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[rednectum]

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!

i think you can eliminate that one. when unpackaging new cylinders, the techs can place em front/ rear because they are the same. yall are only seeing rear problems, leading one to believe additional heat is the culprit. marginal casting is the problem.

tis what i glean from this anyway.

[SE08RK]

i think you can eliminate that one. when unpackaging new cylinders, the techs can place em front/ rear because they are the same. yall are only seeing rear problems, leading one to believe additional heat is the culprit. marginal casting is the problem.

tis what i glean from this anyway.

How about if we dissolve some peppermint candy in the engine oil? Or the gasoline? That would seal up a head gasket. It would seal up the leaks and smell good too! Ah hell, that's just wishful dreaming, and its been a fine day.

 And a good day to all too!

[rednectum]

you know what they say about too much sugar. or sugar coating. we are all trying to understand.

[djkak]

....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!...

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!....

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.....

BC

Got me there; any contemporary overhead valve examples? It seems to me that if all that is necessary to make this a better mousetrap is to fasten a flanged liner into an aluminum heat sink, the aftermarket would be on this like a cleaning Lady on a quarter; assuming that Milwaukee’s disinterest is financial.

The purpose of the OEM Kent Moore torque plates are to simulate assembled conditions. The book method to refinish these cylinders is to maintain roundness and taper to within 0.0002”, with the torque plates in place. Some distortion will occur when the torque plates are removed.

I’ll bet that with the CAD technology available today, the tapered design of the cylinder’s heat sink would do a fairly good job of maintaining dimensional stability in the bore at operating temperature; either that or it’s just used to make it look cool. 

djkak

[SE08RK]

you know what they say about too much sugar. or sugar coating. we are all trying to understand.

I believe that you have a pretty good understanding about what's being discussed here, rednectum. The sugar is a silly joke without the slightest semblance of seriousness intended. I'll try to stay closer to the subject.... .

.0002! Man that's close! Being able to subject the cylinder to the exact stresses and torque when machining as in situ has always seemed another of those compromises in the 'exactness required' for these engines. Not long ago, you would bore and finish a cylinder only after measuring the piston that was going to be used. Today - just bore it!

Flanging the TC liners? I just may go do some measuring to see how plausible that may be. The aluminum portion certainly appears to be thick enough and there are heat sink compounds to lube and keep contact for heat dissipation. Why it hasn't been done before is a good question, except maybe the availability and cheapness of the already ready variety.

The RR Merlin used flanged liners, though water cooled. The P-51 Mustang engine - the inverted v12 Allison V-1710 supercharged water cooled super high performance gasoline engine used flanged cylinder liners. Cast-in liners are a recent innovation (last 35-40 years) where the atmospheric controlled die casting process allowed the use of high strength aluminums that would sustain the shrink grip that a liner needs. Keying the liner in is a means of allowing the process to require fewer steps to the finished product - cheaper.

I remember talking to an old mechanic when I was a kid about my Pan Head. I told him about the oil leaks, the smoke and clatter and he asked me how it ran. I said "it runs good" and he says "well then, why are you standing here griping about an engine that runs good - go ride the hell out it!" But that was then, and that motorcycle didn't cost over 33K to get on the road like this CVO did. This 110 sounds very much like the Pan Head did and some even have the oil leaks! I'm going to ride it as the old man suggested and worry about the engine when it self destructs - hoping that it does it during the warranty period. It's all a compromise! 

[SPIDERMAN]

Just to throw a screwball into this discussion. I've gotten a couple PM's from some of the MADMEN on this site that dream of nothing but gears and pistons and cylinders and cams etc etc and they're quietly building motors with AXTEL iron cylinders.

BEWARE THE STOCK LOOKING CVO WITH FUNNY LOOKING CYLINDERS 

B B

[djkak]

.....0002! Man that's close! Being able to subject the cylinder to the exact stresses and torque when machining as in situ has always seemed another of those compromises in the 'exactness required' for these engines. Not long ago, you would bore and finish a cylinder only after measuring the piston that was going to be used. Today - just bore it!

