Chris Wilson
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Posts posted by Chris Wilson
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So why even have the brace if its purpose is not really air control?
Resonance, the heat shield over the header would vibrate like a metal blade Venetian blind against an open window in a hurricane and the brace mass dampens it.
The twist in the blade is an after thought and detracts from its real reason.
How's that for conjecture?
On another site there is a claim that the tank mounted air brakes are actually hand warmers.
(Wow, and here is me thinking that was cylinder heads were for at stops.)
So open the flaps and stick both hands in like pop up toasters whilst riding?
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Mechanical support for the heat shield not the pipe.
It would serve better use as a mitred brace if the shield is only clipped to the header in two points.
(Sure I mentioned that before, then again maybe I didn't.)
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16 hours ago, Lucky Phil said:
Umm, I think you're taking the opinion of a non technical, "social media commentator", millennial a little to seriously. As an aircraft engineer I figure I know something about aerodynamics and as opposed to a previous poster that proffered the idea it's a mechanical support of the header I actually think its an aerodynamic guide/redirector/deflector for hot air from the back of the header away from the foot peg area and riders feet. If you look closely it appears the deflectors forward edge is a little bit inside the line of the inside of the header pipe and captures the the trailing hot air from that area and redirects it back outboard across the lower part of the header pipe and heat shield and away from the riders foot and lower leg.
Guzzi have a fairly proud history with regards to aerodynamics which guarantees nothing but it seems to be functional to me.
Ciao
Hi Phil, good to have a trained eye on this but please accept that I have had 50 years of being involved with model aircraft and kinda know where a bad place for a control surface would be.
Low Reynolds number, shadowed by a bluff body, turbulent air stream all make for an ineffective device.
Not arguing the intention but surely you, with less of a history in aerodynamics could design a better more fuel effective deflector in your sleep?
The poster who mused that the "mad aero tech" would serve more purpose as a mechanical strengthener was me.
And I stick by it.
If you examine the entire body of the header you could well conclude that the heat sheild's wash could easily defeat any effect that the deflector has. It's a far bigger curved wing .....but look it's not worth arguing about further.
Thanks, Chris.
P.S. my guess with all of this is that in testing the bike the riders detected a heat waft coming from repositioned pipes, the accountants said no to double walling, the stylists said make it a feature and the engineers said provide something to obviate the predicted complaints - it doesn't have to work it merely has to be an attempt.
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7 hours ago, po18guy said:
Boat tail bullets. Much more aerodynamic. Greatly reduced drag coefficient. Sometimes the gains are behind rather than ahead.
From reducing drag I agree, but deflection, no matter how it's done increases it.
The so called aerodynamic blade sits in the highly turbulent area behind a bluff object and would accomplish little.
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Just wondering how the "Aerotech" behind the headers claim to work when it's well ..... behind the headers?
Anyone who knows the slightest about aerodynamics can see at a glance that it would do zero.
Calling marketing bullshit on this one.
Chris.
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On 9/13/2021 at 3:15 PM, pete roper said:
Bloody difficult to add a bolt-on reactive drive Chris......
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/mono2para/mono2para.htm
If their is a will there is a way.
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On 10/19/2021 at 7:33 AM, po18guy said:
......but how to soak fins?
Easy, place a bucket full of solvent large enough to contain the entire barrel, lean the bike over until the barrel is inverted in the bucket, leave overnight, rinse and repeat for the other side.
Please send pics.
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20 hours ago, cash1000 said:
How about how to clean up brake calipers back to near their original gold?
Brake cleaner?
If the coating on the caliper is proofed against brake fluid then I can't see a reason why a specific cleaner would effect it.
Chris.
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20 hours ago, po18guy said:
Too bad that motor oil was not silver. Who'd know?
Um, if your oil was silver I would really worry.
That amount of metal particles would be, putting it mildly, bad.
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Don't have a V11 but my Bellagio is "Bella."
And something else in Italian if it doesn't start....
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I find the issue of "startups interruptus" and it's fix basic common sense.
Took my Bellagio to the local auto electrician and Harley enthusiast who knew nothing of Moto Guzzi's and his comment was "wierd".
The only other thing he said was " pick it up this afternoon."
$150AU later and he had re-wired most of the starter circuit including a 40 amp soloniod.
To him it was simply the way it should have been done from factory.
Although I am on my second starter motor with a theoretical diagnosis of the leading brush arcing out and not conducting.
Now that if someone who has no Guzzi experience solve this in moments it staggers belief that 100years of experience could not do the same.
Chris.
