INSIDE LOOK / NEW 121ci VVT M8 Engine / TEAR DOWN

Рет қаралды 30,489

Күн бұрын

VVT being the well known change to the new 121ci from Harley-Davidson, but what else is new?
Well a new 4-5/8" Stroke Flywheel, new piston, new cylinder heads, new intake manifold & throttlebody, new larger fuel injectors, new cylinders, new breather system, new lighter counter balancer, new shift drum design & more!!!!
I was down in Sydney for some updated training on the Revolution-Max engine for the Pan-America & Sportster S line up however I took full advantage of being able to fully tear down & inspect the new 121ci M8 engine while I was there.
I am really excited for what the future holds for this engine! Tuning will be an a great learning curve & I can't wait to get involved with that.
I was able to cc the combustion chamber which came in at 86cc. That is 2cc less than the original M8 engine at 88cc.
I was pushed for time & couldn't get to measuring the complete specs of the cam. All I focused on was the intake valve (rear cylinder) & total lift (rear cylinder).
The cam specs I was able to measure with no oil pressure in the cam phaser (unofficially) were ;
.519" Lift
Intake valve opens 7 BTDC
Intake valve closes 2 ABDC
It must be noted that when we were doing the degree wheel inspections, that the cam phaser had no oil pressure so I can not be sure exactly where 0 is on the phaser as some of the valve spring seat pressure may have been advancing or retarding the cam when I was taking the measurements.
Once the official specs are published by H-D I will post them.

Пікірлер: 122

@CraigHarleyglideout 11 ай бұрын

Can't wait to see cam upgrades

@MasterTechMiller 11 ай бұрын

Me either

@GoGoggansGo 7 ай бұрын

@@MasterTechMillerit’ll be fairly limited for cam upgrades unless they plan on locking out the VCT or limiting it them for movement. Either way when custom tuning comes out and you can take the time to work with it. The gains especially under the curve will be wild, it’s really shocking nobody has gotten on top of the rev max engines for tuning. I’ve yet to see any one take the platform seriously

@TheCuttz1984 11 ай бұрын

This is awesome. Head design looks great.

@six..... 11 ай бұрын

Just feel in the saddle the vvt is a rocket ship compared to non vvt m8s

@stevenmederi4266 4 ай бұрын

Hey Dr Miller , nice to hear from you again , a bit like going back to med. school 😃😃😃

@Fever_Rides 11 ай бұрын

Great overview, Thanks!!

@MasterTechMiller 11 ай бұрын

Thanks for watching

@brandywell44 11 ай бұрын

I always remember and liked the Kawasaki VN2000 motor and the bike and I bought a service manual for them. One of the service items was checking for twist in the conrods which looked very slender for the size of engine. These Harley Davidson rods look similarly slender and just don't look strong enough and slipper pistons always amaze me that they don't twist in their bores. All the lightening work is likely matched with better metalurgy but things have to look right to me too.

@Jack-kt8bs 8 ай бұрын

My 121 reminds me so much of my 1098 DUC

@thexnewyorker7284 6 ай бұрын

Nice vid . Just picked up a new CVO , its fast 😊

@MasterTechMiller 5 ай бұрын

Nice! Enjoy it!

@sid5156 8 күн бұрын

It's been 6 months. 1st are you still loving it? 2nd Any issues?

@ChrisJones-l 11 ай бұрын

Great info as usual, let’s hope they incorporate the vvt, heads etc into all M8s eventually. Given the cubes, compression, heads, intake size etc 150hp with flat torque curve shouldn’t be too difficult.

@chazzcapone. 11 ай бұрын

Amazing technology in the new CVO engine overall. Thanks for the insights 👍

@victorgonza4528 11 ай бұрын

Nice first video I see of the HD vvt system .

