Variable Valve Timing

[VernDiesel]

Recent sneak peak article shows a 121ci CVO with VVT coming. Whats the VVT going to bring to the hot rodding scene. Aftermarket cam grinders going to have to go to work? Think we will be able to convert existing M8s to VVT?

[Hossamania]

Convert existing highly doubtful.

[rigidthumper]

I wonder if they grind the VVT cams to make good power, and the VVT tech simply advances the cams @ low RPM to pass emissions, or if the grind the cams to pass emissions, then retard them at high RPM to make good power?

[turboprop]

Variable Valve Timing has been discussed in professional engine building circles for many years. VVT in essence replaces the camshaft(s) in an engine with something else that can either be changed on the fly or programmed, solenoids that are controlled by a processor of some sort.

On an open platform, an engine developer could could alter every aspect of valve opening and closing that same way a tuner is currently able to control fuel injectors and spark timing. Leveraging this technology against the current harley engine  would be a quantum leap forward. Seriously doubt it will happen anytime soon to a Harley engine.

[hrdtail78]

I wonder if they grind the VVT cams to make good power, and the VVT tech simply advances the cams @ low RPM to pass emissions, or if the grind the cams to pass emissions, then retard them at high RPM to make good power?

Some allow intake and exhaust to be controlled independently.  Control over overlap as well.

Harley seemed to figure out electronic control for the 1250 Revolution Max engine. 

[m1marty]

Variable Valve Timing has been discussed in professional engine building circles for many years. VVT in essence replaces the camshaft(s) in an engine with something else that can either be changed on the fly or programmed, solenoids that are controlled by a processor of some sort.

On an open platform, an engine developer could could alter every aspect of valve opening and closing that same way a tuner is currently able to control fuel injectors and spark timing. Leveraging this technology against the current harley engine  would be a quantum leap forward. Seriously doubt it will happen anytime soon to a Harley engine.

The VVT tables are surprisingly similar to some tables we are already used to (in some car applications) There's definitely a lot of variables involved with messing with them.

[VernDiesel]

"Leveraging this technology against the current Harley engine would be a quantum leap forward."

"Harley seemed to figure out electronic control for the 1250 Revolution Max engine."

Yep 76ci putting out 150 HP. True its also liquid cooled and 60 degrees just saying. Thats basically 2 HP per cubic inch. The M8 would never see that but this could become a substantial improvement for the M8.

It could keep the mid range of a big cam add to the top range with safety and retain more low range torque with smoother safer more controlled operation. Thats what it brought to especially small naturally aspirated 3 & 4 cylinder car engines. At least thats my thoughts. And my thoughts have been know to buy a free cup of coffee.

[Hossamania]

Dual stage turbos would be fun! Mix that in with VVT, now you're talking!

[Ohio HD]

The video below shows how VVT programming was performed in an automotive application, but I would think most of the principals would be the same for any motor. In this case they have dual VVT which is separate VVT controls for the intake cam and the exhaust cam. They also are employing an aftermarket ECU.

I like this guy at High Performance Academy, he goes in to nice details with his explanations, as well as good visual explanation.

[cheech]

Variable Valve Timing has been discussed in professional engine building circles for many years. VVT in essence replaces the camshaft(s) in an engine with something else that can either be changed on the fly or programmed, solenoids that are controlled by a processor of some sort.

On an open platform, an engine developer could could alter every aspect of valve opening and closing that same way a tuner is currently able to control fuel injectors and spark timing. Leveraging this technology against the current harley engine  would be a quantum leap forward. Seriously doubt it will happen anytime soon to a Harley engine.

This should be clarified.

Variable Valve Timing (VVT) is pretty much employed today in I'd say nearly all production vehicles with ICE and camshafts excluding diesels perhaps. Probably some metric bikes.
Either through cam phasers or in Hondas VTEC system they have alternate cam lobes and rockers and alter cam duration and lift.
Or situations like some Dodge Viper engines where they had cams in cams, where they could alter the exhaust timing separate from the intake on "one" cam.

What you describe are camless, AKA free valve engines.
Valves actuated by other means, hydraulic, pneumatic, servo motors, etc.

