Four valve engine?

[polebridge]

Has anyone heard anything about a new Griso with a four value head and 110hp? I saw a photo of it on motorcycle.com.

[Admin Jaap]

They are developing, but I don't think it'll be for sale in 2007... There is a thread on this forum about it.

[pille]

I hope luigi did his homework because in the past every attempt to produce a 4-valve engine has been unsuccesfull. the lario had problems in the eighties and daytona in the nineties! but now with piaggio as supervisor this could be different.

[Skeeve]

I hope luigi did his homework because in the past every attempt to produce a 4-valve engine has been unsuccesfull. the lario had problems in the eighties and daytona in the nineties! but now with piaggio as supervisor this could be different.

 

Before Piaggio pulled the blipvert on the website, the description indicated that it was another CIH design at the very least, if not OHC, but that instead of having a belt driving the cams running off the front of the engine & creating cooling issues, it was to have a chain running off the back of the crank [eg, around the intake tract if OHC, or off to the side if cam-in-head; the pic was quite lacking in detail, naturally, for vaporware... ] which would create all sorts of truly new & unique engine parts [something which so far in their history, Guzzi has been at great pains to avoid for the last 30 years or so to varying degrees. ]

 

Naturally, the immediate response was "I'll hold off & buy one of the 100hp units coming soon to a dealer near me," which created a bit of a problem for the ever-shrinking dealer network, so Piaggio yanked the announcement, since just the prospect of a Guzzi that could actually claim to have some credible performance abilities was cannibalizing sales of the current generation of product.

 

Ride on!

[polebridge]

Before Piaggio pulled the blipvert on the website, the description indicated that it was another CIH design at the very least, if not OHC, but that instead of having a belt driving the cams running off the front of the engine & creating cooling issues, it was to have a chain running off the back of the crank [eg, around the intake tract if OHC, or off to the side if cam-in-head; the pic was quite lacking in detail, naturally, for vaporware... ] which would create all sorts of truly new & unique engine parts [something which so far in their history, Guzzi has been at great pains to avoid for the last 30 years or so to varying degrees. ]

 

Naturally, the immediate response was "I'll hold off & buy one of the 100hp units coming soon to a dealer near me," which created a bit of a problem for the ever-shrinking dealer network, so Piaggio yanked the announcement, since just the prospect of a Guzzi that could actually claim to have some credible performance abilities was cannibalizing sales of the current generation of product.

 

Ride on!

 

According to what I've read it is still a pushrod design.

[pete roper]

No detailed specs have been released yet but the pics I've seen would see to indicate it is another Hi-Cam design. The mentioning of *pushrods* is confusing. Quite a few people describe the *old* Hi-Cam as having pushrods, I wouldn't, to me it simply has followers that operate rockers rather than rockers that operate directly on the cam.

 

My guess is that it will be very similar in design overall to the previous engine but usning Morse chains to drive the cams from roughly where the distributor drive used to be on the camshaft of earlier models. This will be considerably cheaper than the previous Hi-Cam system and I really can't see the beautiful vernier system being seen as either neccessary or cost effective on a *production* motor.

 

I think it will be a nice thing, not as technically exciting as the earlier Hi-Cam but clearly a step forward. As for the question of power? I have a 100HP DAytona RS is my workshop at the moment, it's far too much bike for me. My boring old 2V Griso will make probably about 75-80 at the rear wheel and honestly that's plenty for me. I'll be buying an 8V when they are released but not because I really need any more than I already have.

 

pete

[Skeeve]

I think it will be a nice thing, not as technically exciting as the earlier Hi-Cam but clearly a step forward. As for the question of power? I have a 100HP DAytona RS is my workshop at the moment, it's far too much bike for me. My boring old 2V Griso will make probably about 75-80 at the rear wheel and honestly that's plenty for me.

 

Well, in defense of a 4v update, it has a couple of factors in its favor, regardless of any "need" by an avg. rider [no offense to you Pete; I'm actually using myself as "avg." in this context! ]:

 

1) We've reached an era when any open-class tourer needs to be able to claim 100hp and mean it, just for sales competitiveness. [i know, crazy ain't it! Just a generation ago, that magic figure was only known to GP machines!]

 

2) A 4v motor w/ the magic 100 number can still have a respectably broad powerband, vs. a 2v motor that makes that figure, but has to be tuned so peaky to make it that its not fun to ride or reliable any more.

 

Ride on!

[Guest Nogbad]

I don't get it.

 

Why all the pursuit of power from a Guzzi? If you want power, start from a good place and buy an I4. If you insist on a V2 then buy a Honda SP1 or 2, Suzuki TL1000 or a Ducati.

 

The Guzzi has other characteristics that make it what it is.

[pete roper]

I don't get it.

 

Why all the pursuit of power from a Guzzi? If you want power, start from a good place and buy an I4. If you insist on a V2 then buy a Honda SP1 or 2, Suzuki TL1000 or a Ducati.

