Can't do the multi quote thing on phone so bear with me. If we are talking stock cams with 80+ degree ramp rates and 500 lifts and 6mm pushrods, duals are unnecessary. Like putting duallies on a S10. But that's not at issue here. We are talking max effort engines.

Most of us on here are more in the XER LSL etc camp calling 55 degrees gentle and 600 lift low. With these cams being the norm, duals should accompany them. To be fair, 11/32 pushrods should also, but many don't spring for the parts they should.

For a single spring to have the same pressures as duals, it must necessarily be thicker, higher alloy, or both. Either of the two above decrease fatigue life Both combined is even worse. fatigue goes largely unnoticed for a while, starts to show, then fails without warning catastrophically. Unless you plan regular ultrasonic testing of your valve springs, you're setting yourself up for failure. I am a professional metallurgist and know exactly what I'm talking about. The basic metallurgy supports dual springs for engine longevity, which is the counter argument you are reading.

The test you're referring to seems to be designed to illustrate what too high spring pressure does to pushrods and ultimately to performance. Nobody will disagree that pushrod deflection is bad. But rather than assume one is outright bad, instead one should match the pushrods and springs accordingly. To me, the engine used in the article was poorly set up - almost as if to purposely illustrate the dangers with running too high spring pressure. IMO, nothing will outperform a well optimized dual spring valve train. That engine was nowhere close to optimized.

Now, you can disagree with my professional opinion, and that is fine, but you're also disagreeing with two of the most respected names in the LS world - Tony and Brian. Three if you add Martin to the list, and four if you add Kip. Personally, if I was arguing against the four top guys in their field, I would strongly reconsider my argument. You seem like a smart guy, but in this case I think this article has led you in the wrong direction.

 

I love these discussions . I was hoping somebody else would chime in here from PAC or something. But I'll share my experience on the subject.

From my testing in both a SpinTron and dyno cell...there will never be a beehive on any of my personal engines.

The "mass" argument gets blown out of proportion on valve springs IMO. The valvetrain is seeing the spring rate and open/closed pressure. The entire spring doesn't move on an axis like a valve, retainer, etc...which is where mass is most important (moment of inertia). Parasitic loss is going to be a factor of the spring rate @ it's installed height and lift range. If both springs are setup the same and have 450lb/in spring rates, parasitic loss will be exactly the same. Everybody posting here that has done legitimate testing has basically proven that. I'm not saying a lighter spring doesn't help harmonics at all during high RPM. We're talking marginal differences between the two weights and I just haven't witnessed the gains people say it should achieve. I also haven't done extensive spring testing...so maybe I'm missing something?

Beehives were originally designed to combat harmonic issues at high RPM. For the most part they do succeed at that when looking at high speed cameras and SpinTron reports. SpinTron's don't necessarily tell you everything, though. They save you from designing an out of control valve train and give you an idea on part longevity/durability. My problem with spin rigs is they don't take into account cylinder pressure and combustion....HUGE test variable...especially as valve diameters increase. Basically, they're just another tool in the tool box to give you an "idea" of what's going on.

With all that said...my number 1 problem with beehives is spring fatigue. One of the popular springs many run here are dynamically toast after 150-200 passes with .600+ lift cams. For a race car that's reasonable....street car not so much. Most of the dual springs I've witnessed being tested surpass that and of course have a safety curtain if things do go south.

Like Tony and Brian, I also haven't seen any gain in "power" with beehives. So I just don't understand the risk of beehives for the typical performance enthusiasts lacking sponsorship dollars when things do break.

 

Add another expert name... Randy from Johnson Lifters saying no to beehives.

 

The OEM thing isn't really much of an argument. OEM GM's are subject to <.525" lift usually on really mild lobes. This allows for a much softer material. The lower lift also means the metal isn't stressed as far from it's uncompressed state.

Now look at the aftermarket. Higher ramps rates and lift. Many folks having to take coil bind into consideration. I'll take the safety margin.

 

And it would appear we are all just trying to better clarify and make sense of things for "Know it all"

(Irony would be an understatement)

Like I said earlier.....horse to water. The information is out there.....everyone gets to choose his or her own path

-Tony

 

Oops seems I opened a can of worms with this one! I can't add much other than to say I've run both beehive and duals in different engines over the years and when correctly spec'd haven't had any failures....

Interesting to read both sides of the argument though.

 

There are certain applications where I have had absolutely no problem using beehives over dual springs.

It is just like anything else when modifications come into play: the valve spring becomes a wear item and must be checked on a basis depending upon how you use the vehicle and how aggressive of a lobe you installed. Don't buy a camshaft with XER/LSL lobes and a set of PAC 1518 springs and expect to have a 100,000 mile set-up. It isn't going to happen. Something like a GT2-3 and 1218s? Yeah, that will last a while but it still should be checked every so often.

