Black smoke and soot (I know that black spot on the garage floor) is usually choke setting.

If it runs well and doesn't smoke when warm or on deceleration, then it's likely not the valve seals.
 

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Discussion Starter · #6 ·
I thought I'd pick back up on this thread. I had a new exhaust put on it and routed it straight out the back. The smoke at start up is blue. It still runs good after it warms up and has burned up the oil that has leaked into the cylinders while sitting. So I'm pretty sure it needs the valve stem seals replaced. Any recommendations on brand of seals and valve cover gasket to get? Most auto part stores now seem to only have Mahle. Never heard of them before.
 

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Discussion Starter · #7 ·
In researching this I usually see 2 different size seals. Both say 11/32 valve stem but one shows .500 guide and the other .530 guide. How would I know which I will need?
 

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Discussion Starter · #8 ·
Now I'm seeing 2 sizes for valve stem diameter. 11/32 (which is .34375) and .342. The manual says stem diameter is .3410 - .3417. So does that mean I would want .342?

And is the difference in guide diameter of .500 vs .530 maybe because .530 should be used when guides have been knurled? Which of course I don't know if they ever have been.
 

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1969 Nova . . 2dr . . Chino Valley,Az USA
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Winch . . . .

At one time - - back in late 70's - - my older brother had a Ford truck - - - (he had to drive about 30
miles to work - - - we both worked in the same shop) . His truck had broken a radiator hose , close to his home.
He drove on home - - - got the motor Hot - - - about a week later , his truck started smoking 'blue smoke' .
He kept driving too work .............. the motor still smoking = getting worse .
We did change those " valve stem seals " . . . . (they would just "crumble" , when you touched them .
Before - - his truck would 'smoke really bad ; and used ALOT of oil (after getting his motor hot) .

After we installed new - valve stem seals ..................... his motor (almost) quit smoking ; and his
"using oil - slowed way down" .

you don't think that a small o-ring seal is very important .................... I couldn't believe how much that it
cut - down the "smoking" (it did not completely stop . . . but this truck was "spraying everything it drove
by .

I have also replaced "valve stem seals" on a 65 Chevy Impala - 283 engine. That car also made a hugh
difference , between "old seals & installing new seals" .

A Chev Six engine is even easier . . . . and , gives peace of mind . Look at it as = one more
problem Fixed .
I don't know ( 1.333 mm from ) anything - - - - but, I'd say check your local NAPA store - - should
be just stock Chevy 6 valve stem seals . If you use the "compressed air " = = install a valve on the
end of that cyl air hose (you may need a way too "release the air" . . . in order to move to the next cyl.

like this :


also - - you need this kind of = valve spring remover tool . maybe like this :

OTC® 4573 - Overhead Valve Spring Compressor (carid.com)

When you have everything connected - - turn on your "air valve" . . . . . slowly . . . . because your
engine MAY ROTATE .......... pushing on your "Piston Down , in the cylinder" .
- - - - WATCH YOUR FAN BLADE - - - - it WILL Rotate .................... watch your air hose and YOUR
FINGERS .

I hope this makes sense . really not a bad job to do .......................... afterwards .....................
work on that CARB .

Black Smoke .................

later , jim


Amazon.com: kweiny Engine Air Valve Holder and Cylinder Leakage Testing Assistant Tool Fit with M12 or M14 Thread: Automotive

they show a picture (
on the left side) of the air hose & air compressor .
 

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Discussion Starter · #10 ·
I decided to play with the old Nova today. I added lead substitute to the gas 2 days ago when I filled up and ran it for maybe 10 miles. It hasn't been started since. When I started it today it started great and almost no noticeable blue smoke. A little condensation comes out the tail pipe and drops of I assume oil. Not near the black spot it was creating on the floor before. I have a 2 1/2 minute video of the cold start I would attach but I guess it won't let me.

Then I decided to do a compression test. I followed the shop manual exactly. I got 104 in all 6 cylinders. New 194 should be 130 according to manual. Next I intend to do a leak down test if the poor man's tester I put together will work. It is the compression test hose and gauge coming off a tee with a ball valve shut off in front of that. I figure I can open the valve and let 105 psi in then close the valve and start a stop watch and record how long it takes to leak down to various points. Does that seem like it will work? How long do you expect it will take to leak down10 psi. 20 psi, 30 psi etc? I'll attach a pic of the tester. The gauge isn't hooked up to the tee yet because I bought the wrong fitting. Grrr
 

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Discussion Starter · #11 ·
I think I'm not going to be able to use that compression tester gauge after all. It records the highest psi but then doesn't go down until you push the little button. I need a standard psi gauge. I'll get one to attach directly to the tee.
 

