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[SE08RK]

Question please:

Why did we never hear about this on Porches or VW's? What do the Germans know about this that we don't? Why did HD have to go to Porsche to save their asses with the Evo? WTF are they really missing on these 110's?

Thanks for indulging my obvious inferior knowledge on this subject.

Hoist!

Hoist,

I would venture to say that Porsche or VW or any other manufacturer of these types of cylinders use a flanged liner - more expensive to manufacture. None of the HD cylinder liners are flanged so they are relying totally on the keyed casting joint for stability and location of the liner. A flange on the liner would do two things: allow it to be totally renewed very readily (HD hates the thought of that!) and the liner would be stationary in the aluminum finned jug and held by an appropriately designed head gasket or compression joint between the head and cylinder 'assembly'. Also, the added expense of the mechanical fitment of the liner to the jug would reduce the bottom line for the money people at HD. These cylinders are probably made as cheaply as HD can possibly make them!

B.C.

Coming back in again: The engines that Porsche has helped HD with - mainly the Revolution, is water cooled and the liners are subject to a different set of circumstances - and I would bet that the liners are flanged. I also believe that HD will eventually make these 110's good. They are betting that when the cheapness problems of the build become evident that their warranty responsibility will be long gone - that's business. If they can be held responsible due to an ongoing legal battle over these design and cheapness flaws then the original owners of the 110's will have access to a class action suit, and remedy, against HD that includes us all. And you can bet that right now they are calculation which way will cost the least for them in the long run, fix them now or wait to settle with all of the purchasers of a 110.

[skreminegul07]

Hoist,

I would venture to say that Porsche or VW or any other manufacturer of these types of cylinders use a flanged liner - more expensive to manufacture. None of the HD cylinder liners are flanged so they are relying totally on the keyed casting joint for stability and location of the liner. A flange on the liner would do two things: allow it to be totally renewed very readily (HD hates the thought of that!) and the liner would be stationary in the aluminum finned jug and held by an appropriately designed head gasket or compression joint between the head and cylinder 'assembly'. Also, the added expense of the mechanical fitment of the liner to the jug would reduce the bottom line for the money people at HD. These cylinders are probably made as cheaply as HD can possibly make them!

B.C.

Coming back in again: The engines that Porsche has helped HD with - mainly the Revolution, is water cooled and the liners are subject to a different set of circumstances - and I would bet that the liners are flanged. I also believe that HD will eventually make these 110's good. They are betting that when the cheapness problems of the build become evident that their warranty responsibility will be long gone - that's business. If they can be held responsible due to an ongoing legal battle over these design and cheapness flaws then the original owners of the 110's will have access to a class action suit, and remedy, against HD that includes us all. And you can bet that right now they are calculation which way will cost the least for them in the long run, fix them now or wait to settle with all of the purchasers of a 110.

That's a given.  Something we can all agree on. 
I have a question:  maybe several
These leaks have been ongoing for over a year.  Some have had multiple gaskets changed.  I hate to ask, but why didn't any tech or HD tech support ask, notice, mention to check for the liner having moved?  I am assuming (gasp) that it is supposed to be flush.  When I was a mechanic, if a new motor had a head gasket leak and I changed the gasket I would look for a surface imperfection.  Definetely the second time around.  Isn't this basics?

 

[Chief]

That's a given.  Something we can all agree on. 
I have a question:  maybe several
These leaks have been ongoing for over a year.  Some have had multiple gaskets changed.  I hate to ask, but why didn't any tech or HD tech support ask, notice, mention to check for the liner having moved?  I am assuming (gasp) that it is supposed to be flush.  When I was a mechanic, if a new motor had a head gasket leak and I changed the gasket I would look for a surface imperfection.  Definetely the second time around.  Isn't this basics?

 

I think the difference here is that we're not talking about a 'blown' headgasket in the normal sense. What we're dealing with is the failure of the gasket outside of the crimp, not being able to keep the oil returning from the head contained. This head gasket is sealing two different animals here: 1) The combustion chamber, which I don't think we're seeing any problems with, and 2) The oil return passages, which is where we're seeing the problem.