So Harley introducing a free valve engine? Quantum leap yes.

Harley introducing VVT by means of a cam phaser on the cam? Probably already done either on paper or in prototypes at the powertrain engineering dept. in Milwaukee.

[Ohio HD]

Harley introducing VVT by means of a cam phaser on the cam? Probably already done either on paper or in prototypes at the powertrain engineering dept. in Milwaukee.

We know they have at minimum the concept and a design. Their US patent is already approved. More than likely there are R&D motors already being tested.

https://harleytechtalk.com/htt/index.php/topic,66.msg1434007.html#msg1434007

[SP33DY]

I saw a press release today. They are offering VVT on CVO 121's.

VVT

[Deye76]

I saw a press release today. They are offering VVT on CVO 121's.

VVT

There goes the cam of the month threads.

[Hossamania]

I saw a press release today. They are offering VVT on CVO 121's.

VVT

Not an official release from HD, but strong evidence.

[hulkss]

Proper VVT, like the H-D Pan America, has independent advance and retard for intake and exhaust. The system pictured (guessing here) appears to advance and retard a single 4 lobe camshaft.

[Ohio HD]

Proper is based on the motor design and bring a VVT control to an existing motor design. Much like American V6 and V8 motors that use a single cam. They have a proper VVT for that motor design. One style for each motor design.

[hulkss]

The H-D patent shows an engine with exhaust push rods on one side and intake push rods on the other. There is a cam phaser on each side.

[Ohio HD]

But what's not known is will these drawing be the final used style of VVT. They may have just given a concept to the patent office to get a finalized patent number. What they end up using on the M8 motors may not even look like this unit. Otherwise it's all new motor cases, probably inner primary design, all new valve train components. A new deign in heads to allow seriated valve operations between intake and exhaust valves, and push rods on both sides of the heads. I went through the US patent applications for HD when I linked that data. There are none that offer supporting part changes.

Until they show a new model with VVT, we have no idea what that will look like and how the design will function. 

[turboprop]

Might as well be discussing space, religion or politics.

[To The Max]

I wonder if they grind the VVT cams to make good power, and the VVT tech simply advances the cams @ low RPM to pass emissions, or if the grind the cams to pass emissions, then retard them at high RPM to make good power?

I think this version will only control a single cam with a oil pressure controled phaser and my guess is advance, we will see

[hrdtail78]

The video below shows how VVT programming was performed in an automotive application, but I would think most of the principals would be the same for any motor. In this case they have dual VVT which is separate VVT controls for the intake cam and the exhaust cam. They also are employing an aftermarket ECU.

I like this guy at High Performance Academy, he goes in to nice details with his explanations, as well as good visual explanation.

Good resource.  Here is another: https://www.evansperformanceacademy.com/

[wfolarry]

I have VVT on my car. It shifts at 5000 rpm. When it does it sounds like the secondaries on a carb opening up. Pulls hard to redline [7000]. If Harley does something similar a lot of people are going to be happy with a stock bike.

[tolobill]

Cam phasers, we've seen how they work on Fords 5.4, which is discontinued they need maintenance.

[To The Max]

Cam phasers, we've seen how they work on Fords 5.4, which is discontinued they need maintenance.

Most dont cause a problem these days and nearly all use them . regular oil changes is a must.

[Hossamania]

I'm wondering if the 20w50 oil is going to be too thick for the phasers. As mentioned, clean oil is a must. Most cars use with VVT use 5w20 or lighter.

[FLSTFIDave]

Cam phasers, we've seen how they work on Fords 5.4, which is discontinued they need maintenance.

Most dont cause a problem these days and nearly all use them . regular oil changes is a must.

Still an issue with Ford twin turbo V-6 motors, the 2.7, the 3.5 and now the 3.0.  Some have cam phaser failures.  I have had the 3.5 and no the 3.0.  So far lucky, no failure but I know people who have had failures.

[IronButt70]

I'm wondering if the 20w50 oil is going to be too thick for the phasers. As mentioned, clean oil is a must. Most cars use with VVT use 5w20 or lighter.

