head gasket leak

I have a 750 motor with a set of Maney cylinders , JS rods and pistons, and I am having a very harsd time keeping the head gasket sealed. I first used the flame ring with little luck. Then I went to the copper gasket which worked a little better. Then I tried annealing the gasket and used thin copper wire surrounding the pushrod tunnels, the 5/16 studs, and the 3/8 stud. This seemed to work out but now it is leaking again and getting worse. I tried the CNW breather which worked wel and I can reccommend them. But here comes the oil leak once again.

I too have just been through this with my 750. The flame ring gasket i used leaked oil from around the pushrod tubes. When i removed the old leaky flame ring, i compared it to the Andover one i got from RGM and it was inferior. I think i got it on eBay.

The Andover head gasket is ok. I ran for 5 mins or so, cooled down then torqued. I did about 100 miles and retorqued. I did it again at 300 miles. Now at 400 miles and the Andover one looks like its going to be fine.

I did not try the copper gasket and am not sure if you are having issues with a genuine head gasket or not.

My friend Ron has also been having issues with inferior head gaskets leaking from push rod tunnels. It could be un related though. Good luck with it. Its a pain to have to keep taking the head on and off. I left my head steady and spring off while i was torqing and testing it.

Cheers

My understanding is that Maney cylinder liners protrude above the barrel top slightly, and that the copper gasket deforms to seal both the liner tops and the rest of the head to barrel face.

Does the flame ring gasket also do this? I imagine that it wasn't really designed for this. It would have been designed to seal two perfectly flat surfaces. It might be worth checking with Steve as to which is the best gasket to use in this situation.

Other than that, are you sure that both head and barrel are perfectly flat and damage free?

I second Jerry's comment as I have also (thus far) had zero issues using genuine AN head gaskets. I did notice however that the area around the pushrod tunnels and front studs is not much (on an 850) so this time I applied wellseal around those areas. apart form the wellseal, I do go to some trouble to ensure both surfaces, and the gasket, are scrupulously clean.

Also regarding Jerry's comment about how much, and how quickly, the head gasket crushes after being fitted is also a key point. This amazed me and made me realise it would be very easy to run a newly fitted gasket for too long before re-torque and end up with very low torque on the fixings.

Why not go back and ask the sellers of this stuff what they do?

I have had the same problem when using a 920 Maney cylinder. Steve told me he uses Permatex The Right Stuff. Jim Schmidt uses .005" copper wire. I use a copper gasket & Victor Reinz grey silicone available from Motobins BMW parts in Lincolnshire. This seems to work for me. The problem is the liners protrude .003" to .004" above the cylinder. This is the normal way to make this type of cylinder, but would be better reduced to .001" once the barrel has been used for a few thousand miles. I speak from experience when running a much modified Honda SOHC 750/4 which was relinered to 888cc. This did not leak.

Martyn.

Matchless said:

I have had the same problem when using a 920 Maney cylinder. Steve told me he uses Permatex The Right Stuff. Jim Schmidt uses .005" copper wire. I use a copper gasket & Victor Reinz grey silicone available from Motobins BMW parts in Lincolnshire. This seems to work for me. The problem is the liners protrude .003" to .004" above the cylinder. This is the normal way to make this type of cylinder, but would be better reduced to .001" once the barrel has been used for a few thousand miles. I speak from experience when running a much modified Honda SOHC 750/4 which was relinered to 888cc. This did not leak.

Martyn.

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Thanks for the tip Marty, two tubes are now on their way to me!

For anyone else inspired by this, here's the online shop page:

https://www.motobins.co.uk/mobile/bmw-p ... 10&M3=4085

the gaskets came from Fair Spares so I trust their quality.
Did not realize the liners stood above the cylinders. If so, it is very difficult to see or feel. I would have thought the process would be to install the liners and take a thin pass to insure everything was flat. If there is a .003 difference I would think the flame ring would have handled that. I have always used the red loctite (forgot the number) around the pushrod tubes and front studs. I have never been a fan of the copper head gaskets but tried it with the .005 wire which worked fairly well untill the last few days. I will retorque the head today and cross my fingers.

I bring this post back up again looking for any and all suggestions. I am about to pull off this head again, ATTEMPT #3, and try to solve the leaking problem. The cylinders seem to be sealing well, the oil up front appears to be the problem. Will the mentioned gasket goo really stick to the copper gasket and last for years?

If you are referring to the Victor Reinz silicone, yes it does work with a copper gasket. Whilst I cannot guarantee it will seal forever, it seems to be working for me, & my bike gets thrashed on regular 200 & 300 mile runs. If I have to strip the top end again I will stick the cylinders on a surface grinder & reduce the height of the liners to 0.001" above the aluminium deck. As it is , all is well for the moment.

Martyn.

I just fixed what I thought was a head gasket leak,
This from my post.........

