Conical valve springs.

[MadBill]

Besides the near-absence of discrete resonance frequencies, conical springs have less 'unsprung weight' and lighter retainers than conventional ones. Spintron results show hundreds more usable RPM with reduced seat load.
The last knock against them that I knew of (no 'back-up' in the event of a single spring's breakage) is addressed by the dual versions, whose range I'm sure will continue to expand.

[Newold1]

The importance and issues with all valve springs are many in my opinion.
A great selection of a good valve spring is one of the major separations in an engine between excellence and disaster!

The problems that seem to always arise between one type of valve spring get down to three basics in most thought.

One is poor materials or manufacture, yes all spring companies have made booboos once in a while, some more than others.
Two is improper matching of valve springs to camshafts, valve train weights, rocker ratios and rpms.
Three is trying to use the wrong spring for the wrong job.

I think all types of valve springs have pluses and minuses obviously and on the internet we hear about a lot of valve spring problems and all the exact issues and details many times are not clear and correct so a lot of misunderstanding and misinformation gets spread around.

As for beehive springs in performance uses all three of the above problems have come into play. Obviously they can be great valve springs look at the MILLIONS that are in use in OEM engine uses and many in higher performance OEM engines without problems or major failures.

Beehive and Conical springs do some things that straight valve springs can't do. One is they have variable spring rates available. They can reduce spring mass and allow smaller lighter retainers and that reduces overall valve side mass.

Something beehive and conical springs can't do is provide an inner spring to increase to high spring rates and sometimes give the added protection against valve drop on their spring breakage. There is apparently some dual conical springs coming to market and that is the cats meow in my thinking.

Current uses and successes show that in high valve lifts, high acceleration lobe profiles, heavier valve train mass at high rpms that the good old dual valve springs matched to use still tend to be the best choice with current offerings.

Your use in a racing application like yours with your heavier valve mass weights would get my vote for a good dual spring use as others with a lot of experience recommend. JMO

[andyf]

Is there any thought that you can run lower seat pressure with conicals? I saw the 150# installed seat pressure also and thought they would never be used with a solid roller. I could see the smaller retainer weight and harmonic and spring surge control benefits.

The Comp engineer I worked with didn't think there would be any problem running my engine with that seat pressure. I'm not sure if he knew what the seat pressure would be once the retainer and locator were installed or not. Maybe he had factored that into the equation already but he didn't say. I was a little surprised that the 150 lb seat pressure turned into 200 lb seat pressure once the spring was installed with the locator and retainer.

The good news for me was that the locator dropped right in place on my heads without any machine work and there does not appear to be any clearance issues or any coil bind problems. The conical springs reduce total weight by roughly 1 lb over the dual springs that were on there and they provide a lot more rocker arm clearance. Even if they don't provide any other benefit I'd say the extra clearance could a reason to use them in some applications.

The weight savings is nice but the springs are fairly expensive so I suppose a person just has to sort that out. If they end up providing a little more RPM then there are some guys who would want them for that reason. I don't think my engine was having an issue with spring harmonics so I'm not expecting to see an increase in RPM but I'll find out in a few weeks when I have the engine back on the dyno.

[HDBD]

Put the springs in a mill vise over night then remeasure

[andyf]

Anyone got a good explanation of how the performance of a conical spring differs from that of a beehive? I asked Comp and got bafflegab.

In theory the conical spring will be more resistent to resonance than a beehive spring since every coil on the conical spring has a different natural frequency. On a beehive spring the coils on the bottom half of the spring are all the same so they will share the same natural frequency.

The conical spring will also be a little bit less weight than the beehive spring but the difference might be small. One big advantage of the conical spring is that you can get dual conical springs. I don't think you can design a dual beehive spring.

One cool thing about the conical spring is that the end that moves is the end that is light weight. The same is true of the beehive spring but the effect is more pronounced with the conical spring. It is a fairly significant weight savings when you look at it as the total of (weight x distance moved).

[MadBill]

Good explanation; makes you wonder why there even are beehive designs!

