Stock cam question

[Chris]

I'm working on the idea of settling for a stock cam to help with the reliability of my engine. Working on all of the CR/DR/quench issues to see what I come up with. Does anyone know what the lobe seperation and the intake lobe centerline for the stock HO cam is, or where I can find that information?

[John]

From one of my notebooks
87 -95 Lobe separation angle 112 degrees
96 up Lobe separation angle 107 degrees

87 -95 Intake centerline 110 degrees
96 and up intake centerline angle 100 degrees
John

[Chris]

Thank you very much!!!

[Chris]

I had this information somewhere, but I have misplaced (lost) it. Is the lift .405" int and exh and the duration 270 int exh for all years?

[Flash]

That is the Renix(upto90) cam spec

The problem that i had when trying to compare DCR between stock cam was.......Renix was figured on a "seat to seat IVC spec. Were as both HO, cams were figured with @.050 lift spec.

Not only do you need two different DCR calc. but now there is a vareation............that i found hard to believe was correct.

If you find seat to seat spec for the HO cam PLEASE, pass then on to me, as i will enter then in my Dyno simulator,

I would love to do DCR of the three cam.......But they have to be SEAT to SEAT spec for it to be accurate(In my opinion!)

Flash.

[John]

I had this information somewhere, but I have misplaced (lost) it. Is the lift .405" int and exh and the duration 270 int exh for all years?

From the same notes Chris

Valve Lift (Intake) 0.424" 0.408" 86-95/96 up
Valve Lift (Exhaust) 0.424" 0.414" 86-95/96 up

Intake Duration @ .050" Lifter Rise deg 197 188 86-95/96 up
Exhaust Duration @ .050" Lifter Rise deg 197 192 86-95/96 up

John

[John]

That is the Renix(upto90) cam spec

The problem that i had when trying to compare DCR between stock cam was.......Renix was figured on a "seat to seat IVC spec. Were as both HO, cams were figured with @.050 lift spec.

Not only do you need two different DCR calc. but now there is a vareation............that i found hard to believe was correct.

If you find seat to seat spec for the HO cam PLEASE, pass then on to me, as i will enter then in my Dyno simulator,

I would love to do DCR of the three cam.......But they have to be SEAT to SEAT spec for it to be accurate(In my opinion!)

Flash.

Let me do some more digging through my stuff, I will get back to you, think I have that too. But I need a crib sheet to find all the notes.
John

[John]

Flash what simulator are you running. I have Desktop Dyno 2003. Can you use my cam files.
John

[John]

Chris, what year camshaft are you wanting to use?
John

[Chris]

Not for sure. My XJ is a 95, but the motor I'm stroking to put in it is a 93. I don't guess it really matters what year I put back into it, I'm just trying to get the numbers right for me to:
1. Not have to worry about cam failure in the next few thousand miles
and
2. Be able to run on 87 octane....mid grade at the MOST.

[seanyb505]

Lot of cam info here: http://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm

[John]

Flash what simulator are you using. My files are Desktop Dyno 2003. Don't know if you can use that data format.
John

[Flash]

Flash what simulator are you running. I have Desktop Dyno 2003. Can you use my cam files.
John

No, it won't or more likely i don't know how to get then cam files to be excepted

But if you can find so seat to seat spec's i can enter them manually

Mostly put then in my Simulator for storage as my DCR calc is not part if this program.

[John]

Here's what I have for the 99 H.O. cam
Seat to seat timing

Intake valve timing
Seat to seat duration 253.3
Intake centerline 114.3
Intake valve max lift 0.407

Exhaust valve timing
Seat to seat Duration 259.0
Exhaust centerline 100.3

Cam lobe center angle 107.3
Valve overlap 41.6

IVO 12.4
IVC 60.9
EVO 49.8
EVC 29.2
Intake lift at valve 0.407 for intake and exhaust

Is that what you was looking for?
John

[Flash]

Here's what I have for the 99 H.O. cam
Seat to seat timing

Intake valve timing
Seat to seat duration 253.3
Intake centerline 114.3
Intake valve max lift 0.407

Exhaust valve timing
Seat to seat Duration 259.0
Exhaust centerline 100.3

Cam lobe center angle 107.3
Valve overlap 41.6

IVO 12.4
IVC 60.9
EVO 49.8
EVC 29.2
Intake lift at valve 0.407 for intake and exhaust

Is that what you was looking for?
John

Thanks John!!!!
Before i add these spec' to my Simulator.........A couple of questions
I thougth that the early and late HO cam were in the .420-.430 lift? Hmmmm maybe I'm thing of the MPP cams

What about the Early Ho Spec's.........I have been told, several time that the only difference between early and late HO was the later was advance several degrees.......

Do you have any thing that back that up??????
Please don't be offended here but,
I have spec for the early and late HO......but as i have said before they were @ .050 spec............Mine seam to be different in other ways too.
Take a look at these spec's
-------EARLY HO-----------------------------LATE HO------------------RENIX(SEAT TO SEAT OR ADVERTISED SPEC)

Cam lobe Center Line Angle 112*.........95.........................120

Over lap -27..........24.........................46

@.050 int Duration 197..........228...SEAT TO SEAT...270

@.050 exh Duration 197..........200...."................" 270

Int Center line 120..........94.........................120

Exh Center Line 104.........96.........................104

Int Gross lift .424........408...................... .405

Exh Gross Lift .424........414....................... .405
VALVE EVENT TIMING

IVO -21.5.......20...SEAT TO SEAT.....15

IVC 38.5.......28.........................75

EVO 22.5.......16.........................59

EVC -5.5........4..........................31
NOTE: I DO NOT know how accurate these spec's are.............Pretty sure on the Renix cam!!!!
What say you?