Too many people treat valvetrain like a Ronco Rotisserie.

 

I've got the conical springs from Comp Cams going in my Trans Am. They had about 420lbs open load if I remember correctly, I posted a bunch of info a while back.

I have to go back to the dyno for a retune, so if I were to swap some duals out on the dyno for some good ol' fashioned testing, anyone have any suggestions what duals they'd like to see tested?

 

I would say BTR platinums...that is a commonly used dual around here.

 

OEMs do what they do to meet certain criteria. Some of those are cost per unit, NVH, and warranty.

We as end users can all install a camshaft with a much higher lobe intensity than any OEM can or will. That is why a GM yellow beehive spring won't work on any performance cam. Its not up to snuff.

There are a lot of things an OEM could do, but won't because they aren't catering to just performance enthusiasts. The vehicle has to work for the folks who just cruise around and never get the motor over 3500 rpm.

That is why most motors come with cast/hypereutetic pistons. OEMs don't want cold piston slap. But all of us would love them. Why don't OEMS use forged rods and good bolts. Weight and cost. PM rods and cheap bolts are "good enough" for 100K miles in the powertrain as tested.

I'll use a prime example. Look at the low tension rings in the 2001 Z06. Great for making a little more power. But folks who drive like a grandma use oil, complain, and GM has to re-ring every 2001 Z06. So GM goes to a higher tension ring after that. Lesson learned....

A beehive spring is "good enough" for GM to get what it wants. Good enough is not necessarily "the best". There are a lot of folks out there who look at cost and go a beehive is "good enough" for them. Again, not necessarily the best option, just "good enough". That is a subjective assessment, just like people who run a dual spring do so because it is "good enough" for what they are doing. And in many cases a beehive is "not good enough".

The common argument is that a beehive controls harmonics based on the way it is wound, and it drops retainer mass. I get that. But again you get a steel retainer on a beehive that weighs about the same as a Ti retainer on a conventional spring. Again, that is "good enough" for some people. And, as long as the springs never break, then their opinion may never change. However, once they break a spring, and destroy a motor. I suspect they might change that opinion that it is "not good enough", and they opt for a dual spring and TI retainer. Perceptions are people's reality. Our perceptions are based on our experience.

The people responding in this thread responding in favor of duals have enough collective experience IMHO to speak to what is "good enough". They have seen and dealt with both extensively. They've seen first hand what happens in both sets of use cases. Magazines articles and the internet are great things. They provide lots of information. But even most magazine articles are simply one person's experience is a single situation.

I'll be honest. I read a LOT. But, I also spend a lot of time in the machine shop and speaking to people who are dealing with this stuff first hand. Magazines have to balance stories with advertisers, etc.... Sometimes there is a conflict of interest there as well. So I'm just saying if I look at the folks saying "I read it in a magazine, and the theory looks good" vs. "I deal with this every day", I'm going to go with "I deal with this every day".

I think another factor is Cognitive Dissonance. Basically people who have choosen single springs face stress brought on by the fact that what they believe is being challenged and it indicates they may be wrong. But I've that happens a lot on discussions forums and is nothing new. Lets talk about what air intake, headers, or wax is best....

To summarize. Most people with considerable experience would tell you to run a dual spring as springs break, and it can save your motor. The perceived gains for a single spring are not worth the risk for many people. Each person has to weigh that cost/benefit analysis and make the best decision for themselves.

 

+1 for BTR dual platinum

 

^^It is a little more than just being "good enough."

GM wouldn't have spent the money designing the beehive for the LS engine if it didn't provide a benefit over the valve springs they were using the Gen I and Gen II motors. It is a good design for a spring and it has its merits, and its limits. Unfortunately, those limits can be found quickly with aggressive camshafts and uncontrolled valvetrain. However, that is not the spring's fault.

That isn't me downplaying dual springs at all, but I think a lot of people are over-springing their valvetrain by blindly going with dual springs on set-ups that don't need it.

Well, I'd say the BTR springs since they are now the popular flavor, and the Lunati dual springs are also pretty popular.

 

That was part of my point earlier. Over springing with weak lifters and weak pushrods will cause performance issues. But that doesn't categorically mean beehives are better. It means the test setup was over sprung. It's a system and it must be designed and built to run as a system

 

I haven't done extensive testing either, but I've seen the testing of others. The mass thing isn't a big deal necessarily because of the MOI, but the natural frequency of the spring itself. Anyone who has done any real research on the subject should know that when a spring gets to its natural frequency, it results in a dip in power and reduces the life of the spring. This can be called nodes or fuss points. Mass and rate are huge factors on a springs natural frequency; more rate and less mass means the frequency of the spring goes up and can be shifted completely out of the power band of an engine.

