Much as I appreciate the thought and effort of them even bothering with testing and posting, look at this: http://www.compcams.com/v002/Pages/386/XE256H-10.aspx That's the best example of nasty spring surge. Nearly every street cam has problems by 4200 RPM. Even the mildest results peak above 4200, and above 4200 is where the larger cams add more power. So why show results with their 981 springs? How are we to evaluate the results when this example has no net gain over the next milder cam? And the 268 showing no net gain over the 262? Over a year ago I messaged them about this, with NO response since. So maybe going public will get noticed, I hope. And why stop there? Blow the dust off this engine, slide the Thumpr in, and post that result. Try the 256 Nitrous cam as well. And the HE series. Billy Godbold, when someone gets you to read this, go put some 982 conical springs in that engine, upside down, with Vortec L31 retainers. That way there can be no spring surge. Then re-test with every hydraulic cam on the shelves that has no overlap at 0.050", which renders them all emissions-friendly if not technically legal. More importantly, extend the testing down to 1500 RPM with no dip at the bottom of every curve, or 1000 RPM with the dip. So many are running 1500-stall converters. So many are running overdrives. Why is the first graph in 400-RPM increments, and the others at 500? That does NOT help our comparisons. Make them all 400. Run all of them to 6200. And add a short sound clip of the idle quality of each. Then you'll gain market share the way tirerack is THE premiere website for tire info. Everyone who wants Godbold to remedy these issues please post "agreed".

 

agreed

 

Absolutely

 

Comp has a lot more than that to improve on, heh.. I'm just putting that out there.

 

Hoping we don't get off topic, but what's your gripe with Comp? I can see very little else worthy of complaint in this forum.

 

Comp needs to add some valvespring designers to their team. Nearly all their spring recommendations are wrong.

 

I never noticed. How many people do you think go by those listings, anyway? I've yet to communicate with anyone using the springs recommended. Better to gripe that the 4.3 cams have 0.500" lift instead of keeping it to 0.475". Or how they're making over $100 profit per cam for the LS1s, even custom grinds, but I've attacked that issue before. Come on guys, let's get enough agreements here to merit sending them a link to this thread. Please?

 

Seems a few on this board have done that, with hyd rollers and not made the power expected because of valve float or surge. I think it happens more than most think, however alot of head swap guys just use the springs that came with the heads, and just go by lift capacity.

I agree tho i would like to see them test that combo again with the right springs.

 

Their solid lifters are absolute crap for what you pay for them. I've seen some terrible failures on their high-dollar lifters, and not from user error.. either. That, and I find their tech support to be extremely lacking on critical information in most respects. To be fair, I haven't talked to everyone there - but every time I've talked to Lunati, Crower, or Bullet they're on the dot every time.

 

They have some questionable stock grind profiles, but if you are really looking for power they do have a good program for calling in a custom grind.

With that being said, I have given COMP 4 chances as I know valvetrain failures are common and most of the time can be user setup issues.

I am done it has just caused me too much heart ache and switching brands has solved the problem each time so take it for what it is worth.

Failure 1: 23,243 miles SBC GEN 1 383 Modified Vortec heads. Marine XFI XM270 cam. Broke it in on a single valve spring on a double setup, with Majik 40 weight oil. Changed out to Mobile one and installed the other part of the spring. was using COMP 1.6 magnum rollers rockers and Comp flat tappet lifters. Also using COMP pushrods. Springs were 280lbs over the nose. Had the lifter on 7 and 5 mushroom and the cam flattened.

Failure 2: 38,032 miles, Rebuilt engine above used Crane cam, switched to retrofit roller. used Comp retrofit rollers, and new comp pushrods. One of the retrofit roller set ups shedded its link bar, and wiped the cam.

Failure 3: 50-60K miles SBC GEN II Roller block with Edelbrock RPM performer heads. Custom grind based on the XM276. Used stock chevy roller lifters. Trick Flow Push Rods, Harland Sharp 1.6 rockers. The cam failed, the rollers just ate a groove into most of all the lobes. Mobile 1 Oil.

