Best engine design for a motorcycle?

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Originally Posted By: grampi
So the perfect engine design is one that has never been, or never will be mass produced?


3 cylinder 2 stroke engines were very common back in the 60s and 70s. Also very popular on outboard engines. Direct injection is an emerging technology that can be applied to both two-strokes and four stroke engines. There isn't a strong indicator about whether or not it will revive the 2-stroke, but initial signs point to the emergence of 2 stroke DI engines.

Supercharging is a bit of a pipe dream on my part. Supercharging was common on 2-stroke engines before it was legalized in race use.

I hope we will see the engine design in production.
 
I've changed my mind. The big 500cc two stroke single is the best engine design for a motorcycle. Light, powerful, easy to repair, fun to ride. It's everything a modern engine is not!
 
Originally Posted By: Cujet
I've changed my mind. The big 500cc two stroke single is the best engine design for a motorcycle. Light, powerful, easy to repair, fun to ride. It's everything a modern engine is not!


For a dirt bike I'd have to agree with you, but a 500 single 2 stroker isn't much good for a street bike. They vibrate too much.
 
I think one of the best things for the design of a motorcycle would be to keep the engine, clutch, and trany oils separate.

WHY: You could use the best oil for each.
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? To Cujet, from: JimPghPa.

Cujet, on another thread about oil for air cooled engines on generators you suggested M1 15W-50 for small air-cooed engines.

While I still think GC is a great all around oil for my region of the country, and it does hold up in high temperature high shear applications, I see your point about M1 15W-50 being a great oil for very hot days. I want to stock M1 15W-50 incase we have to use the gen-set to supply whole house AC on very hot days. Power outages are more likely when the grid is over-loaded on the hottest days. How many hours do you put on an oil change of M1 15W-50 in small air cooled gas engines?
 
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My 1980 Honda 750 4 cylinder was so smooth that you would think it was an electric, and one of the quietest set of pipes I ever heard. The 4 wide arrangement was wide and heavy.

I had a friend who had a 1970's 400 Kawasaki 2-stroke 3 cylinder and he use to beat the heck out of it, moving and standing still. He would sit at a red light and bury the tack. We all thought that engine would blow up on him some day. But it seamed the more he beat it the better it ran. He sent a letter to Kawasaki about how he beat it and how it held up and performed so well, and they sent him a coupon for a free complete engine tune up. He never did blow that engine.
 
"I think one of the best things for the design of a motorcycle would be to keep the engine, clutch, and trany oils separate.

WHY: You could use the best oil for each."

And what's the big advantage of that?

When you have engines/transmissions that run in the same oil providing stone axe reliable service for hundreds of thousands of miles and costing considerably less to buy and maintain, why the need for unnecessary complication? I don't see any advantage there at all.
 
Originally Posted By: JimPghPA
I think one of the best things for the design of a motorcycle would be to keep the engine, clutch, and trany oils separate.



Already done by HD -- too bad it's an 80 year old design...
 
Originally Posted By: boraticus
"I think one of the best things for the design of a motorcycle would be to keep the engine, clutch, and trany oils separate.

WHY: You could use the best oil for each."

And what's the big advantage of that?

When you have engines/transmissions that run in the same oil providing stone axe reliable service for hundreds of thousands of miles and costing considerably less to buy and maintain, why the need for unnecessary complication? I don't see any advantage there at all.


It depends on how much weight and cost it adds. The advantage would be lower cost oils, longer OCI, and less wear. I think spending over $100 for an oil change on a large bike like my neighbor did for his Harley last spring is too much.
 
Originally Posted By: JimPghPA
Originally Posted By: boraticus
"I think one of the best things for the design of a motorcycle would be to keep the engine, clutch, and trany oils separate.

WHY: You could use the best oil for each."

And what's the big advantage of that?

When you have engines/transmissions that run in the same oil providing stone axe reliable service for hundreds of thousands of miles and costing considerably less to buy and maintain, why the need for unnecessary complication? I don't see any advantage there at all.


It depends on how much weight and cost it adds. The advantage would be lower cost oils, longer OCI, and less wear. I think spending over $100 for an oil change on a large bike like my neighbor did for his Harley last spring is too much.


Theoretically it may be the way to go but in reality, it appears not to be.

HD are one of the few that run separate engine/transmission/primary drive components. Not by a sophisticated stroke of genius. On the contrary, it was a cobbled design to put a water pump engine into a motorcycle frame. Hence a separate transmission and primary drive.

Considering the plethora of very sophisticated motorcycle engines that are far superior in every aspect to the HD design, it makes no sense to re-invent the wheel and build a unnecessarily complicated, cumbersome inefficient engine just to have the opportunity to buy and use three different lubes instead of one.