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1 hour ago, pete roper said:
Chris, the dash reading is simply ambient temp, it's sensor lives up by the dash and doesn't have any feed into the ecu. The ambient air temp sensor is in the airbox and the engine temperature sensor is in the back of the RH head.
Yep, I agree.
The point was that at 52c in the blazing sun on a summer's day surrounded by diesel trucks and stopped in traffic with no air flow over the engine, I was almost passing out.
And the engine ran faultlessly.
If it was my old K75 BMW it would have boiled it's fuel easily and burnt my thigh when the fan cut in .
As you might say, I part my buttocks at your water cooling.
Chris.
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53 minutes ago, Lucky Phil said:
He could have tried playing with the engine temp trim which you can adjust as a % for each temp break point so richen it up when it's cold. Also there's the option of the start enrichment map which enriches the fuel delivery for 4000 engine revolutions which is around 3 min running until it gets some temp into it. These parameters make a massive difference to cold start and running as I found out when I used the V11 2 valve engine temp break points and warm up trim initially on my Centauro engine. With the much larger and completely different 4 valve head design the engine temp trim % and break points were totally wrong for the Centy engine and it was nearly impossible to start and ran poorly until up to around normal engine operating temp. At or around normal engine temp it ran very well but starting and cold were really bad.
Ciao
Hi Phil, I believe that the slight fuel increase was very easy to do and had maximum effect at low speed and minimal at high.
As mentioned, this bike is extremely tolerant to heat and I have ridden along Parramatta Road in summer with the dash reading 52C and it was fine - the rider not so much.
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Ok, Pete is witness to all of this, basically I had Beetle map Mk1 installed to a stock standard Bellagio.
And life was good, better fuel consumption, slightly more power and no popping on over run but - that only applies on a country run where your engine is thoroughly warmed up and you are surfing the mid range.
The bike was remapped in winter, combine that with a destroked 1200 that suffers massive barrel finnage suitable for that larger motor and you get an extremely cold blooded bike that takes minimum of 3 minutes to warm up or it stalls regardless of the fast idle collar setting.
My thoughts were that that the AFR was too dry and cold at off idle settings, and here Mark modified the map to include very slightly more fuel across the map - and it worked.
Downside, very slight popping on over run but FAR better manners in city cycle where speed bumps and slow roundabouts would easily cause a flame out.
To sum up, I am sure that Mark got the map right from square one but the gross amount of finnage and overcooling defeated that from the start.
One fault had to be reintroduced to counteract another.
If I ever have cause to remove the barrels then I would be sorely tempted to grind back the fins somewhat.
Chris.
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I had a reinstatement on the Bellagio.
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7 hours ago, Lucky Phil said:
Not sure but what you're referring to is the inlet valve. Hemi heads are pretty poor for combustion efficiency with their orange peel shape with any sort of decent compression pistons and so lots of ignition lead hence why the modern 4 valve narrow angled valve head with tumble scavenging instead of the swirl scavenging totally eclipsed it about 40 years ago. Everything has its day and the Hemi design lasted for nearly 100 years.
Ciao
Hi Phil, yes the inlet valve, it's extremely close to the head gasket area.
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How does the Chrysler head pictured on the right operate when the exhaust valve fouls the head seal?
I know that the claim will be ' bad camera angle' be jeez that is close!
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On 10/3/2021 at 7:18 AM, VtwinStorm said:
Beat me to it, po18guy! I was going to mention the Tatra.
Really don't see the Tatra following the then current automotive practice.
It's a rare curiousity that has been forced into service.
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Haven't seen many automotive V8's with air cooling, front exhausts, rear side intakes, solid engine mounts, off centre drive shaft, no diffential, hand operated clutch, foot operated gears etc.
I know it's tempting to draw parallels but you could do the same with any IC engine of that period.
Chris.
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Ever try to get an oil level that is parallel to a windage plate when you only have a side stand?
Even with one person on the bike and another with a strong light looking down the filler hole it's very difficult.
I find that an accurate dipstick the ONLY way to check a Bellagio's level by yourself short of using a cradle of some kind to hold the bike upright.
This is the main reason why I am not tempted with metallic rods as a dip gauge.
As noted, using the original as a true gauge is possible.
Chris.
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If this has a polished chrome dipstick then I found that hard to read an oil level with the oil simply running down every time it's retracted and giving a false reading.
And how does one get a reading when it really matters, riding and in the saddle?
Chris.
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I think that by the time IC engines are outlawed the laws on transport will have changed.
The freedoms we take in travel may not exist and personal forms could become less and less.
Could all be a moot argument.