"And also I found the intake rocker cover leaking, its eventually fills a cavity on the top of the head and when it cant hold anymore oil it runs out forward right where the #9-10 heads nuts are!
I thought the leak from the front push rod openings then blew oil to the back of the head and on the rocker cover and intake manifold. Maybe the other way around. "

Perhaps this is a far out suggestion. Re-torque the head bolts after months, not miles.

This suggestion is based on purely theoretical considerations, not direct experience. Many materials have a Time-Temperature-Load envelope in which plastic deformation occurs, also called creep. I do not know for sure if copper head gaskets fall into the envelope, but it is a possibility.

Here is an example of plastic deformation that many may be familiar with. If one tins (applies solder) to a stranded copper wire, then crimps a terminal on that wire, or inserts it into a terminal block using a screw to secure the wire, I guarantee that wire will easily pull out of the terminal after several months. I have personally seen it happen on several occasions. The soft solder deforms under the load over time, which in the case of solder is a few months.

I would think (again from theory, not experience) copper has a similar behavior, I just do not know off the top of my head if the temperatures at the head gasket are within that envelope wherein deformation occurs. If plastic deformation is the culprit, re-torquing will work harden the copper and eventually no further deformation should occur.

FWIW, I recently checked the torque on my Atlas head. It has been many years since the head was off. I found every bolt and nut was loose.

Slick

I retorqued about 2 weeks ago, nothing needed. I tried the .005 copper wire which worked for a short while but it is steadily getting worse.

I retorqued my FA head yesterday, last time a year ago, prob 1500 miles. Two bolts were a bit
loose, one less loose the rest tight. All were backed off just a bit and retorqued.
Copper head gasket with Wellseal and silk thread about the pushrod holes.
This was done as it had begun to have a very slow seep from the front.
Runs fine, we shall see how the leak does.

Onder said:

I retorqued my FA head yesterday, last time a year ago, prob 1500 miles. Two bolts were a bit
loose, one less loose the rest tight. All were backed off just a bit and retorqued.
Copper head gasket with Wellseal and silk thread about the pushrod holes.
This was done as it had begun to have a very slow seep from the front.
Runs fine, we shall see how the leak does.

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Thanks for providing the info. I would like more feedback to determine if plastic deformation is a factor to be considered when torquing heads. Anyone else? It would be a help to all.

Slick

seattle##gs said:

I have always used the red loctite (forgot the number) around the pushrod tubes and front studs.

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As long as you are using the red loctite on the stud to head or stud to barrel interface. If you are using red loctite on the stud to nut interface you will be masking the torque when you attempt to retorque.

seattle##gs said:

I have never been a fan of the copper head gaskets but tried it with the .005 wire which worked fairly well untill the last few days. I will retorque the head today and cross my fingers.

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For the top hat of the sleeve, Maney gave me the figure of 0.002" proud but there might be manufacturing differences or differences due to the incomplete setting (pressing) of sleeves; the latter of which should disappear after initial use. It might be worth a call to Steve Maney to ask what head gasket he recommends for use with his aluminum barrels. I doubt the top hat standing proud has anything to do with your oil leak.

There was another thread on this forum recently where comnoz showed the head surface irregularities after initial clean up passes in a mill. It might be worth a look and see what you are working with as it may not be a gasket problem.

Steve told me he uses a copper gasket & puts a little Permatex The Right Stuff around the pushrod tunnels & oil drain hole. The leak on my engine was certainly not caused by the new Fullauto head, as I checked it before fitting. I remain convinced the liner protrusion is the problem. I have been running Norton twins for over thirty five years, & with iron barrels have not had problems with oil leaks.

I've been running and have run through 7 Steve Maney barrels and never had a problem with the top hat of the cylinder liner giving any problem whatsoever and quite frankly, this is the first I have ever heard of anyone even suggesting that the top hat standing proud would contribute to, or be the direct cause of, oil leaks.

Where we have really stepped up the compression ratio we opt for a groove cut into the top hat of the sleeve and insert a thin stainless steel safety wire which more firmly grips the solid copper gasket (and effectively stands even more proud of the deck surface) and still no problems with oil leaks.

To the OP, I seem to recall someone asking about or investigating using the thin copper wire trick on both sides of the gasket but I have never done this nor know if anyone else has and what the results are.

Again, I would suggest having a very close look at (measurements) the condition of the head deck surface.

prob 'been beat to death but haven't run across the norton deal..

by re-torque, is it loosen re -tighten or just tighten up?

Slacken & then re torque one bolt/nut at a time.

Matchless said:

Steve told me he uses a copper gasket & puts a little Permatex The Right Stuff around the pushrod tunnels & oil drain hole. The leak on my engine was certainly not caused by the new Fullauto head, as I checked it before fitting. I remain convinced the liner protrusion is the problem. I have been running Norton twins for over thirty five years, & with iron barrels have not had problems with oil leaks.

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I have had some leak problems with Maney barrels. The best thing I did was to clean the top of the barrel thoroughly and then apply a little green -wicking grade locktite to the gap around the top edge of the liner.
Once that gap was filled the leaks went away.
I used a flame ring gasket -no additional sealant. Jim