What's involved in installing new valve seals on the intake valves on my '70 SS 454? Do I have to pull the engine, or just the heads? Or both? I'm trying to picture the seal location and different seal designs. I'd much appreciate it if someone could enlighten me a little! My thanks in advance!

Tim

Tim, If you are just replacing the valve guide seals, you don't need to pull the engine or the heads. You will need a spring compressor that works with the heads on the car and You will also need something to hold the valve from falling into the cylinder. You can use an adaptor to let you use compressed air to hold the valve (requires a compressor), or you can use the poor man's trick of stuffing some rope into the cylinder through the spark plug hole and the bring the piston up to TDC. Either way will work.
If you are using the small o-ring style seals, these go under the valve spring retainer. Just compress the spring, remove the valve locks, remove/replace the seal, put the valve locks back on and un-compress the spring.
If you are using the "umbrella" style seals, remove the valve spring and slide the seal onto the valve stem using the plastic cap over the top of the stem to avoid damaging the seal. and reassemble. That's it...

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Tom Wood
Gold Member #66
502 Powered '66 SS

Some pictures of my '66 under construction;
My 66 Pictures (http://people.ne.mediaone.net/tkmwood55/photos.htm)

70chevy...
If your heads are original, the guides are not machined for a positive type seal. The standard BB seal is Orange in color and is just a tall umbrella type seal. (some cheaper ones are black).
If somebody has worked on the heads before and machined the guides for a positive seal, then you could be putting on a positive seal. But you will not know what size until you see a guide. They could be .562", .530" or .500". And even smaller than that, but that is rare. In race applications when running a triple spring with say...an 11/32" valve, the guides may be machined to .475" or thereabouts for a very small seal. Stock BB valves have a 3/8" stem.
Assuming that your heads are using stock seals, then you would just replace them with stock seals. The heads have to be removed to machine the guides for a positive seal.

As for changing them on the car, you'll need to acquire a compressed air hose fitting to screw into the spark plug hole with the cylinder that you are working on at top dead center firing. TDC #1 firing is a good place to start. This will put the valves closed and you will apply compressed air through the spark plug hole to keep the valves up. You want that cylinder at TDC just in case you accidentally push a valve down so that it will not fall into the cylinder which would require pulling the head off ! Then you will need a spring compressor made for this job to compress the spring and remove the keepers and retainer. Sometimes a "rap" with a hammer before compressing it will shock the keepers and make it easier to remove them as they can get stuck in the retainer over the years.
Do one cylinder at a time. You can go in the order of the firing order, rotating the crankshaft 1/4 turn to do the next cylinder. 18436572
If the condition of the seals appears to be good when you get in there, then that smoke on start-up isn't the seals. It's the guides. We all know what that means...Rebuild time !

ps....remember...one revolution of the camshaft is equal to 2 revolutions of the crankshaft.

Nate

TW...
there are no o-ring seals on a BB. http://www.chevelles.com/forum/redface.gif

Nate

When I did mine on my truck, I found that a small telescoping magnet was the ticket for removing the keepers after you compressed the spring. Very helpful when your hands are all oily.

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Mark
69 Chevelle SS

Gentlemen....just to clarify one small issue here. When you put air into that cylinder which you put at #1 TDC you will discover shortly that you have moved the piston in that cylinder briskly through its power stroke. http://www.chevelles.com/forum/biggrin.gif Compressed air has the ability to turn your engine quickly.

That is a good time to keep all dangling digits away from fan , pullys and belts.

If you don't have an air compressor and use the rope trick, turn the motor by hand & don't use the starter.
And as Charbilly says becareful of the motor turning when the compressed air is applied. When I replaced my valve springs, broke one, I used a fly wheel turning tool to keep the motor from turning.

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Nathan Brandt
The more cubes the better!!!
70 SS 396 4spd under restoration
71 SS 454 clone 8.8 1/8 on pump gas and 8" slicks
60' 1.949 & 77 MPH
Team Chevelle # 1143
My 71 SS 454 clone (http://www.chevelles.com/showroom/nate71.jpg)

Thanks for the replies guys! The heads are Merlin ovals with 2.19" and 1.88 valves, with hard seats and guides for unleaded or reg. fuel. The engine has less than 4,000 miles on it, was broken in by the book, i.e. the way the builder described. But it's using about 1 qt. of oil every 300-400 miles and fouling the plugs in the process. I went to R45TS plugs, because the cooler ones fouled so quick with the oil consumption. Hopefully I'm not getting ring blow-by. I checked the intake manifold, i.e. pulled it and looked, and there was no trace of oil being sucked past the gaskets; so the builder thinks it might be the seals on the intake valves. He just said he'd locate and send me different seals to try, so I don't know what type are on there, and what type he will send. What do you think my chances are that they will help? Thanks again for the info; what great site

One more thing: I did prior to installing a 4-row HD radiator, get a couple of alarming engine temps while idling in line at Burger King summer before last. I mean like 245 degrees. It cooled very quickly as soon as I revved up to leave, was @ 190 within about 60 sec. Could that have any bearing on oil usage? Thanks again for taking time to reply

tim

Nate, I guess I was thinking of the small block seals http://www.chevelles.com/forum/smile.gif . My 396 BB heads have the positive type seals, not the originals, so I wasn't sure what came stock.

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Tom Wood
Gold Member #66
502 Powered '66 SS

Some pictures of my '66 under construction;
My 66 Pictures (http://people.ne.mediaone.net/tkmwood55/photos.htm)

Good Save !!! http://www.chevelles.com/forum/biggrin.gif