dabore84 Posted April 17, 2008 Share Posted April 17, 2008 Hello people, Surfing on the net I found this two pictures. They show a race custom guzzi. The most shocking mod is, that the air intake and the injectors are on the oil cooler spot and the exhaust tubes are now behind the cylinders. Never seen something like that before and is very cool, specially with those termi exhaust pipes What do you think? The pictures came from tlm.nl site http://www.tlm.nl/koffiehoek/gallerie/ Link to comment Share on other sites More sharing options...
BRENTTODD Posted April 17, 2008 Share Posted April 17, 2008 Thats pretty neat they turned the heads around smart thinking boys. Link to comment Share on other sites More sharing options...
jihem Posted April 17, 2008 Share Posted April 17, 2008 What do you think? must be damn hot on that seat The Ghezzi's exhaust system is under-the-seat also, altho the exhausts are using the normal channeling of the two exhausts and then divide it and send it to the left of the bike to end up under the seat. I suspect we may loose a few ponies there, but it sure looks the part. Link to comment Share on other sites More sharing options...
macguzzi Posted April 17, 2008 Share Posted April 17, 2008 If you keep looking there are lots of Guzzis like that comon mod on round and square barrels Link to comment Share on other sites More sharing options...
raz Posted April 17, 2008 Share Posted April 17, 2008 Cool. I saw a post about a wierd Guzzi chopper a while ago that also had the heads turned around like that. Apparently it should be pretty easy to accomplish (basically swap the LH and RH heads and fabricate a camshaft for it) but there could be severe heat problems at the exhaust side, as someone mentioned then. Link to comment Share on other sites More sharing options...
badmotogoozer Posted April 17, 2008 Share Posted April 17, 2008 Used to be popular with the old Triumph guys. I've seen a few modded like this. "Ram Air" was the theory... Link to comment Share on other sites More sharing options...
DeBenGuzzi Posted April 17, 2008 Share Posted April 17, 2008 if they could find some way to do that from the factory it would appeal to more ppl I bet, it looks cleaner and could be cleaned up even more I imagine. The only downside really is what to do with all that heat, ouch. Link to comment Share on other sites More sharing options...
badmotogoozer Posted April 17, 2008 Share Posted April 17, 2008 That's the problem with this - the exhaust never gets the cooling airflow that sucks the heat out of the head. Marginal performance tradeoff. Link to comment Share on other sites More sharing options...
antonio carroccio Posted April 18, 2008 Share Posted April 18, 2008 Still like Enzo's bike... Link to comment Share on other sites More sharing options...
mike wilson Posted April 18, 2008 Share Posted April 18, 2008 Used to be popular with the old Triumph guys. I've seen a few modded like this. "Ram Air" was the theory... Cobblers theory. The air has to _suck_ (sorry, Pete) the fuel out of the carbs. If it is at higher pressure than atmosphere it can't do that - it's forcing the fuel back into the carb. This can work with injectors but there will be severe difficulties matching fuel and air flow due the (now functional) ram-air effect. Link to comment Share on other sites More sharing options...
Skeeve Posted April 18, 2008 Share Posted April 18, 2008 Cobblers theory. The air has to _suck_ (sorry, Pete) the fuel out of the carbs. If it is at higher pressure than atmosphere it can't do that - it's forcing the fuel back into the carb. This can work with injectors but there will be severe difficulties matching fuel and air flow due the (now functional) ram-air effect. Every (functioning) carb I've ever seen has a "reference" line at the edge of the carb bellmouth that feeds into the float bowl; this normalizes the pressure in the float bowl against ambient to enable utilization of the relative vacuum created by the constriction in the throat of the carb created by the slide/butterfly (1) ["Welcome to fundamentals of carbeurator theory 101"... ] Now, as to needing to balance the "ram air" pressure in the fuel tank so that gas can get the float bowl, that's a different matter irrelevant to your statement above. Anyway, the ram air theory behind reversing the heads has some merit, tho' not due to "ram effect;" it's more a matter of getting cooler, denser air from the front of the bike before it has a chance to heat up in its trip around the hot engine. Unfortunately, as someone else already pointed out, the ex. pipes kinda need to be in front on an air-cooled engine, at least 4 strokes, to keep the ex. valve from burning up. On a water-pumper, putting the header exiting the rear has some interesting advantages, so much so that when noted bicycle maker Cannondale was looking at branching out into dirtbikes, their prototype had the "reversed but really forward" engine config... Ride on! (1) -yes Virgina, there are butterfly carbs out there w/o any kind of slide at all; I think Revco builds one... Link to comment Share on other sites More sharing options...
