Skeeve

No way to tell if that pipe is truly a reverse-cone meg w/o hacking it apart, but the external profile looks like an attempt to appear like a (minimally) reverse-cone meg. The real deal has a hole no bigger than the header inlet at the back end of the reverse cone. Remember, the idea is to generate the power of a pure megaphone exhaust w/o letting the sound out quite as much... That pic you show basically looks like a muffler that been manufactured to look like a reverse-cone meg [which, as I posted earlier, would be too loud to pass EPA noise certs.] A reverse cone meg was the response to the early attempts to limit noise output at race tracks. If I'm not mistaken, one of the other names for it was a "Brooklands pipe," as they were among the earliest racetracks to have to deal w/ adverse public reaction to their events. Not saying that Todd's pipe doesn't function well, just saying that the clear muffler innards visible takes it out of contention as a 'true reverse cone megaphone."

A megaphone pipe is just that: - a reverse cone meg has a cone "cap" on the end of the megaphone, that reverses the pressure wave by having it reflect off the reversed-cone "cap" while still letting the exhaust flow escape from the hole in the "cap": - Reverse cone megs are loud [no baffles]. Megaphone pipes are so effin' OhMyF!@%kingGod LOUD that they're not even allowed on racetracks any more. Reverse cone megs are to 4 stroke engines what unmuffled expansion chambers are to 2 smokes [only louder.] Would that the "loud pipes save lives" Harley-ridin' doofuses would discover that w/ reverse cone megs they could have loud pipes and power at something other than WFO both... at least that way they'd be able to get out of their own way!

Looks kinda like you tried to make your LeMans into a japper crotch rocket, but like the man said, whatever works for you: looks are secondary to function!

Ray: The stock plastic holder seems to fail most often when people mess with it; if it ain't broke, don't fix it! [A good rule to live by, generally, I find... ] If it fails, your best bet is to replace it with another plastic holder; this thread has shown that the brass holder really only seems to be the replacement of choice if you live in colder climates [western WA state where it rains more than it shines, Sweden, etc.] If & when you feel compelled to replace the holder, smear the threads of the holder w/ copper antisieze before you screw it into the head. Put some teflon tape on the threads of the sensor before you screw it into the holder. If you ever get a PC3 and get a custom map done, make certain you do so on the hottest day of the year, with the engine good & hot, near or below sea level [is there a dyno shop in Death Valley? ] - that way, you'll never have to worry about running too lean [which is worse for the engine than too rich, generally] and don't worry about tweaking the holder after that: change the holder to another type & you'll have just wasted the money you spent on a custom map! Don't worry too much about the contention & friction you may have seen over this topic while reading this thread: some of these guys just like to yank each other's chains, & do it regardless of provocation...

True. It's already as hard as it's going to get [if you chill it properly.]

Well, it's looking d@mn sharp, whatever it is! I don't care what anyone sez, those red wheels look purdy to me! FWIW, cast aluminum alloys typically aren't anodizable w/ any success; the magnesium, copper, zinc or manganese that they add usually interferes w/ the aluminum doing its "thang." Wrought aluminum grades are typically what one sees anodized... At least, that's the story the way I heard it. Please give us more closer/sharper/bigger pics of the final results! I think your V11 will definitely make BotM at some future date!

"notched side facing related rocker" s/b "grooved end toward rockers" from what I make of the issue. Seems pretty obvious in the Guzzi-supplied pic: the dumbells have a groove machined on one end near the pivot "ball," and these ends are both up toward the valve rockers in the pic. The usual machine-translated Italian is certainly no help: in this case, a pic is worth probably 10,000 words!

AKA "having your Superman underwear on..."

Funny, the one I'd looked at I was pretty certain was brass. Maybe my memory is going... they say that's the 2nd thing to go when you get old. I forget what the 1st thing is...