The problem most are having with the -07A gasket is no longer dripping oil beow the exhaust port, but rather oil traveling laterally along the surface of the gasket and migrating down the stud pockets, which are outside the base o-ring, and then weeping out onto the deck between the engine and tranny.

The crimp area of the gasket is not faileing as far as I have heard, but instead it is the outer edges not doing their job properly.

[SE08RK]

Perhaps it's time for H-D to consider the alternatives to their cast aluminum & iron sleeve parts.  Chrome plated aluminum bores have been around for decades (had them on my first two bikes in the 60's).  There is also Nikasil, or just high silicon carbide content aluminum alloys.  Many Japanese bikes utilize coated aluminum bores, as do some marine engines (ie. Mercury), and there have been more than a few in auto's as well (BMW, Jaguar, GM, etc).  As with all things in life, there are trade-offs involved.  But at least you wouldn't have to worry about sleeve creep, and the heat dissipation would be greatly improved as well.  The following article describes a new process developed by Yamaha in 2002 that shows a great deal of promise: 
http://www.yamaha-motor.co.jp/global/news/2002/07/31/innovation.html


Jerry

Yes, I agree with this too. GM attempted the high silicon content aluminum cylinder block with the Vega four cylinder engine. The process was to etch the aluminum from the surface of the casting leaving the silicon as the wear surface then iron plate the aluminum piston. That means that the Yamaha method is not really that new - but the Japanese are famous for claiming a technology was their origination. The Nikasil system, which I have had experience with, is a very effecient one with fantastic longevity and very good wear characteristics as long as there is ample lubrication. The slightest deficiency in lube will cause scuffing in the bore and then shortly the total destruction of the cylinder, so there is no margin for error or forgiving of the system. Nikasil also has no small shop re-coating method since the process it very specialized in chemicals and safe handling methods - and the EPA would not allow a small company to do the process. The pistons for use in Nikasil bores must also be iron plated - another drawback. Hirth aircraft engines use Nikasil jugs that will last about 100 hours then must be changed - expensive! These jugs then go to the junk box for recycled aluminum - no recondition at all.

The farther toward making a one piece cylinder of aluminum or other high silicone alloy, the farther we go away from the ability for a small company or individual to have any sort of modification ability at all. At least with iron liners, a moderately prepared shop can bore a set of cylinders out and fit some pistons. The aluminum cylinders would have to be modified by inserting an iron liner and the manufacturing process would probably prevent this modification by going to a thinner section to start with.

I'll take a properly designed iron lined aluminum cylinder.

BC

[SE08RK]

I think the difference here is that we're not talking about a 'blown' headgasket in the normal sense. What we're dealing with is the failure of the gasket outside of the crimp, not being able to keep the oil returning from the head contained. This head gasket is sealing two different animals here: 1) The combustion chamber, which I don't think we're seeing any problems with, and 2) The oil return passages, which is where we're seeing the problem.

The problem most are having with the -07A gasket is no longer dripping oil beow the exhaust port, but rather oil traveling laterally along the surface of the gasket and migrating down the stud pockets, which are outside the base o-ring, and then weeping out onto the deck between the engine and tranny.

The crimp area of the gasket is not faileing as far as I have heard, but instead it is the outer edges not doing their job properly.

The earlier (smaller OD) cylinders didn't have the problem of slipping, so my guess is that the techs were in the dark about it. The likelihood of this is beyond the ordinary. Who would think that HD would stoop to cheapening up their engine parts to this point?

Good analogy of the head gasket leak and is very logical. The metallic ring in the head gasket, placed there as a compression seal, is ineffective if the friggin cylinder has dropped away from it! The rest of the gasket sealing surface is just that - surface. So oil drain back and residual cylinder oil trapped at the junction is allowed to creep to the edges. Drip...

BC

[Hoist!]

This is some really excellent stuff here. Keep it coming! Thanks a lot SE08RK, dj, Jerry, Phil, and Chuck!

Hoist!

[Chief]

The earlier (smaller OD) cylinders didn't have the problem of slipping, so my guess is that the techs were in the dark about it. The likelihood of this is beyond the ordinary. Who would think that HD would stoop to cheapening up their engine parts to this point?

