I'm Posting to add some INFO or perhaps a WARNING Re; Com CAMS Cast Hardened Lobe Treated Roller.

I was browsing around at Team Chevelle Site and came across this Thread: http://www.chevelles.com/forums/show...ller+cast+core
Re: Comp CAMS Cast Rollers Vs Billet Camshafts and its got me concerned. I for one thing I just realized the cam I'm running now is Cast and not a Billet. I am running a Cast Roller with Crower Hippo Oilers. Seems there have been allot of Failures reported with these cams probably because the purchaser was not aware that the Roller they purchased was NOT a Billet.

From what I can deciphered from the thread is that the Cast Rollers can not handle high Spring Seat Pressure and Rates that the Billet Shafts can handle with the same Profile. Therefore; it is understood that, your RPM must be limited or you’re inviting trouble. Consider MAX RPM of 6200. Seems Comp CAMS does not recommend a Seat Pressure over 169lbs and a Rate not higher then say 496lbs (which is too high by opinion) conducive to their 929-16 & 953-16 Spring Packages for Cast Rollers; where as, Billet Shafts can handle considerably more pressures with the same Lobe Profile and can maintain 7000+rpm.

If you have mind to hit 7000rpm and hold it there with your BBC I understand that a REAL Comp CAMS Tech will recommend you order a Special Grind Billet with the same Lobe Profile as the Cast Roller Shaft and specify they install the CAST Distributor Gear so you will not have to use Bronze or expensive composite Distributer Gears. The Tech will recommend the appropriate springs that have much higher Seat and Rate Pressures. Unfortunately for me I must not have been talking to a REAL Comp CAMS Tech as he did not make the above recommendations when I ordered the CAM.

Comp CAMS CAST Roller Camshafts can be identified buy there part number ending with the # “8”. Comp CAMS Billet Rollers part numbers end with the # “9”.

I’ve looked at some Failure PIC’s re: these Cast Rollers and there pretty Scary. I’m fortunate that I came across this thread before my Engine was broken in and I attempted to rev 7000rpm.

I am not attempting to BASH Comp CAMS for selling CAST Roller shafts but I was always under the impression that ALL Roller Camshafts were Billet and Comp CAM does NOT emphasize the difference in their product. GM uses Billet Shafts for all their Rollers; WHY not Comp CAMS?

In the mean time, I will have to keep the revs below 6000rpm and keep close watch. I will be pulling the intake off after 5000 miles for inspection and more then likely change out the Cast Mechanical Roller for a Billet. When I order the Billet Roller and springs it will probably be from Lunati or Crower rather then put my trust in Comp CAMS again.

If you have Experience with tComp CAMS CAST Roller Camshafts or are in the same position as I am and feel deceived Please POST, as I require allot of convincing if I am to keep this camshaft.

What pisses me off the most about this finding is that I have put out money for a Forged Crank, Forged Rods and Pistons Plus Severe Duty Valves and to unknowingly install a NON BILLET Camshaft is upsetting to say the least especially after discussing the engine build up with a Comp CAMS Tech. I've been building cars for over 35 years and expect bloopers but this is my first experience with Comp CAMS.

This is an example of what I'm getting at: Link at TeamCamaro Forums Re: Flaky Roller CAM: http://www.camaros.net/forums/showthread.php?t=93714

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PS: I will be phoning Comp CAMS on Monday to verify their Position regarding their Cast Roller Camshafts and let you know what they say; especially, about sufficient Spring Prasure to rev 7000rpm without flaking these Cams.

 

I just got off the phone with Eric a Comp CAMS Tech RE: Spring Pressures Vs Durability and Flaking issues with their “8” Series Cast Roller Cams. As I stated previously I was unaware that the CB-288R-10 Grind, PN 11-692-8, were the “8’ Suffix on the Part Number designated a CAST CORE and was NOT a BILLET CORE when I purchased the Cam.

I am presently running the recommended 929-16 Comp Cam Springs Install at the Specified Height of 1.88” with 148 lb Seat Load, the Spring Rate is 437lb/”. I Informed Eric that since I have bought the Cast Roller Comp Cams now recommends the 953-16 springs rated 148lb installed at 1.95 having a rate of 472lb/”, But their catalogue shows a Rate of 496lb/” for these springs – what ever. Eric said that I would be fine with the 929 springs on the Cast Core Cam as long as I did not hold the rpm above 6000 rpm for any length of time or buzz the engine above 6500 rpm. He stressed the importance of the installed height relative to seat load pressures over the Spring Rate factor specifically for the durability their Cast Core Roller Cams. He went on to say that the 953 with the higher Spring Rate would be more forgiving then the 929 if I happened to buzz the engine over 6500 rpm. I referred to the 933-16 springs with following specs of 170lb at 1.95” installed and 490lb Rate. He said as long as the installed height was an accurate 1.95” the Cast Core would handle it.

I reminded him that people have PIC’s on line showing Extreme Flaking of their “8” Cast Roller Cams and that I was concerned then told him that I would be pulling the Intake at 2000 miles for inspection at which time, if all looks OK, I will more then likely install the 933-16 Springs. He responded by saying that the inspection was a good thing and should be done regularly because this was NOT a Billet Cam. He went on to say that the Cast Roller Cores will show Signs of TRACKING compared to Billet Cams but should NOT show signs of Flaking providing the springs are installed correctly and the Engine NOT revved beyond the Cams Specifications, which I assume is 6500 rpm. We both concurred that the Higher Spring Rates of the 953 or 933 would provide better protection if the engine did happen to buzz beyond 6500 rpm; however, I stated lobe damage can occur if the seat pressure was insufficient bouncing the valve on the seat during higher revs this he concurred. Eric informed me that Steel Distributor Gears are used on these Cams but recommended the Light Weight Bronze Tipped Fuel Pump Push Rod.

