bigmackloud

So I'm in the middle of my engine build and I've got to make a final decision on the camshaft. Some quick details specific to my personal applications: LS1 block, JE flat top pistons, Eagle H beam rods, LS6 intake, 80mm TB... most likely PRC LS6 Stage 1 CNC ported heads setup with dual valve springs, and 42lb injectors. Long tube headers, Corsa exhaust. Target is 11:1 CR (via either milling the heads or a thinner head gasket... pending measuring the piston out-of bore at TDC). Hoping for 420-430rwhp??

The car isn't a DD nor is it a dedicated race car. Needs to be street driveable and live a long life of HPDE days.

My main question is regarding cam ramp rates. As I've read, some cams, even with the same lift/duration specs, may have different ramp rates... which will have an impact on the life of the valvetrain components. However, ramp rates aren't as widely advertised so it's difficult to compare between brands. And a lot of the discussion threads are 5-10 years old, and cam grinds progress over time.

So I'm looking for some suggestions. I've read very good things about Cam Motion. Vengeance Racing cams are ground on Cam Motion cores. Texas Speed grinds their cams in-house; anybody know what cores they use?

Here are a few that I'm considering...

CM Titan 4 - 227/232, .612/.595 113+4
VR VRX4 - 228/230, .588/.592 112+4
Texas Speed - 228/232, .600/.600 112 or 114
TSP Torquer V4 - 231/234, .629/.615 LSA?

Thoughts? Suggestions?

Joshboody

I'm also curious about cam and ramp rates.

Your build is very similar to what I've planned. I was thinking 225-ish and 0.550 max lift, on the conservative side and using a lighter spring. I don't see myself revving much over 6k, so the area under the curve maybe better with the lower duration but will have rpm available if needed.

93Polo

Cam Motion's lobes are typically not rough on spring. I would call Vengeance as the specs appear to be Comp XE-R lobes which some cam gurus on LS1tech thought closed the valve quicker than needed.
Vengeance I believe offers CamMotion now.

I would also give EPS a call they are know street friendly cams. The 226/230 EPS cam has made some great power. A friend is running the Titan 4 and HPDEs and loves it.

01badvette

I can attest for the TQR V4 @ 111LSA, on a stock bottom end I made over 430rwhp and 400rwtq, it has decent street manners under 3K RPM's and really pulls hard from 3-6800rpms. I use my car for AutoX and HPDE and it has performed flawlessly. I will be replacing the valve springs in the spring of next year but more as a precaution but I have around two summers of AutoX or HPDE almost every weekend on them and the cam and have had zero issues.

synner

You can download the comp cams lobe profile info, I've not seen any other cam vendors release that info. You'll likely need a custom cam since most places don't stock anything for road racing. Vendors also don't post what lobes they use. It's horrifying to go to some of these vendors and ask and they don't know. I had one tell me LSA, lift, and duration are all there is. I got a custom Brian Tooley cam with .600 lift, very long duration, low LSA, and gentler ramp rate lobes. If you want street friendly you could go a hair less on duration and a bit higher on LSA. I would definitely get a billet core with all the comp cam horror stories.

93Polo

I would go CamMotion, they have been doing well with their cores.

Street friendly is a very debatable term and some "radical" cams can drive very well on the street with the datalogging and tuning which many shops do not put enough time on. I think the OP is in the ballpark with a 226-228int/230-234exh.


I still stand by my recommendation of the Titan4 or EPS cam. Tick and Smallwood are 2 other vendors worth calling.

I would not get overly hung up on lift as the OP is correct is asking about ramp rates. The old LPE GT2-3 was short duration/high lift and known to be stable.

synner

I know a few people who were told to ignore lift because the cam is fine for RR and they ended up with a new crate motor. They were in the .62X and higher .61X range. I agree however that street friendly is largely based upon the quality of your tuner.

Socko

I have Brian spec me a custom grind also and it worked exactly how i asked him to make it work based on my heads and use. Which is 90 street days a year and 6 track days a year.

Huc and extreme rpm lobes are easy to control.
the cam was 227/236 something like .598 and .578 lift i think 110+3 or 113+3
It didn't drive perfect but it held idle at 800 rpm as long as i didn't crank the wheel really hard on decel. lol

It made 438/409 wheel with tea stage 1 heads and stock intake and manifold from ls6.

My motor was built to 11.2:1 but it was possibly slightly less cause i think the heads came out 1 cc bigger then I wanted. So 111:1 is about right which made dcr around 8.4-8.5:1

cammotion perf

Hello bigmackloud,

For many cam companies, LS ramp rates have gone through a few trends. Initially most companies started out putting old school fairly soft small block Chevy lobes on their LS camshaft offerings.

Over time, camshaft makers started taking advantage of the LS engines 55mm camshaft architecture with more aggressive lobes.

Then people got greedy and started putting more and more violent lobes in pursuit of even more power. Those people quickly learned that once you go too far, you start breaking stuff and in many if not most cases you start losing power due to stability issues.

In addition, many people started complaining about valve train noise with aftermarket camshafts. So, many started looking for camshaft manufacturers to help make quieter valve train for their cars.

Now that the LS engines have been out for 10 years, most smart LS enthusiast have learned that there is a balance to proper camshaft lobe design. You need a lobe that will not shock the hydraulic lifter and will not cause valve train instability yet is still aggressive enough to capitalize on the LS's potential.

While some try to look at lobe catalogs and try to predict what will work best based on duration at .006", .050", .200" and lift, we at Cam Motion look at acceleration rates, loft, jerk and more. I don't think you will find any camshaft manufacturers that will share that type of info.

