Best engine design for a motorcycle?

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Originally Posted By: rickg
Giggling here at the just another cow in the herd ??? I would guess for every 1800 on the road there were about 10 Harleys to match it. there is a bunch of the VTX's on the road, but no where near the amounts of Harleys..


Yep, HDs have become the modern day cookie-cutter bikes...
 
Originally Posted By: BigCahuna
I guess the 1800 was so powerful everybody just couldn't stand it so they stopped making it.Kind a like the big Suzuki they quit making.Or the Honda Rhune.Yeah, i guess the motorcycling public isn't ready for such wonderful machines.The only good thing about them is you can buy them for a song, for spare parts.,


I'd ride a VTX1800, better yet a Kaw Vulcan 2000.
 
Better check the cams on those VFs They have wicked problems.... [/quote]


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.
 
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.
 
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I have worked on dozens of those engines. I'm not asking you to believe me, talk to others that have owned them, or go to the VFR forums and research.

Otherwise, just wait.........BANG!!
 
dblshock: Here you go --

"The engine's downfall was premature camshaft wear in some early models; both V45, 1000 and V65. In retrospect, the wear was caused by inadequate oil flow to the heads/cams driving for a long time on low rpm (under 3000) and at cold start /engine warmup procedure, non-accurate valve adjustment, and sometimes insufficient maintenance. Owners have often modified their oiling systems and successfully eliminated the wear problem, and some companies, like DRP, sell kits / oilmods to do this modification.

But this came too late to save the engine's reputation. Honda itself at first denied there was a problem, then blamed inadequate or incorrect maintenance for the problem. They changed the maintenance interval, and developed and sold a special tool for 'proper' valve-lash adjustment. They eventually made changes to the design and production methods of the engine which eliminated the problem.

But it was too late. The 1st generation V4 was discredited, and the first V4 revolution failed. While Yamaha (The Vmax) and Suzuki (the Madura) had both responded to the Honda V4s with V4 engines of their own."

--Cycle World
 
so you run for the most part over 3k and use what then was unheard of 5W-30 and your golden...

most of these engines went well past 60k far more than I will be able to with 9k & 14k on the other and if I did and loved it, I'd get them fixed, so what? I have $3500 into the pair and they look oem new right down to the warning stickers..the engines really snort for the size/vintage you could at least stipulate.
 
I had the first year V-65 ('83) and that engine couldn't have been built too badly because I put 26K miles on it and the engine spent most of its time running at redline. When I sold the bike it ran like new and didn't use a drop of oil.
 
Originally Posted By: dblshock
so you run for the most part over 3k and use what then was unheard of 5W-30 and your golden...

most of these engines went well past 60k far more than I will be able to with 9k & 14k on the other and if I did and loved it, I'd get them fixed, so what? I have $3500 into the pair and they look oem new right down to the warning stickers..the engines really snort for the size/vintage you could at least stipulate.

If you have 14,000 miles, more than likely the cams are already worn. Hope not and maybe not all of them were bad. I had one back in 1983. Good one to have "had" as in no longer have. I still to this day am leary of Honda V4s, actually any V4 from just this one bad design almost 30 yrs ago.
 
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.
 
Originally Posted By: dblshock
so you run for the most part over 3k and use what then was unheard of 5W-30 and your golden...

most of these engines went well past 60k far more than I will be able to with 9k & 14k on the other and if I did and loved it, I'd get them fixed, so what? I have $3500 into the pair and they look oem new right down to the warning stickers..the engines really snort for the size/vintage you could at least stipulate.


dblshock:

First you said it didn't have any problems, then you said Honda wouldn't make a bad engine, and now you are saying just don't run it under 3k rpm.

Are you beginning to believe us? That's the 1st step....
 
Any VFRs after '86 are OK. Once they went to the 2nd Gen motors with the gear-driven cams all the cam problems stopped.

If you really want a VFR V-4 get the Gen III bikes from '90-94, they are probably the best of the breed. Gear-driven cams, shim-under-bucket tappets, carbureted, single-sided swingarm, etc.

The Gen II and Gen IVs are good bikes too. I would avoid the Gen I motors unless I wanted to replace the cams with Mega-Cams and new cam chains and tensioners. BIG BUCKS..
 