Guest ratchethack Posted April 19, 2008 Share Posted April 19, 2008 For an air-cooled motor, having the exhaust side of the heads tucked away out of the wind altogether, instead of as directly as possible facing into the blast at speed, is more than a theoretical problem. It presents a prohibitive practical problem. But as we're so often reminded, people will do almost anything to their motorcycles to attract attention for posing purposes -- even to the extent of rendering them practically unusable for riding. Air cooled heads on backwards = Rider's head on backwards. "Ram air effects" for a road bike = loopier than a bag o' squirrels. Yes, I know they've been selling "ram air" f'er half a century. PT Barnum was a terrific salesman, too -- ya gotta give 'em wot they're buying. . . . Link to comment Share on other sites More sharing options...
pete roper Posted April 19, 2008 Share Posted April 19, 2008 My guess is they will find out pretty quickly why people stopped doing this experiment in the 1970's. By reversing the heads you get inadequate air flow to cool the exhaust sides properly and the heads fall off the exhaust valves. Also any sort of 'Ram Air' system requires a large air box to act as a plennum chamber and doesn't start to deliver any real, tangible, benefits until you're going at 130MPH plus. It's a gimmic. An interesting and stylish gimmic but it won't deliver any performance increase. As mentioned above you can't simply whack the heads on left for right, you need to grind up a different camshaft. Terrific waste of effort. It's a nice looking machine but.... Pete Link to comment Share on other sites More sharing options...
DeBenGuzzi Posted April 19, 2008 Share Posted April 19, 2008 My guess is they will find out pretty quickly why people stopped doing this experiment in the 1970's. By reversing the heads you get inadequate air flow to cool the exhaust sides properly and the heads fall off the exhaust valves. Also any sort of 'Ram Air' system requires a large air box to act as a plennum chamber and doesn't start to deliver any real, tangible, benefits until you're going at 130MPH plus. It's a gimmic. An interesting and stylish gimmic but it won't deliver any performance increase. As mentioned above you can't simply whack the heads on left for right, you need to grind up a different camshaft. Terrific waste of effort. It's a nice looking machine but.... Pete thats all well and fine but am I to be informed you have TWO!!!!! griso's now????? WTF, I hate you, can I have one? Link to comment Share on other sites More sharing options...
dabore84 Posted April 19, 2008 Author Share Posted April 19, 2008 Every (functioning) carb I've ever seen has a "reference" line at the edge of the carb bellmouth that feeds into the float bowl; this normalizes the pressure in the float bowl against ambient to enable utilization of the relative vacuum created by the constriction in the throat of the carb created by the slide/butterfly (1) ["Welcome to fundamentals of carbeurator theory 101"... ] Now, as to needing to balance the "ram air" pressure in the fuel tank so that gas can get the float bowl, that's a different matter irrelevant to your statement above. Anyway, the ram air theory behind reversing the heads has some merit, tho' not due to "ram effect;" it's more a matter of getting cooler, denser air from the front of the bike before it has a chance to heat up in its trip around the hot engine. Unfortunately, as someone else already pointed out, the ex. pipes kinda need to be in front on an air-cooled engine, at least 4 strokes, to keep the ex. valve from burning up. On a water-pumper, putting the header exiting the rear has some interesting advantages, so much so that when noted bicycle maker Cannondale was looking at branching out into dirtbikes, their prototype had the "reversed but really forward" engine config... Ride on! (1) -yes Virgina, there are butterfly carbs out there w/o any kind of slide at all; I think Revco builds one... For an air-cooled motor, having the exhaust side of the heads tucked away out of the wind altogether, instead of as directly as possible facing into the blast at speed, is more than a theoretical problem. It presents a prohibitive practical problem. But as we're so often reminded, people will do almost anything to their motorcycles to attract attention for posing purposes -- even to the extent of rendering them practically unusable for riding. <_> Air cooled heads on backwards = Rider's head on backwards. "Ram air effects" for a road bike = loopier than a bag o' squirrels. <_> Yes, I know they've been selling "ram air" f'er half a century. PT Barnum was a terrific salesman, too -- ya gotta give 'em wot they're buying. . . . My guess is they will find out pretty quickly why people stopped doing this experiment in the 1970's. By reversing the heads you get inadequate air flow to cool the exhaust sides properly and the heads fall off the exhaust valves. Also any sort of 'Ram Air' system requires a large air box to act as a plennum chamber and doesn't start to deliver any real, tangible, benefits until you're going at 130MPH plus. It's a gimmic. An interesting and stylish gimmic but it won't deliver any performance increase. As mentioned above you can't simply whack the heads on left for right, you need to grind up a different camshaft. Terrific waste of effort. It's a nice looking machine but.... Pete Learning new stuff every day on this forum. Link to comment Share on other sites More sharing options...
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