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By Gene Purser - 7 Years Ago
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  Pardon my lack of knowledge but I've been away from Y blocks a long time and bought this car with a 272 (supposedly rebuilt) last year. The car is using a quart of oil every few hundred miles. Recently when pointing the nose of the car down on a steep driveway a puff of blue smoke belched from the right side exhaust. I checked the exhaust and get an oily smudge from the right side, but the left is clean. So I figure a head drain is plugged, pulled the valve cover and everything is clean as you would expect on a rebuilt engine. I did notice two things: There is a drain/overflow tube from only one rocker stand on each side, and it is directed at the pushrod hole. It seems as If I remember there should be one on each end rocker stand, and it should point to the drain hole. Oh, I pulled all the spark plugs on that side and three have light grey tips and one is brown (front plug). I would expect black oily tips with it using this much oil. Any advice, comments, or things to check will be greatly appreciated.
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By charliemccraney - 7 Years Ago
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There is only one overflow tube per shaft, so that is correct. A compression test and leak down test should help you narrow down the cause.
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By Gene Purser - 7 Years Ago
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Thanks Charlie, should they dump into the push rod hole or into the drain at the bottom of the head?
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By 57RancheroJim - 7 Years Ago
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Drain to the push rod hole is correct
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By 2721955meteor - 7 Years Ago
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have you checked the valve seals on the cylendr that shows oil on the plug. with a fresh engine it is possible the return tube is not aimed properly and
splash floods that intake valve. the valve seals that come in ovhaul kits are marginal. i use 289/302 seals . also remove bleed tubes and plug the holes that way oil drains out holes at ether end of head along with decent lube to all the rockers and valve train. like fe series ford engines.
you will get lots of feed back and ideas. good luck
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By KULTULZ - 7 Years Ago
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Gene Purser (3/6/2018)
The car is using a quart of oil every few hundred miles. Recently when pointing the nose of the car down on a steep driveway a puff of blue smoke belched from the right side exhaust. I checked the exhaust and get an oily smudge from the right side, but the left is clean. I pulled all the spark plugs on that side and three have light grey tips and one is brown (front plug). I would expect black oily tips with it using this much oil. Any advice, comments, or things to check will be greatly appreciated. The fouled plug shows me (IMO) that it is oil fouled due to a bad (and/or flooded) stem seal. A wet electrode would show (IMO) a bad oil ring.
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By Gene Purser - 7 Years Ago
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Thanks to all for the information. May i get a brief description of what I'm up against checking/replacing the stem seals? Do I need to pull the head? I'm assuming I need to concentrate on #1 cylinder.
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By PF Arcand - 7 Years Ago
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Cylinder head looks nice & clean. Yes, you need to consentrate on that cylinder. Wondering if something went wrong with the re assenbly like the oil ring was broken maybe? .. Hopefully not, but good luck finding the problem..
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By KULTULZ - 7 Years Ago
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Gene Purser (3/6/2018)
Thanks to all for the information. May i get a brief description of what I'm up against checking/replacing the stem seals? Do I need to pull the head? I'm assuming I need to concentrate on #1 cylinder.
What type seal was the head assembled with?
http://www.felpro.com/technical/tecblogs/valve-stem-seals.html
Regardless, the valve(s) seal can be serviced on the cylinder head with special service tools.
You are using a lot of oil. Was the engine broken in properly or/and does the ventilation system work? Leakage?
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By KULTULZ - 7 Years Ago
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2721955meteor (3/6/2018)
have you checked the valve seals on the cylendr that shows oil on the plug. with a fresh engine it is possible the return tube is not aimed properly and splash floods that intake valve. the valve seals that come in ovhaul kits are marginal. i use 289/302 seals . also remove bleed tubes and plug the holes that way oil drains out holes at ether end of head along with decent lube to all the rockers and valve train. like fe series ford engines. you will get lots of feed back and ideas. good luck
GOOD INFO HERE!
The quality of the seal is paramount. Use quality/proven parts.
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By Gene Purser - 7 Years Ago
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I don't know how the engine was broken in, or the type seal on it now. I'll muddle through replacing them, though. I've been wrenching on cars as a hobby since I was a teenager (75 now), built a few engines and cars, so I'm not completely lost. I see different types of valve spring compressors available. Can someone give me a picture of one that will work well for this application?
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By KULTULZ - 7 Years Ago
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Maybe Consider -
Danaher Tool Group KDS3271 Universal Overhead Valve Spring Compressor- Designed to remove valve springs on cars and light trucks
- Features a removable handle that allows the use of a 5/8 inch socket or wrench in confined areas
- Backed by a lifetime warranty
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By 2721955meteor - 7 Years Ago
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ther is a tool available at most parts stores that makes it easy to chang valve seals. cost in canada was 30.00. just be sure to have the cal youare working on is at TDC.you should have a decent magnet. check the intake valve first as it would be the most likely culprit. before starting use a good small flash light and look at the valve seal. possible that asembler never installed 1.get a good manual and it will walk you threw.
