Pentastar camshaft specs?

[IcyHat419]

Hi all, I've got a 3.6 vehicle I'd like to meddle with. Been reading a lot about the engine and I have some quite good reference tips from various website searches on how to get there.
My only last piece of the puzzle to know how to dial in the vvt and spark tables are the engine's cam specs.
On the open web I've only found two things:
https://www.pentastars.com/engines/specifications.php
And
https://www.wranglerforum.com/thread...tions.2455699/
Latter of which boils down to "get an oem service manual" but also "it might not be in there?".

Does anyone know the validity of the first website's listed timing and duration?

[LilSick]

Does anyone know the validity of the first website's listed timing and duration?

i am wondering how can they state 10 deg overlap present, when there are two cams, each with vvt?

and i was told that the intake has advertised duration of 272 deg; 267 at .005" (.15mm)

never checked it myself tho - lets see that website is sayin:

Attachment 160913

you can check their math - do the intake first:

they claim the intake valve is opening on the intake stroke, not on the exhaust stroke like 'normal'

that is prolly cuz the stock tune has the phaser holding the intake cam full retard at idle

they say it is opening 2 after tdc and closing 82 after bdc - and we know the intake stroke is 180 deg

so i subtract the 2 outta the 180 because it is 'after', then i add the closing number; so 178 + 82 = 260

260/2 = 130

then i add the 2 that i had subtracted back in to find the intake lobe centerline

130+2 = 132 ILC

hella retarded in that position but not nearly the 147 or more the oem tune claims.


the ex will be more normal as they say it opens on the combustion stroke like 'usual':

59 bbdc and closing 12 deg atdc and we know the ex stroke is 180

so 59 + 180 + 12 = 251

divide that by 2 = 125.5

then subtract out the closing number like usual 125.5 - 12 = 113.5 ECL

113.5 i am gonna guess is slightly advanced if compared to its center position

so with the intake is hella retarded and the ex slightly advanced from its center position there would be 10 deg of overlap present

checks out

[GoldenGorilla]

The pentastar was used in several different vehicle types so I wouldn't be surprised if there were different cam profiles in different years. Especially with all the failures in the first 2 years. The jeep forums usually have the FSMs posted for the wranglers if you search.

And if you're not aware, Pentastar rocker coatings are still failing and taking out cams.

[IcyHat419]

Yes, rather impressive that after 15 years they haven't selected approriate materials for the rocker and cams to then case harden to solve the issue.
Vehicle is at 148k and shows no misfires but it does have some slight stumbling during idle so that and the timing set is a future concern area for me.

Lilsick, I'll take the assumption of those cam specs considering the stock calibrated lock positon for the intake is so far in its retard range to begin with.
I've been using a very basic VVT table change and spark tables from a 2018 challenger for a couple days and everything looks good so far. I just need to dial in the actual approriate VVT settings for aircharge/flow instead of a blanket X setting per RPM column and start comparing logs.

My next question is the tune file shows the cams can be advanced/retarded significantly more than any stock file uses in any cell. What would be the purpose of this, is it actually usable? I.E. the intake settings show it can be put to a value of 70 with a max of 140. I currently have the PT table scaled from 105 to 124, low to high rpm and it definitely has had a positive effect on perf behavior with how the 62TE is responding to shifts.

[LilSick]

Lilsick, I'll take the assumption of those cam specs considering the stock calibrated lock positon for the intake is so far in its retard range to begin with.

there is no lock position

there are springs in the intake phasers holding those cams fully retarded until their solenoid valves use oil pressure to advance them

the engine has to be running for that to happen

you cannot degree a cam in a running engine


the exhaust phasers have springs in them holding those cams fully advanced until their respective valves use oil pressure to retard


you are only using 19 degrees of your allowed 40+ movement

i take advantage of a lil bit more than that when i tune them

30+

[Bbdperformance]

Do remember the 3.6L is not only a VVT cam set up, but also a VVL it uses both so it has a high and low lift with VVT

