Choosing a solid roller cam
Thread Starter
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
Choosing a solid roller cam
So here is my criteria:
355ci motor
6" rods
10.27:1 compression
Comfortable at street driven RPMs (1000-3000)
Racing RPM range 4500-7000
Shifting 6800 RPM
Easy on Parts
With the AFR heads and their good exhaust port, I am all about a single pattern cam.
If easy on parts translates into lift under .55 I will use AFR 180 heads. If easy on parts translates into lift around .6 I will use AFR 195 heads.
I am unsure on the appropriate intake manifold, a weiand stealth (Dual plane) or Team G (single plane).
Thoughts?
Cammotion has a 270 at .02 lobe, 238 at .05 and .325 lift
This will make a nice mild .52 lift with 1.6 ratio
Lunati offers a 278 at .02, and 242 at .05, and 158 at .2, and .371 lobe lift
This would make a nice .594 lift with a 1.6 ratio rocker ratio
Compcams has a 274 adv, and 236 at .05 and .376 lobe lift
This would make a nice .602 lift with a 1.6 rocker ratio
Crane cams has a 278 at .02 and 228 at .05 and .338 lobe lift
This would make a nice .541 lift with a 1.6 rocker ratio
355ci motor
6" rods
10.27:1 compression
Comfortable at street driven RPMs (1000-3000)
Racing RPM range 4500-7000
Shifting 6800 RPM
Easy on Parts
With the AFR heads and their good exhaust port, I am all about a single pattern cam.
If easy on parts translates into lift under .55 I will use AFR 180 heads. If easy on parts translates into lift around .6 I will use AFR 195 heads.
I am unsure on the appropriate intake manifold, a weiand stealth (Dual plane) or Team G (single plane).
Thoughts?
Cammotion has a 270 at .02 lobe, 238 at .05 and .325 lift
This will make a nice mild .52 lift with 1.6 ratio
Lunati offers a 278 at .02, and 242 at .05, and 158 at .2, and .371 lobe lift
This would make a nice .594 lift with a 1.6 ratio rocker ratio
Compcams has a 274 adv, and 236 at .05 and .376 lobe lift
This would make a nice .602 lift with a 1.6 rocker ratio
Crane cams has a 278 at .02 and 228 at .05 and .338 lobe lift
This would make a nice .541 lift with a 1.6 rocker ratio
Last edited by Guru_4_hire; Mar 30, 2008 at 11:28 AM.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
Easy on parts to me would also be a gentler ramp rate. Also with your compression the higher duration would be a consideration. I would choose the Comp cams cam with 1.5 rockers on a 355. With AFR heads on a 355 you don't need a .602 lift to pull well at the upper end. I would run DD sims and DCR calculations before deciding. You will probably give up a little power with a milder ramp but use less spring pressure and be easier on valvetrain parts. Hard to find a compromise between maximum power and easy on parts! JMHO. 
Last edited by 63mako; Mar 30, 2008 at 12:40 PM.
Thread Starter
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
The 278 lobes really hurt DCR.
The .6 requirement is 2 fold, I read an article by Mr. Vizzard that said small blocks like .6 lift, and if a change rockers let me use ALL that AFR 195s have to offer I am all about it.
If I go with AFR 180s to maintain the myth and/or reality of low RPM velocity, There probably isnt a lot of benefit to cams with more than .55 lift.
Depending on the LSA, the overlap gets kinda large (I am trying to keep it around 50 degrees), and changing the LSA affects the DCR.
With the 278 lobe I would use 114 LSA and that puts my DCR way out of whack (7.9)
With the 274 lobe I would use 112 LSA and that puts my DCR in a good range (8.15)
With the 270 lobe I would use 110 LSA and that puts my DCR at the high side (especially since DD2K says the engine will like 5 degrees of advance) at 8.44:1
The .6 requirement is 2 fold, I read an article by Mr. Vizzard that said small blocks like .6 lift, and if a change rockers let me use ALL that AFR 195s have to offer I am all about it.
If I go with AFR 180s to maintain the myth and/or reality of low RPM velocity, There probably isnt a lot of benefit to cams with more than .55 lift.
Depending on the LSA, the overlap gets kinda large (I am trying to keep it around 50 degrees), and changing the LSA affects the DCR.