@MasterTechMiller 11 ай бұрын

Thanks for watching

@curtisg5117 11 ай бұрын

Great video, glad you took the time to post it up. Hope the paint does not come off the springs. I have 3000 miles no major issues so far. I changed the air filter and put khrome werks slip-ons with performance baffles in and se tuner she moves. If you find out how to change speed limiter that would be great! lol

@GMAN0444 6 ай бұрын

That was my concern as well with the paint on those springs. Last thing anyone needs is a paint chip clogging up a oil port

@KennethSmith-k7l 23 күн бұрын

Mine have no paint but mine are also cnc ported that come in s/e kit

@302BAGGER 11 ай бұрын

Thanks mate been dying to know, need a video of what’s compatible to our m8’s!!

@roderernst9990 10 ай бұрын

Love the balancers ,want some! ha ha

@MasterTechMiller 10 ай бұрын

Pretty cool looking right

@3nuts-502 11 ай бұрын

Would be interesting to see one with trask turbo!! Looks like it’s built for boost

@MickOTooleroadglide 11 ай бұрын

Thanks for sharing Tommy that’s amazing insight on the new 121

@MasterTechMiller 11 ай бұрын

Thanks for watching

@hunter_mf 11 ай бұрын

Interesting thanks for sharing the video !

@MasterTechMiller 11 ай бұрын

Thanks for watching

@johngarland1641 11 ай бұрын

Interested to see how these heads flow compared to the older M8 and if they are backwards compatible to make a higher compressions better breathing M8 with the revised ports,chamber etc without the VVT.

@MasterTechMiller 11 ай бұрын

From initial observation it looks like they will bolt straight on. The engine temp sensor has been relocated to the front cylinder on the new M8 VVT Heads & so have the knock sensors. That shouldn't prove to be a difficult hurdle to over come so I'm hoping they will be able to be a direct fitment

@mickrose6450 11 ай бұрын

Love ya work🍻👍

@MasterTechMiller 11 ай бұрын

Thanks for watching

@huibertdegraaf9622 11 ай бұрын

Finally they vent the head through the transmission cover instead if spitting it into the intake or out for that matter. Seen another video where the white paint was coming off the springs into the engine. Like who puts painted springs in a engine. ? Harley I guess

@kennethwise7108 11 ай бұрын

I learned that HD "King of the baggers" won't be running this VVT motor.

@MasterTechMiller 10 ай бұрын

There are a few things to consider why. 1. Lack of tuning for the VVT Engine 2. The large amount of tuning available for the Original M8 Platform. 3. Teams can use the largest displacement engine available from the OEM (135ci) 4. A tuned up 135ci engine will make more power than a non tuned 121 VVT engine.

@2trdmustanggtfordf1hdsgsfa80 11 ай бұрын

Glad to see those pesky crankcase vents are removed from the head. Hopefully we can stop installing oil catch cans IOT stop the insane oil carbon buildup.

@brendans5567 11 ай бұрын

Thanks for the insight into the new 121 . The VVT system is simpler than I thought it would be. You mention the Cam duration is variable , but I'm sure you know the system can only advance or retard the Cam, and not alter the duration, as that is ground into the Cam.

@MasterTechMiller 11 ай бұрын

Yes my apologies in my choice of words during the video. No scripts here, just point the camera & start talking. Occasionally, I will make a mistake & mix up my words. There is a lot going on in my head & when it's running in top gear & my mouth is only in 4th gear the delay can catch me out. Yes the timing variable, not the duration. The duration is a fixed spec of the cam profile. However to get technical, the phaser system works off cam torque acruationl & can senses the shift in the cam coming over the nose of the lobe on the closing of the valve & when its ramping up to open the valve. So of for example the timing was advanced at the opening of the valve them retarded duration the opening & for the closing of that valve then it would, ever so slight increase the duration.

@DK-xy8gk 2 ай бұрын

For the money they demand for cvo models, which this motor would be fitted to. I would expect a screaming eagle cam plate and oil pump.

@MasterTechMiller 2 ай бұрын

@DK-xy8gk So far it is only offered in the 135ci Screamin Eagle Crate motor

@IANNICHOLSON-u4x 2 ай бұрын

I do NOT quite understand WHY they take HEATED coolant from one head and deliver into the 2nd head ? I understand the concept of removing more heat from the cylinder with less air But , wouldn't it make more sense to cool both SEPARATELY ? Maintaining EQUAL Head Temps for equal tuning of combustion ?

