centeroff Posted December 23, 2011 Share Posted December 23, 2011 I checked the lash on my Ballabio,it was a little too clattery,but running good.I got a factory owners manuel with my bike,and the specs were very tight .004 int. .006 ex. my other Guzzi's I always set at .008 and .010,I thought what the heck mabey in the last 30 years or so they've come up with a tight lash profile.So I set them to spec,the tappet noise was diminished considerably,but the engine was un happy,it killed the bottem end power,even droped the idle 100 rpm,so much for the tight lash theory.I set it to my old specs and the engine is happy again..008 and .010 still seem to be the numbers. Steve Link to comment Share on other sites More sharing options...
ramon68 Posted December 23, 2011 Share Posted December 23, 2011 What about the tappet noise? Diminished? Link to comment Share on other sites More sharing options...
drewscura Posted December 23, 2011 Share Posted December 23, 2011 That sounds exactly like my experiences. The Scura's previous owner told me that he set them loose and loud, because that's the way he liked it. So, I set out to try every setting I had ever read about. I tried Euro specs, U.S. specs, and Raceco Specs. The Raceco, I believe is the loosest, which is where it was before, and just so happens to be where it is now. Running the closer tolerances definitely keeps the valvetrain quiet, but at the cost of driveability issues. A lot of spitting, sputtering, and the occasionally backfire. It even stalled a couple of times. So I tried looser and looser settings until I ended up where it is now. Runs like a sowing machine, a loud one, luckily the clutch drowns it out. Link to comment Share on other sites More sharing options...
gstallons Posted December 23, 2011 Share Posted December 23, 2011 Ha ! Link to comment Share on other sites More sharing options...
rex007can Posted December 23, 2011 Share Posted December 23, 2011 Doesn't timing have something to do with that? Link to comment Share on other sites More sharing options...
gstallons Posted December 23, 2011 Share Posted December 23, 2011 You affect the valve timing when you increase or decrease the valve clearance. The same can be said for point type ignition systems. When the clearance is decreased, the timing advances. Link to comment Share on other sites More sharing options...
Mike Stewart Posted December 24, 2011 Share Posted December 24, 2011 Basicly you are decreasing the valve overlap (the time when both valves are open) and duration which is why the bike will idle stronger and at a lower rpm. It would be cool if someone had a dyno to see if there is any horsepower lost at top end with running looser valve clearence. By the seat of my pants, I have never felt any difference in performance, but it Does make a huge difference on idle quality and stalling when coming to a stop. Mike Link to comment Share on other sites More sharing options...
rex007can Posted December 24, 2011 Share Posted December 24, 2011 You affect the valve timing when you increase or decrease the valve clearance. The same can be said for point type ignition systems. When the clearance is decreased, the timing advances. Exactly my point. Wouldn't matter much at hight RPM at full advance. But on idle it would likely make a bigger difference. I wonder if changing the timing would be better than running with loose valves. Just curious if anyone's tried it. Link to comment Share on other sites More sharing options...
luhbo Posted December 24, 2011 Share Posted December 24, 2011 Try running it with the inlet tight, the exhaust wide instead. It should give you both, stable idle and uncompromised top end. And only one valve tickering. Just an idea, actually. Those running timing gears could try to advance the timing 2 to 3 degs. Works quite well what I've heard. Hubert Link to comment Share on other sites More sharing options...
centeroff Posted December 24, 2011 Author Share Posted December 24, 2011 I do not have the specs on this late model cam shaft,and I don't want to take my new toy apart and put a degree wheel on it and check cam timing yet. But closing up the lash does advance the cam timing by a small amount,depending on how steep the ramps are,it will also effect TDC overlap,and I don't know how sensitive these EFI computors are on these bike. This bike came with the accesory mufflers and a different ecu,I guess to recalibrate for the exhaust. If anyone on this forum has taken the time to check cam timing on a V11 Sport and would like to post it I would sure appreciate it. Steve Link to comment Share on other sites More sharing options...
Mike Stewart Posted December 25, 2011 Share Posted December 25, 2011 I did spend a few hours degreeing my cam when I had my engine apart for new Mike Rich pistons and repainted the 2002 dreaded peeling paint on the engine cases. First, I had the cam specs. from the workshop manual, BUT it was very vague on what the checking clearance was So, I went with 1mm. and while the opening and closing was off by a few degrees, they were centered. Meaning, I felt the cam was centered which could make up for the error of using the 1mm. spec. Now, having the V11 Sport engine apart, to adjust for timing error would be hard. The cam and crank key ways are some what narrow, so having an offset keyway made is possible but I can't see correcting anymore than perhaps 1 or two degrees. On that note, bigger valve lash to me does not advance the valve timing as the opening and closing of the valves are BOTH effected (still being neutral). Meaning, the duration is decreased but the timing is in fact the same as in opening and closing on a whole. I could be missing something, but then again, I just had a wonderful Gin Martini! Merry Christmas, Mike I do not have the specs on this late model cam shaft,and I don't want to take my new toy apart and put a degree wheel on it and check cam timing yet. But closing up the lash does advance the cam timing by a small amount,depending on how steep the ramps are,it will also effect TDC overlap,and I don't know how sensitive these EFI computors are on these bike. This bike came with the accesory mufflers and a different ecu,I guess to recalibrate for the exhaust. If anyone on this forum has taken the time to check cam timing on a V11 Sport and would like to post it I would sure appreciate it. Steve Link to comment Share on other sites More sharing options...
docc Posted December 29, 2011 Share Posted December 29, 2011 Try running it with the inlet tight, the exhaust wide instead. It should give you both, stable idle and uncompromised top end. And only one valve tickering. Just an idea, actually. Those running timing gears could try to advance the timing 2 to 3 degs. Works quite well what I've heard. Hubert My memory fails . . . my manuals say 0,10 mm intake/ 0,15 mm exhaust (0.004 / 0.006) - is that "euro spec?" And some US manuals went on to specify 0.002/0.004? The "RACECO" spec is - 0.006/0.008? ) or 8/10 - I forget . . . Link to comment Share on other sites More sharing options...
luhbo Posted December 29, 2011 Share Posted December 29, 2011 ... My memory fails . . . my manuals say 0,10 mm intake/ 0,15 mm exhaust (0.004 / 0.006) - is that "euro spec?"... Probably. My manual says the same at least. I thought one could try .1 for the inlet valve and .25 for the outlet, or maybe vice versa, means .15 for the outlet and .2 for the inlet. Basically I try to adjust the valves as tight as possible, so if the positive effects on idle and transition could be achieved with only one valve a bit wider this would do also. Hubert Link to comment Share on other sites More sharing options...
Chuck Posted January 1, 2012 Share Posted January 1, 2012 If I remember correctly..always a problem at my age.. Pete said that .005 and .007 was a good compromise for big blocks. (other than the LeMans 1000). I've been using hat for quite a while. Link to comment Share on other sites More sharing options...
docc Posted January 3, 2012 Share Posted January 3, 2012 Really interesting theory to let the outlet run looser . . . Link to comment Share on other sites More sharing options...
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