I fail to understand the expense of oil aspect when you can buy a gallon of Rotella T 15W40 for $12.00. Cross that one off.

I can run that oil in my Valkyrie for 8000 miles according to my operator's manual. That's a very long OCI for conventional oil. So no advantage there.

As far a wear goes, that six cylinder Valkyrie engine will run for hundreds of thousands of miles with minimal maintenance. That advantage is also out.

Bottom line is that separate oil baths equals more expense, more complication, less efficiency and no gain.

Sorry, I see NO advantage to that whatsoever.
 
BMW also runs separate Engine, Transmission, and Final Drive sumps. Their design is modern... But the separate oiling systems don't really seem to offer much in the way of benefits, and they add a significant weight penalty to the engine design.

I believe that BMW does it on the R series bikes because of the transverse engine layout. The transmission has to come off the bike in order to service the clutch.
 
Originally Posted By: burning1
BMW also runs separate Engine, Transmission, and Final Drive sumps. Their design is modern... But the separate oiling systems don't really seem to offer much in the way of benefits, and they add a significant weight penalty to the engine design.

I believe that BMW does it on the R series bikes because of the transverse engine layout. The transmission has to come off the bike in order to service the clutch.


BMW has tried to discontinue the air/oil-cooled "Boxer" engines ever since they unveiled the K-Bikes and the traditionalists have resisted that move. BMW knows and has admitted that the Boxer design is very dated. BMW's new K-Bike engines DO NOT have separate transmissions or clutches. They are just like all the other mainstream Asian and European designs that are shared-oil transmissions. The original Boxer engine evolved just like HD from a non-motorcycle engine design that was modified to fit in a motorcycle and then a separate transmission was bolted on.

The R-Boxer engine design is very expensive to manufacture and hence BMW's willingness to discontinue it.

In BMW's defense, they used that layout and design because it facilitated the use of a shaft drive to the rear wheel, something that HD does and will not do.
 
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The original BMW boxer design was for aircraft applications. The BMW logo is supposed to represent the view of the snow topped mountains and sky through a spinning propeller.
 
Originally Posted By: boraticus
The original BMW boxer design was for aircraft applications. The BMW logo is supposed to represent the view of the snow topped mountains and sky through a spinning propeller.


Did you come up with that all by yourself?

Here's what BMW says:

"According to the company’s journal, “BMW Werkzeitschrift” (1942), the BMW logo emerged when a BMW engineer was testing the company’s first 320 bhp engine. He admired the reflection of the shining disc of the rotating propeller that radiated like an aura of two silver cones. In between the two cones, the blue from the sky shined that made the ‘rotating propeller into four areas of color – silver and blue’. The engineer, who envisioned this image, also saw three letters – B M W – reflected on the propeller. Thus, the BMW logo was born.

However, according to a BMW spokesperson, the BMW logo does not symbolize a spinning propeller (although the imagery did appear in post-WWI advertisements). On other note, this statement is considered by many as merely a bogus claim made by the company to give a logical explanation to the public about the BMW logo’s creation. In fact, the first BMW aero-engine test took place in March 1918 – six months after the BMW logo had been created. Additionally, the founding myth of the BMW logo, the propeller, was a component of the engine that was never manufactured by BMW."
 
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Originally Posted By: Zedhed
Originally Posted By: boraticus
The original BMW boxer design was for aircraft applications. The BMW logo is supposed to represent the view of the snow topped mountains and sky through a spinning propeller.


Did you come up with that all by yourself?

Here's what BMW says:

"According to the company’s journal, “BMW Werkzeitschrift” (1942), the BMW logo emerged when a BMW engineer was testing the company’s first 320 bhp engine. He admired the reflection of the shining disc of the rotating propeller that radiated like an aura of two silver cones. In between the two cones, the blue from the sky shined that made the ‘rotating propeller into four areas of color – silver and blue’. The engineer, who envisioned this image, also saw three letters – B M W – reflected on the propeller. Thus, the BMW logo was born.

However, according to a BMW spokesperson, the BMW logo does not symbolize a spinning propeller (although the imagery did appear in post-WWI advertisements). On other note, this statement is considered by many as merely a bogus claim made by the company to give a logical explanation to the public about the BMW logo’s creation. In fact, the first BMW aero-engine test took place in March 1918 – six months after the BMW logo had been created. Additionally, the founding myth of the BMW logo, the propeller, was a component of the engine that was never manufactured by BMW."