@MasterTechMiller 2 ай бұрын

@user-rx9ww3ws6n The front cylinder & cylinder head gets the majority of the wind passing over it. The rear cylinder & cylinder head is blocked by the front one. It's a known fact that Harley's rear head always runs slightly hotter than the front one so it makes sense to prioritise the cooling to the rear head as the front one has the additional aor flow passing over it that the rear doesn't get. Each cylinder is capable of individually tuning so I can & do tune each cylinder independently of one and other so AFRs, ignition timing & temps are optimised.

@johnbeardsley7360 9 ай бұрын

hello, I just installed on my 2022 fatboy a 117ci stage 4 with 515 cam 64 mm throttle body and se high flow heads and the power comes on way to high for my taste. Before this I used a s&s 465 cam on a stage 2 and it came on about 2200 rpm and kept going to my next shift and is how I like it, however this cam doesn't work with the stage 4....can you recommend a cam for this build, thank you john...not looking for crazy hp but more than my stage 2 and ride ability is most important. I felt like if anyone knows its you.

@smitt1970 11 ай бұрын

I seen this video the other day, and I am interested more in the crankcase venting. So, I went to my local dealer, and checked one out. Surprise! yes it does vent from the trans top cover, but the way it looks, the vent hose from the cover goes up under the tank, couldn't see where it ended. to me, I am thinking that it goes to the intake manifold, couldn't see a catch can. would you be able to see if it is actually a catch can? I am sure that the EPA isn't going to let it go to a breather. so I would like to know more about it. Thanks

@MasterTechMiller 10 ай бұрын

Yeah so hose from the Trans cover runs up & over the rear cylinder head & is routed back into the air box. It simply vents into the air box & not directly into the intake like previous models. With the added oil separation system in the trans cover & not directly routing it into the intake will GREALTY reduce the oil mist going back into the intake

@michaelmitchell5909 11 ай бұрын

Ya man, can't wait to see what you can do with this motor...shit I'm still riding a 95" t.c. turd....lol Hopefully one day I can afford a M8 114.

@MasterTechMiller 11 ай бұрын

Cheers mate. 🍻 You'll get yourself an M8 soon enough

@michaelmitchell5909 11 ай бұрын

@MasterTechMiller ...thanks for the positive response man....

@kennethwise7108 10 ай бұрын

@michaelmitchell5909 screw that nonsense Michael, don't waste your money on it. Have Greg Dahl make you a bad ass Twinkie. It'll smoke this thing and last WAY longer

@MasterTechMiller 10 ай бұрын

@kennethwise7108 keep commenting on my videos mate. It helps the algorithm boost my videos to more people's feeds.

@michaelmitchell5909 10 ай бұрын

@kennethwise7108 ...hi Ken. Ya I was thinking about that too, that's why I was asking tatro about the 100" kit or get a stroker crank and make it a 106", but that's gonna be alot of money either way....

@ihateemael 11 ай бұрын

very interesting thx. I wonder if one of those new cam plates, cam and phasor would bolt straight into an existing m8?!! ps: why on earth those thick head gaskets? must be using existing barrels?

@MasterTechMiller 11 ай бұрын

The existing M8 doesn't have the ECM capabilities to run VVT unfortunately. I'd say due to the higher comp ratio & piston sitting proud calls for the very thick gasket? I'm yet to measure the cylinder height but I will get to it

@levi_madeley 8 ай бұрын

By design, im not sure Duration adjustable.

@MasterTechMiller 8 ай бұрын

@2009bagger1 8 ай бұрын

Has harley released any cams or motor prts yet

@jcrean3 8 ай бұрын

Air cleaners and Stage I cals

@SilverIndian 11 ай бұрын

Still they didn't solved the carbon build-up problem. I saw a video from an onwer removing the valve cover & looking the pistons heads.. Lots of carbon at early low mileage CVO 2023 engine..