Flanging the TC liners? I just may go do some measuring to see how plausible that may be. The aluminum portion certainly appears to be thick enough and there are heat sink compounds to lube and keep contact for heat dissipation. Why it hasn't been done before is a good question, except maybe the availability and cheapness of the already ready variety.....

I remember talking to an old mechanic when I was a kid about my Pan Head. I told him about the oil leaks, the smoke and clatter and he asked me how it ran. I said "it runs good" and he says "well then, why are you standing here griping about an engine that runs good - go ride the hell out it!" But that was then, and that motorcycle didn't cost over 33K to get on the road like this CVO did. This 110 sounds very much like the Pan Head did and some even have the oil leaks! I'm going to ride it as the old man suggested and worry about the engine when it self destructs - hoping that it does it during the warranty period. It's all a compromise! 

I agree that 0.0002" is a small number and does seem a little fussy; although in practice two tenths is not at all difficult to maintain; a broader tolerance would get the job done faster though. I believe that 0.0002” has been the standard in high performance automotive applications for many years.

My experience with automotive machine shops coincides with yours in that they simply bore all cylinders to a given dimension rather than taking the time to iindividually fit each piston. Today it seems that most of the H-D cylinder work is done for high performance applications. In these cases I believe a reasonable expectation is that each piston is custom fit and the bore’s roundness and taper is held to 0.0002” or less.

There is a challenge when finishing an H-D cylinder, with its large exposed spigot at the bottom. Friction created by the rigid hone can heat the spigot area to a higher temp than the rest of the cylinder, causing it to expand more. If you don’t modify your stroke to account for this, you might be forced to deal with it later. 

Your thoughts about compromise and balance ring true with just about everything in life, I have found. Right now I’m working on the balance between my speedometer and the State Patrol’s. This one always feels more like all balance and no compromise.

djkak

[djkak]

Just to throw a screwball into this discussion. I've gotten a couple PM's from some of the MADMEN on this site that dream of nothing but gears and pistons and cylinders and cams etc etc and they're quietly building motors with AXTEL iron cylinders.

BEWARE THE STOCK LOOKING CVO WITH FUNNY LOOKING CYLINDERS 

B B

Hoist brought that up awhile back. I believe that those big iron cylinders are tough as nails, but I’m not sure that I would be comfortable blazing through the California desert at warp speed in late July with a pair of those between my legs.

Back in the days when iron cylinders ruled the roost, a sharp carbide in the boring bar was your best friend.

djkak

[SE08RK]

Yes, and the VA State Police are forced to do the dirty work for this state, since with the 'remedial fees' that they just enacted - $1000 speeding 'fee' on top of the regular fine for residents only! It doesn't pay to live and pay taxes in VA anymore, they'll screw you anyhow!
 
Sorry to get on that! But what you say is very true and they are using laser to detect your speed now. The police seem more predatory than safeguarding lately, especially on the highway, like mercenary? But some people get away with most anything, like the stereo types story again. "Who's tha man in tha black Jap sedan that just cut you off - Shaft - that's who"   --going too far away from the topic, I am----

The iron lined aluminum cylinders are much more efficient than solid cast iron. Aluminum will transfer and dissipate the engine's heat far better than the iron, so what we have right now is the best 'compromise' or the best of both worlds. And I will guarantee that those iron cylinders are a product of China! But, the quality of their castings are very much better than years past where you had to grind a bore out because if the glassy hard inclusions in the cast iron. The iron foundries in the USA are so EPA'd that they are stuck making man hole covers, dam shame. I make some castings once in a while in my back yard and I sometimes look up to see if the EPA is flying around looking at all this heat going up into the sky - bound to be illegal!

Iron is very intimidating to work with in its molten state! It's so hot that a drop of water into the crucible doesn't have time to turn to steam, it separates into hydrogen and oxygen and explodes sending droplets of super hot molten iron into the sky. A drop of molten iron hitting a person in the head is fatal. It will cauterize a hole down through the skull and down into the brain. You be seriously dead!