That's the idea behind the beehives and conicals. The frequency is driven up by the reduction in weight and the varying coils, each with their own frequency dampen or virtually eliminate the bad harmonics. Does this equal results in every application?

Expert? Read the boldface text in his quote...

No, you're not. I perfectly understand your position and premise. I just don't agree. It's not a lack of knowledge as you are trying to imply. I just haven't fallen for the scare tactics.

Aren't you afraid of dropping a valve with those single springs??

I'd like to see the BTR's or maybe the AFR springs Tony recommends. I would definitely be interested in seeing your results, especially since the BTR springs have less spring pressure than the conical springs (400lbs vs. 420lbs. respectively).

I agree with most of what you said, but in regards to the OEM thing, I think it shows that the issues with the beehive aren't necessarily inherent of the beehive design and that you don't have to go slapping on dual springs for every application. Reading this thread may give people a phobia of single springs when they're run successfully in plenty of applications. Obviously a stock spring isn't meant for a aftermarket camshaft, but that's why there are aftermarket springs.

Beehive and Conical springs have their place. I have no doubt in my mind that a dual spring can produce better power than a beehive or conical spring in certain applications. Conversely, I have no doubt in my mind that a beehive or conical can do better than a dual in some applications.

Springs break. I get that too. It's not always the springs fault though. Poor handling, poor prep/installation, and poor maintenance are killers too. I've seen people store springs in a Ziploc bag and others bang the rev limiter before letting the engine warm up. Those people need to have dual springs because they're idiots. Duals are more idiot proof.

 

I was kind of selling myself short on that "bold faced" comment. I've spent 12+hr days, weeks at a time, in front of test equipment. The testing at hand wasn't focused directly on valve springs...thus the comment I made.

I have a pretty good grasp on spring frequency, surge, etc. The MOI I mentioned was directed towards the valve and retainer itself. Again, what looks great on paper hasn't really done much in my testing.

Anyway, no need to argue about this. Just sharing my "limited" experience.

 

I wasn't saying that beehives are better, either. Beehives and dual springs and triple springs all have their applications. Automatically defaulting to "beehives are junk, duals are better" isn't a correct mindset, though, which seems to be the consensus on most LS forums.

 

To me, a valve train needs the least amount of spring to keep the valves stable. That's all. Under springing causes valve instability. Over springing causes pushrods and lifter issues which show up as valve instability. I think you and I are agreeing here. It's the whole system that matters.

 

I think we are agreeing here, as well.
The only thing that I think is a good benefit despite the application is a thicker pushrod.

 

Beehives are more resistant to harmonics in the way they are wound. But I believe most will argue the best way to combat harmonics is by tight control over installed height. You set it up close to coil bind and you remove a lot of the issues with harmonics. But again, many people out there don't take the time and effort to check those sorts of things.

The valvetrain is a system. Too much spring, and not enough pushrod, and then your pushrods flex, etc.... Just having too much of one thing doesn't guarantee success. But when it comes back to pushrods, many people just use what is "good enough". They don't consider a good thickwall pushrod.


I have helped a friend put his car together, and when he bring it out to race, I drive it for him. It an HK Racing 347 in a C5, and it makes ~515-520 RWHP which for a 347 is fairly decent. I shift the car @ 7400-7500. Its an LSK lobed cam, and we use Morel Lifters, Manton pushrods, Jesel J2K rockers, and a stout dual spring.

The combo before that was an LGM G5x3 combo, with XE-R lobes, and we ran a dual spring on it as well. It made 503 RWHP in a stock bottom end 346.

Our selection was based on what we were going to do with the car, and what we expected to do which was beat on the motor drag racing. Duals were a no-brainer.

Sure, i would agree you can get away with a single on a 224 with .500 ish lift. You might even get away with it on something slightly more. But on the other hand you might not. 918's had an issue back in the day with a high rate of failure. Comp changed the spring and the issues have been reduced. But springs fatigue and break at some point. Maybe not while your combo is together, but they will fail.

Again, many folks here have seen it and the cost benefit of a dual spring vs a single is much more attractive over a single vs a trashed motor. YMMV

Again the argument I see here for singles, cheap or stock pushrods is "I can get away with them", and "they are good enough for what I'm doing", not they are the best for X situation.

 

LOL!!!! "515-520 HP on a 347, which is fairly decent". I'm swinging for the fences on my build, and I won't hit that.

You have the pushrods to support those springs, too