I thought I'd throw this out to the touring guys, as the amount of riding years, experience, and number of bikes owned is not comparable on ANY other forums...

So we've all heard the old "motor should last forever as long as you don't make a bunch of performance mods", or something similar. My question: How true is this really? Most of us (on average) settle for some form of stage one. Would changing out the headers (gettin rid of cat), slipons, free flowing air cleaner, and new tune (map) really affect motor life? I'm of the belief that this set-up has always allowed my motor to run cooler/less lean. Seems to me that this would actually be a long term benefit to the air cooled motor... Maybe even increase life. But I've got nothing to base this on, except common sense. Has anyone seen any long term studies? Any first hand experience? Things you may have noted over the years? I appreciate the input/discussion.

 

Although there's always a "cost" in wear and longevity on a hot rodded motor, it's negligible if it's done right and not beat to death every day.
The longer the stroke the faster the pistons are moving in the bores and that will cause a little bit of extra wear and tear on that area of the motor.

Larger displacement engines will tend to generate more heat and that is never a good thing.

In my opinion, having built hundreds of motors over the years, 88" to 95" is the optimum size for these big twin motors, headwork and cams can work wonders for performance and I know from personal experience that in most cases a small displacement motor can leave a big inch motor in the dust if it's set up properly.

 

I have an '06 SG that's been bored to 95", cammed, high compression pistons and head work with a PCIII, Big Sucker and Rinehart TD's. It's detuned to about 100 ft lbs/100 hp.
It now has 50K trouble free miles on that build and will travel many more before it gets another top end.

 

Having been on this forum for a few years, I've read my share of stories that span the spectrum.

I've read about guys that have completely rebuilt their bikes with excellent results and others that frig up a simple spark plug change.

Some plan the their mods with care and are rewarded with fine-running machines whereas others haphazardly throw parts together then soon experience some bazaar performance issues whining like little girls the entire time.

And some riders take the time to learn their machines and how to care for them. Others proudly claim they "ride like they stole it..." and then scratch their butts trying to fix "unexpected" problems.

I have seen no scientific studies but rely on my own experience and wisdom. I've ridden for many years, crossed the US more than a couple times, and have enjoyed thousands of trouble-free touring miles. I no longer ride with guys that carry hundreds of dollars worth of tools and parts. And I certainly won't ride with guys that spend thousands of dollars on paint, chrome, and other fancy do-dads.

Remember, these are just machines made by humans. Over time, materials, technology, and skills change.

Yes, I modify my bikes but all those mods trend towards the touring I do. I carry a tire pressure gauge and that's about it.

 

Like what's been said, don't beat it to death at every twist if the throttle and it'll last much longer. But usually (I think) most modern engines benefit a lot from the small tuning enhancements and opening up the exhaust some due to the emissions crap that's now mandated. Intake not so much because they want that open for better efficiency. So those simple mods can make an engine run cooler and more efficiently. But any time you increase HP/TQ you're increasing the forces at work on all components down the line an connected to the engine and a lot of internal engine parts as well. It's just a balancing act, find what works and stick with it. Of course the man behind the throttle has a big part in how things last too.

And don't forget maintaince, not up on oil changes and things that require a check and things will wear out prematurely. Bad/dirty/over heated oil doesn't do much for lubrication.

 

The candle that burns brightly, burns briefly.

The more power you get out of your engines, the more stress that is produced to engine, driveline, brakes, etc.

The well built engine will last longer than a poorly designed one.

The more power produced, the more attention to detail is necessary.

Cruisers last longer than racers.

YMMV.

 

VERY WELL STATED

 

No engine will last forever, without proper care and maintenance. A general rule is the
more power your engine makes, the more maintenance it takes.

I have a friend with a pumped up 95 inch Twine Cam Full Dresser, with just over
147,000 miles on it & it still runs vary strong.

 

I agree with your thoughts that simply doing stage 1 will help motor life by reducing oil temperatures and pinging. I got better gas mileage after stage 1 as well, so I know the motor isn't working as hard either...

 

Well, this was my thought. But does the negligible HP and torque increase cancel out the "easier/cooler" running motor? I can't imagine it does... Seems like it's commonly accepted that these machines are choked off by the EPA stock.. But again, these are commonly accepted ideas that I've never seen substantiated. I just can't believe that the heat from these lean running bikes isn't putting undue stress on them. I mean, why else would they start developing auto fans and auto cylinder shutdowns during warmer weather?