Valve chamber cover gasket split

SAJ

SAJ

Well-known member
I just noticed the smell of burnt oil on the exhaust every now and then. On checking, the gasket under my valve chamber cover had split at the top hole on either end. The gasket had then "walked out" by about 5/8 inch at the top on each end.
The bolts were still well nipped-up, but took about 1/4 turn to fully tighten.
The cover is aluminium, with a full-flow filter union cast in ( Snyders). The gasket is compressed fibre of good quality, also from Snyders.
I surmise the expansion differential between the aluminium cover and the block has caused the gasket to split and "walk".
On a rally for 2000 miles, one of our members lost all his oil and cooked his bearings through a lost lower cover bolt, so I have checked mine quite often for tightness since then. New split washers were installed when I replaced the original iron cover, too. It's been on for 7000 miles.
I will replace the gasket and Hylomar it to the block and grease the cover, so hopefully it will move without dragging the gasket. Expansion is an "irresistable force".
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What do others think
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Some may criticise my use of an aluminium cover, but that's what comes with the full-flow oil filter kit. It's my choice to fit this filter, and also an air filter, which is not that easy on right hand drive with the steering column very close-by.
The engine runs beautifully, and has 7000 miles on it since it came from Schwalms via Snyders. 5.5 head, Stipe touring grind, Babbitt bottom, Stipe shocks, V8 clutch, lightened flywheel, Zenith carb. etc etc.
 

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Well to start with, it totally surprises me someone felt compelled to drive 2000 miles without the need to check the engine' oil level at least once or so during that time!! :rolleyes:


Otherwise, I think you have summized fairly accurately the reason why this is happening on your engine. I truly doubt doubling up on gaskets, or using a threadlocker on the cover bolts .
 
I can't tell what your gasket is made of,but if it is a rubberized/cork composition you may have created the leak.A paper,or at least a thin gasket will pretty much stay put.If you lube up one of the thicker gaskets as you tighten it they tend to squirt out the sides.I've seen the rubberized gaskets split and come out the sided of the oil pan before the lock washers compressed.They seem OK dry,but gasket goo acts as a lube when assembling.It looks like yours has been that way for some time,by the looks of the line running up it.
 
I would guess that the gasket was over tightened and was crushed, especially if it was the cork/rubber composite gasket. I have had this happen.

I use the original type heavy paper gasket with Permatex #2 on the cover and the block (in small quantities) and just tighten the bolts a small amount. The gasket will "creep" - all gaskets do - so I re tighten occasionally especially in the first few hundred miles after installation.

Good Luck

Dick
 
The gaskets that come in the engine sets are not the same as the gaskets Ford sold --I have seen cork gaskets in sets --it is not a good use for cork, the paper gaskets are 1/2 the thickness of original so I am not surprised that there are problems, the original is of a hard thick paper almost like the cardboard used in those hard paper tubes for shipping ---about 1/32 thick---I had a package of 10, now down to 5

I like Hylomar, use it all the time,if I was to remove my valve cover and the gasket was to stick to both parts I would Hylomar the surface and put it together, but for your use I would try something that would "glue" the gasket to the block, then you can grease the surface of the cover.

The last time I put the cover on I used one of my NOS gasket, no sealer.

If your cover has been overtightened it could be warped,and even if it hasn't it should be checked to see if that end that spit out the gasket is flat

The original type of lockwashers are fine, perhaps use new ones , if you decide to double the gasket you need to glue the 2 together or it will be more likely to move

Overtightening can cause gaskets to split and move out of position.
 
