[Z Code 400]

Back in the 1980’s, a few guys that we raced with started using Comp Cams. Even then, we noticed they seemed to have a lot of lobe failures, compared to running cams from Isky or Sig Erson, which were both hugely popular in the Central Valley at that time.

We had a local speed shop offer us a Comp Cams once as part of a sponsorship, so we chose one that was really close to the .550”/.550” – 250°/250° @ .050” – 109° LSA Isky EE-390 we were running in our 429 Ford at the time. We were turning 6800 with the 429 and only running 130 lbs on the seat and 285 lbs open pressure.

When we installed the Comp Cams (248°/248° - 110° LSA) shaft and it idled like crap when directly compared to the Isky, but we decided to give it a try. The engine felt really strong off-idle and up through the gears, but the motor fell flat on its face at 5500 rpm. We called Comp Cams and gave them the run-down on our combination and we were told that we needed at least 350 lbs open to keep the lifter on the lobe with the ‘aggressive’ Comp profiles.

We swapped springs and were able to get the engine to rev to 6500, but we lost ET and MPH. No amount of tuning ever brought us back to our previous ET and MPH.

We put the Isky back in and went back to 285 lbs open pressure and went right back to 6800 rpm and our previously high & consistent ET’s and MPH.

I spoke at length with Richard Iskenderian about Comp Cams in general and he told me the profiles were very jerky and required a lot more spring pressure to control. Isky used to be in the habit of testing their competitor’s profiles and the Comp Cams at that time were horrible from a dynamic stability standpoint.

That’s the last time we used a Comp profile.

Over the years. I have found Comp Cams advertising campaign laughable, especially placing the greatest emphasis on the idle sound a camshaft will produce. Years later, they came out with the ‘Thumper’ line of camshafts and printed the following description on their website:

“The reason these camshafts have such an aggressive exhaust note is that the lobe profiles and grind characteristics chosen by the COMP Cams engineers produce a combination of early exhaust valve opening, long exhaust duration, and a generous amount of intake and exhaust overlap to maximize the rough-idling characteristics….”

As if this didn’t already sound silly enough, Billy Godbold of Comp Cams recently said this about the ‘Thumper’ line of camshafts:

“The valve timing events of our Thumper camshafts are almost identical to our road racing applications, especially 24 hour endurance events. The reason we employ this strategy is that drivers get tired and don’t want to shift, so this cam lets the car pull if it’s a gear high in a turn or a gear low on a straight. You get an early torque peak and a long, gentle fall off. It’s more fun to drive….”

Now valve events are simply a number on paper, which is different than a lobe profile. I could understand his statement if he was describing a particular lobe profile, but to simply say the ‘valve event’ is nearly identical to a ‘road racing application’ really tells you nothing.

Harold Brookshire, the mastermind behind Ultradyne cams, recently made the following statement about Comp Cams. “There isn’t anyone at Comp who knows anything about camshaft design….”

Last year, I was helping a guy with a camshaft install and I noticed his #995 Comp springs had much higher spring pressures than listed in their catalog. I called Comp Cams and no one could answer my question. I was passed around to several people until I was put on the line with Scooter Brothers. I explained the discrepancy to him and he said, “Our new profiles are so fast and abrupt that it takes a lot of spring pressure to keep the lifter on the lobes.”

I then asked him how he felt about 300+ lbs open pressures on a street motor and longevity. Scooter said, “These are hobbyists that drive their cars only every once in a while. The benefits of our aggressive lobe profiles require a lot of spring pressure. It’s a trade off and even though the high spring rates will shorten lobe life, it isn’t going to be noticeable on a weekend-driver application…..”