Key features regarding the 3.6L Pentastar camshafts and their profiles include:
Dual Overhead Camshafts (DOHC): Each cylinder bank has its own intake and exhaust camshaft.
Variable Valve Timing (VVT): The engine uses a dual independent cam phasing system, allowing for independent control of intake and exhaust cam timing. This enables optimization of low-end torque and high-end horsepower.
Variable Valve Lift (VVL): Some versions, specifically the upgraded engine released around 2016, feature a two-stage variable valve lift system on the intake valves.
This system utilizes a 3-lobe cam drive for each intake valve.
One inner lobe provides high lift (.410 inches) for higher power demands, while two outer lobes provide low lift (.230 inches) for improved efficiency at lower speeds and loads.
The system switches to the high-lift lobe around 2,800 rpm.
Camshaft Lobe Lift:
Intake: 42.425-42.725 mm (1.6703-1.6821 inches).
Exhaust: 42.385-42.685 mm (1.6687-1.6805 inches).
Valve Lift:
Intake: 10.8 mm (0.4252 inches).
Exhaust: 10.8 mm (0.4252 inches).
Valve Opens/Closes:
Intake Valve Opens: 14 degrees ATDC.
Intake Valve Closes: 251 degrees ATDC.
Exhaust Valve Opens: -229 degrees BTDC.
Exhaust Valve Closes: 9 degrees ATDC.
Centerline:
Intake: 132 degrees ATDC.
Exhaust: 111 degrees ATDC.
Lobe Overlap: 0 degrees @ 0.150 mm (0.0059 inches) lift.
It's important to note that these specifications are for the VVT version of the engine. The VVL system in some versions adds the capability to switch between different lift profiles. Tuning modifications can be made to the VVT values to adjust the timing of the intake and exhaust camshafts independently, and in some cases, the VVL crossover point can be adjusted for improved performance.

[LilSick]

did you read that before you copied and pasted it?

a good portion of it does not add up...

prolly written by AI

[veeefour]

there is no lock position

there are springs in the intake phasers holding those cams fully retarded until their solenoid valves use oil pressure to advance them

the engine has to be running for that to happen

you cannot degree a cam in a running engine


the exhaust phasers have springs in them holding those cams fully advanced until their respective valves use oil pressure to retard


you are only using 19 degrees of your allowed 40+ movement

i take advantage of a lil bit more than that when i tune them

30+

False, they have mid lock as almost every modern DOHC vct actuators hence the parameters for lock?

The ability of you posting everything that comes to your mind either right or wrong, everywhere here and there is beyond me...
image.png

[LilSick]

False, they have mid lock as almost every modern DOHC vct actuators

147 deg mid lock huh? yeah ok. school us. i am open minded...

you do realize that there is no lock pin position when a hemi is running, don't you?

maybe that is why the scalar for lock pin is not used in the gen III hemi calibration?

looks like the engineers used a value of 120 deg as a place holder instead of 0

or 3,226

they coulda put 191 deg C in there... it would not make any difference

[IcyHat419]

Thread is about Pentastars not a hemi...lilsick i've seen you do this in just about every thread someone makes about the pentastar. We get it you want people to have a v8 and you want them to pay you for a tune, not give advice. Cool.
The factory "lock pin pisition" for the Pstar is 128* for intake cam and 117* for exhaust cam. Cam calcs suggest the intake is set 2* advance and the exhaust 8.5?* or something along those lines, but again that assumes those publicly available numbers are correct which I can't confirm.

[veeefour]

147 deg mid lock huh? yeah ok. school us. i am open minded...

you do realize that there is no lock pin position when a hemi is running, don't you?

maybe that is why the scalar for lock pin is not used in the gen III hemi calibration?

looks like the engineers used a value of 120 deg as a place holder instead of 0

or 3,226

they coulda put 191 deg C in there... it would not make any difference

Since when 3.6 Pentastar is considered to be a Hemi? LMAO

[LilSick]

The v8 is not a hemi either

Please substitute ‘Mopar engine’ where my idiotic self said hemi and explain this mid lock concept of yours

[veeefour]

The v8 is not a hemi either

Please substitute ‘Mopar engine’ where my idiotic self said hemi and explain this mid lock concept of yours

You must be on crack jezus...