@danr919 11 ай бұрын

Change oil and service regularly as bike needs care like anything. Do that an carbon will never be a problem and many kms you will get out of it.Carbon will be the least of your worries.

@danr919 11 ай бұрын

Thanks again for the insight and probably the only detailed look into the engine not many of us will probably own and pull apart. Great work mate 👍

@SilverIndian 11 ай бұрын

it has nothing to do with oil changes. . .its running lean from the factory...needs tuning and research to fix that issue

@danr919 11 ай бұрын

@@SilverIndian it has to run Lean from factory to meet EPA Harley can’t change that. It has to do with re circulating blow by into the intake which engines have done for many years. Bottom line service and look after the bike in stock form and carbon build up wont be a Issue to the motorcycle producing many years and Kilometres. So Carbon build up isn’t a problem. It’s only a problem because you read to much on internet with company’s pushing products to sell to gullible people. I currently have a twin cam 96ci with 150,000kms dead stock never rebuilt and a 103 with 44,000kms with cams pipes tune and it’s caused more dramas then in stock form

@MasterTechMiller 11 ай бұрын

@Toyota_MK4_ The biggest issue is folks riding these air cooled V-Twins around like a sissy. Not getting the combustion temps & pressures up high enough to burn off the carbon deposits. They tend to 'lug' them around in too tall of a gear at too low rpm ranges resulting in excessive carbon deposits & build up. Sure, factors such as fuel quality/octane rating, environment & service discipline all can contribute to this aswell. The fact that Harley-Davidson & every other mass production motorcycle or car manufacturer has to route the crank case vent back into the intake manifold is a EPA requirement. It's widely known that Harley's have oily intake manifolds because lots of guys out there take their air filter off to service their bikes at home & see it for themselves. Can you imagine if you took ANY internal combustion engine gasoline powered motorcycle on the market today and took the crank case vent hose, ran an external hose out of the intake manifold & pointed it towards yourself while wearing a white shirt. Then go for a 100km ride & tell me how clean your shirt is.

@RichardRamsey-l8o 5 ай бұрын

My 2024 CVO 121 VVT makes a Ticking noise. Reminds me of a Valve Train noise. However I had Harley look at it and they said its normal. Could you explain this. Only seems to be prominent on Cold start and for the first 5-10 Mins after Start up. Once engine is hot. Noise goes away.

@MasterTechMiller 5 ай бұрын

Yes it's normal. It's related to the VVT Cam phaser. Once oil temp comes up to operating temps the system is working alot smoother & the noises reduce. That's the short answer. I could go into more detail about the entire system, but just know it's normal & nothing to worry about. The Revolution Max engine found in the Pan America & Sportster S models is exactly the same if not louder on cold starts with the same noises

@RichardRamsey-l8o 5 ай бұрын

@@MasterTechMiller In that short time that its ticking. Its not doing any damage? Sounds to me like the Lifters are draining out the oil and takes time to fill back up.

@RichardRamsey-l8o 5 ай бұрын

@@MasterTechMiller I appreciate the Feedback and makes me feel better about it. I really enjoy my Legendary Orange CVO.

@MasterTechMiller 5 ай бұрын

@@RichardRamsey-l8o beautiful colour!

@MasterTechMiller 5 ай бұрын

@user-df7df1eb8z No, nothing to be concerned about. Because the engine is idling & going through it's warm up cycles, when cold starts happen, the VVT system is in overdrive as it is making constant adjustments to the valve timing. Remember, the engine is at low running speeds, which gives off erratic MAP (manifold absolute pressure) readings, which is one of the readings the VVT system uses for adjustments. Then, as the idle speed slows even further as the warm-up cycle is completed, the VVT system is again making many adjustments to give the best efficiency & smooth running to the engine. At cruise speeds, the RPM, MAP & Throttle position is relatively constant & the VVT is quieter.

@InfamousCreep 11 ай бұрын

👍👍👍👍

@lordmomon3718 6 ай бұрын

What size is the new intake manifold size? 58mm or 62mm?