Recently, there has been a lot of discussion about the metallurgical quality of lifters, but the single greatest factor that influences lobe wear is spring pressures. ZDDP is important to, but we ran our 427 and 429 Fords exclusively on Shell Aviation Engine Oil which has no metallic anti-wear additives and we never lost a lobe. One reason for this is we have always stayed under 300 lbs open pressure on street engines with flat tappet camshafts and even Scooter Brothers acknowledged that those were "ideal pressures for long lobe life", but the abrupt, jerky valve motion of their profiles just won’t allow lighter pressures.

I also asked Scooter about the NASCAR grinds that they provide to some of the Winston Cup teams and he said, “I really can’t disclose any details, but those are nothing like our commercial grinds. Those lobe profiles don’t even appear in our catalogs…”

I spoke with Kent Ford a few years ago, who was famous for his head work on Bill Elliot’s 351 Fords. When I mentioned Comp Cams he said, “They are all about fad marketing. Their NASCAR grinds are all just copies of what Mike Jones is doing and they still can't duplicate his lobe profiles……”

I know that going against the accepted ‘trends’ here in this forum quite often creates a lot of negativity, but I think this is an important point to ponder. For every person who tells me they have good luck with Comp Cams, there are several more who are experiencing problems, noise or lobe failures.

If you are racing or driving your car only on weekends, you can easily get away with more spring pressures, but, for any street engine that is driven on a regular basis, I would suggest a more dynamically stable camshaft profile from Crane, Lunati, Crower, Iskenderian or Bullet Cams with 300 lbs or less open pressure for maximum longevity.

I hope this information proves interesting and helpful…Robert

[Z Code 400]

Just for comparison, the custom Isky solid profile we used in our 325 and 352 CID Small Block Chevrolet oval track applications was .585"/.585" - 330°/330° SAE - 284°/284° @ .050" on a 106° LSA. We used valve springs with 135 lbs on the seat and 295 lbs open pressure.

This engine made its power between 4500 and 8500 rpm, yet we were able to run a valve spring that would have been at home in a street motor. In fact, the valve spring Isky recommended for our application was a dual spring (#6005) installed at 1.750" and specifying 135 lbs seated and only 315 lbs open pressure.

Now consider that we could spin the Isky profile 8500+ with 290 lbs open pressure and the Comp Cams #995 spring, when installed at 1.700" is advertised as having 130 lbs on the seat and a whopping 375 lbs open pressure at .550" lift. It's obvious that the Isky profile generated less heat, less parasitic drag and was simply more dynamically stable than Comp's lobe profiles.

Comp recommends and sells these #995 springs (as a kit) with camshafts as mild as the XE274 and with .488"/.491" valve lift and a 1.52:1 rocker arm, that's over 350 lbs of open pressure. Now, if you follow the 'trend' of using a 1.65:1 rocker arm on this camshaft, you push the lift up to around .535" and open pressures now approaching 375 lbs.

According to Comp Cams, the benefits of their “aggressive, modern lobe profiles” are worth the shortened lobe life, since the "average hobbyist" only drives their vehicle every now and then. What about those folks who really drive their Pontiacs on a regular or even daily basis???

What about the enthusiast who spends the hard earned money for the correct cam and lifter kit and ends up with over 350 lbs open pressure???

I think herein lies one of the reasons the Pontiac community is losing so many camshafts...Robert

[screamingchief]

Honestly,there is plenty of good and bad in most all cam companies if you wanna go looking for that sorta thing...

I'm not refuting the comments about comp's marketing strategies,but the onus is on the consumer to resist that and understand the true nature of the beast.

You can absolutely get a good cam from comp,with "dynamically stable" lobes if that's what your after,you just wont find that sorta cam being marketed heavily by comp.

Their "specialty grinds" listed for pontiacs in the catalog section at the end of the main catalog listings are far superior to most of the "catalog/shelf" pontiac grinds listed in the main catalog pages if you asked me.

The "b" series solids (290b6 or 300b6) are still among the best solid lobes you can find for a pontiac.

And with custom ground flat tappet and roller grinds/lobes they still have lots to offer the high performance consumer,and are absolutely viable and competive with most other cam companies.