Nope. Read it somewhere. Thanks for the update though. I stand corrected.
 
boraticus:

I wasn't trying to "bash" on you -- I respect your opinion here as it is usually very balanced and logical.

I've just heard that statement so many times from so many people, I knew where it came from. I wish I had a dollar for every time I have heard that.
 
Originally Posted By: Zedhed
boraticus:

I wasn't trying to "bash" on you -- I respect your opinion here as it is usually very balanced and logical.

I've just heard that statement so many times from so many people, I knew where it came from. I wish I had a dollar for every time I have heard that.


No offense taken Zedhed.

As I have previously said, I owned an R100 back in the early '80s. During the years of ownership, I had read some rags that had made that claim. Thanks to your knowledge of the subject, I'll no longer be spreading erroneous rumours....
 
Originally Posted By: Steve128
Originally Posted By: Zedhed
Originally Posted By: dblshock



I've heard that and also that it's overstated...5W-30 is spose to do the trick of wetting the rear lobes by 2000rpm anyway, mine are on the lite oil and both work perfect..good looking too.


Right, wait and see then.....

Even Honda admitted they made big mistakes on the Gen I VFs. Bad hardening on the cams, bad lifter geometry, oil starvation. They last until about 30K and then the cams are shot.

Just go to the VFR forums and get educated.


And if you do go to the vfrdiscussion forum, this is what you find. A production problem, not oil starvation, cam issues, etc.

The great camshaft crisis in 84 about off killed enthusiasm for the
VF... as you know every stop gap measure was tried in curing the
problem but the real culprit was Honda's short cut in machining steps
of the cam bearing blocks... they dropped the line bore step and
machined the cam bearing blocks separately... this resulted in mix
match of clearances... in short the cams flopped about... hard coat
damage soon followed... For a cure Honda... in 86... went back to the
more accurate and expensive method of line boring the cam bearing
blocks... You can note the external difference in the head design...
the 84's & 85's rubber valve cover gasket is flat... whereas the 86's
rubber valve cover gasket is half circled covering where it was line
bored...

Honda was typically silent for a long time and this led to all sorts of home
cures including better top oiling kits... shorten oil change intervals... larger
gapped valve clearances... installing new cam tensioners... auxiliary
cooling fans kits... etc etc etc... but none of these address the root cause...
Only after Honda took a lot of stick did they finally go back to the timely
process of line boring the cam bearing blocks on the head so the
tolerances complimented each other...

In the void of official guidance Mechanics went to great lengths to address
the symptom but failed to establish the root cause... the hard coat damage
was still miss matched cam bearing blocks... the evidence they needed to
look at carefully is the fact the edges of the cams fails first... their pet
theory of a lack of oil would make the center fail first...

Honda would never modified their engines by depleting critical oil
form the main galley and take a chance to starve the main bearings
just to reroute oil to the top end... it's a kin to robbing Peter to
pay Paul... there's only so much oil an engine will pump...

Publicly American Honda was silence... then they blustered refusing to
acknowledge they had a problem... but in private they we working at a
fever pitch to establish a root cause... but it was the owners who
blamed it on all the wrong things and then some... and you can see it
continues today...

Naturally Honda's final corrective action was to sell owners a new line bored
head... at cost I think... all in all Honda's great camshaft crisis almost kill
the publics love affair with the V4...

Unfortunately for the V65 engine... all the years 83 through
86... were affected by the short cut at the factory and thus
don't have line bore cam bearing blocks... you can verify
this by identifying the valve cover gasket...

To tell the difference between line bored head and the one that gots
the short cut... take a look at the valve cover gasket... if your gasket
sports little half circles molded into the rubber... then you have the
expensive line bored head... no little half circles... then you have the
short cut heads...

If you venture inside the valve cover... it is possible to identify 3
types of cam shafts... the original... a second generation with a small
oil hole in the cam lobe... and the final type with both the oil holes
and closed end caps...

From vfrdiscussion.com.



V65 Sabre Vf1100s

Well I enjoyed mine!!!!. They were AWESOME machines to ride all day long at 120+ down 395 in Oregon, O YEAH BABY, handling and lean for days. The warp drive kicked in @ 6-7 grand with 10.5 red line, was mid to top end power(121hp) and with six speed gearbox, Air suspension, dual disk front brakes, shaft, 5 gallon gas tank nice LCD read out, adj handle bars... Better power to weight ratio (6-1) than Porsche 911(9-1)! Very, very fast comfortable sport tour. I believe it was designed to motor the autobahn for three hours.

V4 are making a comeback and there is a reason... I like the big v twin i own now, (Victory Kingpin). It's half the cylinders and I am too. :>P
 
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