Enough of this cheerful stuff!

Looking back at the photo in your first post...if you lay a straightedge across the top of a slipped cylinder, do you see an indication of the liner slipping down? And in that case, wonder what would happen if the cylinder were set up in a hydraulic press inverted and the liner were pressed back up? Do you suppose that the liner has actually become free in the jug? Also, wonder if HD has done any destructive testing to determine what is going on here; I guess we'll never know about that. I keep watching this 110 and haven't seen any cylinder activity but I'm just getting to the mileage that members here who have had the problems began to encounter them. I'll scream like mad when I see something, and I'm anxious about it - as if it is 'when' and not 'if'. This is such a pathetic defect! They made a cheap to manufacture cylinder, then tried to cheapen it even more ruining the only thing left that was good about the HD engine - longevity. 'course the timing chain helped there too!

BC

[Hoist!]

Hoist brought that up awhile back. I believe that those big iron cylinders are tough as nails, but I’m not sure that I would be comfortable blazing through the California desert at warp speed in late July with a pair of those between my legs.

Back in the days when iron cylinders ruled the roost, a sharp carbide in the boring bar was your best friend.

djkak

Axtell's not offering solid CI cylinders. I did try to go with solids, but used the Axtell Alum cylinders, with Liners. They are MUCH more heavy duty than the HD design, and are the same type that they use in all bore sizes. I was told the only solid cylinders they have are solid Alum w/the Nikalsil you spoke of earlier. I was told not to go that route due to long term reliability and reservicing issues.

Hoist!

[Twolanerider]

Axtell's not offering solid CI cylinders. I did try to go with solids, but used the Axtell Alum cylinders, with Liners. They are MUCH more heavy duty than the HD design, and are the same type that they use in all bore sizes. I was told the only solid cylinders they have are solid Alum w/the Nikalsil you spoke of earlier. I was told not to go that route due to long term reliability and reservicing issues.

Hoist!

This reminds me.  I need to check and see if the Axtell jugs I'm getting have made it to Sumax yet...

[djkak]

....Looking back at the photo in your first post...if you lay a straightedge across the top of a slipped cylinder, do you see an indication of the liner slipping down? And in that case, wonder what would happen if the cylinder were set up in a hydraulic press inverted and the liner were pressed back up? Do you suppose that the liner has actually become free in the jug? Also, wonder if HD has done any destructive testing to determine what is going on here; I guess we'll never know about that. I keep watching this 110 and haven't seen any cylinder activity but I'm just getting to the mileage that members here who have had the problems began to encounter them. I'll scream like mad when I see something, and I'm anxious about it - as if it is 'when' and not 'if'. This is such a pathetic defect! They made a cheap to manufacture cylinder, then tried to cheapen it even more ruining the only thing left that was good about the HD engine - longevity. 'course the timing chain helped there too!

BC

The cylinder in the first post has not failed; I don’t have a bad one to photograph. Once the liner begins to move, for all practical purposes the cylinder is no longer serviceable. The early S&S EVO Sidewinder cylinders mentioned awhile back were notorious for liner shift. I did try straightening the head gasket surface and trimming the protruding liner at the base on a couple sets of S&S cylinders. This would buy some time, but the rate of slippage increased on these “repaired” cylinders.

My experience over the past 20+ years is that liner movement on H-D cylinders is rare. I can easily count on one hand the number of H-D cylinders that I have encountered which have failed in this manner. I see one or two posts that mention a broad date range for this failure; that has not been my experience.

It is my sense that historically these types of malfunctions originate in the Foundry manufacturing the cylinder blanks. The duration of this problem causes me to question whether this is true in the case of the 110’s. With adequate QC in place, it seems unreasonable that that the cycle time required to recognize and correct a malfunction like this would take anywhere near this long. Once discovered I assume that SOP would be to identify the parts from the offending production run and scrap them.

At this point we really don’t know for sure if the root cause of the leakage is related to liner movement. Another thing that complicates the “field diagnosis” is that the method to seal top end oil returning through the head gasket has changed with the advent of the 110’s. It is possible that we are dealing with more than one problem.

