HarleyTechTalk

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?

Convert existing highly doubtful.

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?

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.

Quote from: rigidthumper on March 19, 2023, 04:28:51 PMI 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. 

Quote from: turboprop on March 20, 2023, 02:03:46 PMVariable 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.

"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.

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

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.

Quote from: turboprop on March 20, 2023, 02:03:46 PMVariable 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.

Quote from: cheech on March 22, 2023, 07:53:23 AMHarley 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

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

VVT

Quote from: SP33DY on March 22, 2023, 02:56:52 PMI saw a press release today. They are offering VVT on CVO 121's.

VVT

There goes the cam of the month threads.

Quote from: SP33DY on March 22, 2023, 02:56:52 PMI saw a press release today. They are offering VVT on CVO 121's.

VVT

Not an official release from HD, but strong evidence.

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.

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.

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.

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. 

Might as well be discussing space, religion or politics.

Quote from: rigidthumper on March 19, 2023, 04:28:51 PMI 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

Quote from: Ohio HD on March 21, 2023, 02:46:16 PMThe 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/

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.

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

Quote from: tolobill on March 29, 2023, 05:51:45 AMCam 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.

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.