Steve128:

That's just one take from the VFR forums, I have also read there that the issue is not decided among the bad heat-treating, oil starvation, and the rocker geometry.

The Gen II motors used the rocker arms too, but they were redesigned so there was one cam lobe for each valve, not one lobe for 2 valves (forked rocker) Many said that 2 valve springs put too much pressure on one cam lobe and that contributed to the premature cam wear.

Others said that the angle of the rockers put too much pressure on the lobes -- hence Honda having a special procedure to address this.

There were lots of theories and none conclusive. All everyone knew was the cams "cratered" prematurely and Honda said nothing until they redesigned the engines in '86.
 
Originally Posted By: Zedhed
Steve128:

That's just one take from the VFR forums, I have also read there that the issue is not decided among the bad heat-treating, oil starvation, and the rocker geometry.

The Gen II motors used the rocker arms too, but they were redesigned so there was one cam lobe for each valve, not one lobe for 2 valves (forked rocker) Many said that 2 valve springs put too much pressure on one cam lobe and that contributed to the premature cam wear.

Others said that the angle of the rockers put too much pressure on the lobes -- hence Honda having a special procedure to address this.

There were lots of theories and none conclusive. All everyone knew was the cams "cratered" prematurely and Honda said nothing until they redesigned the engines in '86.


Back to the topic, I am just encouraged there are so many people still passionate about motorcycles. Many good thoughts on this thread.
 
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Originally Posted By: dblshock
I'd doubt Honda would make an engine that many years if it didn't work.


They did though. Mine had cams like the lunar surface at just 12,000 miles and the bearing faces were totally shot. When I sold it, at 12k, I had already replaced the tensioners once and they were already failing again. The top end was complete junk but the cylinder walls were still pristine.

After the way the stealership treated me I won't be buying any more Hondas. But that is another story, for another day.
 
Perfect engine design for a motorcycle?

Supercharged inline, 3 cylinder 2 stroke engine, with direct injection.

The 3 cylinder 2-stroke engine is the smallest engine with a perfect primary balance. It's a very compact engine design, making it suitable for transverse layouts, and can be built to a relatively large displacement. The 2 stroke supercharged engine can produce insane power outputs, and modern expansion chambers and supercharging can somewhat widen the power-band.

Direct injection ensures that very little unburned fuel is permitted to escape out the exhaust pipe, and supercharging eliminates the need to use the crank case as an air pump. This design permits the use of an oil lubricated crank case, and would eliminate the need to pre-mix 2-stroke oil into the fuel
 
Originally Posted By: burning1
Perfect engine design for a motorcycle?

Supercharged inline, 3 cylinder 2 stroke engine, with direct injection.

The 3 cylinder 2-stroke engine is the smallest engine with a perfect primary balance. It's a very compact engine design, making it suitable for transverse layouts, and can be built to a relatively large displacement. The 2 stroke supercharged engine can produce insane power outputs, and modern expansion chambers and supercharging can somewhat widen the power-band.

Direct injection ensures that very little unburned fuel is permitted to escape out the exhaust pipe, and supercharging eliminates the need to use the crank case as an air pump. This design permits the use of an oil lubricated crank case, and would eliminate the need to pre-mix 2-stroke oil into the fuel


So the perfect engine design is one that has never been, or never will be mass produced?
 
Originally Posted By: grampi
Originally Posted By: burning1
Perfect engine design for a motorcycle?

Supercharged inline, 3 cylinder 2 stroke engine, with direct injection.

The 3 cylinder 2-stroke engine is the smallest engine with a perfect primary balance. It's a very compact engine design, making it suitable for transverse layouts, and can be built to a relatively large displacement. The 2 stroke supercharged engine can produce insane power outputs, and modern expansion chambers and supercharging can somewhat widen the power-band.

Direct injection ensures that very little unburned fuel is permitted to escape out the exhaust pipe, and supercharging eliminates the need to use the crank case as an air pump. This design permits the use of an oil lubricated crank case, and would eliminate the need to pre-mix 2-stroke oil into the fuel


So the perfect engine design is one that has never been, or never will be mass produced?

I think some outboard boat engines are built this way.

Also, this design sounds similar to the Detroit Diesel 2 stroke engines. However, I was always told those engines were fuel hogs, and they were also unreliable and burnt too much oil.
 
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