Solid lift cam to roller Q's
#3097365
11/26/22 08:26 PM
11/26/22 08:26 PM
|
Joined: Aug 2009
Posts: 2,039 Mooresburg, Tn
'72CudaRacer
OP
top fuel
|
OP
top fuel
Joined: Aug 2009
Posts: 2,039
Mooresburg, Tn
|
I have run a Mopar Performance .590 solid lift purple cam for years. Want to switch to a solid roller, but stick to something "comparable"., or basically the same cam, except for it being a roller. Do I leave the duration the same and change the lift or do both need changing to keep it the "same"? Bowtie guys tell me that a solid roller needs about .100" more lift than a sft cam to maintain, but with mopar lifters being so much larger, do they "act" like a roller already?
Thanks, Brian
|
|
|
Re: Solid lift cam to roller Q's
[Re: '72CudaRacer]
#3097389
11/26/22 09:36 PM
11/26/22 09:36 PM
|
Joined: Jan 2003
Posts: 12,019 Benton, IL.
DaveRS23
Special needs idiot
|
Special needs idiot
Joined: Jan 2003
Posts: 12,019
Benton, IL.
|
Changing the cam, lifters, push rods, and valve springs with plans to keep the same level of performance. Kinda curious as to why.
Master, again and still
|
|
|
Re: Solid lift cam to roller Q's
[Re: DaveRS23]
#3097392
11/26/22 09:52 PM
11/26/22 09:52 PM
|
Joined: Aug 2009
Posts: 2,039 Mooresburg, Tn
'72CudaRacer
OP
top fuel
|
OP
top fuel
Joined: Aug 2009
Posts: 2,039
Mooresburg, Tn
|
Changing the cam, lifters, push rods, and valve springs with plans to keep the same level of performance. Kinda curious as to why. Combo is well sorted out. Tired of trying to find a .590 & lifter kit and tried of dealing with junk cam & lifters. Brian
|
|
|
Re: Solid lift cam to roller Q's
[Re: '72CudaRacer]
#3097399
11/26/22 10:13 PM
11/26/22 10:13 PM
|
Joined: Jan 2003
Posts: 12,019 Benton, IL.
DaveRS23
Special needs idiot
|
Special needs idiot
Joined: Jan 2003
Posts: 12,019
Benton, IL.
|
I seem to read as many complaints on forums about roller cams and lifters as I do flat tappets. So much crap out there today. Personally, I don't know which way I would go today if I were doing a project. Good luck!
Master, again and still
|
|
|
Re: Solid lift cam to roller Q's
[Re: '72CudaRacer]
#3097415
11/26/22 11:26 PM
11/26/22 11:26 PM
|
Joined: Aug 2003
Posts: 43,123 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,123
Bend,OR USA
|
You need to keep in mind that the roller cam lobes are design to open the valves quicker and the effective duration from .050 lobe lift opening back to .050 closing is a lot longer than a flat tappet cam will be if you go of the .050 duration numbers. As far as the timing and jetting I would leave both alone and go see how it performs before touching it Try it, you may REALLY like it
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Solid lift cam to roller Q's
[Re: Cab_Burge]
#3097479
11/27/22 10:14 AM
11/27/22 10:14 AM
|
Joined: Dec 2021
Posts: 1,118 Loudoun County, VA
Brad_Haak
super stock
|
super stock
Joined: Dec 2021
Posts: 1,118
Loudoun County, VA
|
I posted this years ago, but it sounds like a good thread to bring it back up. It's the solid ft cam that Dwayne Porter spec'd for my old Stage VI combination compared to the solid roller he got me for my Victor heads. Both cams were profiled in the 452's block and the roller was checked using .800"-wheel IMM lifters. I'm sure due to the bigger roller wheel than the standard .750", the roller cam came out a tad bigger than the supplied spec card:
The solid came came from COMP's XX .875"-lifter family and is an older NASCAR-type lobe. It isn't as aggressive as the later .904"-type lobes, but has still proven to make good power and RPM.
COMP XX @ .020" - 297.5 (adv 298) @ .050" - 266 @ .100" - 232 @ .200" - 178.5 (adv 180) @ .300" - 121.5 @ .400" - N/A
Lobe lift .3975 (adv .400) Gross lift .596 (1.5); .636 (1.6) LSA 108 Lash range .016" - .024"
The COMP RX roller series is a moderately aggressive endurance lobe which Dwayne has said has been very successful for his customers looking for decent valve train life when running a solid roller.
COMP RX @ .020" - 300 (adv 298) @ .050" - 266 (adv 265) @ .100" - 233 @ .200" - 184 (adv 183) @ .300" - 134 @ .400" - 68
Lobe lift .434 Gross lift .651 (1.5); .694 (1.6) LSA 108 Lash range .018" - .026"
2021 Challenger 6.4L Scat Pack 1320 100% stock: 1.680, 11.894 at 113.75 (DA 175 ft) weight reduction, wheels, tires, Hellcat air box: 1.661, 11.686 at 115.97 (DA 710 ft)
1973 Challenger 452 ci street/strip [2008] pump gas, DOT radials: 1.454, 10.523 at 126.44 (DA 514 ft)
|
|
|
Re: Solid lift cam to roller Q's
[Re: Brad_Haak]
#3097557
11/27/22 02:22 PM
11/27/22 02:22 PM
|
Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
|
master
Joined: Oct 2007
Posts: 4,206
New York
|
A larger tappet wheel does enlarge the "area under the curve", but also distorts the tappet motion slightly by changing speed on both sides of the lobe. .050" difference probably has minimal effect; a much larger roller may need more spring tension.
Harley-Davidson has used .855" rollers 1929-83 on all engines, and minimized the side thrust vector by offsetting the tappet center line advanced (earlier) w/r/t the base circle CL. This places the roller over the rising lobe (rather than along side it). It has been suggested that the optimum amount of offset is ½ the lobe height. H-D 4-cam motors (1929-* 750, 900, 1000, 1200 & 1300cc) with lobes between .220” and .440” all used ⅛” offset, single-cam big twins (1936-83 1000, 1200 & 1340cc) are 3∕32”.
Boffin Emeritus
|
|
|
Re: Solid lift cam to roller Q's
[Re: DaveRS23]
#3097716
11/28/22 10:44 AM
11/28/22 10:44 AM
|
Joined: Jan 2003
Posts: 13,357 Marion, South Carolina [><]
an8sec70cuda
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 13,357
Marion, South Carolina [><]
|
I seem to read as many complaints on forums about roller cams and lifters as I do flat tappets. So much crap out there today. Personally, I don't know which way I would go today if I were doing a project. Good luck! You can't use cheap roller lifters. There are chinese lifter sets on ebay for les than $300. Not everyone needs a set of $1300 Isky lifters, but you have to use decent stuff. Not to mention, used roller lifters are about the same as used aluminum rods...they're all advertised as having dyno time only, lol.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
|
|
|
Re: Solid lift cam to roller Q's
[Re: an8sec70cuda]
#3097746
11/28/22 11:58 AM
11/28/22 11:58 AM
|
Joined: Jan 2003
Posts: 14,492 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,492
So. Burlington, Vt.
|
For a bracket race type application, the only argument I can see for not using a roller is it one simply can’t afford it. Or, it’s an engine platform where roller cam parts are difficult to come by.
BBM? It’s a no brainer for me.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
|
|