Good analogy of the head gasket leak and is very logical. The metallic ring in the head gasket, placed there as a compression seal, is ineffective if the friggin cylinder has dropped away from it! The rest of the gasket sealing surface is just that - surface. So oil drain back and residual cylinder oil trapped at the junction is allowed to creep to the edges. Drip...

BC

But if the liner has dropped and the crimp has lost its clamping load, I would expect to have one nasty compression leak that would be much more noticeable than just the weeping oil we are seeing.

[SE08RK]

But if the liner has dropped and the crimp has lost its clamping load, I would expect to have one nasty compression leak that would be much more noticeable than just the weeping oil we are seeing.

The metal edge is basically to prevent the gasket material from eroding from the fuel, oil, and all that other flaming activity going on in the chamber. The metal crimp ring helps to some extent and probably the better the wider it is but the gasket material is what does the major sealing. The gasket is what the crimp is supported by. I believe the oil leak is part of a combination of occurences. Like maybe a non resilient, cheap assed head gasket that has taken a set and remains shrunk after the initial head torque and when the engine heats up and expands there in a loss of seal of the gasket - especially around the edges. So when the engine cools even slightly, oil is squeezed out from under the gasket next to the drain back hole at the lowest point of both heads - exhaust spring pocket on the head. The locater tubes at the drain holes in the mating surfaces of the head and jugs are not really tubes but pieces of rolled sheet stock so there is a crack along the seam side - not a sealed drain tube, a leak!

[Hoist!]

The metal edge is basically to prevent the gasket material from eroding from the fuel, oil, and all that other flaming activity going on in the chamber. The metal crimp ring helps to some extent and probably the better the wider it is but the gasket material is what does the major sealing. The gasket is what the crimp is supported by. I believe the oil leak is part of a combination of occurences. Like maybe a non resilient, cheap assed head gasket that has taken a set and remains shrunk after the initial head torque and when the engine heats up and expands there in a loss of seal of the gasket - especially around the edges. So when the engine cools even slightly, oil is squeezed out from under the gasket next to the drain back hole at the lowest point of both heads - exhaust spring pocket on the head. The locater tubes at the drain holes in the mating surfaces of the head and jugs are not really tubes but pieces of rolled sheet stock so there is a crack along the seam side - not a sealed drain tube, a leak!

Pardon my ignorance, but why is all this only basically occurring on the rear cylinder? Soley because the rear gets that much hotter than the front? Or does the front happen to be designed properly, even by the chance of HD getting lucky in the front?

Hoist!

[djkak]

But if the liner has dropped and the crimp has lost its clamping load, I would expect to have one nasty compression leak that would be much more noticeable than just the weeping oil we are seeing.

The head gasket “fire ring” protects and in the case of the Twin Cam, also seals. Panheads and Shovelheads incorporated the fire ring into the cylinder; these head gaskets did not require a fire ring. When the S&S EVO Sidewinder kits were first introduced, the head gasket supplied with the kit did not have a fire ring and the results were predictable.

In the case of machines like the EVO and small bore Twin Cam’s, the oil return passage through the head gasket surface was sealed by an o-ring. In circumstances where the combustion seal of these machines was compromised, the oil passage seal remained intact. The 110 cylinders do not have enough material between the bore’s edge and the oil passage to allow the use of an o-ring like the small bore machines.

Considering the apparent challenge that Milwaukee faces to seal the oil passage with the reduced surface area, It is my sense that with the 110’s it is more likely that a compromised combustion chamber seal will also result in leakage from the oil return passage.

djkak

[djkak]

Hoist,

I would venture to say that Porsche or VW or any other manufacturer of these types of cylinders use a flanged liner - more expensive to manufacture. None of the HD cylinder liners are flanged so they are relying totally on the keyed casting joint for stability and location of the liner. A flange on the liner would do two things: allow it to be totally renewed very readily (HD hates the thought of that!) and the liner would be stationary in the aluminum finned jug and held by an appropriately designed head gasket or compression joint between the head and cylinder 'assembly'. Also, the added expense of the mechanical fitment of the liner to the jug would reduce the bottom line for the money people at HD. These cylinders are probably made as cheaply as HD can possibly make them!......

With the cylinder liner anchored at the top, the differing expansion rates of the iron and aluminum would necessitate the use of a floating liner. It seems to me that a floating cylinder liner in an air cooled engine would be problematic; heat transfer issues not being the least of them.

