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Purple cam questions?

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GASnBRASS
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Learning to use the board
Posts: 32
Joined: June 23rd, 2017, 7:01 pm
Stroker Displacement: 4.1 / 250ci
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: TJ

Purple cam questions?

Post by GASnBRASS » June 23rd, 2017, 7:52 pm

Interested in using the Mopar purple cam P4529229 in my 4.0 stock rebuild. Primary needs are main power band between 2000-4000 rpm, smooth idle, good torque for low rpm crawling (32RH), and use 87 octane fuel. Have been reading tons about valve duration, overlap, lift, dynamic compression etc. Planning to use a cloyes adjustable double roller that has -4, 0, and +4 settings for the cam.

Questions are:
Is the purple cam compatible with a '98 TJ ECM?
Is the extra lift ok with the stock valve springs?
Would it be suitable for low rpm torque and mid range cruising power (3000 rpm)
Is there an ideal setting on the cam gear to advance or retard it?

The DCR is pretty close for both: stock 7.47 vs purple cam 7.56
These are the stock and purple cam specs:

Intake Duration 253 / 248
Exhaust Duration 259 / 248

Intake @ .050" 188 / 202
Exhaust @ .050" 190 / 202

Valve Lift (Intake) .408 / .440
Valve Lift (Exhaust) .414 / .440

Intake Opens @.050(BTDC) -16 / -7
Intake Closes @.050(ABDC) 24 / 29
Exhaust Opens @.050(BBDC) 20 / 29
Exhaust Closes @.050(ATDC) -10 / -7

Advertised Intake Opens (BTDC) 12 / 16
Advertised Intake Closes (ABDC) 61 / 52
Advertised Exhaust Opens (BBDC) 50 / 52
Advertised Exhaust Closes (ATDC) 29 / 16

Valve Overlap deg (advertised) 42 / 32
Lobe Separation Angle deg 108 / 108
Intake Centerline Angle deg 110 / 108

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gradon
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Posts: 1333
Joined: February 13th, 2008, 5:33 pm
Stroker Displacement: 4.6/280ci
Vehicle Year: 1996
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: DC

Re: Purple cam questions?

Post by gradon » July 3rd, 2017, 11:09 am

Run it

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