And one also must admit other companies are'nt exempt here either,you quote Harold B.,nice guy,we all know he know's his $#!t no doubt,but he is also the man behind Lunati's voodoo series,you wanna see some aggressive lobes,go look at those cams,the warnings are plastered all over them,"these are the most aggressive lobes ever,dont follow our break-in procedures and cam failure WILL occur!".

That marketing is hand in hand with comps marketing.

Now who's selling shiny pretty things to the rubes.

Those voodoo cams also have very specific spring requirements as well,and they recommend pretty "stiff" springs as SOP for those voodoo lobes too.

Now again,granted Harold know's his stuff,he also knows cam design dont mean squat if nobody buys the cams to begin with,company goes out of buisness,the rest of the world keeps spinning on and on.

Lunati is another one of those companies that you can find both good and bad if you look hard enough.

Though I hear thru the grapevine that may soon change,as the company has changed hands and the new owners plan is to put the company right.

This was posted on another forum:

As the designer of the VooDoo cams, here is what I know.

At the SEMA show, a group of private investors from North Carolina bought Lunati away from Holley.
The investors invited Ron Coleman, the owner of Comp Cams, to join with them as another private investor.
Comp Cams, the company, owns no part of Lunati.
The investors have asked me to do future cam designs for Lunati, both in my VooDoo line, and in the Lunati line.
I have heard that they intend for Lunati to return to being "The Racer's Cam Company".
If anyone is interested in VooDoos, or other cams that I have designed, or will design, please let me know.
Tuesday my phone number will be 662-562-7400, and I will answer as "UDHarold".
I also have Morel lifters, and Pacalloy valve springs.

UDHarold

So,even he (Harold B.) must understand that it's a fine line to walk,and one really should'nt burn too many bridges in their endeavours.

Holley does'nt even have the Lunati brand on their website anymore,the site is in limbo as far as I know at the moment,cant find it out there in www. land right now...

A few other cam companies are presently stuck in the stone age in some respects,relying on selling the same lobes they've sold for years and years with almost no change,but again that is both good and bad,it's good in that if you find an application that can use one of those grinds you can be confident they can provide that,but it also does'nt show much in the way of advancement or improvement with the modern designs and equipment.

Meanwhile a few other companies have feet in both the new and the old schools,which to me is the best strategy.

That said,marketing does absolutely nothing for me when selecting a cam,I dont even look at that crap,and I dont blindy follow the "lead" of the cam companies when it comes to some specific areas of concern,as there are often some bias from them on those subjects.

I use what best suits the given application,and that can invaribly differ to favor most any brand if the situation calls for such.

Current cams include:
2 comps (one 290b6 solid and one custom ground "street" solid roller)
2 Crowers (one #60210 hydraulic and a custom ground solid #E27941)
1 Crane (#134052 "energizer" for my brothers 390 FE)
And soon to add one UD solid (the 288/296 solid to go with the Comp and Crower solids)
And possibly a Lunati hydraulic for my 350 (looking at a kit my friend has,cam #07701)

So I dont have any real bias one way or the other...

[Z Code 400]

Bret,

There can be no doubt that some of the Comp lobe profiles are good designs, but what is immediately evident is the high spring pressures they require are not well suited to daily-driven street applications.

Now Lunati has made a few good Pontiac camshafts over the years, most notably the old #30706 and #30702 and now that Harold has come out with the Voodoo line, a few things are changing. I'm not so sure the Voodoo line of camshafts are a good choice for a daily driven street machine either.

One of the things that Harold stresses on the Voodoo profiles is the effort put into opening the valve quick with lots of duration per thousandth (aggressive) and then slowing the acceleration rate near the nose to keep the lifter on the lobe. Harold prefers the asymetrical profile as it allows a slower, more stable closing ramp, which is good for dynamic stability.