What, that the whole injection setup on our Guzzis is one factory-produced kludge stacked on top of another, and we'd be better off figuring out some way to plumb in a MAF from some Ford [or Fjord, if you prefer Norwegian otto-makers! ] and a sparkplug-washer CHT sensor, & converting the hole used by the Guzzi engine temp sensor into some sort of dual-plug application? Yes, in that case, I do have a full grasp of this particularly slippery enchilada! Mas salsa roja y queso, por favor! But I'm fairly certain that in my case, I'm just going to pull out the stock plastic standoff, drill a hole for a copper rod in the base, add the heat sink under the sensor, and put some teflon tape on the threads when I reinstall the modded stock part. I figure that'll get me 50% of the way to your GM sensor, be fun to do, and I won't have to hunt down some linen-reinforced phenolic to make a new standoff out of, altho' that could be fun in its own way. Oh, & lane split ["share"] religiously on hot days! Luckily, I still live in CA where that's legal... Eventually, I hope to $crape up the ducat$ to TuneBoyeeee or PCXXIV&1/2 the durn thing & forget about such devilish little details...

Well, given an insulating mount and a temp sensor w/ a probe tip sufficiently isolated from the rest of the sensor body, relying upon radiated heat instead of conducted heat would allow for the decreased influence of heat transients while allowing correct sensing of substantive changes in heat output. Also, it would mean that since so much less heat was being input to the sensor body, it would remain far more sensitive to slight but consistent changes vs. those too small to overcome its own heat soak. I think ol' Ratch' might just be on the right track w/ his GM sensor kludge... All hail Empiricist Ming! 'er, Hatchracket! er, Hackratchet? Well, whatever his name is... he's empirical! Experimental. Whatever. That's what counts!

Greg: Do you sit watching the thread counting posts so you can keep getting the top post on the respective page#XX saying "Can we possibly hit page#XX?" 'Cause if not, your timing is phenomenal!

"Yeah but..." Dave, the only reason I can think of to make the sensor holder partly [or in case of the original design, wholly] out of brass is because aluminum oxidizes rapidly, forming a layer of aluminum oxide within minutes of exposing fresh metal. No big deal, this is part of what makes aluminum better than other materials in some applications. But in this case, you'd have two layers of Al2O3 coating the threads in the head and the threads on the sensor holder. That's two layers of an insulator [a very effective one, too, I might add: your coffee mug is made out of it! ] vs. only one w/ a brass holder. Aluminum-on-aluminum mating surfaces might be problematic, mechanically too: self-fusing & galling issues come to mind as potential reasons for Guzzi spec'ing brass. Copper is definitely better, but it tarnishes upon exposure to weather, so maybe that was a non-starter for "warranty" issues? WRT aluminum's lower density, it's a non-issue for this discussion: thermal diffusivity is given per unit volume, as the density of the respective materials is factored out of this physical definition.

The nearest shop w/ scooters for hire, for their biggest, baddest, most-like-a-Guzzi scooter available?

One thing to keep in mind is that the trip odo is incorrectly calibrated from the factory. Do some noodling around here at v11lm and I'm sure you'll find the post where someone discovered that the trip odo reads in 2 klicks, while the permanent odometer correctly displays the miles traveled. The originator of that post checked his bike against fixed mile markers, which is how he made the discovery. I imagine this is a non-issue on V11s for distribution in countries where they do everything in kilometers... Still, you've got some pretty serious mileage woes, even adjusting for the wonky trip meter. First things first: check the valves and adjust the TPS; it could very well be that the TPS is set up for the stock ECU, instead of the (iirc, different) setting for the Guzzi Ti-ECU. Of course, I could very well be wrong about that, but it seems to me that most complaints of absurdly cr@p mileage have revolved around incorrect TPS settings. Oh yeah, & clean your air filter! Best of luck!

Actually, this has some merit, if the thread is fine enough: you can adjust the air-gap to achieve the general characteristic of heat flow to the sensor tip as you desire... As for the best gas to use, that's easy: radon, as it is the heaviest noble gas available! Of course, there's that whole radioactivity downside... Hmm, shall we stick w/ xenon? Damn the $$$, full -liness ahead!