I run a 113” Road Glide that has somewhere near 15,000 miles on it. The head gasket area of the cylinder and head are as dry as a popcorn fart. The 113 cylinders are not bored out 110 cylinders; the OD of the spigot and liner is larger on the 113; the bore is +0.060” over the 110.  It seems likely that the 113 cylinders are sourced from the same Foundry as the 110’s and probably all of the other smaller bore cylinders as well. If all of the large bore Twin Cam’s, including the 113 were failing, the easy assumption would be that there is shortcoming in the design of the large bore TC cylinders. I don’t have a sense for that yet; although that is the reason that I started the topic.

I would be interested to see or hear about the long term success of a 110 with straight gasket surfaces, which has been repaired with Cometic head gaskets and a modified head bolt torque procedure; the Cometic folks have one. I don’t use Milwaukee’s torque/twist method in high performance applications. I have landed on 40 to 45 ft lbs. I believe that 20 years ago S&S recommended something like 60 to 65 ft lbs for the EVO Sidewinders; it was not uncommon to see these engines pull cylinder studs. If a 110 leaker was repaired with the above method and failed again, I would be very interested in whether the liner had moved in the cylinder.

I wonder if there is a legitimate destructive test that involves throwing the cylinders off of a cliff; I'll bet it would be popular.

djkak

[SE08RK]

Very interesting.. I had a suspicion a while back when someone mentioned symptoms of these head gaskets leaking oil that it may be something that you have eluded to. I agree that these liners may possibly be the problem but the past history of the fabrication process and success of the 88 cylinders certainly leads to some serious doubt.

 My experience with the TC is recent, and by that I mean that I bought a TC in '04 and then began to accumulate parts for the engine. I have bought several pairs of cylinders and heads of various years and accumulated many other parts in anticipation of doing some mods and for trial and error. Some of these TC cylinders that I have bored have gotten excessively hot in doing so and have had to allow them to cool to the touch in order to remove them from the boring table - done partly due to a recent recondition of the boring bar so to test its cutting capacities and another reason is a trait: always in a hurry. A pair of these cylinders were used by a young fellow that has no regard for the engine or his health - youth is bliss! Stock HD head gaskets were used and they have done fine, no indication that the localized heat did any damage.

So I believe that you may have hit on something with two things: the possibility of the studs pulling from the cases and that the torque method HD recommends is flawed. The twist method, as I have known and used it with aircraft engines, is for a situation where the studs are tensioned to 75% or so of their yield point so as to utilize the heat treated alloy to it utmost, utilizing its elasticity. These alloy studs are sized to work within the cold and hot static dimensions of the assembly and usually in these applications the studs are discarded and newly heat treated ones are fitted. HD left out the step where the studs are discarded after each disassembly of the upper end. And.. so I agree with your 40 -45 ftlb torque as a more accurate sustained and acquired torque - with proper preparation of the threads a given. Possibly in the low range of torque for the size thread and stud size for my (and your eluded to) suspicion that the studs are/were pulling from the cases. Which is very possibly why HD replaced some entire engines when these failures were first found. ( I'm a conspiracy theory sort, since I put nothing past a company that is so secretive. They give us license to surmise and theorize about their policies!) They may very well have realized an inadequacy in the cases where the thread area allowance for the cylinder studs is too small and see no alternative but to replace the culprit engine.

Can we start some rumors with a friendly discussing of this stuff ??!!

Where's the cliff? I'm ready to do some destructive HD engine parts testing. That's a good one!

Thanks dj!

[Chief]

the fin above the exhaust port is clear: front & rear.

not that they won't reciprocate, but they are labeled.


 my replacement engine seems solid.



TN



a blueprint of the 110ci engine would be nice.

TN,

You must be thinking about the head, not the cylinder. The heads are definitely F&R, but the cylinders are interchageable.

[SE08RK]

The cylinders are identical before use, after which they should remain with their broken-in pistons and locations. That's probably old hat to most of you....

BC