We too are always looking to get the most out of the product while maintaining quiet operation and valve train stability. I think you will find that our reputation indicates that we are doing a great job of that.

For your average enthusiast, the best thing they can do is go to companies with a great reputation for achieving results. If you look our results from NHRA Top Fuel 3x World Champion Antron Brown to LS Drag Radial Champion Anthony Manna and 2015 LS Real Street Champion Louie Philipides and countless others I think you can see that we are committed to and know how to make power. And, if you listen to the testimonials in the forums and on Facebook, I think you will find that the street car crowd loves the smooth, quiet operation of our street cams.

bigmackloud

Often on the forums it's quoted that you shouldn't go above .600 lift for a cam used for extended periods at high rpms (ie, road racing). What are you thoughts on that topic?

Are all Cam Motion cores the same ramp rate? If two different brands are both using a cam motion core (and similar lift/duration specs), is there any chance one of them has a more aggressive vs gentler ramp rate?

I'm also curious of the performance difference between very similar cams, but one having slightly more duration vs slightly more lift.



I also emailed Tick Performance (they also use Cam Motion cores). They recommended their Street Heat stage 2 cam... 231/235, .625/.605 113+3.

cammotion perf

There are several considerations when determining how much lift is appropriate for your application. First, we must consider your rocker arms. If you are using the stock rocker arms, you are limited by the design of the rocker arms. Stock rocker arms do not have a roller tip. If you use too much lift, it can damage the valve tip and the rocker arm. For most LS enthusiasts running stock 1.7 ratio LS rocker arms, I like to limit lift to the .620s area. Another consideration are valve spring limitations. You must choose a valve spring that has the proper lift and spring rates for your lobe profile, valve train weights, RPM range and application. If you email all the details of your build to Steven at CamMotion.com, I can help you get exactly what you need.

I will clarify the terminology a little. What is referred to as a "core" is generally referring to a "roughed-in" camshaft before the final machine work is done. Our camshafts start out as a piece of billet steel. This steel billets can be made of various alloys. Our most common are 5150, 8660 and 8620 steel alloys. The 5150 and 8660 cam "cores" go through an induction hardening process whereas the 8620 goes through an oven hardening process called carburizing.

The camshaft starts out as a piece of billet and is milled to a shape that is close to the final product. Then it goes through a hardening process. After it is hardened, then the bearing journals and lobes are finish ground. So, the core itself does not dictate the aggressiveness of the lobe. It does limit the approximate duration and lift, but not the lobe design. The final shape of the lobe is determined during the final grinding process. Many companies that use our cores have their own proprietary lobe designs that differ from ours. So, the core itself does not dictate that lobe design of the final product.

There is no easy answer to this question as it is highly dependent on the engine engine combo. All of these parts work together as a system. So changes in duration and lift will affect each combo differently.

That will be an extremely versatile camshaft for a performance LS1 or LS2 engine. In order to determine if that is ideal for your appliaction, I would need to see all the details of your build.

C6 Monterey

So....how would you interpret what Patrick G told me (pertaining to your comments above)?: "Patrick G (227/232 .629"/.615" 113LSA +2) using his custom Texas Speed lobes – He says his compares favorably with the BTR2 cam, except his lobes are a little more aggressive with more lift."

Thanks.

93Polo

A big part of which will perform better will depend on where your heads are flowing best.

kmagvette

I agree on flow. In my C5Z, with a much smaller cam (0.574), long durations, GMPP Heads, and a 90mm TB on a modified LS6 intake, I got 447 rwhp and just over 400 ftlbs over a wide rpm range. The grind was nothing special, just a stock Comp Cams grind. If intereste, I can dig out the cam specs. The engine was tuned for stoichiometry, no leaning out for max power stuff.

I think I had to go to 39 lb injectors too.

All the flow is not free, with the large TB and cavernous intake ports, port velocity at idle was low an the engine idled like crap, easy to stall in the pits. On the track it was a screamer. Perhaps the idle issues could have been tuned out. I never tried because i didn't care enough to.

NICK YOSKIN

Google, Comp HUC lobe!

NSFW

You can get a rough idea of how aggressive a cam is by comparing the duration at 0.006 lift to the duration at 0.050 lift. You can get a little more info by comparing duration at 0.050 to 0.200, if the .200 duration is even available (some vendors don't share it). As far as I know, those are the only commonly-available numbers. And one of my favorite quotes is "If you can't say it with numbers, it's only an opinion." But the most interesting numbers aren't widely available (like acceleration & jerk, as Cam Motion mentioned), so we mostly have to base our decisions on opinions anyway.

I've been nerding out over cam specs for a while now, with basically the same purpose - not a DD nor a race car, just want a lot of reliable HPDE / lapping days. I like the specs and customer descriptions of TSP's Torquer V2 (232/234 @ 112, 0.600 lift), but I'm probably going to ask Cam Motion to come up with something to suit my preferences because that approach really appeals to me.

I figure that if I go with .600 lift and "gentle" lobes (for some definition of gentle...) then valvetrain life will be acceptable. And I need it to drive smoothly at 1500 RPM because I'll be on the freeway for an hour or two getting to the track and back. And what's the lowest RPM I'm likely to want good power? And what's my rev limit going to be? And then I'll ask for a cam that will give me the most power possible with those constraints. I don't yet know the answers to those two questions, but when I do it'll be time to order a cam. I don't trust myself to be able to translate cam specs from web pages into something that will meet my goals, and that's why I like the idea of having a discussion with someone at Cam Motion who can design a custom cam.

tlrskunk

Sending email