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[vagabond6542]

is this fix working for you? i having the same work done, plus getting some cams installed (575) by dealer. had to be rentlentless to get warranty for my seeping at the rear base. which was always there since the first time i had head gasket problem. any revisions of the parts?



TN

are there any 110's that hasn't had the head gasket problem?

Gone over 5k on the motor, so far no leaks noted.
Has anyone correlated the high rear temps to the rear jug leaking?
High heat will expand metal. Especially jug bolts.
Just a thought.

[Chief]

Gone over 5k on the motor, so far no leaks noted.
Has anyone correlated the high rear temps to the rear jug leaking?
High heat will expand metal. Especially jug bolts.
Just a thought.

That's my theory. Differing coefficients of thermal expansion in mating parts leads to varying clamp loads allowing oil seepage. The larger the temperature change, the more the mismatch becomes apparent.

Time to get out a tube of Yamabond and fix it for good.

[djkak]

I’m going to take another whack at the Twin Cam head gasket leakage. The visual aid attached is a photo of a TC-96 cylinder and head gasket.

First a little background: the bore diameter of a TC-110 is 1/4” (0.250”) larger than the pictured TC-96 cylinder. The cylinder stud/head bolt pattern is identical between the TC-96 and TC-110. A TC-110 cylinder head will bolt right on to a TC-88 or TC-96; not that you would necessarily want to run this combo, but they would physically bolt up.

Increasing the bore by 0.250” in the 110’s means the head gasket fire ring must be moved away from the center point of the bore one half the distance of the 1/4” bore increase, or 1/8” (0.125”).  Keep in mind that the bore diameter is the only thing that changed; all of the other holes on the gasket surface remain unchanged from the TC-88 and TC-96 to the TC-110.

Take a look at the head gasket in the lower center area of the photo. There is only 0.100” of material between the oil passage o-ring seal and the edge of the fire ring. If the fire ring must expand 0.125” to accommodate the larger bore, and there is only 0.100” of gasket material between the fire ring and the o-ring, the 20+ year old method of sealing engine oil passing through the head gasket surface is no longer viable. And this is without considering the necessary 40%+ reduction of the o-ring’s cross section to accommodate the movement of the fire ring.

In searching for the answer to the question: what changed significantly between the TC-96 and the TC-110 that would cause oil to leak from the cylinder head gasket? I believe the reduced surface area available to seal the oil return passage, together with an underdeveloped gasket design resulted in the leakage. It’s my sense that the durability testing of the early TC-110 head gasket didn’t stress the new design in the same manner that the numerous thermal cycles experienced during normal street use would.

It is worthwhile to consider that all of the above applies to a greater degree to the 4.060”, 113” SE “bigger bore” cylinders, yet the laminated steel gaskets that come with these cylinders do a great job of sealing the return oil passage.

For what it’s worth, it appears that all Twin Cam head gaskets will be updated and commonized to the latest TC-110 design.

As always, all of the above banter is JMHO.

djkak

[Hoist!]

Thanks for your take on that dj. What you say makes sense. But it makes more sense that they have the larger bore engines have their own unique gasket design rather then working with existing templates. And if the oil returns lack of adequate clearance around it, due to the increased diameter, it makes sense to have external oil return lines. This eliminates this issue completely.

Why is the 113 having no issues? And if that's proven already, why not take the same approach for the 110? This has not been an easy pill to swallow. If mine leaks again, I'm thinking of going with external oil lines and ductile iron cylinders. This dance that everyone's doing with HD's getting kinda old!

As always, great info man!

Who is this guy anyway?

Hoist!

[Midnight Rider]

I’m going to take another whack at the Twin Cam head gasket leakage. The visual aid attached is a photo of a TC-96 cylinder and head gasket.

First a little background: the bore diameter of a TC-110 is 1/4” (0.250”) larger than the pictured TC-96 cylinder. The cylinder stud/head bolt pattern is identical between the TC-96 and TC-110. A TC-110 cylinder head will bolt right on to a TC-88 or TC-96; not that you would necessarily want to run this combo, but they would physically bolt up.

Increasing the bore by 0.250” in the 110’s means the head gasket fire ring must be moved away from the center point of the bore one half the distance of the 1/4” bore increase, or 1/8” (0.125”).  Keep in mind that the bore diameter is the only thing that changed; all of the other holes on the gasket surface remain unchanged from the TC-88 and TC-96 to the TC-110.

Take a look at the head gasket in the lower center area of the photo. There is only 0.100” of material between the oil passage o-ring seal and the edge of the fire ring. If the fire ring must expand 0.125” to accommodate the larger bore, and there is only 0.100” of gasket material between the fire ring and the o-ring, the 20+ year old method of sealing engine oil passing through the head gasket surface is no longer viable. And this is without considering the necessary 40%+ reduction of the o-ring’s cross section to accommodate the movement of the fire ring.