 

The Guzzi has other characteristics that make it what it is.

 

On the one hand I'd agree, but on the other I wouldn't

 

The thing is that the Guzzi combustion chamber is a horrible anachronism that can't possibly continue to comply with polution regs. Pushrods are also noisy, the fact that current motors have ceased to rattle fills me with both awe and suspicion.

 

The earlier Hi-Cams are/were lovely, but they were designed by a race engineer. The Nuovo Hi-Cam will hopefully be not only quieter and cheaper to produce but will also keep all we love about Guzzi without sacrificing anything as well as giving more power which is what people want.

 

Personally my 'G' goes more than fast enough for me on the road but if you could give it 10-15 more foot/pounds of torque in the midrange I'd be rapt! I reckon that's possible with the new design (If it's what I think it is.)

 

Pete

[Guest Nogbad]

Pete,

 

If you can put aside the prejudice about H-D, the engine in my Buell does about 20% better mileage than the V11, makes more power, and has a much fatter midrange. The layout and bore / stroke ratio of the H-D engine, particularly the 1203 version belong in the first part of the 20th century and not the 21st. Nevertheless, it's a great road engine. Modern heads and hydraulic lifters take care of the noise / combustion issues, but it is still a 2 valve design, and a design that meets Euro 3 without a CAT!

[Greg Field]

As Nog has pointed out, engineers from a company that hasn't had a reputation for performance since at least 20 years prior to the time Guzzi gave up seeking performance have come up with an air-cooled pushrod two-valver that makes really respectable power and torque and doesn't blow up. Guzzi could do it, too

[Skeeve]

Pete,

 

If you can put aside the prejudice about H-D, the engine in my Buell does about 20% better mileage than the V11, makes more power, and has a much fatter midrange. The layout and bore / stroke ratio of the H-D engine, particularly the 1203 version belong in the first part of the 20th century and not the 21st. Nevertheless, it's a great road engine. Modern heads and hydraulic lifters take care of the noise / combustion issues, but it is still a 2 valve design, and a design that meets Euro 3 without a CAT!

 

As I've posted repeatedly, Guzzi could stand to apply some of the engineering fundamentals that H-D used to update their engines starting back in '84...

 

The only real advantage Harley has over Guzzi is in the combustion chamber. Harley has an advantage on meeting emissions vs. MG in that their under-square engine means they've got comparatively more time to complete combustion before the exhaust valve opens. The noise issue also benefits from the long-stroke Harleys use: lower peak rpm means you can use hydraulic lifters w/o negative performance affects, quieting valve clatter. We all know the route Guzzi went instead; decrease valve lash specs [fortunately, those of us here in the U.S. can revert to world-spec settings on our own... ] And the fuel mileage comes back to better combustion chamber design; a more efficient burn means you can go leaner on the fuel before running into issues w/ ping, etc.

 

Look at pics of the 1200 heads & imagine that chamber on a v11 mill instead of the hemi-head Guzzi used (uses.) Heck, even Dodge(Daimler-Chrysler) doesn't even use a true hemi-head anymore - they just trademarked the name for advertising purposes! [smart, that... ] All of which just makes me think more & more about getting a set of Mike Rich's pistons for the v11, which seem to be about the best that can be done short of a very ex$pen$ive combustion chamber redesign...

 

[Guest Nogbad]

For efficiency (ignoring power to weight and specific power per cc issues) you want a slow engine speed and a long stroke. See the most efficient IC engine in the world

[dlaing]

Pete,

 

If you can put aside the prejudice about H-D, the engine in my Buell does about 20% better mileage than the V11, makes more power, and has a much fatter midrange. The layout and bore / stroke ratio of the H-D engine, particularly the 1203 version belong in the first part of the 20th century and not the 21st. Nevertheless, it's a great road engine. Modern heads and hydraulic lifters take care of the noise / combustion issues, but it is still a 2 valve design, and a design that meets Euro 3 without a CAT!

The transmission in the HD probably helps a little. (no 90 degree angle change in direction of force as used in the Guzzi shaft).

Also the lighter weight.

How is the durability of Buells compared to Guzzis?

How is the gearbox in the Buell?

Prejudice aside, the only thing I don't like about the Buell is the toy size wheel base and the not so great styling. Oh yah, and the cylinder layout that demands a fan to cool the rear cylinder Oh, and some of the handlebars integrated into the triples.

XR1200 is much prettier But I guess I am about the only one that likes it.

[Guest Nogbad]

 

XR1200 is much prettier But I guess I am about the only one that likes it.

 

I like it.

 

There are some alleged durability issues which can be found on the UKBEG site, but in general a lot of Buell riders as a breed seem to be much more "gas and go" hooligan riders than Guzzisti if the forum is anything to go on. There are a few gearbox output shaft bearing issues reported.

 

My bikes have never tended to break, whoever made 'em, so I guess even a fragile design will be ok if treated appropriately.