Don't know if there is any truth to this but I was told the 20w oil is needed for the cars to pass start up emission standards. How can any engine operating in hot climates survive long term with 20w oil? It's like water. 

[Hossamania]

My Ford van uses 0w20, V8 motor, in all conditions.

[Ohio HD]

This thread is going way off track. Thanks for contributing.

It'll be interesting to see what if anything Harley Davidson does with the M8 platform and VVT.

[Hilly13]

Well they did it, anyone got an insight as to how it operates as yet?

[FLSTFIDave]

I too am very curious as to how Harley is doing the Variable Valve Timing.  Engine specs show it has a nice torque increase.

[HogMike]

I too am very curious as to how Harley is doing the Variable Valve Timing.  Engine specs show it has a nice torque increase.

Dave: HP and TQ are still below what we have on OUR 2019's!
LOL
Price increase is just a "little" bit more than last year.

Weight is a little bit lighter.

 The VVT is a modified version of the HD patent drawings.

I still want to see the transmission! Some changes there.

[FLSTFIDave]

I too am very curious as to how Harley is doing the Variable Valve Timing.  Engine specs show it has a nice torque increase.

Dave: HP and TQ are still below what we have on OUR 2019's!
LOL
Price increase is just a "little" bit more than last year.

Weight is a little bit lighter.

 The VVT is a modified version of the HD patent drawings.

I still want to see the transmission! Some changes there.

I have seen a couple videos, no one talks about the transmission changes.

True hp is way less and torq is less then in our 2019's.  I have 62K on mine.

[VernDiesel]

What I saw was the 2023 1/2 CVO
117ci    102 HP 125 TQ 10.2-1
121ciVVT 115 HP 139 TQ 11.4-1

for chits n giggles my non emissions compliant F35A cammed
114ci    132 whp 130 TQ 11.5-1

[Propflux01]

Of course it will be less, they are emissions compliant, where our 'upgraded' bikes are not. Moving from 117ci 102 HP 125 TQ 10.2-1 to 121ciVVT 115 HP 139 TQ 11.4-1, a 4 CI difference isn't that much. From the higher Hp, it would appear the VVT carries out a bit further, or is flatter across the line.
     

[Dan89flstc]

VVT in essence replaces the camshaft(s)   

VVT does not necessarily replace the camshaft, this technology has been used in the automobile industry for decades.

[To The Max]

From what i have seen this version has a single cam a phaser and they simply advance the cam timing at pre-determined rpm . and i think the cam guys are already on to it.

[Hilly13]

Really interested to see how it works mechanically and what the software looks like.

[FSG]

[Hilly13]

You are very good at digging stuff up FSG 

[FLSTFIDave]

Very interesting picture you found FSG.  One dealer was saying 20 degrees the cam can be shifted.


Can't wait to ride one

[FSG]

[Hilly13]

Pretty cool, in twin cam speak 40° would be like a 255 off idle to a 267 at full revs with everything in between, I'm sure the grind can be improved apon but for many there will probably be no need, I do wonder how they have set up the software, with that compression and intake close variability managing timing could be tricky, surely there must be more to it than advanced knock sensing.

[hrdtail78]

Is the 40 degrees cam or crank?

[cheech]

Is the 40 degrees cam or crank?

Post 41 

[hrdtail78]

Is the 40 degrees cam or crank?

Post 41 

Got it, thanks.

[Propflux01]

Very interesting! Will stick out a bit it seems. Gonna put a hurt on cam companies I bet.

[Hilly13]

Is the 40 degrees cam or crank?

Post 41 

Got it, thanks.

wish I could pop around for beer to chew this over, be my shout obviously

[VernDiesel]

"Going to put a hurt on cam companies I bet"  I'm hoping just the opposite.  That cam companies can take advantage of the this. Allowing us to use more cam so to speak while retaining low end torque, manners, & control as well as retain most of the longevity of a smaller cam. The new Revolution motor with the benefits of VVT (plus more) is pretty phenomenal. 2 HP per cubic inch. The cams used in the Pan American for its displacement would be very radical & race like without VVT. Can it take the m8 a giant leap. No but a good step better IMO. Lol couldn't you also make it have a pretty wild idle.     