In searching for the answer to the question: what changed significantly between the TC-96 and the TC-110 that would cause oil to leak from the cylinder head gasket? I believe the reduced surface area available to seal the oil return passage, together with an underdeveloped gasket design resulted in the leakage. It’s my sense that the durability testing of the early TC-110 head gasket didn’t stress the new design in the same manner that the numerous thermal cycles experienced during normal street use would.

It is worthwhile to consider that all of the above applies to a greater degree to the 4.060”, 113” SE “bigger bore” cylinders, yet the laminated steel gaskets that come with these cylinders do a great job of sealing the return oil passage.
For what it’s worth, it appears that all Twin Cam head gaskets will be updated and commonized to the latest TC-110 design.

As always, all of the above banter is JMHO.

djkak

Howie...does the part highlighted in red answer your question?  Different gasket material...

[Hoist!]

Howie...does the part highlighted in red answer your question?  Different gasket material...

I saw that, but with an even bigger bore, it can't be that simple. They could've gone to that material anytime and stopped this mess in its tracks! I for one will be awful pissed to find out that's all it would have taken. I guiess I'll find out myself soon enough. I'm using Cometics now. We shall see!

Hoist!

[Chief]

I saw that, but with an even bigger bore, it can't be that simple. They could've gone to that material anytime and stopped this mess in its tracks! I for one will be awful pissed to find out that's all it would have taken. I guiess I'll find out myself soon enough. I'm using Cometics now. We shall see!

Hoist!

It's a strong possibility, not confirmed though, that Cometic is the manufacturer of the 110 gaskets. From what I understand, they have the patent on the 3-part laminated steel gasket design.

[Midnight Rider]

I saw that, but with an even bigger bore, it can't be that simple. They could've gone to that material anytime and stopped this mess in its tracks! I for one will be awful pissed to find out that's all it would have taken. I guiess I'll find out myself soon enough. I'm using Cometics now. We shall see!

Hoist!

It probably cost them a few more dollars for each unit, thus the reason.  Knowing HD like you do, you don't really think they'd spend the extra 20 bucks or so to give you a proven gasket when they can try and improve one they are getting from China or somewhere for 5 bucks a set, do you?  

[djkak]

Thanks for your take on that dj. What you say makes sense. But it makes more sense that they have the larger bore engines have their own unique gasket design rather then working with existing templates. And if the oil returns lack of adequate clearance around it, due to the increased diameter, it makes sense to have external oil return lines. This eliminates this issue completely.

Why is the 113 having no issues? And if that's proven already, why not take the same approach for the 110? This has not been an easy pill to swallow. If mine leaks again, I'm thinking of going with external oil lines and ductile iron cylinders. This dance that everyone's doing with HD's getting kinda old!

As always, great info man! ...
...
Hoist!

I believe Milwaukee, like any manufacturer is challenged to manage manufacturing costs, in part through the commonization of components; maintaining the same head bolt pattern would go a long way towards accomplishing this. That theory is supported by Milwaukee’s commonization of the earlier, time tested head gasket design of the TC-88 and TC-96 to the latest design which no longer uses a separate o-ring to seal the oil return passage.

Regarding external oil return lines or the laminated steel SE head gaskets; you or I would consider these options if we were building our own engines. It is my sense that a properly designed “production” head gasket would do the job just as well in a stock machine at a much lower cost. If I may state the obvious; the trick for Milwaukee is getting together with a vendor to adequately develop and test the new components prior to releasing them. In this case I speculate that the effect of repeated hot and cold cycles on the new gasket was not adequately simulated in testing; regardless of the number hours logged on the test engines.

Let’s hope that you don’t have to mess with your head gaskets again. If you must revisit this, I suggest running the Screamin’ Eagle, high compression, laminated steel gaskets (or equivalent). I don’t see a specific application for the 110; maybe the ’08 SE catalog will have one listed. I am running these gaskets in my 113 with somewhere around 17,000+ miles and they are as dry as a popcorn fart.

You mention the possibility of running ductile iron cylinders: I don’t have any experience with them outside of boring several hundred pre-EVO H-D cylinders. IMHO iron makes a great cylinder liner, but is a lousy heat sink. Iron is tough and if a lined aluminum cylinder isn’t robust enough to get it done for you, then maybe an iron cylinder is a better choice. If you are going to be pounding your machine “Hoist style” through the Sunbelt in July or August, you might want to reconsider your decision to run iron cylinders. It is my sense that an iron cylinder would be a good choice for the drag strip and not so great for an over the road machine; JMHO.

