djkak, I disagree with your assessment of the 07 and later Twin Cams in the paragraph above. Your logic that the Motor Company is building a better motor because they have increased the mileage periods of the warranty may be your reasoning but mine (in that same train of thought) would be that the Motor Company has figured out that very few of their motors ever make it to 75K miles so why not increase it. Are there any facts to support my opinion NO (that's why it's an opinion), are there any to support yours?
I’m just compiling a list of possible causes, then narrowing that list to help make a decision based on what I feel is most likely to return a positive outcome.
I used the ESP as an indicator and applied simple logic. It gets dark outside; the sun is be going down. The mileage is increased; the machine is more reliable. Sure there may be an eclipse, or even a nuclear winter going on, but there is a good chance that the sun is going down, and that the machinery is more reliable. As the possibilities are explored and narrowed, these things may or may not remain on the list.
There are a couple of other indicators that are worth considering. Prior to 2013, H-D’s 103 Stage-4 “race” package was not something that you would install and then forget about. If you have 20k miles on this stage kit, and it hasn’t ingested a tappet roller, that would be remarkable. Today the 103 Stage-4 is a street legal package that is supported by the Factory Warranty and ESP. I believe that this is a significant indication. I also believe that studying the differences between these two packages and exploring ways to implement them on the other machinery would return value.
Relative to the early versus late Twin Cam’s, I believe that another indicator is the sheer number of machines in the field. If there are a million, ’07 and later Twin Cams in the field, there will be four million tappet rollers to deal with. My sense is that if the rate of tappet roller failures was increasing, I don’t believe that we would be discussing whether the stock machinery is more or less reliable; as time went on, the sheer number of issues would sort that out for us.
I understand your thought process, but I'd really like to know why you feel a need to continue to replace lifters annually if your no longer using the Jim's lifters. Why has it become such an issue that you and others feel a need to replace a part that up to 2007 was hardly ever replaced?
I believe the stock 110’s experience a higher rate of tappet roller failure per mile than the other stock Twin Cam’s. Valve trains like those in the earlier 103 Stage-4, the 113 HTCC, and the 131 place even greater loads on the tappets.
If I had a strong sense of the limits for a chosen set of tappets in a big engine, I would run them to somewhere around 70%, then replace them. It doesn’t make sense to run the machine to the point of failure, and there isn’t enough field data or experience to establish reasonably accurate benchmark limits for a chosen tappet.
The bottom line is that I replace my tappets annually for the same reason that you, or anyone else would. I wouldn’t be caught dead on the road with a mangled 131, if a set of stock $120 tappets, or even the $275 tappets, a few gaskets and o-rings, and an hour of time may prevent it; it’s insurance.
I’m interested in increasing the service life of the tappets in this engine, as anyone would be, so I’m exploring ways to accomplish this. On the other hand, my Wife’s 1550 Stage-2 has nearly 80k miles on it. I freshened the camchest prematurely at 40k, and I’ve chosen to continue running it, rather than take it apart prematurely again.
Help me understand your challenge here. Are you saying the oiling systems in the 2007 and later motors are the same as the 99 to 2006?
This thread can be a little tricky because the issue changes a little from “why do the 110 lifters fail and the others don’t” to “All ’07 and later tappet rollers fail prematurely, and the earlier machines don’t”. This may cause some confusion as different points are addressed and interpreted.
Relative to pressure relief oil being ported to the low pressure feed circuit, this occurs in all year Twin Cam’s. The contention is that this results in excessive aeration, resulting in tappet roller failures.
My pushback is that this phenomenon will be present in all Twin Cam’s. When exploring differences between early and late Twin Cam’s, or late model 96, 103 and 110, nothing substantial changes there, yet the failure rate between the 96 or 103 and the 110 appears significant, and the failure rate between stock and some big engines is quite dramatic. I wouldn’t put this hypothesis at the top of my list of possible solutions because it is one of the few things that remain reasonably constant throughout the different configurations.
OK, I understand your pressure thought but pressure and aeration are two different animals I think.
I addressed pressure because it was on the table. My point there is that these lifters will operate over very broad range of pressure without collapsing to the point of hammering.
So you chose to change lifters yearly but you can't tell us why? Your knowledge and experience is a bazillion times more than mine but I also wonder why I feel the need to change lifters in my 110's but not the pre 07 motors.
I believe that the 110 valve train places greater loads on the tappets than the valve trains of other stock Twin Cams.
JMHO, and I apologize for the big megablot.
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Topic: Lifter failures (Read 37354 times)