Timing Gear set

[docc]

4 hours ago, ScuRoo said:

Harmonic vibrations...

Had no visual comprehension on how an engine created these - I guess I just kinda assumed it was produced by the combustion bangs💥

...turns out it’s more related to the stroke travel speed differentials!

Amazing F1 in-depth explanation in 1st half of this vid (the 2nd half is pure tech-sex!) just learned me!

But... it’s in the noggin’ now! 

 

Holy cow! That is so geeky! I watched it beginning to end, paused, replayed parts, and took notes . . .

Brian Garvey's explanation of secondary vibration (and the Formula 1 solutions) is stunningly clear. Even I get it (now)! When he put up the image of the timing gears from the Cosworth TJV10 (24:05), I grabbed a screen shot to remind myself part of why I would like Joe Caruso's gear set in my Sport. Elegance!

(At 16:04, Garvey says, "You never turn an engine backwards."  Why is that? Any engine?)

[Lucky Phil]

7 hours ago, ScuRoo said:

Harmonic vibrations...

Had no visual comprehension on how an engine created these - I guess I just kinda assumed it was produced by the combustion bangs💥

...turns out it’s more related to the stroke travel speed differentials!

Amazing F1 in-depth explanation in 1st half of this vid (the 2nd half is pure tech-sex!) just learned me!

But... it’s in the noggin’ now! 

 

Yes thats what creates secondary vibrations. The piston travel in the first and last 90 deg of crank rotation is greater than the second and 3rd 90 degs.

Ciao

 

[docc]

59 minutes ago, Lucky Phil said:

Yes thats what creates secondary vibrations. The piston travel in the first and last 90 deg of crank rotation is greater than the second and 3rd 90 degs.

Ciao

 

That is such a wild, non-inutive concept. I could never get my mind wrapped around that. Garvey's Teaching Jig is fabulous. Such a good teacher, as well, IMO.

[Lucky Phil]

1 hour ago, docc said:

That is such a wild, non-inutive concept. I could never get my mind wrapped around that. Garvey's Teaching Jig is fabulous. Such a good teacher, as well, IMO.

It's all geometry docc. That's why there's a practical limit to the capacity of a traditional flat plane crank 4 cylinder engine before you need balance shafts. It's generally around the 2.0 litre mark give or take. Doesn't mean you can't have a 2.5 4 cylinder engine without a pair of balance shafts turning at 2X engine speeds but the secondaries get a bit much for a DD.

Some engines don't need the cam drive dampers such as VFR Hondas and MV Agustas and the Guzzi.

 

Ciao 

[docc]

12 minutes ago, Lucky Phil said:

It's all geometry docc. That's why there's a practical limit to the capacity of a traditional flat plane crank 4 cylinder engine before you need balance shafts. It's generally around the 2.0 litre mark give or take. Doesn't mean you can't have a 2.5 4 cylinder engine without a pair of balance shafts turning at 2X engine speeds but the secondaries get a bit much for a DD.

Some engines don't need the cam drive dampers such as VFR Hondas and MV Agustas and the Guzzi.

 

Ciao 

That cam drive Garvey disassembled is absolutely incredible. It looked like two different size sprockets pinned together like a reduction drive. But noooooooooo! Too cool. Thanks, again, for the vid @ScuRoo !

[ScuRoo]

2 hours ago, Lucky Phil said:

Some engines don't need the cam drive dampers such as VFR Hondas and MV Agustas and the Guzzi.

That’s some surprisingly illustrious company there that Guzzi isn’t usually compared with tech wise...

 

“Whatcha talkin’ bout Willis?” 🧐

Can you expand on that a bit more please  LP?

 

[Scud]

Great video. 

My LeMans V has Caruso's gears (installed by previous owner). I noticed an improvement on my Scura when I went to the valtek chain tensioner from the stock bit. I put my name on the list a while back for a set of Gears for the Scura. 

[Lucky Phil]

2 hours ago, ScuRoo said:

That’s some surprisingly illustrious company there that Guzzi isn’t usually compared with tech wise...

 

“Whatcha talkin’ bout Willis?” 🧐

Can you expand on that a bit more please  LP?

 

Well non of those mentioned have harmonic dampers and seem to work just fine. Probably because they don't have a massive long train of gears from the crank to the cams, not sure. 

Ciao

[ScuRoo]

3 hours ago, Scud said:

I noticed an improvement on my Scura when I went to the valtek chain tensioner from the stock bit. I put my name on the list a while back for a set of Gears for the Scura.

Wow! Scud that’s excellent  - you’ll be able to subjectively compare your findings each step from

OEM tensioner

—>  Valtek improve 

—> Gears impact
 

That’s a great opportunity for a step by step comparison if you wish.

In the interests of backyard garage ‘scientific investigations’ maybe consider logging your findings on the Valtek improvement more comprehensively here prior to eventual gear install - so your opinions on the OEM —> Valtek can always be future viewed as unadulterated in relation to your eventual gear findings.

 

Now with respect to the F1 vid I’ve been contemplating the relative effects of TDC -> mid-stroke = fast

Mid-stroke -> BDC = slow

Presumably with the camshaft turning at half speed to crank speed there’s somewhat of a ‘muffling’ or ‘dampening’ effect to the cam just by the very nature of effectively turning at half the crank speed. Would that be true?

Also, as gears provide direct connection the timing is immovably more accurate, right?

Now, with chains I’m presuming the chain ‘absorbs’ at minimum the mathematical difference between the TDC->mid-stroke fast & the mid-stroke->BDC slow?