@MasterTechMiller 5 ай бұрын

58mm & the Screamin' Eagle option for the normal M8 is 64mm

@kennethwise7108 11 ай бұрын

Damn, hardly any skirts on the pistons

@MasterTechMiller 10 ай бұрын

How should they have designed them & why?

@kennethwise7108 10 ай бұрын

@MasterTechMiller I have an idea that I need to get patented which completely does away with any runout of the flywheel halves and makes them perfect. No scissoring and indestructible. Aside from that weakness the motor looks like a great improvement. I spoke with the Screamin' Eagle guys at HD and they have no interest in running this motor in their King of the Baggers Season

@MasterTechMiller 10 ай бұрын

@kennethwise7108 yeah ok mate. You didn't answer my question in relation to your statement about 'hardly any skirts on the pistons'. How should have Harley designed there pistons & why?

@kennethwise7108 10 ай бұрын

@MasterTechMiller The obvious is that with shorter skirted pistons there is significantly less support. Thus, it will wear out the piston and cylinder walls quicker due to the increased wobbling effect. I didn't mention ANYTHING about fixing or remedying this problem. I merely made a statement about how "short the skirts were". As an engine builder, I wouldn't even want one! More power to those people who don't consider things of this nature prior to purchasing the bike. Many probably don't even care about the longevity of a motor. This motor won't last 100,000 miles (160,930 kilometers). IMPOSSIBLE!!

@MasterTechMiller 10 ай бұрын

@kennethwise7108 you better pass this information onto the Engineers at Harley-Davidson. I'm sure they've obviously not considered any of the points you've just mentioned.

@richardrussell500 11 ай бұрын

Where are they sending the vented transmission vapors to?

@MasterTechMiller 11 ай бұрын

The intake manifold as per EPA requirement. The added oil separator, length of the vent hose & the fact it has to travel 'up hill' now greatly reduces the chance of oil mist re-entering the intake manifold that everyone cries about.

@richardrussell500 11 ай бұрын

@@MasterTechMiller I am glad to see HD finally ditching those head breathers for a much more effective way of venting the crankcase... many people will still use catch cans or vent to the atmosphere to keep the hot oxygen depleted air from entering the combustion chamber creating better engine performance. thanks : - )

@richardrussell500 11 ай бұрын

@MasterTechMiller 11 ай бұрын

@@richardrussell500 absolutely 💯

@richardrussell500 11 ай бұрын

I am looking forward to long-term reviews on this new engine... the M8 has had its own problems over the years. Sumping and overheating are the two biggest concerns.

@crunchytheclown9694 11 ай бұрын

Russian r and d with euro prices ?

@FRWD_FXLRST 8 ай бұрын

Does this mean normal M8 came work or don’t work?

@MasterTechMiller 8 ай бұрын

Current M8 cams will NOT work in the VVT M8 Platform.

@simeonhines9805 10 ай бұрын

Biggest question, current M8s, can we vent trans cover, the case vent side, and plug head breather?

@MasterTechMiller 10 ай бұрын

Yes! Absolutely. I have done that on a few bikes now. Keep in mind, when you vent the trans cover it relieves the head breathers so the chance of oil in the intake is reduced greatly so you can keep them in the head if you like or just put bolts in there to block it off.

@simeonhines9805 10 ай бұрын

@@MasterTechMiller thanks. Lots of inquiring minds want to know

@MasterTechMiller 10 ай бұрын

@@simeonhines9805 no problems

@simeonhines9805 7 ай бұрын

Do you jabe a recommended size of hose for venting trans cover?@@MasterTechMiller

@MasterTechMiller 7 ай бұрын

@@simeonhines9805 5/16"

@brandot.7466 8 ай бұрын

Thanks for all great info. can you tell me there is electric wires coming out of the transmission.... And on the non VVT 2024 road glide and street glide wires come out of the cam cover. THANKS

@MasterTechMiller 8 ай бұрын

Wires from the transmission is for the gear position sensor. The wires coming from the cam cover on both the VVT & Non VVT Engines is the cam position sensor.