Are there any mass produced, high output application successfully using an air cooled cylinder with a floating liner?

djkak

[skreminegul07]

The metal edge is basically to prevent the gasket material from eroding from the fuel, oil, and all that other flaming activity going on in the chamber. The metal crimp ring helps to some extent and probably the better the wider it is but the gasket material is what does the major sealing. The gasket is what the crimp is supported by. I believe the oil leak is part of a combination of occurences. Like maybe a non resilient, cheap assed head gasket that has taken a set and remains shrunk after the initial head torque and when the engine heats up and expands there in a loss of seal of the gasket - especially around the edges. So when the engine cools even slightly, oil is squeezed out from under the gasket next to the drain back hole at the lowest point of both heads - exhaust spring pocket on the head. The locater tubes at the drain holes in the mating surfaces of the head and jugs are not really tubes but pieces of rolled sheet stock so there is a crack along the seam side - not a sealed drain tube, a leak!

Is it then possible that the orientation of the seam of the oil return tube might predetermine whether or not a leak will occur?  Is this a random event?
Not random as far as the front or rear but as far as why some leak and some don't.

Lot's of good discussion going on here.  I hope Milwaukee is monitoring.

[SE08RK]

There were sleeve valve aircraft engines mass produced before and during the second WW. The liner reciprocated as a means of valving. They were air cooled!

 It's all a compromise in manufacture and efficiency. Good sense would ascertain the need for a head gasket with some sort of protection to an eroding inner edge. Possibly a method to produce such a quality gasket was beyond their capabilities at the time? Would they admit such a deficiency in an already marketed engine? We are left to guess and try to make reason for their choice....

The cylinder liner is basically anchored at the top with a cast-in liner - that is if the keying method is satisfactory. The top is where the greatest heat is generated and also where the greater mass of the cylinder is and so will also shrink the most on cooling. This is the reason for the necessity of torque plates to achieve an accurately machined or measured bore in air cooled cylinders. The lower end is cooler and less dense so will compress greater when torqued than the top so the relaxed bore is larger at the bottom to allow for another of those compromises - the greater expanse at the top. (This cold upper tightness is a major reason for a period of warm-up of an air cooled engine before hard running to reducing the possibility of yanking a cold piston apart, or scoring a liner or piston.) A Harley cylinder is tapered when cold, the tight end being the top where the mass is, and the top grows with heat.

Water cooling would solve a multitude of problems but, I feel sure that something very desirable about these engines would be lost....they would not be a Harley Davidson engine any longer. The engine noise would be gone, no more valve train noise because the temperature would always be the same; where the thermostat says it should be, so the cylinder would always be the same - no growth. Fins would be added for aesthetics only since they wouldn't be required any longer....This 110 may be a lunk, but it has the best of it all - old and new. It leaks oil as Harley's always have, it's noisy as hell and burns lots of gasoline. What more do we want....?

BC

[SE08RK]

Is it then possible that the orientation of the seam of the oil return tube might predetermine whether or not a leak will occur?  Is this a random event?
Not random as far as the front or rear but as far as why some leak and some don't.

Lot's of good discussion going on here.  I hope Milwaukee is monitoring.

I would have enjoyed seeing solid tubes used. I'm not so sure that the rolled tubes may not be another source for the oil that a poorly sealing gasket is allowing to pass. I also hope HD is taking time to realize that we bought their product in good faith, and expect them to take charge and correct their problems, and on these 110's, not the next batch!

[SE08RK]

The head gasket “fire ring” protects and in the case of the Twin Cam, also seals. Panheads and Shovelheads incorporated the fire ring into the cylinder; these head gaskets did not require a fire ring. When the S&S EVO Sidewinder kits were first introduced, the head gasket supplied with the kit did not have a fire ring and the results were predictable.

djkak

Sort of a shame that some of the older methods weren't carried over. The spigotted cylinder location ring - or "fire ring" - was a great way of locating the head on the cast iron barrel and the plumbing 'T' intake manifold did the rest... Not making fun, just thinking back. The best thing that ever happened to a Pan Head was to put Shovel Heads on it! Those days were pure bliss, didn't hear gear noise or valves clattering back then! And oil leaks?