Harley ownership

[Jack Giesecke]

Originally Posted by Ben Eberle

Every time I spend all day removing junk just so I can get acces to those 16 valves that have to be adjusted by swapping shims that the dealer does not have in stock, a Sportster or Buell starts to look mighty good to me. Any dam fool can make a complicated machine and confuse it for high tech.

Long stroke engine: A long stroke minimizes the surface area of the combustion chamber. The less surface area the combustion chamber has, the lower the thermal losses. An engine's job is to convert heat energy into mechanical energy and every BTU of heat that escapes from the combustion chamber to the cooling system is a BTU of heat that the engine will fail to convert into 778 ft-lb of energy. My 50 mpg car has a long stroke engine and a tiny radiator.
Minimizing combustion chamber surface area also makes it easier to meet emission standards.
Another factor in favor of long stroke engines is that because the flame travel is shorter, the burn is finished sooner meaning less spark lead. Less time spent exposed to hot gasses means lower thermal losses and better efficiency. Also, it allows a higher compression ratio for a given fuel octane rating without detonation.

The advantages of a short stroke engine: They can rev higher and there is room for larger ports needed for high rpm breathing.

Four valve heads: Thermal efficiency wise, the main advantage is that the spark plug can be in the center of the combustion chamber which minimizes burn time and thus spark lead. The later the spark plug fires, the less time the hot combustion gasses are exposed to the combustion chamber before being expanded. A two valve head can achieve the same thing with double spark plugs or by having smaller valves to make room for a central spark plug.
BTW, my 50 mpg car meets automobile emission standards with a two valve head.

Air cooling: One benefit is that air cooled engines have a less thermal mass than water cooled engines. It takes fewer BTUs of heat to get a pound of aluminum up to operating temperature than it does to get a pound of water up to operating temperature. Since a cold engine pollutes more than a hot engine does, a fast warm up is a real benefit to meeting emission standards. In case you are not aware, the EPA emission certification tests start with a cold engine.

All that's fine and good, so we should expect harleys winning in motoGP, right? Actually, you left out another formula to a high horsepower engine, more cylinders/pistons, less combustion chamber area, lower piston speed due to less stroke added to the fact that it is over-square means even higher rpm which translates to horsepower. DOHC 4 valve head's valves can be angled straight down for a flatter piston/combustion chamber shape for more efficiency while the direct cam on valve actuation allows for less valve float (valve train mass) and higher RPM/horsepower.

It's all in what you wanna do, go fast or draw a plow through gumbo sod. Besides, I'm quite sure a big inch hog's combustion chamber is a lot bigger than a SV650 (which also makes about 70 hp stock).

Now, I still ain't knockin' hogs, they're good street bikes and, yeah, to a lot of folks, the fuel efficiency of a low RPM long stroke motor is more important than going fast. Also, all that torque is great for hauling stuff like trailers and sidecars, things that a street bike might do, especially a big tourer. And GL1800s get awful fuel mileage. You can get 45mpg out of an EG standard all day long. The approaches are totally different, but there's a reason HD always quotes torque figures and not horsepower for their models, I mean, horsepower being a function of crank speed and torque.

[ysr612]

you of course are both wrong. If oversquare is good then why is the modern tz 250 undersquare. square is the least surface area per vol for and ideal IC engine as a sphere is for any shape. as was said large piston give more head real estate for valves so that is one of the big pluses for over sq

I give up go find your own piston IC design book.

short on this is

what I was saying is 'it is all a compromise longer stroke gives more burn time greater fuel eff. On the other hand it limits the amount of fuel air that can be sucked in and burned therefore limits horsepower.' This is why the BMW car (yes they make cars too) 528 E was under square and all of the others are over square.

[Chirpy]

Originally Posted by MagnaMan

Please. Please. Please. Pay attention to your reading and quit jumping to conclusions. I said that in the 80s the significant even that turned the company around was talking to it's employees. This one event was so definitive that it is studied in business schools and executive management training seminars ever since.

But I did not say that it was the ONLY thing they've ever done since then!!!! In fact I alluded (parenthetically too) that they had made strides in technology.

I'm going to drop out any conversations like this in the future because it appears that there's a lot of "assumers" on here and I'm tired of getting flamed for things I never said.

I'm out to go riding.

Dude, you're awfully touchy. You were talking about styling, and fooling people into buying what was built. Now you're talking about management style. You need to pay attention to what you are reading, and what you have said, and try to stay on one track.

Maybe then you wouldn't be so fussy.

The biggest problem with the Magna? The motor has all the personality of a sewing machine. Yes, great torque, linear delivery, volumetric efficiency and all that stuff..just no soul. If practicality ruled, we'd all be riding CX650s.