Drrr... Ratchet is correct, thermal conductivity is the essence of the matter here, as far as getting the heat that the sensor is supposed to sense to that said sensor... Dave is correct in that there may be other concerns, such as weight or mass, involved in the selection. WRT Dave's question why the sensor can just be mounted directly: don't forget, the more embedded in the head the original sensor was, the more likely it was to be sensing it's own heat via conduction thru the sensor body, rather than the tip. Given how kludgy the entire factory-bodged inclusion of this sensor was [as has been determined during the course of the prior 40-something pages in this thread], it's not too surprising that we still require some sort of stand-off for the GM sensory bodge, given its thermoplastic housing. FWIW, the ideal material from a performance/weight standpoint would be beryllium, but since it has other distinct handicaps such as expen$e and toxicity, I'll leave any disputes over my assessment to back-channel chatter... Pure [well, pure enough to be called copper rather than bronze or brass] would be the ideal material for conducting the heat from head to sensor, given the limited nature of our application. Let's all just agree on that & move along, O.K? Ride on!

WRT the Vetter mileage tests: The faster an IC motor spins, the more fuel it burns, it's as simple as that. In normal usage, keeping the motor spinning near it's torque peak will provide the best combination of mileage and responsiveness. For simply seeking best mileage, a good fairing and the tallest gearing the motor can pull on level ground while putting down the road at minimal rpms will be the answer, as substantiated by Vetter's mileage competitions. Your comment about an overdrive top gear is pretty much why all the "I never use top gear" comments over on Wildguzzi are there: the speed limit in the States is unsuited to maintaining the minimum rpms that the tall stock gearing on the Guzzi 5-spds requires! Of course, we've heard less of that the last few years since the 70mph national limit went into effect for the majority of the interstates, and enforcement in some areas has allowed a slight "hedging" of 5 to 10 mph over the limit before stopping you for "road tax." Good luck w/ your experiments!

Yep. Big twins post-Shovel & post-Ironhead Sporties (aka "Evo Sporties", altho' that term is technically only appropriate applied to the BTs...) had motors that were specifically redesigned for combustion efficiency [aka "better power & lower emissions."] I believe I've posted repeatedly that Guzzi would benefit greatly from similar efforts applied to their antiquated hemi-heads, but so far the factory has chosen to go the dual-plugging route [applying a metaphorical Band-Aid to the emissions problem...] The Buell Blast essentially uses the front head of one of the Buell "Thunderstrike"(?) heads that Erik found gathering dust in Harley's old race shop: they were a set of Jerry Branch heads that had been tested for something, and then left on a shelf. Dropped onto the ~50hp Sportster motor of the late 90s, they immediately pumped out about 20 more ponies, which made them pretty much perfect in Erik's eyes for his bikes, so he got Harley to put them into production. They've since been superseded by more modern designs, but they're essentially what comes on the current 883s & Blast, iirc. Anyway, that's your totally non-Guzzi history lesson for the day...

Once again, the Pundit of Bungendore saves everyone else a lot of grief... Thanks, Pete!

Forced induction. Unless Guzzi dusts off their 4v small-block heads, it's the only way...

The retained heat in the cylinder head will affect such diverse factors as preheating of the fuel-air charge, flame front propagation speed, quenching, etc., and these in turn will affect how fast the motor turns (& how well it burns) at idle [which is a key regime in emissions testing.]

Actually, yes, per Dr. John... also useful for sandwich storage, according to him.

Or using an applique on the original, yes, that works too...

Not a valid experiment. So seriously flawed that I'm not even going to bother pointing out why. Anyway, I believe your point is that Guzzi's intent was for slow sensor response, and we're all committing an error by attempting to defeat this. This is a valid argument, but neglects the problems experienced by several? many? w/ the slow sensor response affecting the fueling to [subjectively] an excessive degree.