VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc '55 v8 oil consumption

My '55 has a 283 with earlier (off-set screws on the valve covers)low compression heads. It runs great, but it has always used some oil since it was rebuilt 25 years ago. I've driven it about 25,000 miles, and it now uses about a quart every 150 miles. It doesn't smoke, and there isn't any smoking at start up. I know the only way to be sure of what is going on is to tear it down, but I'd like to hear your suggestions. Could it be the rings never seated properly? Could it be leaking around the valve guides? What tests can I do to find out the problem? Compression test is one I guess. Any ideas would be appreciated.
Sid

A leak down test will tell you what you need to know.
Richard

The small blocks with the early heads (pre mid 1959) often had an oil consumption problem. Too much oil got up on top of the heads, would not drain back fast enough, and the valve springs splashed oil on the guides.
If it were my car I would replace the valve seals first and consider placing a wiper type seal on the guide. If this dosen't work I would replace the rings as they may have been of a poor desigan. Compression tests and leak down tests prove nothing about the oil ring.

Hello Chev Nut, Thanks for the info. The wiper type seal you refer to, is it what I used to hear folks call "umbrella seals"?
Sid

Itis the seal that slips tightly over the gide (does not move up and down) and has a seal the rubs on the valve stem. An umbrealla type seal would also help along with the new O ring seals properly installed.
There should be a "tin" oil shedder on top of the spring and under the retainer cap-on out side oand top of the spring

Several years ago someone was telling me about installing umbrella seals without removing the heads. It was done with air pressure. Would this kind of fix help my situation?
Sid

Sure enough, Sid. Here is what you need: A snap on air nipple with spark plug threads on the opposite end. You can purchase one at some auto parts stores or make your own from an old sk. plug if you have a welder. while you are are at the store you can buy a special lever arm tool which lets you depress the valve spring to remove the keepers. The cylinder you are working on needs to be at TDC (valves closed). Insert the air supply to spk plug hole, you need about 90 psi to hold valves closed. Attach lever arm to rocker arm stud and depress the spring (if the valve starts to push open whack the spring assembly with a rubber mallet and try again). The keepers may also need to be tapped to remove. Pull off the spring and remove the hardened seal from the valve stem. With oil lube slide the umbrella seal on the valve and reverse the process. The keepers stay in their groove better with a little grease on them.
Back up a minute- when you request new seals there are two choices: a simple black rubber umbrella or a hi-tec Teflon variety which seals better (price difference!)
Before installing the seal wiggle the valve stem- there should be very little movement. If stem wear is excessive no seal will prevent oil consumption. I have had them worn enough on V-8s to use a qt/ 200 miles. Complete valve job time!
Gene's comment about poor piston ring seal sure is a possibility. I would attack the valves first, a lot cheaper and easier. May the luck be with you. Dan

Thanks Dan, sounds like a good project for a cold winter day. We might have some of those in Mississippi before long.
Sid

The two items are more readily available from a prats house or? that selld KD tools. The air fitting is KD #2912 and the lever device to compress teh spring is KD # 912....I have both and you are welcome to use them. Probably will find them is you do a computer search of the KD numbers.
When installing the O ring seal on the valve stem it is important to compress the spring FIRST and then slip the O ring on the bottom grove. Then keepers in the top grove. The valve guide clearance can bet up to .003" and feels like a lot more so measure if in doubt.

Thanks Gene, I appreciate the info. Not sure what I want to do yet. I'll study the situation.
Sid