With the 278 lobe I would use 114 LSA and that puts my DCR way out of whack (7.9)
With the 274 lobe I would use 112 LSA and that puts my DCR in a good range (8.15)
With the 270 lobe I would use 110 LSA and that puts my DCR at the high side (especially since DD2K says the engine will like 5 degrees of advance) at 8.44:1
Last edited by Guru_4_hire; Mar 30, 2008 at 12:46 PM.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
The 278 lobes really hurt DCR.
The .6 requirement is 2 fold, I read an article by Mr. Vizzard that said small blocks like .6 lift, and if a change rockers let me use ALL that AFR 195s have to offer I am all about it.
If I go with AFR 180s to maintain the myth and/or reality of low RPM velocity, There probably isnt a lot of benefit to cams with more than .55 lift.
The .6 requirement is 2 fold, I read an article by Mr. Vizzard that said small blocks like .6 lift, and if a change rockers let me use ALL that AFR 195s have to offer I am all about it.
If I go with AFR 180s to maintain the myth and/or reality of low RPM velocity, There probably isnt a lot of benefit to cams with more than .55 lift.
Last edited by 63mako; Mar 30, 2008 at 12:54 PM.
Thread Starter
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
That torque at the bottom might go up with a dual plane. The numbers are that High early from the 180 heads, high port velocity that flow big numbers. Pretty nice for a 355. Torque over 400 Ft lbs from 2000 RPM to redline Peaking at 500or higher between 4500 and 5100 RPM. Peak HP flat between 6000 and 6500. My build had similar goals 383 10.4 comp, Split single plane, AFR 195 Race ported, Comp XE 288 HR, .520 and .540 lift, 114 LSA, AFR Rev Kit. Max HP flat between 6000 and 6500 RPM. flat torque curve. Tripower. nitrous.
Edit; That is a real nice combo that all parts compliment each other. Very well matched and streetable with some 3.73 gears
Edit; That is a real nice combo that all parts compliment each other. Very well matched and streetable with some 3.73 gears
Last edited by 63mako; Mar 30, 2008 at 01:40 PM.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
Flattened the torque curve. Raised 25 ft lbs @ 2000 but cost you that in your 4500 and up. also cost you a ton of hp. Not worth it. That single plane combo is killer for a 355 with 180 heads, relatively low lift and gentle ramp rates.
Thread Starter
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
You have to remember that the DD2K dual plane = teh suckiest suck that ever sucked.
I think that if I used something like an RPM airgap or a 8016 stealth things would look differently.
Of course the weiang Team G 7530 intake manifold is 2500-7200 RPM for a single plane.
If I get the Team G they make a divider plate that can be used to help with the torque and vacuum situation.
I think that if I used something like an RPM airgap or a 8016 stealth things would look differently.
Of course the weiang Team G 7530 intake manifold is 2500-7200 RPM for a single plane.
If I get the Team G they make a divider plate that can be used to help with the torque and vacuum situation.
Last edited by Guru_4_hire; Mar 30, 2008 at 01:58 PM.
Thread Starter
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
+2hp
AFR doesnt advertise flow numbers above .5 for the 180cc heads.
Interestingly enough, going to AFR 195cc heads only ups it 7hp, and another 3hp for the 1.6 ratio rockers.
AFR doesnt advertise flow numbers above .5 for the 180cc heads.
Interestingly enough, going to AFR 195cc heads only ups it 7hp, and another 3hp for the 1.6 ratio rockers.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
Bet you will sacrifice some noticable bottom end and midrange torque and valvetrain durability for that 10 hp.
Safety Car
Joined: Aug 2001
Posts: 3,892
Likes: 13
From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Ignore DCR, virtually worthless equation. You will never hear a real cam designer even talk about DCR, some will ask you what it even means. There are wayyyyyyy too many variables that would go into figuring a true DCR that it makes it almost completely worthless to even discuss it. If you have noticed it is rarely talked about on any of the performance boards and is laughed at on the serious performance boards.
Last edited by 69 N.O.X. RATT; Mar 30, 2008 at 03:12 PM.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
Ignore DCR, virtually worthless equation. You will never hear a real cam designer even talk about DCR, some will ask you what it even means. There are wayyyyyyy too many variables that would go into figuring a true DCR that it makes it almost completely worthless to even discuss it. If you have noticed it is rarely talked about on any of the performance boards and is laughed at on the serious performance boards.
It really don't matter in a serious race only build, just bump the octane rating on your fuel until your out of detonation. On a street, pump gas motor I think you really need to consider it.