I hope I’ve explained that adequately... so far!

So... with the high rate of varying our speeds up & down accelerating & decelerating chains effect the accuracy of the ignition event by an amount somewhere along & within the range of the TDC to BDC speed differentials?

Whew! #@$&@#@ if I can collect my thoughts & try to relate that again...

Am I on the right track here? I’m sure there’s more to it but in general terms...

Trying to visualise what those actual conceptual differences are between chain  & gears.

[Lucky Phil]

4 hours ago, ScuRoo said:

Wow! Scud that’s excellent  - you’ll be able to subjectively compare your findings each step from

OEM tensioner

—>  Valtek improve 

—> Gears impact
 

That’s a great opportunity for a step by step comparison if you wish.

In the interests of backyard garage ‘scientific investigations’ maybe consider logging your findings on the Valtek improvement more comprehensively here prior to eventual gear install - so your opinions on the OEM —> Valtek can always be future viewed as unadulterated in relation to your eventual gear findings.

 

Now with respect to the F1 vid I’ve been contemplating the relative effects of TDC -> mid-stroke = fast

Mid-stroke -> BDC = slow

Presumably with the camshaft turning at half speed to crank speed there’s somewhat of a ‘muffling’ or ‘dampening’ effect to the cam just by the very nature of effectively turning at half the crank speed. Would that be true?

Also, as gears provide direct connection the timing is immovably more accurate, right?

Now, with chains I’m presuming the chain ‘absorbs’ at minimum the mathematical difference between the TDC->mid-stroke fast & the mid-stroke->BDC slow?

I hope I’ve explained that adequately... so far!

So... with the high rate of varying our speeds up & down accelerating & decelerating chains effect the accuracy of the ignition event by an amount somewhere along & within the range of the TDC to BDC speed differentials?

Whew! #@$&@#@ if I can collect my thoughts & try to relate that again...

Am I on the right track here? I’m sure there’s more to it but in general terms...

Trying to visualise what those actual conceptual differences are between chain  & gears.

With respect to the piston motion the crank isn't accelerating/decelerating it's the piston that is for a constant crank speed not the other way around. 

At low engine speeds like idle the crank in a 90 deg V twin with have varying acceleration during the 2 cylinders full cycle but at 3000 rpm of so it will be on no consequence to the cam drive chain.

Ciao

 

[ScuRoo]

Great stuff fella’s! Enjoyed researching this topic.

This gear opportunity has been fascinating in gaining a greater understanding of ignition camshaft drives - there’s a helluva lot more involved I had no real appreciation for to such a granular degree.
Learning new understandings on concepts which seem, as Docc puts it, “non-intuitive” can be quite humbling!

Like for example, I’ll never be quite so unthinking of my RPM’s as just some simplistic spinning speed ever again!

“Periodic combustion impulses result in rotational speed fluctuations of the crankshaft. Ignition and combustion within a cylinder cause a rapid rise in gas pressure and an angular acceleration of the crankshaft. Gas compression in the next cylinder causes immediate deceleration. Torque pulsations result in crankshaft torsional vibrations which reach the camshaft(s) and auxiliaries via belt or chain drives.”

https://www.rotec-munich.de/wp-content/uploads/2019/12/torsional-vibration-measurement.pdf

As usual, Mr Cameron always offers a compelling motorcycling perspective.

https://www.cycleworld.com/story/bikes/about-motorcycle-engine-cam-drive-systems/

It’s Christmas Eve & the missus has got some concert playing on the box - so Merry Christmas!

[docc]

On 12/10/2021 at 8:12 AM, docc said:

I need to learn to be be more patient….

Just a couple days after I posted above, I hear from Joe! He says the job has made it to the shop floor. Accounting for the heat treating, completion is expected  February. Joe is also making the relieved cam flange available.

Great excitement to get an email form "Giuseppe Caruso" saying that the gear manufacturer is hoping to deliver our V11 gear sets at the end of February. I am not sure if these are all built-to-order and spoken for, or if there are any additional sets available. Reach out to Joe Caruso if interested . . .

joe.caruso@ntlworld.com

 

[docc]

Very excited to hear from Joe Caruso that he is taking delivery of the current run of V11 gearsets this weekend. He tells me all of the sets are spoken for and intends to make another run of V11 gears "later in the year."

I asked him to advise me if any of the current run cancels and I will post them here.

[docc]

On 7/2/2021 at 2:39 PM, Pressureangle said:

Mine were 670 UK pounds in February, shipping in. I'd expect that with materials skyrocketing, they'll be more today.
E.

Joe has the current batch of V11 gears now.

675£, so no big change.  Today, that looked like about $890 US.

I also asked for the bronze cam flange, so my order comes to 765£ (~$1,008 US)

[docc]

On 7/19/2021 at 9:14 PM, docc said:

Valid point to see the cost relative to the factory parts. I could not find the cost of the Valtek tensioner to include. This makes the extra few hundred dollars seem absolutely sane. I knew I could count on my fellow inmates on the ward.

GU01054500  Timing System Gear              $298.77

GU14072001   Pinion                                        139.96

GU28058060  Chain                                          70.35

GU30057810  Chain Tensioner                         68.76

GU30147700  Oil Pump Gear                           138.18

                                                                                     $686.02 USD

 

 

LuckyPhil's reminder to consider the cost of replacing the factory parts really puts this in perspective. Especially factoring in shipping costs from the two or three suppliers to get those Guzzi parts . . .