[FloridaJim5]

"Going to put a hurt on cam companies I bet"  I'm hoping just the opposite.  That cam companies can take advantage of the this. Allowing us to use more cam so to speak while retaining low end torque, manners, & control as well as retain most of the longevity of a smaller cam. The new Revolution motor with the benefits of VVT (plus more) is pretty phenomenal. 2 HP per cubic inch. The cams used in the Pan American for its displacement would be very radical & race like without VVT. Can it take the m8 a giant leap. No but a good step better IMO. Lol couldn't you also make it have a pretty wild idle.     

Great Idea!  Instead of a smooth idle, maybe there could be a "Race Idle" or "Sounds like an Evo Idle".  I'm not really joking.....that would be awesome.   

[Ohio HD]

Generally cams that have higher duration and more overlap is what gives a choppy idle. VVT has no effect on those values of the cam as they're ground into the profile of the cam.

VVT moves the entire cam either advanced or retarded, which moves the area in the RPM where the power band is.

[VernDiesel]

"Moves the area in the rpm where the power band is"  Appreciate that, read it several times thought about it  but still trying to fully wrap my head around it. Never been a cam guru for sure.

I've read about some of the benefits VVT brings to the Mfgr with respects to emissions even performance for an OEM bike. Beyond that what do you think or hope VVT can bring to the m8 performance aftermarket?

[Hilly13]

Aftermarket tend to be less EPA focused 

[Ohio HD]

This is an example of changing cam timing with VVT. This is a CVO 117 cam, I don't know the 121 cam specs. The light blue cells are what changes when the cam is advanced or retarded with the VVT unit.


You cannot see attachments on this board.

[FSG]

HD VIDEO  is in the Section

[hrdtail78]

Sounds great.  With same plate.  Retrograding back to normal cam operation will be easy for the aftermarket crowd.  Which I think will be an option until the tuning catches up.

[FSG]

[FSG]

and from the same vid you can bet that is the gear indicator driver

[Ohio HD]

I can see it now, new S&S cam phaser with up to 30° timing changes at the cam, with their cams. I assume DJ and TTS would need to be on board with it too.   

[Ohio HD]

I'd say watch for this from S&S and or Feuling.

When performing a performance upgrade on Dodge Hemi's, they drop a limiter in the cam phaser to stop the VVT from working. Then they run a conventional camshaft for performance use.

I suspect that'll be something that HD aftermarket offers before long.

[Hilly13]

HD VIDEO  is in the Section

What section would this be FSG?

[Coyote]

HD VIDEO  is in the Section

What section would this be FSG?

https://harleytechtalk.com/htt/index.php/board,21.0.html

[cheech]

and from the same vid you can bet that is the gear indicator driver

They finally have the Parts manual on the SIP and it confirms.
Been looking for it occasionally to confirm.

[FSG]

 

[Propflux01]

I went to a dealer in Belgium and saw a CVO 121 with the VVT. It doesn't stick out as far as I thought it would, but the floorboards are definitely narrower.

[FLSTFIDave]

I have seen the Road Glide in Dark Platinum, looks good.  I have seen the Street Glide in Whiskey Neat, looks great.  Whiskey neat is by far the best color in my opinion.  Sounds a little different the a regular M8

The torque curve is very flat as one would expect. You can see the advantage of VVT in the curve in my opinion.

[Hilly13]

Decent for a stock bike aye 👍

[Eccool]

Does VVT have anything to do with the smoothness of the engine?  Every ride review video that I've seen, the reviewer is practically raving about how smooth it is.  Jerry Palladino even compared it to a six cylinder Gold Wing.  Thanks!

[To The Max]

Going by what i have seen in the automotive industry yes . VVT gives you a more efficient engine over a broader range .

[hrdtail78]

Does VVT have anything to do with the smoothness of the engine?  Every ride review video that I've seen, the reviewer is practically raving about how smooth it is.  Jerry Palladino even compared it to a six cylinder Gold Wing.  Thanks!

I would think that would have more to do with engine bore/ stroke and counter balancer.  Not saying that an efficient engine in a good state of tune doesn't contribute.