Jump to content
IGNORED

Timing Gear set


Ray Sandoz
 Share

Recommended Posts

On 7/19/2021 at 9:53 PM, Lucky Phil said:

Never cool, too much "look at me" going on there. Better the warm inner knowledge you are a man of quality, distinction and elegance and have no need to descend into tawdry displays of engineering opulence. The nod and a wink is all thats required.

Ciao    

I had no idea when I signed up that I would be conversing in such rarified air.

  • Haha 4
Link to comment
Share on other sites

Back in the day :oldgit: I bought a new Centauro. Like most at that time, it barely ran except at WFO.

I made it my life's work :D to sort it, and it took 2 years of trying everything on the COG at the time. I got it running beautifully.. all the little glitches they came with *except* the very occasional miss around 3400 or so. The final solution for that was the brass temp sensor holder to replace the plastic piece.

  • Like 3
Link to comment
Share on other sites

1 hour ago, Chuck said:

Back in the day :oldgit: I bought a new Centauro. Like most at that time, it barely ran except at WFO.

I made it my life's work :D to sort it, and it took 2 years of trying everything on the COG at the time. I got it running beautifully.. all the little glitches they came with *except* the very occasional miss around 3400 or so. The final solution for that was the brass temp sensor holder to replace the plastic piece.


Interesting. I tried that, also "back in the day", only discovering later that my Sport responded markedly better to the exact opposite (low mass Engine Temperature Sensor Holder modification). Differ'nt animules, we all is.

 

  • Thanks 1
Link to comment
Share on other sites

9 hours ago, GuzziMoto said:

I am not saying anything about what causes the hiccup.

I am just pointing out that throttle position, engine load, and whether you are accelerating or decelerating have little to do with cam chain tension. The cam drive is not in that transfer of power path.

The Cam chain is actually in a power transmission path, the path to transmit force or power if you like from the crank to the load, which in this case is the valve train. That load varies with rpm. The tension on the cam chain is related to the load it's being asked to transmit. More rpm requires more energy to drive the valve train so the load on the cam chain/drive is greater. Also F=ma so Force = mass x acceleration so the valve train and cam drive all have mass. The faster you accelerate that mass the more force is required and the cam drive needs to transmit. So it follows that the more rpm the engine is turning and the rate at which it gets there increases the load or force on the cam chain. At steady state throttle opening and engine load the force on the cam drive is constant. 

Ciao

Link to comment
Share on other sites

1 hour ago, Chuck said:

Back in the day :oldgit: I bought a new Centauro. Like most at that time, it barely ran except at WFO.

I made it my life's work :D to sort it, and it took 2 years of trying everything on the COG at the time. I got it running beautifully.. all the little glitches they came with *except* the very occasional miss around 3400 or so. The final solution for that was the brass temp sensor holder to replace the plastic piece.

When I rebuilt the Centy engine Chuck I had the option of the plastic or the brass temp sensor holder, I went with the brass. I can't remember which was the later version but read somewhere recently it was the plastic which wouldn't make sense to me as i would always go with the later updated part when I have a choice. Anyway part of my logic at the time I do remember was the plastic holder seemed to have the sensor bulb suspended in mid air within the holder which didn't seem like a good idea with regards to responsiveness so I went with the brass holder and also applied some high temp grease inside to surround the sensor bulb and transmit heat from the holder to the bulb more directly. Did it work? not sure as I have no comparative data but it runs nicely :huh2: 

Ciao

  • Like 4
Link to comment
Share on other sites

  • 1 month later...
1 hour ago, ScuRoo said:

Not thinking of buying gears ⚙️

...but better a Guzzi than it’s kissin’ cousin 🤤

61AF7163-FCF3-4FF8-93FF-CAC4DC7D3B87.jpeg

Hmm, hunting tooth non integer gearset to the cam? I wonder.

Ciao

Link to comment
Share on other sites

I love the idea that a beautiful design like that sprung from an individual engineering mind. A pair of hands at a drawing board guided by an individual engineeringly brilliant mind created that out of nothing. To me it's creative art and a thing of beauty. 

Mind you I'm on my second glass of red wine and in a few hours and I might just see it as a heap of old useless shit.

Ciao

  • Like 3
Link to comment
Share on other sites

One can only imagine the days, weeks, months drafting and erasing, recalculating with a "stone-age" slide rule. Actually, it would be considered an amazingly short design period these days. In Parilla's case, the street bikes used but a single lobe of a single cam to operate both valves. IIRC, the valves were set at 110º, which was then considered to be the ideal lobe separation in a normal, two-lobe cam. As wide as they were, the valve angle worked with the deep, aircraft-type combustion chambers of the day. High cam with short pushrods and rockers. Sounds familiar...

PARILLA%20250.png

  • Thanks 1
Link to comment
Share on other sites

  • 5 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...