Chris.
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To trace a leak I have always completely degreased, puffed the area with white talcum powder and then fired her up.
It is immediately obvious where the source is by the dark staining in the powder.
Chris.
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On 2/24/2010 at 10:20 PM, pete roper said:
It's the baffling in the muffler itself that is important. Pipe length and diameter, (And any taper in the overall design.) that will control the accoustic tuning of the pipe. What I'm convinced is neccesary is actually nothing more than a glorified 'Blockage' to slow down the egress of the spent gasses. "But surely," people will say "You want the gasses out?" and yes, you do but also remember that as they exit the system they are cooling rapidly and conracting so a longer time within the pipe means less volume of gas to flow. Running substantial overlap on the cams with a very narrow included valve angle means that there is a LOT of opportunity for new mixture to exit the exhaust valves on overlap and that is exactly what it will do if it is encouraged to do so. Because the speed of sound is a constant you can only rely on the percussive wave moving back from the end of the exhaust to work to this end over a quite narrow rev range. So trying to use what many describe as 'Back Pressure' but I preffer to think of as a restriction, within the entirety of the exhaust system from valve head to the end of the muffler will have a far greater ability to discourage the expulsion of fresh charge than relying on accoustics alone. Because of the amounts of gas being expelled at different RPM and loadings the restriction within the pipe will also vary due to the density of the gasses being expelled varied by heat.While I'm not certain I would think that this would mean that you could expect a more usefull result over a wider range than you would get relying on percussive tuning alone.
I may be completely wrong. But working on those principles the results I'm seeing make sense, to me at least. It is my belief that the engine is timed and it's ability to breathe is designed to work with a restrictive exhaust because that is what is demanded by modern emissions legislation covering both noise and pollutants. While I'm sure you can build a map to make the engine produce bulk power up top I'm convinced that to completely release its full 'Potential' it would need not only a new map but completely new valve timing to make it behave like an 'Old School' hot-rod. I'm sure that someone will, eventually, go down that path and hopefully the results will be spectacular and please them.
My aim in everything I do is to maximise the, if you like, 'Base' potential of the machine by exploiting its strengths and minimising its weaknesses WITHOUT embarking on a remanufacturing programme that could cost tens of thousands of dollars. I also think that in this day and age there is no reason for loud, open, antisocial pipes. Especially if we live, as most of us do, in fairly urbanized environments where our actions impact on our neigbors. You can have a bike that sounds GREAT to you, the rider, without having to deafen everybody in the next suburb and if, as in the case with this engine as it is timed now, making more noise also makes it LESS efficient?? Well, if you *have* to go down that path you're a wanker. Don't get me wrong, I love the sound of a well tuned 'Old School' motor but if I had to live with it every time I rode or, worse still, if I had some numb-nuts over the road who several times a day pulled his incredibly noisy and poorly-performing shitheap out and blasted off up the street making enough noise to wake the dead I too, like Mr & Mrs Average, would get the shits. While I'd just go over the road at 4.00AM and do the 'Dog Turd in a Burning Paper Bag' trick to the idiot in question Mr. & Mrs Average will simply vote for politicians who will enact ever more draconian legislation targeting internal combustion vehicles. None of us need that!
Also there is more of a challenge in getting the best out of something that has been deliberately engineered in a counter-intuitive way. Every time you have a win it's like you can give yourself an elephant stamp because you've 'Beaten the System'. I know it's puerile but I still enjoy doing that
Pete
Long time since the above quote was posted but since the author is definitely around I have to ask why the you say that the speed of sound is a constant when it is heavily dependant on temperature and the medium it flows through.
That and reflective acoustics, return waves tend recognise the first reflective wall they come to which may or may not be the intended baffling.
The pretzel is such a chicane that it wouldn't surprise me that it acts as a tuned length and keeping more heat trapped into the header system and less at the muffler end.
Having tight and varied curves as a reflector instead of the classic perpendicular wall broadens the range at which the signal reflects and in turn broadens the rpm band in which it works.
To me the header/pretzel is a sacred combined system designed for broad power and the muffler keeps that system pressurised and heated to adjust the speed of sound for the reflected wave.
Take away the standard muffler with its restrictions and you lessen heat in the header/pretzel system and slow the speed of sound.
Just my thoughts and look forward to others.
Chris.
Flat tappet inspection on early 8V's
in Newer models
Posted
Should have had an eagle screeching in the background and drone cameras flying into the work shop ... Oh, wait .... that might infringe copyright too.
Best to stick with Colin the rubber chicken and voice over some clucks at points of interest.
Chris.