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I think if you have 105 in all cylinders, the motor is basically sound. I would install the valve seals using your tool to hold the valves closed with compressed air. I'm not a 6 cylinder guy, so I can't advise you which seals to buy, but replacing them is not a hard job. You may have to tap the retainer to get the keepers to loosen up. Sometimes they get stuck together and take a good wack to loosen them up. Once the spring is compressed, use a magnet to fish the keepers out. Use a little grease on the keepers to hold them to the valve when reinstalling. I prefer this type of compressor, but I have used the one twin shadows shows above and that will work too.
418581
 

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Discussion Starter · #13 ·
I'm pretty sure that's all I will do at this time. I would like to do a leak down test just to see what is shows and to have done it once. I played with it a little more and I need to figure out how to lock the crankshaft in place. I thought maybe leaving 5 spark plugs in would create enough compression that compressed air wouldn't push the piston down but it does.
 

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1969 Nova . . 2dr . . Chino Valley,Az USA
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Hey Dean . . .

I do like your type 'valve spring compressor better ' , , , , and worth the extra $ $ $ .
The type that I showed . . I bought one (years ago ) . . . and it broke - - on about the second
spring , that I used it on .

Winch . . . . I would still "install new valve stem seals ; anyway , it's not a hard job . . . . . . . . .
and , does make a lot better seal on your engine . Well worth your time & effort .

. . . jim
 

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I'm pretty sure that's all I will do at this time. I would like to do a leak down test just to see what is shows and to have done it once. I played with it a little more and I need to figure out how to lock the crankshaft in place. I thought maybe leaving 5 spark plugs in would create enough compression that compressed air wouldn't push the piston down but it does.

1st thing = "Remove All Spark plugs" = and , leave them out . . until job's done .
2nd thing = "REMOVE Your BATTERY Cables" .

you won't need to do anything .......................
You DO NEED an "Air Compressor" . . . . .
The "spring compressor tool"
The "Air hose & Fitting (to screw into the spark - plug hole) . . . . and , a valve (too HOLD the air in
the cylinder ; and to "release the air" ; when you need to move = too the next cylinder) .

WHEN - - you move to the next cylinder - - - - install that = Hose ; (spark-plug type fitting) ; then ,
compressed - air ........................ the (next) cylinder / piston - - - WILL PUSH DOWN to the bottom ,
AND - - your Motor WILL Turn . . . . . . Thus - - - Be Careful ;
watch
your Fingers / Hands . . . and , Air Hose . Make sure all things are clear . . . and ready for any (engine) movement .
Another GOOD Reason , for the Valve (on the air hose) . . . . so , you can control the
amount of air , that you start putting into That Cylinder . . . . start slow . . . . when , everything
stops moving (and , your SURE) . . . . . then, open the "air valve" . . . . that keeps the Valve
from "dropping into the cylinder" .

You may want too do a "search - for "Installing / Changing Valve STEM SEALS" . . . . . first .

Plus , look at the above "Post" . . . showing the two 'different valve spring compressor tools' .
I posted one type - - - 'drm101' . . . posted a much better type . . . just make it easy on
yourself , and buy the best tool (for the job) . your call .

later . . . jim
 

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Discussion Starter · #16 ·
Sorry Jim, but I'm not following you at all. Somehow you have to lock the engine so that the compressed air doesn't push the piston to the bottom of the cylinder. It has to remain in one spot with the valves closed (which would be near the top of the compression stroke). I first tried it with all the spark plugs out just to see how easily the compressed air pushed the piston down and that was very easy. I then tried it with the other 5 plugs back in and it made some difference but not enough to keep the piston from going to the bottom. So somehow I have to lock the engine as I test each cylinder. If I had a manual trans it would be easier but the powerglide isn't going to keep the engine from spinning.
 

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Discussion Starter · #17 ·
Hold the phone guys. I'm getting confused with another thread I have about doing a leak down test. That test is what will require the engine to be locked not when I replace the valve stem seals. It will be OK for that procedure if the piston goes to the bottom of the cylinder. Here is a pic of a poor man's leak down tester I am putting together. When I took the pic I didn't have the right type fitting on the tee for the gauge. For the purpose of what I did this afternoon I just removed the tee.
 

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Well it's been eons since I worked in a machine shop but regarding the seals you want a "Positive Control" type valve seal that mounts stationary on the top of the guide and creates a positive seal around the stem. It basically wipes the stem clean as it moves up and down. If things are worn and tolerances loose the factory O-ring type or Umbrella types will do little to nothing to stop the oil consumption. A lot of the PC type seals require machining to the top of the valve guide but there are other versions (Hastings maybe? ) that don't. I believe the un-machined guides measures .530 on the OD but check it. These are the seals you need to do the install the way you are describing. Just be sure they clear the inside of the spring including any flat damper spring that may be present.
 
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