The common Pontiac valve spring found in most of the Lunati kits is #73949 which is a 1.440" OD x .750" ID Dual Spring that installs at 1.650" with 120 lbs, has a rate per inch of 367 lbs and features 300 lbs at .500" lift.

Again, note that increasing the rocker arm ratio (as is a common trend with Pontiacs) will quickly push this spring into the +300 lbs range.

I think Comp does have some good roller profiles and these will easily accomodate the high spring pressures without complaint. However, I think there are a number of better sources for lobe profiles on the market today...Robert

[A.W.Dille]

I had also noticed that on the Holley website as I had been thinking of trying one of the new grinds ( I know I said I'd never run another Lunati, several times) in my low compression 400 in my GP and had found them gone. Robert your spring specs are close to the Isky's that my machinest installed in my 670's several years ago for the Lunati that I'm still using.

[Z Code 400]

Originally Posted by screamingchief

"I use what best suits the given application,and that can invaribly differ to favor most any brand if the situation calls for such..."

I agree with you SC....

For an oval track application, I wouldn't think of using anything but Iskenderian. Their profiles have proven themselves hundreds of times in our engines.

For street cars, I really like the work www.bulletcams.com has been doing for me. I have sold quite a few camshafts that I have put togther from their different lobe profiles and everyone has been very pleased with the results.

I think the K2801 is a good camshaft for the money, but I am willing to spend the extra $60.00 to get a custom profile, even in a mild street application.

My (4) most recent grinds have been designed around the Ultradyne lobes that are very dynamically stable. No dyno results yet, but the seat-of-the-pants meter is promising!!!...Robert

[Z Code 400]

AW,

I've been doing a bunch of low SCR camshafts lately. The results have been very, very good indeed.

Just received favorable reports this week from So. Cal where a 389 Tri-Power was dropped to around 9.00:1 SCR and fitted with my personal favorite 'off-the-shelf' grind for low SCR Pontiac applications; the Isky 256/262, custom ground on a 112° LSA.

The owner is absolutely thrilled. His engine had been built with high compression and a radical camshaft that was all wrong for his transmission and gearing. He opted for a set of lower compression heads from SD Performance and the milder camshaft profile.

Whatever 'power loss' he might have encountered is far offset by being able to run on our California fuel without pinging...Robert

[Z Code 400]

Originally Posted by screamingchief

"That said, marketing does absolutely nothing for me when selecting a cam, I dont even look at that crap, and I dont blindy follow the "lead" of the cam companies when it comes to some specific areas of concern, as there are often some bias from them on those subjects. I use what best suits the given application,and that can invaribly differ to favor most any brand if the situation calls for such...

I agree with you, SC...that is a sound approach.

However, my concern is that I see a lot of 'hobbyists' that put good money into their engines and end up buying a 'matched cam & lifter kit' to eliminate any guesswork and end up with a bad combination, or at the very least, one that isn't well suited to lots of street duty.

Obviously, if the engine is driven only on weekends, the added pressure and reduced lobe life will be of little concern. But if you drive your car like I do mine, 25,000 miles this year alone, then cam and lifter life is a very big deal indeed...Robert

[Cliff R]

With the limitations imposed by the diameter of the flat tappets, the "whiz-bang" lobe profiles don't offer nearly as much performance improvement as the makers of them would like for us to believe. Reducing actual off the seat valve timing, even with greatly improved .050" numbers based on the .002" or .006" specs, does NOT mean that the new cam will make more power and enjoy a broader power range than the one it replaced.

I haven't observed a single valid back to back test to date to prove that any of the "tight" LSA grinds currently being used make more power anyplace than standard lobes on wide LSA's.

I wouldn't even consider using a cam with a 110LSA or tighter in a 455 engine unless the .050" duration were greater than apprx 240 degrees @ .050".

From what I've seen, all that you are going to do is further enhance the fantastic abilities of the 455 engine....trying to make tons of power very early in the RPM range, and running out of wind before 5000rpm's.