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By Tedster - 7 Years Ago
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Even the el-cheapo imported from you-know-where valve spring compressors will do the job. They look very similar to the one pictured. About $10 or $12 delivered, from that auction site. Alternatively you could rent one from an auto parts store. Normally I dislike cheap junk tools, but unless you plan on lots of valve spring work it's tough to justify the added expense for one time use.
Recently did this with my Y block in my truck. I had an eye towards replacing valve springs. These are often overlooked as a source of trouble, they are important and wear out. If the valve springs on your engine are original this is something to think about, they are not expensive. It will run noticeably smoother and better power.
Anyway since I was already "in there" it was a no brainer to replace the valve seals too. I can say that removal and replacement of the springs has a certain hair-shirt element to it with the heads installed. It is a PITA. There is clearance to install the valve spring tool (and remove valve springs) for each cylinder, even under the stock single pot brake master cylinder. Be careful not to lose the valve keepers across the garage, or drop them down the oil return passages. A mechanic's magnet tool is your friend here. I'd seen movies like this before and knew it could cause trouble, so I took my time. Took me several hours to do all 16, including measuring/shimming the assembled valve height to stock specs.
Keeping the valves from dropping into the cylinders (then you WILL be removing the heads) can be done a few different ways. Applying shop air is one method. What worked great for me was to take a few feet of rubber vacuum hose and tie a knot in one end. Stuff it in the spark plug hole up to the knot. Roll over engine by hand until you feel resistance. The valve springs can then be removed/reinstalled for that cylinder without the valves dropping down into the engine.
Naturally, I also removed the rocker arm shaft assemblies and ended up replacing those as well, and the rocker arms themselves, and all of the pushrods for good measure. Valve stem seals cost $5, but when the springs, rockers, rocker shafts, pushrods get thrown in there it growed. Lucklily I somehow stopped myself from rebuilding the entire engine.
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By KULTULZ - 7 Years Ago
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Tedster (3/7/2018)
Naturally, I also removed the rocker arm shaft assemblies and ended up replacing those as well, and the rocker arms themselves, and all of the pushrods for good measure. Valve stem seals cost $5, but when the springs, rockers, rocker shafts, pushrods get thrown in there it growed. Lucklily I somehow stopped myself from rebuilding the entire engine.
I feel your pain. You are not alone... 
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By 56_Fairlane - 7 Years Ago
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Tedster (3/7/2018)
Keeping the valves from dropping into the cylinders (then you WILL be removing the heads) can be done a few different ways. Applying shop air is one method. What worked great for me was to take a few feet of rubber vacuum hose and tie a knot in one end. Stuff it in the spark plug hole up to the knot. Roll over engine by hand until you feel resistance. The valve springs can then be removed/reinstalled for that cylinder without the valves dropping down into the engine.
I replaced the seals on another type of V8 engine by threading a cord into each spark plug hole, one by one and compressing it by turning the engine. I used a simple and cheap lever type spring compressing tool that attached to each rocker stud on that engine which unfortunately won't work on a Y-block.
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By Gene Purser - 7 Years Ago
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OK, I need the benefit of your experience again, please. I used a small inspection mirror to look at the umbrella seals on some of the valves. On all I looked at, the umbrella is up under the keeper and I can see exposed stem where it goes into the guide. I used a small screwdriver to reach in the spring and push a couple of them down onto the guide. I then ran the engine a few seconds and the seals stayed in place on the head. It can't be that simple, the seals must be working themselves up the valves. What is going on?
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By Tedster - 7 Years Ago
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Well, that's what they do. The standard issue "umbrella" type don't stay in a fixed position or aligned with the valve guide boss.
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By Gene Purser - 7 Years Ago
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Thanks. The seals are present. I ran a piece of wire about .115" diameter in the drain holes. When it gets to the depth about where the head gasket would be I have to force it through. It seems as if the drains are restricted. With the engine cold I started it with the valve covers off. Oil fills the bottom of the head to just before running over the valve cover gasket which is stuck to the head. I'm wondering if the restriction in the drains would allow the oil to build up in the valve covers at higher engine speeds and flood the stems? Should the drain be restricted or wide open? I'm grabbing at straws to hopefully keep from pulling the heads.
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By Tedster - 7 Years Ago
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There is dogleg in the heads, this is the source I Suppose of the poor oiling inherent to Y block, at least with the substandard oils of the day. It was a known problem. Anyway a wire is unlikely to make it through. Some have suggested forcing grease, others compressed air, to clear blockage. Make sure both sides have good oil flow. If you check rocker shafts and rocker arms they are almost certainly trashed if oiling has been a problem. "Rebuild" means something different depending on who ya ask, I'll tell ya that.
