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| Head cracking a common problem? https://slantsix.org/forum/viewtopic.php?t=45263 |
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| Author: | terrylittlejohn [ Thu Jun 16, 2011 3:42 pm ] |
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i have found that you need a small bead of copper silicone on the lifter side of the head gasket on the top side or oil will seep out.if the engine has only been run a few minute the gasket hasn`t stuck yet so removing the head shouldn`t hurt the gasket. |
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| Author: | Doc [ Thu Jun 16, 2011 3:47 pm ] |
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Quote: ... I see oil seeping from the back of the engine where the head and block meet on the passenger side. I mean seriously, there's not even any kind of oil pressure there, right? ...
Yes, there is pressurized oil at the lower, rear corner of the head to block sealing surface, it is a oil passage that feeds the rocker arm shaft and lifters, in the Hydraulic engines.There is a 1/4 inch hole that goes thru the head gasket and into the rear-most, lower head bolt hole. DD 
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| Author: | green1970 [ Thu Jun 16, 2011 9:28 pm ] |
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The leak is not from the vc. It's from where the head and block meet. Why did your brothers van go through that many heads and gaskets? I think I am going to try to pull the head back off in the morning and replace the head gasket with a better quality one if I can find it and put a little copper silicone on there. I did not know about that oil passage... I am assuming that is the"special" bolt the manual was talking about. That could be the hole problem. I would guess if oil is trying to come out that passage and can't because the hole is blocked it will leak out right there. I didn't mean to make it sound like I didn't care about the carb running rich. I just know more about the carb and feel more comfortable messing with it than the head. I wouldn't drive the car like it is running now. I will post what I find tomorrow. |
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| Author: | Reed [ Thu Jun 16, 2011 9:50 pm ] |
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Quote: Why did your brothers van go through that many heads and gaskets?
The answer to that question is a long involved tale discussed in numerous other desperate posts by me elsewhere on this site. Suffice it to say that it was a combination of poor maintenance, poor driving, poor mechanic skills, and a quest to improve power and economy.If the oil leak is a small one, you might be able to just wipe it off with a rag and smear a bead of RTV sealant over the leaking area. This would save you pulling the head. I doubt the smoke and running problem is caused by the head. Of course, pulling the head and putting a small bit of sealant directly between the gasket and block and head surfaces, but the Mickey Mouse smear technique can work and save you a lot of effort. Good luck and keep us posted. |
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| Author: | terrylittlejohn [ Fri Jun 17, 2011 4:23 am ] |
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nothing wrong with fel-pro gaskets,i have had some gasket leak oil at the thin lifter side of the head after cutting the head so i use copper silicone all the time now even with spray sealer on copperhead gasket,watch around the oil feed hole, you don`t want to plug it with sealer when you torque the head. |
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| Author: | green1970 [ Fri Jun 17, 2011 9:19 am ] |
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Well, I took all the head bolts out one at a time to find the elusive special head bolt. No such luck. Unless it is just shorter, because I didn't think to measure them, mine are all the same. I did fire her back up and she will run on high idle all day. When she first started up the idle was smooth, no smoke and it sounded good. After a few seconds the smoke came and it started running a little rough. I payed close attention to the smoke this time. It looks more like oil than a rich condition but when I went around back it smelled really rich so maybe it's a combination of the two. That leak is pretty bad. The car probably ran for about 2 or maybe 3 minutes and there was a puddle of oil bigger than my hand on my driveway. Is there a place to get these head bolts? I looked around a little online but am having no luck. |
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| Author: | Joshie225 [ Fri Jun 17, 2011 10:09 am ] |
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You don't need new head bolts. There is a special rocker shaft bolt, but no special head bolts. You need to remove the cylinder head. You need to make sure the head sits flush on the block with no gasket. It is possible the locating dowel pin at the back of the block is keeping the head from seating properly. The leak you describe, and as others have noted, is likely from the passage which feeds the head and rocker gear. This is a pressure leak and a smear of RTV on the outside of the head will not fix the leak. Also, you need a known good carburetor. Borrow one if you must. A remanufactured carburetor is almost certainly not a good carburetor. |
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| Author: | Reed [ Fri Jun 17, 2011 10:48 am ] |
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I realize I should have qualified my smear cure with the proviso that the engine in my brother's van is a mechanical lifter motor. I don't know if the smear trick will work on a hydraulic lifter motor. I think you are best to follow Josh's advice and pull the head and put the sealant directly between the head, gasket, and block. |
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| Author: | green1970 [ Fri Jun 17, 2011 3:20 pm ] |
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Well, I ordered another gasket. Should be here in the morning. I got some of the copper silicone too. From what I have been told, traditionally you don't want to put silicone on the block/head mating surface. Then again I've never heard of oil leaking out from under the head either. Should I run a bead just around the pushrod area or the whole block? Should I do the block side, the head side or both? I will try to take the head off either tonight or tomorrow and check out the dowel pin. I think I should mention that when I removed the head bolts today I could hear a suction while taking them out. I put a little bit of oil on each of them when I assembled it. This shouldn't build at the bottom of the threads and prevent a proper torque would it? |
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| Author: | Fopar [ Fri Jun 17, 2011 4:06 pm ] |
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If you look at the head gasket, on the pushrod side it will have a little bead of some sort of sealer. That is where I put a little bit of silicone sealer to help, just don't get carried away. Richard |
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| Author: | green1970 [ Fri Jun 17, 2011 7:38 pm ] |
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Alright, I will try it out tomorrow. I'm really diggin your intake setup Fopar. That's awesome! |
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| Author: | terrylittlejohn [ Sat Jun 18, 2011 5:27 am ] |
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richard is right,i have found that in some cases oil leaks from the lifter side when the head is cut, it runs along the lip of the block and seem like it is just coming from the back corner because of the angle of the engine.all you need is a smear, not a thick bead, on the lifter side, just follow the thin side of the block on three side not the cylinder side.like josh said make sure the dowel in the block is not keeping the head from seating , that will cause the same problem. i did see, how much was the head cut? |
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| Author: | green1970 [ Sat Jun 18, 2011 12:06 pm ] |
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SUCCESS! No more oil leak. I took the head off with the intake and exhaust still attached this time and it actually made it a lot easier to handle just a little heavier. As soon as I got the head off you could see the problem. The gasket must have gotten caught last time and bent up at the back side were the oil leak was. Got her all back together but am still having trouble with that stupid carb. It says it was rebuilt in 07. The thing about it is that it ran like a dream before. Now it is loading up and flooding. That will have to wait for a few days. I have been spending way too much time with the car and not enough with the family. Thank you all for your help. I really appreciate all of your input. |
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| Author: | terrylittlejohn [ Sat Jun 18, 2011 3:24 pm ] |
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most carbs have sediment on the floor of the fuel bowl, when you take the engine apart and shake the carb around it loosens and restricts the small passages so you need to dissamble the carb and blow everything out. |
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| Author: | Reed [ Sat Jun 18, 2011 3:32 pm ] |
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