For the medium compression ratio street/strip 455 engine, the three best cams that I have observed in action, are the Wolverine 5059 (234/244/112), the factory 041, and the Crower 041 clone. Interesting that all of these cams have wide LSA's, and advertised duration over 300 degrees.......FWIW......Cliff

[Cliff R]

Just another "tid-bit" about cams. Crane used to offer a couple of off the shelf SBC grinds, specifically the 280 and 300H BLAZER cams. I don't remember the exact specifications, but they were among the very best aftermarket hydraulic flat tappet cams that I ever used in SBC 350 cid engines produced thru the early 1970's.

By 1974 the SBC cylinder heads on factory engines were so pathetic in exhaust flow that most of the camshaft manufacturer's started offering dual pattern camshafts to compensate. The compression ratios were also very "low", so they started pulling out a lot of actual valve off seat timing. They all followed suit, and today the vast majority of cams available for all types of engines are dual pattern, with LESS advertised duration. With all these modern grinds available, we still use the old 327/350hp (224/224/114) camshaft in most of the 350 engines prepared here. Like the Pontiac 041 grind, it uses a wide LSA, and very generous off the seat valve timing specifications. For 327 thru 358cid SBC engines, around 10 to 1 static cr, it is difficult to find a better camshaft for all around street/strip use. The only other cam that we have found to work any better, is the factory GM hydraulic roller "HOT 4" camshaft......Cliff

[Z Code 400]

Cliff's points should be well taken....He knows!!!

High SCR applications will benefit greatly from longer seat timing and wider LSA's. With 10.50:1 SCR, the later intake closing events with profiles featuring 300° of duration @ .006" lift and wider LSA's (from 113° to 116°) will reduce the DCR sufficiently to allow these engines to operate (with proper tuning) on some of the better 92-93 octane pump fuels available.

However, when you intend to use lower or varying quality fuels, reducing the SCR is prudent. A good rule of thumb to remember is 9.20:1 for 92 octane fuels, 8.90:1 SCR for 89 octane fuels and 8.70:1 for 87 octane fuels. Again, this guideline will depend largely on the DCR of the finished combination.

Although you might be able to successfully run a 10.50:1 SCR 455 with the Wolverine #5059 camshaft, it may not run without pinging when the quality of fuel varies, in high ambient temperatures over 100°F, and/or when the combination is not in a near-perfect state of tune.

Engines with lower SCR's will benefit from short seat timing @ .006" lift, generous duration figures @ .050" lift and relatively tight LSA's. The theory here is to chose a camshaft profile that will increase the engine's DCR to a point close to that of an engine with a higher SCR and less DCR through the 'bleed off' effect of a long duration camshaft.

While a high SCR application will always make more power overall, in many cases, the lower SCR application, with a properly chosen camshaft profile, will often make more torque at a lower rpm. Although these tight LSA/low SCR combinations will not make the 'broad' power that is common to wide LSA/high SCR applications, they will have greater octane tolerance and very good low and mid-range performance.

Here in California's Central Valley, we receive numerous reports of engines running 9.50:1 SCR that will not run on our oxygenated 92 octane fuel in +100° F summer temperatures without pinging, even after the addition of aluminum radiators and electric cooling fans.

For street engines in this environment, I prefer not to push the envelope with respect to SCR.

A customer recently wrote to me with a California based 406 with 9.98:1 SCR that would ping (on 92 super) anytime the ambient temperatures were above 80°F, even with coolant temperatures of only 180° to 190°F and conservative ignition timing.

Several camshafts were changed, including some of the larger Crower grinds, having generous overlap figures at .006" lift and 290° to 300° duration and nothing would stop the pinging.

The heads were eventually swapped to lower the SCR to around 8.90:1 and the camshaft was replaced with a .467"/.467" - 270°/276° @ .006" - 220°/226° @ .050" - 111.5° LSA custom profile. Following these modifications, the engine ran without pinging on 87 octane, even in 100°F temperatures.

