4v Vs 8v

[Kiwi Dave]

Removing the snorkel is hardly a big job.  I reckon try it and see.

[Moto]

...Another thing notable about the 8V is that it's single plate clutch assembly is a heavier than the last of the twin plates, especially at the flywheel periphery. I love that. So far AFAIK there are no 'Lightweight' aftermarket offerings available....

Pete

If you love that, you'd luuurve the older flywheels! I just made a table of flywheel weights to put them in context for our newer members: http://wildguzzi.com/forum/index.php?topic=81955.0

I'm a heavy flywheel maniac. Or at least a maniac for heavy flywheels.

Welcome back!

Moto

[beetle]

Good to see Peter Roper giving some thoughts based on real rider feel and meshing in nicely with some solid factual knowledge. Like Kev, I flinch a bit when I read things like "a bit of a dip in the torque at blah rpm but a good linear power delivery", remember ,POWER is Torque x RPM , so you will not get "linear" power with non linear torque, best example of linear torque and power is an electric motor. My old mate Issac Newton from Cambridge, told me the other day while we're were enjoying an apple under an old oak tree. Power is force x times distance / time , (or in English), work done is force x distance, and the rate of doing that work is force distance / time, that is what POWER is, you don't "make" power, is a numerical value given to a calculated figure of the rate at which you have done that work.  Having said that I'm convinced that we each know what we all mean so I'll move

pedant
/ˈpɛd(ə)nt/

a person who is excessively concerned with formalism, accuracy, and precision, or one who makes an ostentatious and arrogant show of learning.

[beetle]

 Oops. Almost forgot the smiley. 



 

[pete roper]

If you love that, you'd luuurve the older flywheels! I just made a table of flywheel weights to put them in context for our newer members: http://wildguzzi.com/forum/index.php?topic=81955.0

I'm a heavy flywheel maniac. Or at least a maniac for heavy flywheels.

Welcome back!

Moto

My old SP, (Which is for sale if anyone's interested.) has an Eldo flywheel. It's like riding a tank! 

Pete

[oldbike54]

 Dang you Ozzies are tough on each other  Oh , and Mark , he never mentioned Watts 

 Dusty

[beetle]

It's the Australian way. Taking the piss.

[oldbike54]

It's the Australian way. Taking the piss.

 Yeah , Ozzies and Okies have that in common 

 Dusty

[Huzo]

Yeah kiwi save, that's a complex as hell method I reckon I'll try. Thanks.

[PJPR01]

Huzo...here's my "seat of the pants" compare, as I have a 2V Norge and a 4V Griso at the moment.

The 2V Norge is indeed velvety smooth, liquid pulling from stop to as high as I want to run it and above 5K it gets just unbelievable smoother...sometime s hard to believe.  Bike has 24K miles on it.

The 4V Griso revs freer/faster I feel, accelerates a bit quicker, but has a bit of a buzz to it thru the handlebars (bike only has 300 miles on it so far) but still maintains the twin feeling.

I would say the 2V Norge is a like a well behaved Labrador...smooth, elegant, athletic, while the 4V Griso is like a German Shepherd...capable of athletic behavior but more aggressive by nature and stance. 

Tomorrow I plan on putting a 100 miles on each of them...my Guzzi Biathlon for the day!

[Cool Runnings]

I wish my 8V had about 125 hp. 

[Cool Runnings]

 

2014 BMW R nineT First Ride - MotoUSA

https://www.youtube.com/watch?v=jYHlIwanMGQ

[Gliderjohn]

My two cents worth from my experience with my 2011 Norge 8V. I have not ridden a four valve so I cannot give that comparison. Until my break in service my motor had a dip and was generally not happy around the 4K to 4.5K area. Not sure what was done at the service or if just breaking in but that bad spot became very minimal and the motor now has a very nice strong steady pull from down low, can do a fairly strong smooth pull in 6th from around 2,500 rpm on.
It does have a "kick" from around the 5K-5.5K on, but not abrupt just more what I would call coming on the cam. No controllability issues at all. I really, really like this motor in everyday life.
Harpers have just completed the rolleriztion job but I have not yet picked up the bike so I am curious if I it will have any different feel.
GliderJohn

[Chuck in Indiana]

2014 BMW R nineT First Ride - MotoUSA

https://www.youtube.com/watch?v=jYHlIwanMGQ

That's why they make all kinds. Maybe you should get one. They're obviously superior. 

[bpreynolds]

2014 BMW R nineT First Ride - MotoUSA

https://www.youtube.com/watch?v=jYHlIwanMGQ

Every direct comparison article or youtube video I've seen always has the Griso coming out mostly on top.

[oldbike54]

That's why they make all kinds. Maybe you should get one. They're obviously superior. 

 Wouldn't matter Chuckie , if MG built a 150 HP motorbike that weighed 375 LBS , handled like a GP bike , rode like a K1600 beemer , and came with a 500,000 mile unlimited warranty , some folks would still bitch 

 Dusty

[Huzo]

Due to the fact that I'm relatively clueless at operating the forum I'm left wondering if the post about the definition of "pedant" applies to me, jeez I hope so, but I'll brace myself for for disapointment of finding out otherwise. I'm reminded of that wonderful saying that goes like " There's only one thing worse than being talked about, and that's not being talked about"....... Ahhh. Personally I prefer Watts to Horse Power but I guesss it's of little consequence. 