[andyf]

I think the beehive design is smaller so it fits into more places. The conical springs that I have are 1.650 diameter at the bottom which is getting pretty big. Beehives are smaller that that at the bottom so they'll fit OEM engines.

That is just my guess. It could also be cost. The OEMs are very cost focused so if the conical spring was better (cheaper) they would use it.

[midnightbluS10]

Kibblewhite Beehive springs on the old British OHV bikes in racing retain their pressure longer than multiple springs .That's not a bad thing

yeah.. funny how Comp Cams takes all the credit for their design though I imagine they may have just generalized about the ovate wire and let people run with the rest of the story.

I think some are confusing the difference between beehive vs conical. They are somewhat different and the shape naming should be fairly evident. Good description of benefits and some comparison pictures located here.

http://www.hotrod.com/how-to/engine/140 ... arches-on/

I've never seen anything where Comp "takes all the credit for their design". Care to share some of that? I've seen them call the design itself unique and revolutionary but never that they were the ones who came up with them. It's widely known that they were first used in aircraft engines in the 1900s. Why would Comp try to change the narrative when it's already known that they didn't make them first? IMO, that doesn't really make much sense. You can even find them in stock automotive applications going back to the 30s. Possibly even earlier. The '64 Olds 394 had them. So did the 215ci Buick and Olds engines from 61-63. Thanks.

[Newold1]

I really like the all around advantages of dual conicals. I think these type of valve springs are really going to get big in the performance market.

[gregsdart]

I would think either beehive or conical springs used in two locations (isky rev kit!) would be worth serious development if there is room for them? If it works , it could make for some improvements in cam choice and rpm range?

[piston guy]

I think Erson was the first to sell Buick conical springs to be run upside down on a small block Chevy to avoid cutting the spring seats. Sig bought them from Associated and offered a dual conical too. That was 40+ years ago. He never offered retainers so they could be run "the right way".

[hoffman900]

Kibblewhite Beehive springs on the old British OHV bikes in racing retain their pressure longer than multiple springs .That's not a bad thing

yeah.. funny how Comp Cams takes all the credit for their design though I imagine they may have just generalized about the ovate wire and let people run with the rest of the story.

I think some are confusing the difference between beehive vs conical. They are somewhat different and the shape naming should be fairly evident. Good description of benefits and some comparison pictures located here.

http://www.hotrod.com/how-to/engine/140 ... arches-on/

I've never seen anything where Comp "takes all the credit for their design". Care to share some of that? I've seen them call the design itself unique and revolutionary but never that they were the ones who came up with them. It's widely known that they were first used in aircraft engines in the 1900s. Why would Comp try to change the narrative when it's already known that they didn't make them first? IMO, that doesn't really make much sense. You can even find them in stock automotive applications going back to the 30s. Possibly even earlier. The '64 Olds 394 had them. So did the 215ci Buick and Olds engines from 61-63. Thanks.

Billy Godbold from Comp in another interview was really clear that Comp didn’t invent the concept. He did mention the difficulty in producing them and be repeatable and their methods are proprietary.

[andyf]

They could be a little hard to make which might be why the price is high. We checked all 16 springs in the box and the spring pressure was consistent. The one piece of advice I'll pass on with these springs is to double check the inner spring. The installed height for the inner spring is less than the outer spring since both the retainer and the locator have steps on them. So the inner spring is compressed more on the seat and could bind sooner than the outer. It only takes a couple of minutes to check the inner only and then check the outer only just to know what you're working with.

[midnightbluS10]

I think the beehive design is smaller so it fits into more places. The conical springs that I have are 1.650 diameter at the bottom which is getting pretty big. Beehives are smaller that that at the bottom so they'll fit OEM engines.

That is just my guess. It could also be cost. The OEMs are very cost focused so if the conical spring was better (cheaper) they would use it.

Largest beehives I've seen were 1.440" and I bet you could find them bigger for certain applications.

[Newold1]

Valve springs by design generally have their pressures determined by the wire size, shape and type. Hence heavier pressure springs are available in matching OD's with stronger wire and this increase spring pressures without increasing the size of the spring.