There are two ways to approach engine building and each one has distinct advantages and disadvantages. Since I drive my car on the street, I chose a lower SCR that was compatible with our lower quality fuels and a camshaft profile that improved the DCR.

The narrow LSA and advanced camshaft position create an earlier intake closing event, higher vacuum, better throttle response and builds torque earlier in the rpm range. Although this shifts the entire powerband down slightly in the rpm range at the expense of higher rpm performance, I feel this approach is ideal for a daily driver where varying fuel quality is likely to be encountered...Robert

[Half-Inch Stud]

Isky
Lunati
Ultradyne Bullet
Crane...I've been told that CRANE is quite good.
.
.
.
COMP..I was put off by COMP using the "Magnum" name that ISKY MAGNUM used in the 70's & 80's.


HO Racing & Nunzi High Lifts were made from/by who?

[screamingchief]

FYI:I found the new Lunati website guys:
www.lunatipower.com

The common Pontiac valve spring found in most of the Lunati kits is #73949 which is a 1.440" OD x .750" ID Dual Spring that installs at 1.650" with 120 lbs, has a rate per inch of 367 lbs and features 300 lbs at .500" lift.

I agree that lunati spring is'nt nearly as bad as the new comp #995-16 springs specs,the problem that I see is when somebody installs them without checking their IH and uses them at the stock 1.60" IH by default,but that is the same issue with most any spring and inexperienced builders.

And I still prefer the crower springs as my first choices.

Again, note that increasing the rocker arm ratio (as is a common trend with Pontiacs) will quickly push this spring into the +300 lbs range.

Do note that the notes and accessories listed for the voodoo line of cams from lunati seems to imply that a fella should stick with the 1.5 ratio as SOP,likely for that very reason.

There can be no doubt that some of the Comp lobe profiles are good designs, but what is immediately evident is the high spring pressures they require are not well suited to daily-driven street applications.

Understand that just because comp tells you to use more spring pressure does'nt necessarily mean you need more spring pressure,that suggestion applies mostly just to the XE lobe series,and a select few of their "aggressive" custom racing lobes,not every lobe series comp offers requires such,thus the reason I mentioned and often recommend the comp pontiac "specialty" grinds,as those are based on less aggressive lobes,and those cams were well proven "back in the day" before they developed and marketed the XE series to replace those.

This is what I meant when I said you gotta understand the nature of the beast,and not blindly following comp's lead.

Originally Posted by Cliff R

With the limitations imposed by the diameter of the flat tappets, the "whiz-bang" lobe profiles don't offer nearly as much performance improvement as the makers of them would like for us to believe. Reducing actual off the seat valve timing, even with greatly improved .050" numbers based on the .002" or .006" specs, does NOT mean that the new cam will make more power and enjoy a broader power range than the one it replaced.

I haven't observed a single valid back to back test to date to prove that any of the "tight" LSA grinds currently being used make more power anyplace than standard lobes on wide LSA's.

I wouldn't even consider using a cam with a 110LSA or tighter in a 455 engine unless the .050" duration were greater than apprx 240 degrees @ .050".

From what I've seen, all that you are going to do is further enhance the fantastic abilities of the 455 engine....trying to make tons of power very early in the RPM range, and running out of wind before 5000rpm's.

For the medium compression ratio street/strip 455 engine, the three best cams that I have observed in action, are the Wolverine 5059 (234/244/112), the factory 041, and the Crower 041 clone. Interesting that all of these cams have wide LSA's, and advertised duration over 300 degrees.......FWIW......Cliff

Again,the most often made mistake on these deals is the person choosing these cams gets tunnel vision and concentrates on just one or two specific aspects of a cams design,and he pays attention to just those aspects,and totally neglects other aspects in favor of those supposedly more "important" aspects.