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By miker - 7 Years Ago
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If you’re filling the head with oil, it’s a drain deal. The dogleg is the pressure side up from the cam bearing. Sounds like you’ve got good oil supply to the rockers, and that’s the important thing. I didn’t go review this whole thread, but there’s been a lot of discussion here about restricting the oil tubes out of the rockers. Either tapping a drilled set screw, pinching the tubes etc. Might run a search for that.
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By Gene Purser - 7 Years Ago
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Tedster, just to be sure we are talking the same thing: The restriction I am talking about is at the drain holes at each bottom end of the heads. This is allowing oil to build up in the heads under the valve covers. Are you talking about the dogleg in the oil SUPPLY to the rockers? I'm not defending this "rebuild", just trying to get to the source of the oil burning. I'll do what I have to do, trying to diagnose it now. Thanks for sharing your knowledge.
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By Gene Purser - 7 Years Ago
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miker (3/8/2018)
If you’re filling the head with oil, it’s a drain deal. The dogleg is the pressure side up from the cam bearing. Sounds like you’ve got good oil supply to the rockers, and that’s the important thing. I didn’t go review this whole thread, but there’s been a lot of discussion here about restricting the oil tubes out of the rockers. Either tapping a drilled set screw, pinching the tubes etc. Might run a search for that.
Thanks Miker, but right now I think I might need to get more oil out through the oil tubes, or get the oil from the rockers out of the valve cover area faster. I know the oil will thin some/drain faster when it is hot, but the engine will be pumping more oil at higher RPMs.
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By KULTULZ - 7 Years Ago
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Gene Purser (3/8/2018)
Thanks. The seals are present. I ran a piece of wire about .115" diameter in the drain holes. When it gets to the depth about where the head gasket would be I have to force it through. It seems as if the drains are restricted. With the engine cold I started it with the valve covers off. Oil fills the bottom of the head to just before running over the valve cover gasket which is stuck to the head. I'm wondering if the restriction in the drains would allow the oil to build up in the valve covers at higher engine speeds and flood the stems? Should the drain be restricted or wide open? I'm grabbing at straws to hopefully keep from pulling the heads.
There is your problem, slow drain-back. You mentioned you park it on a grade and at start-up she smokes out the right pipe.
You need to run a brush (think rifle brush) down the drain holes. How they can be sludged/blocked so soon is beyond me. Maybe something wrong with the head gasket install?
The umbrella type seal rides on the valve stems. When they come up, the stems/guides receives lubrication. Your problem it seems is flooding. Did you modify/pressurize the rocker arm shafts on assembly?
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By Gene Purser - 7 Years Ago
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I do believe the gasket is partially blocking the drain holes. The head gaskets have the corner exposed on the upper front corner of the heads, which I understand indicates that they are installed correctly. There is no sludge there. The rockers are not pressurized, the tubes are open
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By Gene Purser - 7 Years Ago
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I dug out a set of heads that have been up in my shop attic for about 30 years to check out how the drain holes meet the block. I found that the return oil has to go around a head bolt that runs down through the drain passage. That is the reason only a small wire will pass. I guess I'll have to accept that IF the oil is coming by the guides I'll have to pull the heads and get them reworked. If I go that far I'll think about a larger Y block or a 302.
Thanks for all the suggestions and ideas. This site is the best.
Gene
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By KULTULZ - 7 Years Ago
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Gene Purser (3/9/2018)
I dug out a set of heads that have been up in my shop attic for about 30 years to check out how the drain holes meet the block. I found that the return oil has to go around a head bolt that runs down through the drain passage. That is the reason only a small wire will pass. I guess I'll have to accept that IF the oil is coming by the guides I'll have to pull the heads and get them reworked. If I go that far I'll think about a larger Y block or a 302. Thanks for all the suggestions and ideas. This site is the best. Gene
...hmmph...
It seems that if the return passages are somewhat blocked by the head bolts, that Engineering would have allowed for that.
Two questions to ponder-
1) Were the oil return tubes on the rocker assemblies modified to lessen return flow, and
2) Any chance of the builder using a HV/HP oil pump?
Have you measure pressure with a quality mechanical oil gauge?
When you go into forensics and discover the problem, please return to this thread to post your findings.
GOOD LUCK with it!
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By Gene Purser - 7 Years Ago
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The return passage is enlarged at the junction where the bolt passes through.
The return tubes on the rockers are functional and flowing the excess oil.
I don't know about the pump, but it looks like any other.
The car has an idiot light for oil pressure, I haven't put a gauge on it.
I'll surely get back if I tear into with what I find.
Thanks again
Gene
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