So, what is the CONCLUSION? I would think EXTREME CAUTION. If running a Comp CAMS “8” Series CAST CORE ROLLER, you are faced with the inconvenience of pulling the Intake every 2000 to 5000 miles for inspection. This is NOT what I had in mind considering I want Descent Performance which includes ENDURANCE and Reasonable Maintenance Intervals.

If I had known, a that the time, that the “8” Suffix of the Comp Cams Part Number designated a CAST CORE, I would have gladly paid Comp Cams the additional $18 to have the same Profile Machined on a BILLET CORE that can run higher Spring Pressures without the consequence of Cam Lobe Failure.

Right now I have approx 200 miles on the motor. At 2000 miles I will be pulling the intake for inspection of the Cam Lobes. At which time I will POST my findings and inform you of my decision; but I’m really pondering Lunati VooDoo right now.

So there it is. The Woe’s and Travails of a Hot Rodder’s Life ))

 

Wow! This is good to know. IMO a cast iron camshaft defeats the purpose of having a roller cam. The whole idea is that a roller cam can use much more radical lobes than a flat tappet cam, and needs the high spring pressure so that the valve train can follow the lobe contour. I suppose they wanted to hold costs down and avoid the distributor drive problems that a steel gear would create.

 

Pete:

You’re partially correct. It is NOT so much the money saved as it only Costs $18 extra to have a Cast Roller Lobe Profiles machined on a Billet Camshaft and for a couple dollars more have a Cast Distributor Ring pressed onto the Billet Core, thus eliminating the need for Bronze or expensive Composite Distributor Gears. Yes the Billet will accept higher spring pressures but then you have to consider your intended rpm range and that corresponds to Compression Ratio being compatible with the Cams Lift and Duration.

I for one am not a Drag Racer. I prefer a Strong Performance HWY Runner that would be capable of holding near 7000 rpm intervals before the next shift. Although the Profile of the Comp CAM Cast Camshafts falls with in this range they are intended to Buzz to the cams specified rpm for short intervals; thus Higher Springs pressures associated with more Radical Lobe Profiles and Drag racing are not required and as you pointed out the advantages of not using expensive Composite or the Bronze Gears that wear out.

If you Browse the Comp CAMS web Site, say for BBCs for example, you will note that that under the Mechanical Roller Camshaft the Part Number Suffix “8” designating Cast Core range in duration from approx 232 to 262 Degrees @.050 and from .622” to .666” lift which is considerably more then Flat Tappet but not as severe a Profile required for Drag Racing which requires short bursts of power and utilizes much heavier Spring Pressures. A drag set up is NOT an efficient HWY cruiser or Canon Ball. Also the Roller Lifter offers one advantage that is often over looked and that is reduced internal friction that allows the engine to idle easier and rev faster with a cam that is more radical then Flat Tappet but not as radical as Drag.

I have no doubt that Comp Cams have engineered the CAST CORE Roller Camshaft for this Market; however, the problem arises when the driver neglects the Cams Specified Range and attempts to Hi-Rev the engine like a Drag Racer. Due to the Heavy weights of the Roller Lifters and Bigger Valves the Lighter Springs will not hold the Rollers on the Lobe after 6500 rpm causing the lifter to bounce or chatter thus damaging the Softer Cast Lobe which people have reported as FLAKING. If you intend to extend the RPM Range with out Damage you can Grind the same Profile to a Billet Core and use Higher Spring Pressures.

After all these years of Rodding, the concern I’m faced with is the result of my ignorance as I assumed that all Roller Camshafts were Billets and missed the meaning of the “8” and “9” Suffix on the Comp CAMS Part Numbers and the Comp Cams Tech did not elaborate on the matter to inform me the difference when I purchased the Cam.

As I said, I may decide to keep this cam after a 2000 mile inspection but the matter of FLAKING will always be in the fore front of my mind if I do decide to keep it. I will undoubtedly, after a few thousand miles of break in, set the rev limiter at 6200 rpm but would have preferred to set it at 6800 rpm or possibly 7000 rpm using the same Profile.

It is Wise be Safe then Push the limits of Design and that’s a Trait of a Good Hot Rodder ))

 

The material that the cam is made of is of no consequence. It depends on whether it's a solid race roller or a street roller design. The reason for a billet camshaft is because of the enormous valve spring pressure on a race roller design. When You have 300# seat pressure and sometimes 1000# open pressure, You have to have special material in camshaft, lifters, pushrods, spring retainers, valves and rocker arms to handle these extreme pressures. A billet cam requires the use of a bronze distributer gear also. A street roller, whether it is a hydraulic or solid roller don't have to deal with this abuse, thusly don't require the use of a billet material. If You want to use a billet camshaft, be ready for more maintenance due to the bronze gear, etc. The billet is designed for racing and short term use. The reason for the bronze gear is for cam maintenance only. You would rather replace a $60.00 gear than a $400.00 cam. When the bronze wears off the gear, it goes into the oiling system and beats up other parts, IE: bearings and such. When a racer replaces His distributer gear every 50 or so passes, it's for preventive maintainence. I don't hink most of the guys want to replace the distributer gear in their daily driver or even their weekend warrior that often. Before You dive off the deep end, do Your homework, and get ready for the maintainence.

 

Bill:

At this point, it's GREAT to have a Ride that only requires maintenance.