Failure 4: 90 TBI truck 75K on cam XM250 ground with a 112 LS. Used new stock springs, comp lifters, and comp pushrods. Magnum rockers. Valvoline regular oil used. Cam broke in the block as the truck was running.

All these vehicles made great power, but as you can see they all ended in catastrophic failure. I have been using other brands like Crane, Lunati, Crower, and even some small custom grind shops. Have not have on cam go away on me from these other shops. I have not yet used another link bar roller setup. Factory Roller blocks or aftermarket blocks and GM roller lifters are all I have used.

I use engine analyzer pro to help me select cam profiles. I have not come across many cam grinds that are optimized for my combination of parts. Especially when running EFI through out the years. EFI has come along ways and vacuum is not as important as it used to be for driveability, but playing with LS and duration has made things work better.

Sorry if this is not the kind of info that is wanted on this post, If it is not feel free to have it moved or deleted, to keep things on track, or ask me to move it.

 

Attilla- I wouldn't jump to that conclusion right away. Spring surge (valve float) is certainly not something that would leap to mind at only 4200 RPMs. Plus you're talking about old Dart S/R Torquer heads on that test mule, which I will tell you from personal experience are no better than a stock head with a 3-angle valve job. They're going to choke the engine pretty good themselves over about 4500.

Still, 981 springs were invented WAY before the current crop of more aggressive XE cams. I like using them as a "mild upgrade" over stock (even for production line hydraulic roller cams in 87-up engines). They work well for that. But would I trust them to control something like an XE268 or larger? Mmmmm..... probably not if I was serious about things. They were really designed for fitting into a stock head with few or no modifications, before the era of commercially available "beehive" springs and were always a bit of a compromise for high RPM performance.

I would not expect Comp to respond to you complaining about the testing they used for advertisement purposes. They SHOULD respond to a specific problem YOU may be having with their products, however.

I will add that every cam-related problem I've ever had was with a Comp cam. My usual solution back in the day was to replace it with a Crane cam of similar specs (which always worked)! QC has never been Comp's strong suit.

 

Glad to see I am not the only one.

 

All of what you posted just makes me glad that when I went with the XFI grind cam in my Hemi, I stayed with mopar 6.1 valve springs.

Also makes me glad I stayed with a GM production camshaft, rocker arms, and related valvetrain in my L31 setup.

The stock GM 142 cam, advanced from 115 ICL to 111 ICL made 240 RWTQ on a Mustang Dyno all the way down at 1,500 rpm in a 9.4:1 vortec head 350. By my 2,700 rpm stall speed it was making over 270 RWTQ with 295 RWTQ at peak. To have over 80% of your peak torque available from 1,500 rpm clear through the redline without having variable valve timing or intake runner length is impressive.

 

Damon: I understand as well as anyone about how the heads are all done filling that many cubes by 4200 RPM. I'm not asking Comp to re-dyno for me. I've dynoed enough combos to know what I'm doing, and how to get what I want. I'm asking them to realize that these graphs are worse than meaningless, unless you're anti-power-gains AND pro-small-cams. Fixing these issues would help them sell people on the extreme costs of converting to beehive springs, IF they show both sets of results for each cam. As it stands, there's only one graph that's close to exceptionally good: the XR276. Too bad it'd not emissions legal for any Camaro built after 1974. Fast355: Your choices don't exempt you from spring surge. If you don't have these dips in your dyno results, then either the resolution is too poor, ( too much smoothing ) or you got adequately good springs. Going to higher-ratio rockers can induce spring surge to a combo that had none, but it'll never fix spring surge.

 

I had a solid roller comp cam cam core that started flaking and compressing the lobes within 2,000 miles. The only reason I found out is because a cam bearing walked out of the block. Caught that b4 any real damage was done tho.

Dave Crower told me that comp uses 2 cam cores, a cheap one and a $$$ one. Guess which one got sent to me.. You have to ask and pay for a upgraded cam core from comp but not from Crower.
I am using Crower hipo lifters in this motor.

 

I figure my next cam will probably come from Howards. I just get a good vibe from that company for some reason. A little under the radar, though.