383 street cam help

[Bighead440]

Just commenting that I was VERY impressed with the performance of the Comp Cams "Purple Plus" (.904" specific) shelf ".508"" replacement cam (247/254* @.050"). I installed it in a basically all stock 360 with budget Speed Pro 4-eyebrow pistons and J-heads with porting and some serious milling, and made over 400hp. Used massaged 273 rockers with Crane locking adjusters and Rhoads "V-Max" lifters. Would rev willingly over 7000rpm, and sounded wicked.

 

[wyrmrider]

Thanks Big head
That's the larger of the Purple Plus PP292H
292/299 @.006 42 70 38 82 124 overlap 108 LCA install at 104 ICL comp says 3000-6000 10:1
Hydraulic-Strong midrange with a radical idle. Best replacement for the factory street/bracket race cam 3500 install with 10:1 compression.

Do you have the timing @.050 and the .200 duration??
did you calculate your compression? what gears and converter?

 

[rumblefish360]

Thanks Big head
That's the larger of the Purple Plus PP292H
292/299 @.006 42 70 38 82 124 overlap 108 LCA install at 104 ICL comp says 3000-6000 10:1
Hydraulic-Strong midrange with a radical idle. Best replacement for the factory street/bracket race cam 3500 install with 10:1 compression.

Do you have the timing @.050 and the .200 duration??
did you calculate your compression? what gears and converter?

Below is all that Can MP Cams lists for there cams. Unless you have a paper catalog that MAY contain more information.
http://www.compperformancegroupstor...=CTGY&Store_Code=CC&Category_Code=LACAMHFNPPP

 

[Bighead440]

Thanks Big head
That's the larger of the Purple Plus PP292H
292/299 @.006 42 70 38 82 124 overlap 108 LCA install at 104 ICL comp says 3000-6000 10:1
Hydraulic-Strong midrange with a radical idle. Best replacement for the factory street/bracket race cam 3500 install with 10:1 compression.

Do you have the timing @.050 and the .200 duration??
did you calculate your compression? what gears and converter?

PURPLE PLUS HYDRAULICS (.904" MIN. TAPPET) These use the same ramps as the New Nostalgia Plus™ lobes but have more velocity for use with Chrysler/Mopar .904" minimum tappet diameters. CAMSHAFT TYPE LOBE # RATED DURATION DURATION IN DEGREES LOBE LIFT TAPPET LIFT @ TDC THEORETICAL VALVE LIFT @ "0" LASH ROCKER ARM RATIO @ .050 @ .200 106° 110° 1.5 1.6 1.7 Purple Plus Rated Duration @ .006" Tappet Lift .904" Min. Dia. MI 24.0 (11.6/12.4) 6882 280 233 148 .316 .086 .071 .474 .506 .537 6883 287 240 153 .316 .096 .082 .474 .506 .537 6884 284 239 154 .323 .097 .082 .485 .517 .549 6885 291 246 159 .323 .107 .092 .485 .517 .549 6886 292 247 163 .339 .111 .097 .509 .542 .576 6887 299 254 169 .339 .123 .108 .509 .542 .576

 

[Bighead440]

247 163 .339 .111 .097 .509 Intake Lobe
254 169 .339 .123 .108 .509 Exhaust Lobe
108 Lobe Separation Angle

I installed mine at 103* and I calculated compression at 10.33:1 actual static.