Since you know everything about managment, I'm sure you know what happened to the ketchup that Heinz cooked without scorching...

[Chirpy]

Originally Posted by Ben Eberle

Any dam fool can make a complicated machine and confuse it for high tech.

Ding, ding, ding.

But do you get any benefit from the increase in complexity?

[ysr612]

Originally Posted by Chirpy

Ding, ding, ding.

But do you get any benefit from the increase in complexity?

actually what that is called in the worlds where I have been educated, is appropriate technology. People that ride cruisers don't need high horsepower engines that run so smooth that you can't tell if they are running or not. They also don't need engines that will last 200k miles. They need engines and bikes that take them back to the 50's yet don't dump oil all over the garage.

[Ben Eberle]

Originally Posted by ysr612

you of course are both wrong. If oversquare is good then why is the modern tz 250 undersquare.

Because it's a two stroke engine. Undersquare (long stroke) allows the exhaust and transfer ports to be more nearly square or circular instead of flattened for more flow in two stroke engines.

square is the least surface area per vol for and ideal IC engine as a sphere is for any shape.

This is true only if the piston spent 100% of the time at bottom dead center. The average surface area is less with a long stroke engine because the piston is not always at bottom. Furthermore, the gasses are hottest at top dead center and cool off as they expand in the cylinder. When the piston is at the bottom, all available energy has been extracted and it no longer matters if the surface area is higher at that point.

[Tourmeister]

Any further personal slights/attacks and this thread gets locked. The poll was a simple Yes/No question. It was not an invitation to start flaming each other over the merits, or lack thereof, of Harley or any other brands.

[Chris Mitchell]

ok, you all have officially worn me out with all this talk. I just think you ought to find a bike that spins your gears and makes you happy. Isnt it just your opinion against your buddy's anyhow, the final solution is found out on the roads where the rubber meets the road, the good bikes will sell and when the word of a poor design gets around the public will shun it for the most part. You all got way over the top on rock throwing and techno drivel and questionable facts and figures. Cant we all just get along??????

[Chris Mitchell]

or is it guns and knives at dawn down by the river?

[Ben Eberle]

What's wrong with discussing the merits and drawbacks of different engine designs or what is or is not "high tech"? It's not like we were calling each other names and making personal threats, or at least I wasn't.
Sometimes I think that the motorcycle community has gotten so hung up on horsepower per cubic inch as the be all and end all of engine design that we forget that it was originally a means to an end. A way to make more horsepower when the displacement of the engine is artificially limited by racing rules.
What's wrong with using more cubic inches to make more horsepower? Are cubic inches being rationed? Is the world running out of cubic inches? Is it really a less efficient way of making power?
If Harley engines are "inefficient", their excellent fuel mileage is a mighty peculiar way to show it.

[ysr612]

Originally Posted by Ben Eberle

What's wrong with discussing the merits and drawbacks of different engine designs or what is or is not "high tech"? It's not like we were calling each other names and making personal threats, or at least I wasn't.
Sometimes I think that the motorcycle community has gotten so hung up on horsepower per cubic inch as the be all and end all of engine design that we forget that it was originally a means to an end. A way to make more horsepower when the displacement of the engine is artificially limited by racing rules.
What's wrong with using more cubic inches to make more horsepower? Are cubic inches being rationed? Is the world running out of cubic inches? Is it really a less efficient way of making power?
If Harley engines are "inefficient", their excellent fuel mileage is a mighty peculiar way to show it.

I don't think Jack or Ben took my little statement on IC design as a personal attack. They both know what they are talking about and see the compromises differently.

so to ans Ben yes piston port eng have different port needs and I know Jack knew that also. If we are talking about simple then piston port is about as simple and high horse power as you can get the TZ 250 makes a little over 100 hp.

Ben is also right in the comparison of stroke verse volume now I am going to have to see if my kid left home any of his IC design books. I want to see the equation again I know it is the derivative of a sin function.

Oh on the air cooled ver water cooled water cooling does many things

1. it allows you to build with less metal in the cyl allowing the cyl to come to temp quicker that is why you have thermostats.
2. it allows the moving parts to stay at a more constant temp so you can go with closer machining. This can be done with air cooling as well look at the duetch diesel or the 911, however both of these take a long time to get to operating temp.
3. this is not important to this discussion but it allow more horse power to be produced as one of the limiting factors is where do you put the waste heat.

what has been said many times in this thread it is what you want that counts. My choices come from what I find works for me I have been on both. I find it more comfortable to ride long distances on an ex250 then on any cruiser I have yet ridden. there are not many I have maybe four or five over the 1000cc. The ex will go over 100mph with a tail wind and get well over 60 mpg. I my last trip to Virginia the cbr averaged 56 mpg. However during CMRA races the cbr's that I have been on avg low 30 mpg. You do have to respect a bike that you stick on the race track when it has 55k miles on the clock and it preforms flawlessly over 2 seasons.(well a clutch)

[Ben Eberle]

Originally Posted by ysr612

If we are talking about simple then piston port is about as simple and high horse power as you can get the TZ 250 makes a little over 100 hp.