The most commonly overlooked aspect being overlap IMHO,loose a significant amount of overlap and power will almost certainly suffer,even the pontiac engineers knew that,look at the factory cam specs and that is extremely evident they were aware of that fact,as the sole aspect of those cams that consistently increased as you go "larger" in the pontiac OE cam foodchain is the overlap,other than that,most OE cams used longer seat durations,wider LSA's,and limited lift as SOP on most cams.

So where exactly was all that "added" power coming from with those OE cams,,,simple,,,overlap...

But 90% of folks could'nt even begin to tell you what the overlap on their cam is.

This is also why I laugh my a$$ off when folks here suggest the summit K2801 is "an 068 with more lift and a little less duration or LSA",,,it's not,,,not even close,,,it's more like an 067 with more lift and a smidge less LSA if you look beyond the .050" specs.

Show of hands,,,how many here have made that mistake???

I assure all here a cam with those "whiz bang" lobes could indeed be chosen to match/best most any other "old school" lobes out there,and vice versa,it just takes looking beyond one or two specific aspects of a given cam to the detriment of the other aspects of a given cam.

But surely there will be a compromise made somewhere in that choice to accomplish said task,cam choice and design is all about compromise,give a little,take a little,you cant get something from nothing...

Again,understand the "nature of the beast" and you can "cherry pick" cams where ever you so may choose,from any brand you may find that has what you need,as long as the cam is properly chosen,and it's the "right" choice for the given application,it should perform reasonably well.

But this takes more than looking at just the advertised duration,.050" duration,lift,and LSA to do so.

There is still a lot of grey area left in a given cams design,add watching the overlap and valve timing events at both the advertised and .050" points and your starting to get the bigger picture,but even then there is more minutia to be found in cam design.

A top cam designer like Harold B. or Mike J. can look at a set of valve timing events and know more about most cams than most laymen will likely ever grasp.

But I digress...

[Cliff R]

SC, even after all that, we both know full well that nearly EVERYONE in this hobby, including cam manufacturer's compare, and rate their cams based on the .050" specifications.

Hind sight is always 20-20, I know this more than most. Even so, if you go back to our cam test, and run it by Comp Cams, or anyone, anyplace, that knows anything at all about camshafts, I doubt if any of them would expect the "old" 041 grind to outpower the very best flat solid lobes, expecially when the new lobes sport 10 degrees MORE .050" duration, and .060" more lift at the valve!

My memory is pretty good, and until we did a back to back cam test, changing nothing else, we kept hearing that one should "choose a flat solid cam about 10 degrees larger than a flat hydraulic". We also heard that with solid cams, "what you see is what you get", inferring that they will or should make MORE power, even on an apples to apples comparison.

My opinion, the technology with flat lobes and standard Pontiac/Chevy lifter diameters is pretty much "played out". If you want to see improvements in power production without adding duration and/or overlap, go to a roller grind/ Then we are able to get the valves up off the seats much quicker, so the engine truely enjoys more airflow capabilities without significant increases in off the seat valve timing.

If the budget doesn't allow for the roller stuff, a set of Rhoad's lifters and high ratio rocker arms is about the next best thing.....FWIW.....Cliff

[Region Warrior]

Never used Comp products, never will.
Especially thier "1 fits all" 995 springs.
Like i've always said;
Not better cams, just better camvertizing.

Cant prove it, but I believe H.O. Racing used Crane cams.
I've had 744 HL & 041 from both years ago, and found no diff.

And I believe Edelbrock uses Crane for thier 744/041.
Have one each from GM Performance. Thier reboxed Crane's.
Same spec's that Edelbrock lists, but havent had one of thiers to actually check in block.

Always had good luck with Crower/Crane/Isky.
Try'n Lunati next cause i can get thier flat solid lifters and springs VERY reasonable through my local speed warehouse.

Hey Cliff, remember the old Crane Fireball cams?

