Guest Barnapkin Posted June 3, 2006 Share Posted June 3, 2006 I just saw my first pics of the 850 griso. I liked it much better than the 1100 just because of the black frame tube vs. the shiny one. I read that the 850 is a "stroker" motor. This may be the best 850 ever. (OK. old-timers don't gang up on me here) I might have to trade in the monster. I'll bet the 850 is smoother than the 1100. Just like the 750 duc is smoother than the 900. Link to comment Share on other sites More sharing options...
g.forrest Posted June 3, 2006 Share Posted June 3, 2006 i agree, and its definately a better looking machine with clean engine right side. so why doesn't 850 require oil cooler? I just saw my first pics of the 850 griso. I liked it much better than the 1100 just because of the black frame tube vs. the shiny one. I read that the 850 is a "stroker" motor. This may be the best 850 ever. (OK. old-timers don't gang up on me here) I might have to trade in the monster. I'll bet the 850 is smoother than the 1100. Just like the 750 duc is smoother than the 900. 91021[/snapback] Link to comment Share on other sites More sharing options...
Greg Field Posted June 3, 2006 Share Posted June 3, 2006 It is highly unlikely they will bring the G850 to the US. It would cost nearly the same as an 1100. Link to comment Share on other sites More sharing options...
helicopterjim R.I.P. Posted June 3, 2006 Share Posted June 3, 2006 I read that the 850 is a "stroker" motor. 91021[/snapback] I believe it is a 'de-stroker' motor! Link to comment Share on other sites More sharing options...
pete roper Posted June 3, 2006 Share Posted June 3, 2006 I believe it is a 'de-stroker' motor! 91057[/snapback] Correct. The bore remains the same as the 1100 but stroke has been reduced to 66mm! Te shortest of any big block ever made. The thing should be a rev-hound and just begs to have some sort of forced aspiration! Pete Link to comment Share on other sites More sharing options...
dlaing Posted June 3, 2006 Share Posted June 3, 2006 ...and just begs to have some sort of forced aspiration! 91065[/snapback] In other words, anemic. But I am sure it will have a market. Many still yearn for LeMans 850s Link to comment Share on other sites More sharing options...
Skeeve Posted June 3, 2006 Share Posted June 3, 2006 i agree, and its definately a better looking machine with clean engine right side. so why doesn't 850 require oil cooler? 91036[/snapback] Less displacement = less fuel being burned/minute = less heat produced. Not saying that an oil cooler wouldn't be helpful, but as an economy measure (since virtually everything else about the 850 would cost the same as the 1100) it's a no-brainer to eliminate that in favor of being able to bring the 850 in at a lower price point in order to provide adequate product differentiation. Link to comment Share on other sites More sharing options...
Skeeve Posted June 3, 2006 Share Posted June 3, 2006 In other words, anemic.But I am sure it will have a market. Many still yearn for LeMans 850s 91068[/snapback] Actually, they probably went with the de-stroked big bore because it would have a higher peak h.p. output to list on sales brochures & other such "official" documents, thus helping those customers who buy "by the numbers" to make a reasonable? comparison... Of course, those who want to ride a Griso 850 would be much better served by a smaller bore/standard stroke version of the Griso motor, but I guess that's not to be. Weird: I'd think it was cheaper/easier to make all the cranks the same & only have to change the pistons/cylinders than the other way around, but I guess since there's more parts to stock in the supply chain that way, Guzzi opted for the de-stroked crank? At least with the de-stroked 1100 motor, the 850 Griso will have a better rod ratio, which is supposed to help efficiency/power/smoothness or something... Ride on! Link to comment Share on other sites More sharing options...
pete roper Posted June 4, 2006 Share Posted June 4, 2006 In other words, anemic.But I am sure it will have a market. Many still yearn for LeMans 850s 91068[/snapback] No, not neccesarily. the piston speed at any given RPM will be slower due to the shorter stroke. this equals better clinder fill and therefore more *bang*. The biggest problem the 2 valver has is that it isn't very volumetrically efficient. Sticking some sort of blower on it will effectively cure this at higher RPM but it doesn't mean that it will automatically be a slug without. Personally, as an 1100 Griso owner I can hardly fault my set-up, the smaller throttle bodies make it carburete brilliantly and it has more than adequate power for me and I have always thought that forced aspiration is great in theory but stinks in practice as it makes fueling so much more dificult and adds weight. If you're looking for outright power by increasing VE then you can't go past it but it needs clever engine management tro get it to work well. Pete Link to comment Share on other sites More sharing options...
Greg Field Posted June 4, 2006 Share Posted June 4, 2006 Boys, you're missing the point. The 850 Griso is the result of precisely one thing: In the markets for which it is intended, insurance costs are much, much lower for an 850 than for an 1100. The rest is just the details to make it an 850. These details include longer rods, shorter stroke, etc.—which bring with them some advantages—but the 850 motor was not begun in effort to realize these advantages. It was done to sell more bikes in places where insuring big bikes is prohibitively expensive. Link to comment Share on other sites More sharing options...
Guest Barnapkin Posted June 7, 2006 Share Posted June 7, 2006 What I meant by the stroker motor comment was: The stroke was shortened, so the displacement is 850cc. Yet, instead of the total stroke being shortened by say 14mm, the piston crown was shortened by 7mm. There fore the total stroke difference between the 850 and 1064 is only 7mm. This is just like a stroker kit that you would buy for your muscle car etc... Therefore, you will get more torque with that you would have had with completely shorter rods. Link to comment Share on other sites More sharing options...
orangeokie Posted June 7, 2006 Share Posted June 7, 2006 Here, let me add some worth to this thread . . . Link to comment Share on other sites More sharing options...
Greg Field Posted June 7, 2006 Share Posted June 7, 2006 Huuhhh??? The 850 has LONGER rods, not shorter. Cylinders are the same length as on the 1100s, so they needed longer rods to get the piston crown up in the combustion chamber. Git it? Gimme some o' that shit you boys's smokin'. I've had enough reality for one day. Link to comment Share on other sites More sharing options...
jrt Posted June 7, 2006 Share Posted June 7, 2006 Boys, you're missing the point. The 850 Griso is the result of precisely one thing: In the markets for which it is intended, insurance costs are much, much lower for an 850 than for an 1100. 91143[/snapback] Which is precisely one of the reasons I would prefer an 850. Link to comment Share on other sites More sharing options...
Guest Barnapkin Posted June 9, 2006 Share Posted June 9, 2006 This is for greg. Follow along with the attachment. Imagine two different pistons that are available for the same engine. Piston A has a "long" crown length of 25mm. Piston B has a "short" crown length of 15mm. With a given stroke length, Piston B's con rod has to be 10mm longer than the con rod required by Piston A. Since Piston B's con rod, and corresponding crank diameter, is longer, Piston B's engine will have greater torque. Torque is = RxF. Assume the force F applied to the con rod is the same from the combustion in the cylinder for both Piston A and B's engines. Where R is the distance from the center of the crank to the point where the force is applied. That would be where the con rod connects. Piston B's crank has to be larger than Piston A's crank because it has to accommodate the longer con rod through 100mm of travel. I heard that the 850 griso is going to habe a short crown type design. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now