[Trogladyte]

I wish my 8V had about 125 hp. 

If mine delivered that, I'd sleep with it.

[Huzo]

Breed another one Troggy !

[oldbike54]

 Huzo , I think that was just one Ozzie giving another Ozzie a poke 

 Dusty

[beetle]

Due to the fact that I'm relatively clueless at operating the forum I'm left wondering if the post about the definition of "pedant" applies to me, jeez I hope so, but I'll brace myself for for disapointment of finding out otherwise. I'm reminded of that wonderful saying that goes like " There's only one thing worse than being talked about, and that's not being talked about"....... Ahhh. Personally I prefer Watts to Horse Power but I guesss it's of little consequence. 

Well, I did quote you in that post. So yes.

[Huzo]

Great chat fellas, thanks for your input

[Chuck in Indiana]

and at the top end obviously.

Not really so obviously. My Centauro had more torque *and* top end.. it was silky smooth down in the lower rev ranges. The only down side to the 4V engines is that Guzzi can't seem to make them freakin WORK out of the box.  Sorry, but ever since the fatally flawed Lario, every 4 valve has had issues. Hopefully, all that has now been sorted with the latest iteration.. but the 4V engines are wonderful things to operate.

[beetle]

How many times do I have to say it? A properly set up 8V makes more torque everywhere as compared to the pushrod big block. More torque, more horsepower, more revs. It's a better engine, tappet issue notwithstanding.

Not all of us are content to plonk around on mid powered, average torque, low revving Guzzi's. If that's your bag, more power to you, but don't begrudge those of us who like to ride their Guzzi hard, and appreciate the extra grunt and more revs. Get over it.

[oldbike54]

 Yep , 4 valve heads real superiority is in the midrange , the top end kick comes more from being able to run longer cam timing W/O sacrificing bottom end and mid range torque . A bit of oversimplification, but close enough . Sorry for sounding pedantic Mark 

 Dusty

[brenwin]

Steve knows what he is doing. I've lost count of the stories of poorly tuned 8V engines. Poor (or no) PD doesn't help when the bikes sometimes leave the factory with both air bleeds open, TB's not synced, incorrect TPS setting. The same techs were probably good with the 2V. Maybe.

The 8V head had unique characteristics that make it very sensitive to incorrect inlet/exhaust tuning.

The maps in the 2008-2010 Grisos were truly atrocious, and I think this is where the myth of the 2V having better low end torque started.

I sold my 09 8V Griso to a friend who had the Beetle remap done . It's not the same bike. Wheelies off the start line are very doable and the increase in performance is not just mildly noticeable , it's terrific . My 012 Stelvio has had the same transformation . It performs with what seems like more horsepower throughout the power curve (smoother) and a far better top end . Before the remap the bike would start loosing power over 160 kms per hour . That was with full bags . Now runs smooth and strong up to 200 kms/hour with more left . (haven't gone there yet ). We have a great dealership network here with syncing the fueling and general tune up work but the remapping is whats really changed the performance level of these bikes . 
Having had a Norge 2 valve I couldn't imagine going back to that after the recent Stelvio transformation . There is just no comparison .
These guys down under know what the hell their doing .

[beetle]

Sorry for sounding pedantic Mark 

I couldn't see any pedantry. Unless it was so subtle my bogan outback brain couldn't identify it.   

[canuguzzi]

How many times do I have to say it? A properly set up 8V makes more torque everywhere as compared to the pushrod big block. More torque, more horsepower, more revs. It's a better engine, tappet issue notwithstanding.

Not all of us are content to plonk around on mid powered, average torque, low revving Guzzi's. If that's your bag, more power to you, but don't begrudge those of us who like to ride their Guzzi hard, and appreciate the extra grunt and more revs. Get over it.

It doesn't matter what you say or how often.

Motorcycling is as much about perception as it is about facts.

Trying to convince the rider who got the rush of their lives on a Kawasaki Triple that it couldn't compete with new 600 cc bikes is wasting time. They liked the feel of it and nothing can take that way. So it is with 4V vs 8V MG engines. You can prove the 8V makes more power throughout the RPM range, even on a bad out of tune day but that doesn't change the perception that the 4V feels (to them) like it has more torque down low than the 8V.

That you are 100% correct doesn't matter because nostalgia and emotional attachment are far more convincing than any facts or figures you can throw out.

The past stands still but the rubber band to the future just gets tighter every day until it finally snaps. Then the 8V owners will be the ones saying the new liquid cooled V-Twin is hideous, too heavy, complicated and might as well be built in Asia.

[Huzo]

We may as well close this topic now NP, you've said it all. Touche'

[bpreynolds]

We may as well close this topic now NP, you've said it all. Touche'

Not quite yet 
I have found the 8V engine to run greatly hotter than any of my other 5 Geese I've owned.  It's still not as hot as the otherwise fantastic 1100 Breva I test drove a couple times, but still significantly warmer than the other MGs.  Right now in KY, ambient temps are 70F at most and that's actually nice but that neat little comfort now will be changing somewhat as temps increase outside.  Has anyone here tried a map, tuning, whatever that gets it to run a bit cooler?