Yes indeed! Try to design a good two stroke engine and you will quickly find out just how superficial a two stroke engine's apparent simplicity is.

A Stradavarius violin is pretty simple also so it should be a piece of cake to build one just as good.

[ysr612]

Originally Posted by Ben Eberle

Yes indeed! Try to design a good two stroke engine and you will quickly find out just how superficial a two stroke engine's apparent simplicity is.

A Stradavarius violin is pretty simple also so it should be a piece of cake to build one just as good.

I know what you mean.

ps there was someone building violins that if you listened to them they sounded just like the best Stradivarius. The trick was using partially dry rotted wood.

[Jack Giesecke]

Originally Posted by Ben Eberle

Yes indeed! Try to design a good two stroke engine and you will quickly find out just how superficial a two stroke engine's apparent simplicity is.

A Stradavarius violin is pretty simple also so it should be a piece of cake to build one just as good.

The two stroke is EXTREMELY simple in maintenance. I could put a crank in my TZs in less time than you can set valves on an 8 valve Duc! I could whip a top end off those TZs in no time for a top end. Of course, I had a lot of practice at it considering how fast they ate pistons. When I got into 125GP stuff, it only got simpler, one less cylinder.

Yeah, Yamaha tried to over-square the TZ125 in the early 90s and it didn't work. They went back to 54x54mm dimensions and the last TZ/RS125s off the limited production line were square motors. Seems to be what works on 'em.

The complication in two strokes is in tuning them. You have to know a lot of fluid dynamics when tuning pipes, ports, and such, but, you can buy computer models now that help you out. No longer need to be any kind of math whiz. But, just routine maintenance, heck, my old RD400 was bullet proof as any four stroke, 60K on a top end on those things wasn't unheard of and the cranks would last forever if you kept 'em stock. You didn't even need to worry about draining water to take the top ends off, just pull pipes, carbs, four bolts per head, lift off heads/cylinders, pop a wrist pin circlip and press the pin out. That's IT! I loved those old bikes, even if the EPA didn't.

[Ben Eberle]

Originally Posted by ysr612

I know what you mean.

ps there was someone building violins that if you listened to them they sounded just like the best Stradivarius. The trick was using partially dry rotted wood.

Put the best Stradivarius in my hands and I would probably still sour the milk in the refrigerator and chase the rats out of the house. I think that too much credit goes to the fiddle and not enough to the fiddler.

Likewise, if you gave the guy who always finishes last in a club race a factory sponsered ride, he would probably still finish last.

[Tourmeister]

Originally Posted by Ben Eberle

What's wrong with discussing the merits and drawbacks of different engine designs or what is or is not "high tech"? It's not like we were calling each other names and making personal threats, or at least I wasn't.

There is nothing wrong with such a discussion if it remains civil However, it seems that such a discussion is almost impossible when the pro Harley/anti Harley stuff starts to fly Quite a few posts have been removed from this thread so you may not have seen them.

It is said that the only thing certain is death and taxes. I might add that another certain thing is that as soon as the Harley stuff gets into the mix, the thread is destined to degenerate, usually into name calling which is exactly what happened here I don't know why but it really seems to bring out the worst in some people

[Loyd]

*fails to resist*

Do you get any credit for having bag of kitty litter?

[Sleepy Weasel]

Originally Posted by Tourmeister

There is nothing wrong with such a discussion if it remains civil However, it seems that such a discussion is almost impossible when the pro Harley/anti Harley stuff starts to fly Quite a few posts have been removed from this thread so you may not have seen them.

Geez, all this from a simple poll to find out if somebody guessed right about ownership statistics.

[Steep]

Originally Posted by Sleepy Weasel

Geez, all this from a simple poll to find out if somebody guessed right about ownership statistics.

I think you started this poll when I commented that this site seemed more about bashing Harleys and their owners than of embracing Texas motorcyclists.

What do you think of the ratio? The number of Harley respondents is higher than I expected based on the negative comments. I was thinking 85/15.

Steep

[kurt]

According to the actual poll, about 30% of those who responded have owned a Harley. I wish there were a way to allow a poll without additional posts.