[Cliff R]

Sure do, I actually ran a Fireball cam when I still used a 383 engine in my 1970 Roadrunner. I thought it was a really "fast" car back then, managed 14.01 at 99mph in full street trim. Even after installing a 440, Turbo Action converter, 4.56 gears, headers and slicks it only managed 12.30's. If you would have told me I could run deep into the 11's with a Pontiac engine pushing a heavier car, with less gear, less converter, DOT tires and thru the exhaust, I would have told you that your were absolutely NUTS!

We use Comp Cams roller grinds, and have found them to be very accurate, and they have the quickest turn around times in the industry. I just make my own recomendations, as they want to grind EVERYTHING on 110LSA's. I had a customer supply a set of the 995 springs once, they checked 30lbs to high for seat pressure and just over 350lbs over the nose, at an installed height of 1.700". They had been in service briefly, on an ill fated engine, and the dampner had eaten almost half way thru the shims under the springs. I would advice anyone using them to check the spring pressures and grind the knife edge off the dampner before placing them in service.....Cliff

[69Goat1]

I have a 428 I built several years ago before I got into all this Pontiac internet stuff and before I knew Comp cams stuff was junk so in my naivety I bought a Comp Cams Xe 284H and put it in my old .040 over 428 with a set of stock 1968 1 6 D-ports. I used the reccomended 995-16 springs before I knew they were junk according to the Pontiac boards. I played around with it for a few years expecting my engine to pull my 69 GTO to mid-low 13 times... Imagine my surprise when in the most ghastly state of untune (set timing by ear, single plane T-II intake, 850 DP, 3 tube headers, mismatched plug wires, etc...) the car responded with mid 12 ET's right away and never had any sort of lifter noise or anything. Without ever doing anything other than changing carbs, intake, headers, and setting the timing right got it to go 11.81 - imagine my surprise when this happened as I had heard that Pontiac cams needed to be made by Crower or Ultradyne or someone like that and needed at least a 112LS - Mine is so much a no go that it has 110LS, I put it in dot-dot and never looked back - Man I wish I had listened to the guys who said comp cams were junk so I could be stuck solidly in the mid 12's

I ran a nasty old Comp 290B-6 with 106 LS cam in a 455 I had later and it went 11.0's at 123...

Now I have a comp Roller with 108 LS and turned 10.70's on drag radials - same engine, different car this year - gonna go some 10.2's...

Favorite cam I have ever run in my life is that comp XE 284 - glad I still have it

[Z Code 400]

69Goat,

I know a few folks who run the Comp profiles and get respectable performance from them. There are far more folks who have had negative experiences with Comp Cams longevity, even though the XE cams seem to run good and produce good performance in some applications.

As Cliff pointed out with the #995 springs, folks need to beware that Comp changed the spring rates, increasing seat and open pressure on the #995's without ever making the information widely known. Cliff is not the first person who has told me the flat wound damper in the #995 spring filled their engine full of metal either.

The Isky oval track grinds mentioned earlier in this post are an example of the dynamic instability of the Comp flat tappet profiles. Anytime you can turn an engine 8000+ rpm with 290 lbs open pressure and you need 375 lbs to turn an XE274 6000 rpm, you have a superior lobe profile, less heat, greater dynamic stability and less horsepower loss.

Remember the Winston Cup engine failures a few years ago at Daytona??? Is it any wonder that these NASCAR teams are using Mike Jones camshafts now???

[Bumper]

SD performance, Pdude and others big guns use Comp so I would surmise they can't be that bad.

[Overkillphil]

H.I.S., I believe HO used Crane.
As far as Nunzi goes, he would never tell me. However, the few times I was in his shop I saw alot of Comp boxes around. Also two of the 2041 and one 2042NHL cams I bought from him came in Comp boxes. However, they were of course stamped "Nunzi" on the end of the cam. And the engines receiving his cams were happy...
FWIW