Author Topic: A1o oil leak  (Read 2675 times)

Richard

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A1o oil leak
« on: 14.11. 2008 17:35 »
I started the 54 up today to check all ok however the charging circuit is not functioning which should be no problem to sort out BUT I have oil seeping out of two of the head bolts I suspect the head gasket I annealed is not sealing properley and the oil from the rocker box is being forced up the bolts with the compression What do the panel think?
Richard

Offline RichardL

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Re: A1o oil leak
« Reply #1 on: 14.11. 2008 19:35 »
I think I have the exact same problem and am planning a head removal over the winter. When I tried to fix this by tightening head bolts, the original problem got better but not perfect. However, I was working with home-made gaskets that went askew under the rocker box and now have a much more signicant oil leak. I decided to ride with leak, knowing it was only oil and that winter was coming fast.

I am going to try a much more agressive annealing process than I used last time, figuring that I must have left some hard spots.

Richard L.

Richard

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Re: A1o oil leak
« Reply #2 on: 14.11. 2008 22:33 »
Richard
I have decided to remove the head and fit a new gasket rather than use it with oil leaking out as I have spent the last few weeks tidying it up including painting the head and barrells so I would like it to look nice for a few hundred miles rather than be spoilt by oil over a couple of miles.Hopefully that will cure it I wil certainly let you know if it was the gasket.
all the best Richard

Offline RichardL

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Re: A1o oil leak
« Reply #3 on: 14.11. 2008 23:25 »
When last putting mine together I noticed that the stamping procees that cuts the gasket leaves a pretty good burr and misshaped edge. I tried to sand it out. Next time I'm trying harder.

Richard L.

Online Brian

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Re: A1o oil leak
« Reply #4 on: 14.11. 2008 23:34 »
Just a quick note on the annealing process. Its not quite as easy as you might first think. You need a decent heat source, I have a gas burner with about a 2" nozzle. You need to get the whole gasket bright red at the same time and drop it into a large bucket of water. Its no good putting it in a small container or lowering it in. The idea is to cool the whole gasket uniformly at the same time. Once annealed you need to clean it up properly, I use hydrchloric acid on a piece of cloth, dont use anything abrasive like emery paper. Make sure you wear glasses and gloves. The head gasket that is in my 61' A10 has been done three times now and is fine.

Its all good fun.

Brian.

Offline RichardL

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Re: A1o oil leak
« Reply #5 on: 15.11. 2008 00:01 »
I had a feeling the little spots getting heated by my hardware-store propane torch might not be doing a right job. Regarding abrasives, do you not find the burr I mentioned or does is go away with the acid, or, perhaps, is just too soft to matter? Thanks for advice.

Online Brian

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Re: A1o oil leak
« Reply #6 on: 15.11. 2008 00:14 »
If there are some burrs around the edges from the stamping it wouldnt do any harm to remove them but I have never bothered. With the acid cleaning I just rub the gasket with some on a cloth, it gets rid of the oxide. When you put the gasket back in the engine give it a very light smear with grease. Getting a decent heat source is probably the biggest problem, the whole gasket has to be glowing uniformly. The thing with annealing is to get the complete object at the same temperature and cool the whole object at the same time.

It also pays to check the surface of the head and barrell, I use some fine emery paper stuck to a surface plate but glass works just as well. These things are not prone to distorting so that should not be a problem but just something that needs to be checked.

Brian.

Offline LJ.

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Re: A1o oil leak
« Reply #7 on: 15.11. 2008 00:43 »
...But surely heating up a gasket and then dropping it in cold water would harden the metal just as the same process hardens the clutch push rod ends. I have heated up my gaskets evenly to a cherry red and let them cool down gradually allowing the copper to remain soft which then is able to compress easily into any imperfections on the head/barrel mating surfaces as they are tightened down towards each other. (Experiment with scrap pieces of copper or old gaskets) After this I have then given my gaskets a light sandblasting both sides to give an even roughish surface. I have had no problems with this process but it is important to retighten the head once again after a few miles of running in.
Ride Safely Lads! LJ.
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Online Brian

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Re: A1o oil leak
« Reply #8 on: 15.11. 2008 01:11 »
LJ, I have no idea of the science behind it or why it works like it does, but that was the way I was taught about 40 years ago. I have never tried letting it cool slowly. I have always done it that way and have never had a problem. I have also never re-tightened a head, I put them on with a fresh annealed gasket with a light smear of grease and thats it. I havent had one leak yet. Maybe copper behaves differently to steel or other metals, hopefully someone with a knowledge of metalurgy will chime in here with some advice.