Who is this guy anyway?

Look in a mirror Hoist; I’m a resourceful enthusiast who just wants to ride his machine….which sounds pretty good right about now!!

djkak

[Hoist!]

I believe Milwaukee, like any manufacturer is challenged to manage manufacturing costs, in part through the commonization of components; maintaining the same head bolt pattern would go a long way towards accomplishing this. That theory is supported by Milwaukee’s commonization of the earlier, time tested head gasket design of the TC-88 and TC-96 to the latest design which no longer uses a separate o-ring to seal the oil return passage.

Regarding external oil return lines or the laminated steel SE head gaskets; you or I would consider these options if we were building our own engines. It is my sense that a properly designed “production” head gasket would do the job just as well in a stock machine at a much lower cost. If I may state the obvious; the trick for Milwaukee is getting together with a vendor to adequately develop and test the new components prior to releasing them. In this case I speculate that the effect of repeated hot and cold cycles on the new gasket was not adequately simulated in testing; regardless of the number hours logged on the test engines.

Let’s hope that you don’t have to mess with your head gaskets again. If you must revisit this, I suggest running the Screamin’ Eagle, high compression, laminated steel gaskets (or equivalent). I don’t see a specific application for the 110; maybe the ’08 SE catalog will have one listed. I am running these gaskets in my 113 with somewhere around 17,000+ miles and they are as dry as a popcorn fart.

You mention the possibility of running ductile iron cylinders: I don’t have any experience with them outside of boring several hundred pre-EVO H-D cylinders. IMHO iron makes a great cylinder liner, but is a lousy heat sink. Iron is tough and if a lined aluminum cylinder isn’t robust enough to get it done for you, then maybe an iron cylinder is a better choice. If you are going to be pounding your machine “Hoist style” through the Sunbelt in July or August, you might want to reconsider your decision to run iron cylinders. It is my sense that an iron cylinder would be a good choice for the drag strip and not so great for an over the road machine; JMHO.

Look in a mirror Hoist; I’m a resourceful enthusiast who just wants to ride his machine….which sounds pretty good right about now!!

djkak

As always dj, thanks for the info, the response and the entertainment! Here's to being free to ride our machines...!

Hoist!

[TN]

It's a strong possibility, not confirmed though, that Cometic is the manufacturer of the 110 gaskets. From what I understand, they have the patent on the 3-part laminated steel gasket design.

i think this is correct too, but the stock gaskets are not the mls, i'm gonna try them.


TN

[dejavo]

MY builder (Hemi Design) used the harley gaskets on my 113 build. I had nothing but problems. They were leaking oil into the cylindars causing pinging overheating etc. Hemi tore down my engine to determine the cause of the problems and found oil sitting on top of the jugs in both front and rear under the gaskets ,the rings etc were perfect. They rebuilt engine with cometics and no overheating no pinging no oilconsumption. 5000 + miles later the engine runs real strong still no leaks. You dont have to be a rocket scientist to figure the harley head gaskets have been and continue to be a real problem on 110 and larger builds.

[djkak]

MY builder (Hemi Design) used the harley gaskets on my 113 build. I had nothing but problems. They were leaking oil into the cylindars causing pinging overheating etc. Hemi tore down my engine to determine the cause of the problems and found oil sitting on top of the jugs in both front and rear under the gaskets ,the rings etc were perfect. They rebuilt engine with cometics and no overheating no pinging no oilconsumption. 5000 + miles later the engine runs real strong still no leaks. You dont have to be a rocket scientist to figure the harley head gaskets have been and continue to be a real problem on 110 and larger builds.

The gaskets that come packaged with Harley’s 113 cylinders are the three piece, laminated steel gaskets. Are those the ones that gave you the trouble or did Hemi Design install the OEM 110 gaskets?

djkak

[stekat]

I'm jumping in here late, but here's a tid bit that I haven't seen in this post yet.  I've had the same problems as the rest with several attempts at fixing the leaks.  The tech I use said the gaskets are indeed Cometic, but Harley is using the torque specs of the old style.  He called Harley Tech, asked for and got permission to use the Cometic torque sequence.  In fact, Harley said they would probably change to the new sequence anyway.  Since he used the Cometic sequence, I've had no more leaks.  I don't know what the sequence is, but contacting Cometic should get it.  I know it builds more progressively and ends a little tighter.

[dejavo]

Djkak
On the first go round the engine builder used the gaskets that came from harley with the 113 jugs. Size wise they are slightly different then the 110. The cometic gaskets they used are the same as they used on a previous 117 build .(bore is the same- stroke is different)
I was told that the gasket somehow alowed the oil to seep thru. AS I pointed out earlier the change made an enormous difference on the way my engine runs.