 

[wyrmrider]

Thanks Bighead I forgot about the on line lobe list catalog- a good resource and it has "intensities"
the "more acceleration" is just a factor of the lifter size it does not indicate more intensity- you can compare with the XFI and XE lobes and see that MOPAR is actually as easy or easier on the valvetrain
I just wish comp had catalog grinds shorter than the XE274HL
I'm going to post you data over in my Cam thread if you don't mind
BTW readers- do not try this cam in a 8.5-9:1 motor on the street
another BTW this Comp 292 measured at .006 is shorter than a MOPAR 292 which measures at about .008 tappet lift
maybe similar to a MP 286 but with faster ramps so it would also be "bigger" than a MP 284
I formated over in my thread
you could put carriage returns/ enters before each part number to help line them up
thanks

 

[Bighead440]

Thanks Bighead I forgot about the on line lobe list catalog- a good resource and it has "intensities"
the "more acceleration" is just a factor of the lifter size it does not indicate more intensity- you can compare with the XFI and XE lobes and see that MOPAR is actually as easy or easier on the valvetrain
I just wish comp had catalog grinds shorter than the XE274HL
I'm going to post you data over in my Cam thread if you don't mind
BTW readers- do not try this cam in a 8.5-9:1 motor on the street
another BTW this Comp 292 measured at .006 is shorter than a MOPAR 292 which measures at about .008 tappet lift
maybe similar to a MP 286 but with faster ramps so it would also be "bigger" than a MP 284

Because of the split pattern design (bigger exhaust lobe) and higher intensity, I believe it should outpower the PurpleShaft .508 straight pattern from MoPar. I used the "V-Max" lifters that do enhance vacuum and bottom-end a tad, but I was really after the anti-pump-up effect at higher RPM. Seemed to be the perfect combination with this camshaft, normally kinda large for a 367" (.040" over 360) with flat-top pistons.

 

[wyrmrider]

Yes indeed it should
I like that they kept the lift the same on the exhaust- your really need the more duration- less lift on the exhaust even on a LA with the not so hot exhaust path
most use a "bigger" duration and lift cus they do not have special ex lobes
I posted elsewhere where Jones has 50% more duration at .275 than the comparable (much shorter) DC cam
you are running headers? how big and long and collector?
do you have cranking comprssion?

 

[Bighead440]

Yes indeed it should
I like that they kept the lift the same on the exhaust- your really need the more duration- less lift on the exhaust even on a LA with the not so hot exhaust path
most use a "bigger" duration and lift cus they do not have special ex lobes
I posted elsewhere where Jones has 50% more duration at .275 than the comparable (much shorter) DC cam
you are running headers? how big and long and collector?
do you have cranking comprssion?

https://www.holley.com/products/exhaust/headers_and_exhaust_manifolds/all_headers/parts/5204HKR

Never measured the cranking compression. I suspect the "V-Max" lifters might bolster that a tad over standard hydraulic lifters.

 

[Bighead440]

Yes indeed it should
I like that they kept the lift the same on the exhaust- your really need the more duration- less lift on the exhaust even on a LA with the not so hot exhaust path
most use a "bigger" duration and lift cus they do not have special ex lobes
I posted elsewhere where Jones has 50% more duration at .275 than the comparable (much shorter) DC cam
you are running headers? how big and long and collector?
do you have cranking comprssion?

Running closed exhaust, Hooker AERO-FLOWS and an H-pipe, 3" with turndowns.
Runs 96mph in a 68 Dart, with 4.30 gears and 27" Hoosier street slicks, 1/8mi. The same car/gears with my first Magnum 318 (5.2L-lol) retrofit ran 86mph (!) with a dead 11" torque converter (2300 stall?), and a 2-second 60-ft time, with 2.5" exhaust and street tires.

 

[Cesareo Mendez]

Just commenting that I was VERY impressed with the performance of the Comp Cams "Purple Plus" (.904" specific) shelf ".508"" replacement cam (247/254* @.050"). I installed it in a basically all stock 360 with budget Speed Pro 4-eyebrow pistons and J-heads with porting and some serious milling, and made over 400hp. Used massaged 273 rockers with Crane locking adjusters and Rhoads "V-Max" lifters. Would rev willingly over 7000rpm, and sounded wicked.

Hey Bighead440 did you set this cam up dot to dot or advanced any?

 

[Bighead440]

Hey Bighead440 did you set this cam up dot to dot or advanced any?

I had to use the 4* advanced slot on the crank gear to get it to 104* ICL.