PS. I just spent some time looking it up on the internet and it seems that it doesnt matter if you let it cool slowly or drop it in water. Most seem to say that the heating is the important part and the cooling is not important. I guess that cooling it quickly reduces the chance of anyone burning themselves or setting their shed on fire !!!!!!

Offline RichardL

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Re: A1o oil leak
« Reply #9 on: 15.11. 2008 02:58 »
Though not a metalurgist, I coincidentally own a full set of Metals Handbook from the American Society for Metals. How I came by them is a long story. Anyway, reading on annealing (copyright prevents my posting the actual page):

"Annealling is primarily a function of metal temperature and time at temperature. Except for alpha-beta alloys and certain precipitation-hardening alloys, the rates of heating and cooling are relatively unimportant. Source and application of heat, furnace design, furnace atmosphere, and shape of workpiece are important, because they affect the uniformity of results obtained, finish and cost of annealing."

The annealing process causes grain growth in the metal. I suppose this results in softness due to less total grain surface to combat when moving grains against oneanother. Anyway, the annealing temperature for low phosphorous copper (I'm guessing that might be what we get) is 600F-1200F. At the lower temperature considerable time would be required (for formal work, the book says, like, 40 minutes) and, then, you still don't end up with the softest part, as higher temperatures are capable of generating greater final grain size, regardless of how much longer you keep it at the lower temperature. At least, this is how I am reading the charts and data in front of me. By the way, my attempt at annealing consisted of getting a dot of glow to move all over the gasket. While there was an obvious change in hardness, this was clearly inadequate according to the book.

My interpretation of the reason that fast cooling is not so important is that the grains have already grown and the shrinkage (don't be alarmed) would be a small percentage compared to growth due to recrystalization. OK, already, enough!

Back to my origianl question: do others sand or lap their head gaskets due to burrs from the stamping die?

Richard L.

Offline bsa-bill

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Re: A1o oil leak
« Reply #10 on: 15.11. 2008 12:18 »
This came up on another list and apparently copper does not harden when cooled rapidly so the thoughts then were that it made no difference whether cooled slow or fast.
All the best - Bill
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Re: A1o oil leak
« Reply #11 on: 15.11. 2008 14:22 »
My understanding of copper annealing is also that you can quench or leave to cool naturally. My A10 has an annealed copper gasket in it, which I let cool naturally. It was very malleable afterwards and I have had no problem, nor did it need the check tighten I gave it after a few miles. But getting it hot properly is important. There was a good Australian Steam Engine site I was looking at on this a while ago - but can't for the life of me remember what or where it was. But it said the same.
Re the oil leak though - which was why I had my A10's head off a while back . . . there was a dodgy stud, which became a dead thread in the barrel, which  . . . etc. Sorting that and the gasket means I now have rust where once there was slime. Can't win!
Bill

Offline dpaddock

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Re: A1o oil leak
« Reply #12 on: 15.11. 2008 16:33 »
Unless you simply like to experiment with copper annealing techniques, using your precious A7/A10 as the mule, I suggest you go with the laminated gasket and get the seal you want each time, every time.
I've been both ways over the years, and the laminated gasket is by far the best.
David
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Offline RichardL

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Re: A1o oil leak
« Reply #13 on: 15.11. 2008 17:11 »
Dave,
I almost hate to reopen this can of worms, but have you experienced the need for retightening head bolts with the laminated type? I think others have mentioned that.
Then, do you know where to buy the laminated type? They seem to be hard to find. Aside from annealing problems, one reason I think laminated may work for me has to do with the resurfacing necessary after the botched skimming job on head and barrels (you may recall). Appreciate your thoughts Dave (and others).

Richard L.