Thanks for the input.
Brent, the poor chap didn't do the whole rally without checking the oil. A bottom bolt fell out of the valve cover (through-hole) and all oil was lost within a few miles on a dirt road. It was so dusty he said he never heard, smelt or saw anything til it was too late. I think the bolt was left loose for the air cleaner bracket during a late night valve seat re-cutting exercise to fix a problem. And then the air cleaner was not put on, and away he went the next morning. I just ran down to check my own cover bolts and they are blind holes drilled into a boss. So my car is different and cannot lose oil from the holes. I guess his '28 pickup had been repaired/modified. It did seem odd to me that Henry would drill through into the chamber.
I was not considering 2 gaskets or loctite. 2 gaskets sounds a bad idea to me.
Keith, Dick, Kurt, my gasket was not rubberised cork, it was 0.020" compressed fibre. The cover is cast aluminium and bowed outwards evenly now by maybe .020" at the middle. But it is flexible and I can press it flat on a surface plate with just my fingers, when it then sits flat on the plate. It cannot be rubbed down flat due to a protruding boss for the air filter on the inside. It is the "A Fordable" brand I have seen on several suppliers web sites. I think it will pull down fine with the bolts.
I have the original gasket Schwalms fitted with clear silicone to the iron cover. This is .030" rubberised cork and unused except for the first tightening. Plus I have another new .020 compressed fibre gasket.
"squish out" is interesting. I just had a forkhoist lose a thick cork sump gasket like this after a service. The silicone sealer used was too slippery. We cut our own from Neolangite cork sheet and used Hylomar and it stayed in. I had a factory making gaskets and filters in the 70's, so I am familiar with materials etc. I now manufacture Automotive chemicals, Body fillers, polyester resins etc.
But, how tight is correct? Les Andrews says 20 ft. lbs. This seemed like too much for an aluminium cover and .030 gasket and might just distort the cover. So I did them up by feel- probably 15 ft lb.
And did the gasket squeeze out, or did it come out because the bolts loosened? Both give loose bolts afterwards, and mine were still nipped up, though not fully tight.
I was keeping them tight I thought, and with my old eyes I did not see the split pieces hanging out at both ends.
I note Permatex now owns Hylomar and ITW own them both. Loctite used to own Permatex.
Thanks for the help. I might make a steel bolster for the top and bottom of the cover to apply more even pressure now I see how flexible the cover is - totally different from an original one.
http://www.chemspec.co.nz http://autochem.co.nz
 
Thanks for the input.
Brent, the poor chap didn't do the whole rally without checking the oil. A bottom bolt fell out of the valve cover (through-hole) and all oil was lost within a few miles on a dirt road. It was so dusty he said he never heard, smelt or saw anything til it was too late. I think the bolt was left loose for the air cleaner bracket during a late night valve seat re-cutting exercise to fix a problem. And then the air cleaner was not put on, and away he went the next morning. I just ran down to check my own cover bolts and they are blind holes drilled into a boss. So my car is different and cannot lose oil from the holes. I guess his '28 pickup had been repaired/modified. It did seem odd to me that Henry would drill through into the chamber.
I was not considering 2 gaskets or loctite. 2 gaskets sounds a bad idea to me.
Keith, Dick, Kurt, my gasket was not rubberised cork, it was 0.020" compressed fibre. The cover is cast aluminium and bowed outwards evenly now, by maybe .020" at the middle. But it is flexible and I can press it flat on a surface plate with just my fingers, when it then sits flat on the plate. It cannot be rubbed down flat due to a protruding boss for the air filter on the inside. It is the "A Fordable" brand I have seen on several suppliers web sites. I think it will pull down fine with the bolts.
I have the original gasket that Schwalms fitted with clear silicone to the iron cover I replaced. This is .030" rubberised cork and unused except for the first tightening. Plus I have another new .020 compressed fibre gasket.
"squish out" is interesting. I just had a forkhoist lose a thick cork sump gasket like this after a service. The silicone sealer used was too slippery. We cut our own from Neolangite cork sheet and used Hylomar and it stayed in. I had a factory making gaskets and filters in the 70's, so I am familiar with materials etc. I now manufacture Automotive chemicals, Body fillers, polyester resins etc.
But, how tight is correct? Les Andrews says 20 ft. lbs. This seemed like too much for an aluminium cover and .030 gasket and might just distort the cover. So I did them up by feel- probably 15 ft lb.
And did the gasket squeeze out, or did it come out because the bolts loosened? Both give loose bolts afterwards, and mine were still nipped up, though not fully tight.
I was keeping them tight I thought, and with my old eyes I did not see the split pieces hanging out at both ends.
I note Permatex now owns Hylomar and ITW own them both. Loctite used to own Permatex.
Thanks for the help. I might make a steel bolster for the top and bottom of the cover to apply more even pressure now I see how flexible the cover is - totally different from an original one.
http://www.chemspec.co.nz http://autochem.co.nz
 
I, also, went to the shop and checked to see if the bolt holes were through holes. I have 17 blocks on a skid and 3 on stands. I inspected all and none have a through hole in the valve chamber. If you keep tightening the bolts, you will compress the gasket till it mashes out of the sealing surface. This is how a lot of tilly carbs get the mounting flange warped. A long gone friend of mine was notorious for this. In the beginning you do this to make sure the cover or pan or carb is secure but, after a few times the gasket becomes compromised and a leak starts leading to more tightening and more leaking until the gasket is destroyed. I always tighten the 5/16 bolts to about 20/25 FP and leave it at that. I also use the paper type gaskets instead of the cork type. I feel it is too easy to compress the cork too much and most people don't know how to seal the cork.
 