[veeefour]

Thread is about Pentastars not a hemi...lilsick i've seen you do this in just about every thread someone makes about the pentastar. We get it you want people to have a v8 and you want them to pay you for a tune, not give advice. Cool.
The factory "lock pin pisition" for the Pstar is 128* for intake cam and 117* for exhaust cam. Cam calcs suggest the intake is set 2* advance and the exhaust 8.5?* or something along those lines, but again that assumes those publicly available numbers are correct which I can't confirm.

That guy will post a ton of shit without even thinking whats he posting...you can literally ignore 99% of his spam and be happy..

[LilSick]

The factory "lock pin pisition" for the Pstar is 128* for intake cam and 117* for exhaust cam.

Cam calcs suggest the intake is set 2* advance

and the exhaust 8.5?*

or something along those lines

i know what the OEM values in the tune are, and that is how i know the lock pin scalar is hogwash

2 deg adv huh? from where??? when you have a twin cam motor like this there is no ground in lobe separation angle. the lobe centerlines are measured and recorded and that is where they are. you can then adv or retard either cam either direction but doing so creates a new centerline, not a +2 sort of a number.

with the 3.6 i believe the exhaust phaser locks the exhaust at full advance, and the intake phaser locks the intake at full retard when the engine is shut off

once running, oil pressure is available and the phasers control the cam, not lock pin.

we tune them for when they are running...

[LilSick]

You must be on crack jezus...

\/ \/ \/ \/

[IcyHat419]

i know what the OEM values in the tune are, and that is how i know the lock pin scalar is hogwash

2 deg adv huh? from where??? when you have a twin cam motor like this there is no ground in lobe separation angle. the lobe centerlines are measured and recorded and that is where they are. you can then adv or retard either cam either direction but doing so creates a new centerline, not a +2 sort of a number.

with the 3.6 i believe the exhaust phaser locks the exhaust at full advance, and the intake phaser locks the intake at full retard when the engine is shut off

once running, oil pressure is available and the phasers control the cam, not lock pin.

we tune them for when they are running...

Brother the OEM PCM files tell me the VVT system has a lock pin and what those lock pin angles are. It also tells me the cam's adjustment range. I know from comparing files from a bunch of different manufacs that Dodge vehicles are, oh a bit lacking yeah, but I have every reason to believe the VVT system works as is defined in the airflow > variable camshaft page.
WITH THAT SAID,
A 128* intake "lock pin" whether or not an actual lock pin in the VVT phaser exists, and a 117* on the exhaust, correlate to a 2 and 8.5 degree cam advance with respect to piston center. All the math for the cam require these numbers to fit those cam specs. It is what it is.

I have a very, very long way to go on learning how to tune this engine let alone any engine but one thing I know for sure now is those numbers have to be right for the rest of the numbers to be right.

[PurpleRam]

.

And if you're not aware, Pentastar rocker coatings are still failing and taking out cams.

I designed that coating in 1998 for a DOD application, funny thing is it's being used by over 65 different manufactures in 15+ different countries, serval DOD applications(US, Russia, French, German all use it on internal mechanician in HI humidity caustic environments) and the only place we see a recurring failure is in FCA/Stellantis, test after test it keeps coming back to one of the crap cam suppliers They are using, FWIW GM and Toyota have stopped using cores from that company , while hayabusa camshafts use the same coating and have 1 out of (roughly) 1k fail ....... if the core is not 'degreased thoroughly prior to the coating being applied...It fails.....can't paint an oily car fender and expect it to stick....same deal


The lock pin, like in the HEMI Cam phaser is used to keep the phaser in its' "at rest" position when there's no oil pressure retarding or advancing the phaser. Like the Hemi , the clock spring is not strong enough to keep the phaser in full "at rest" position , centrifugal force , Valve spring & cylinder pressure all work hard to counter rotate those phasers.

[veeefour]

https://youtu.be/LujjabNt87Y?si=HJs8mot8ehDobkjK

Just dont be stupid and "sick"...you can lock pin when running - nothing to compare to Hemi as its using completely different actuator...

[PurpleRam]

https://www.youtube.com/watch?v=hLexS1UhkmE&t=4s