I am a noobie here , long time lurker and I dont have a model A but wife wants us to get one. Anyway After looking at your blown gasket I thought I would say that I have read a lot of threads on here and most of you use some type of sealer or grease on gaskets. This is fine , but if you have super smoothe surfaces it will push the gasket out . What you need to hold your gasket is teeth. Take a coarse file and rough up those areas that clamp the gasket. Make you some horizonal teeth on your faces to give the gasket something to hold to. Cork is the worst for moving when tighting .

Just my 2 cents yall carry on , my first post, POPS
 
Thanks James, Hicktick. Because the ali. cover is so flexible and will move thermally much more than the block, maybe I should tooth-up the cover and use gasket shellac on this and then grease the block to allow movement, rather than the reverse, which I suggested above. What about the clearance in the outer bolt holes? There must be quite a fight going on if the cover expands more than the block and the bolts fit tightly in each. Maybe I'm getting too complicated, but I don't want this to happen again. And I don't feel I overtightened things to split the gasket in the first place - probably the reverse, if anything. What does an ex NASCAR mechanic feel, Hicktick? You have impressive credentials.
James, I wonder if "keep tightening the bolts" is the same as "keep the bolts tight" which I was doing? If the gasket crushes, the bolts loosen and retorquing them to the original valye may progressively thin the gasket, depending on what it is made of. Certainy rubberised cork does this, until it fails, but I have compressed fibre sheet I can use and this has very high compressive resistance. Thanks again for the helpful comments
 
Thanks SAJ ,I am just an old wrench , now think of this , when your head gasket blows and you send your head to be surfaced , it gets two things A level surface and teeth. Run your fingernail across the surface and you will feel them. Now if you could have the top of the block cut you would have two perfect surfaces for the gasket to live a long time.Think about it , how slick is the top of a block when you replace the gasket . I would advise you to clean your surfaces good and rough up your mating surfaces with 80 grit , or a file . I would glue my gasket to the block with some 3m yellow glue and leave off the grease. Your old gasket got saturated with oil over time and working loose , but swelled some and split .I allwayes use my fingernail to check how slick a surface is before installing any gasket. If a gasket can move you have trouble . I use a rough file on the top of a block if a gasket has blown.
Hope this helps
 
SAJ said:
Thanks James, Hicktick. Because the ali. cover is so flexible and will move thermally much more than the block, maybe I should tooth-up the cover and use gasket shellac on this and then grease the block to allow movement, rather than the reverse, which I suggested above. What about the clearance in the outer bolt holes? There must be quite a fight going on if the cover expands more than the block and the bolts fit tightly in each. Maybe I'm getting too complicated, but I don't want this to happen again. And I don't feel I overtightened things to split the gasket in the first place - probably the reverse, if anything. What does an ex NASCAR mechanic feel, Hicktick? You have impressive credentials.
James, I wonder if "keep tightening the bolts" is the same as "keep the bolts tight" which I was doing? If the gasket crushes, the bolts loosen and retorquing them to the original valye may progressively thin the gasket, depending on what it is made of. Certainy rubberised cork does this, until it fails, but I have compressed fibre sheet I can use and this has very high compressive resistance. Thanks again for the helpful comments
Click to expand...
You are absolutely correct.
 
Hicktick said:
I am a noobie here , long time lurker and I dont have a model A but wife wants us to get one. Anyway After looking at your blown gasket I thought I would say that I have read a lot of threads on here and most of you use some type of sealer or grease on gaskets. This is fine , but if you have super smoothe surfaces it will push the gasket out . What you need to hold your gasket is teeth. Take a coarse file and rough up those areas that clamp the gasket. Make you some horizonal teeth on your faces to give the gasket something to hold to. Cork is the worst for moving when tighting .

Just my 2 cents yall carry on , my first post, POPS
Click to expand...
Gaskets are made to seal flat, dry, surfaces without ANY grease or spray on or brush on sealers or any other "magic poo-poo."
The exception wound be on upside down or vertical areas, where you might sparingly spray with 3M spray trim cement or contact cement to 1 side of the gasket and the mating surface on the engine to hold it in place. Let the surfaces dry at leats 20 minutes before sticking on the gasket. #2 Permatex or silicone rubber should only be used to seal difficult corners, such as the joints of the pan gaskets where they join the main bearing cap cork, or in some small area where the surface can't be made perfect, or to seal bolt threads that screw into open holes that end in oil areas, or on the threads of trans or diff plugs that have a very slow seep. Silicone rubber products should be only used when they are applied in bead form, to be used INSTEAD of a gasket, and then follow the instructions carefully.
Remember, gasket sealers and "poo-poo's" are a big profit maker for the parts store. You buy a gasket for 87 cents and gasket goop for for $3.97.
 
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