Being the inquisitive bugga that I am I was digging around looking for info on the benifits of conical springs over straights and beehives, this video came to light, it's quite long but if you watch it you will learn a thing or two, if anyone wants to discuss what he has to say after watching it I'm in.

It’s gotta beat what on Tele. 

The link isn't working 

Yeah, ya gotta highlight/select it and click “look up”. Looks like an interesting series.

That video put me to sleep the first time I watched it a few months ago. Had to speed it up to stay interested . He takes half an hour to say what you could in 10 minutes ! Not exactly " leaked new tech" 

Nothing new under the sun they say, however I found the frequency comparison quite an eye opener, the old straight spring hardly changes but the other two ramp up significantly the further they are compressed and that's a desirable factor for a valve spring.

Yes, the coil bind spec really should be different between a straight spring and the Beehive .  

When they make something with a spring rate more applicable to our needs they have to be a winner for sure, a lot say the cost is not worth the gain but the actual cost per spring isn't that bad and a better mousetrap is a better mousetrap, there are some available in the ballpark but more for .600" lift, when you go over that there doesn't seem to be much unless over the nose pressure doesn't bother you, food for thought for sure.

This topic is never ending in a way, so I will cover only what is asked here. David presents a very good video on springs, yes , he is a bit long winded but what you miss by only looking for detail in what he says loses a lot of story that he tells, I have done one of David’s seminars held in Sydney some time back, he tells a more holistic overview of the IC engine, if you want a heads only view of the engine go to a Darin Morgan seminar.



There are a whole lot of other topics related to what can be discussed here just on these few items, so I will get you guys to fire specific questions and I we will see where it goes.

Cheers.

Thanks Hoody, questions, geeze I have a few but I will start with a ramble, stock or similar cams produce an amount of work for the stock beehive spring to control, the stock springs are mostly fine in this application because of their fit for purpose design, although at red line perhaps not so much! 

The stock springs are ok to red line in the stock engine because the limiter is sub 6K, the motor noses over pretty well by then so there is no merit is wringing its neck.
As you point out there are a lot of cams that are referred to as ‘bolt in’  that is exactly what they are, they will bolt in with stock springs, stock pushrods, lifters etc and enhance the engine quite a bit, they need no extra attention to clearancing or installation but bear in mind there is still that sub 6K recommendation with them from Andrews and if you look at the SE dyno graphs most stop at 6K for bolt on stuff, when you get to 259 cams there is a spring replacement recommended.


Answer to 2,   If you look at what David is talking about regarding frequency control, our engine don’t usually get into the rpm territory where this is a consideration, yes we can run these spring tighter but then we will see our seat pressure climb into stellar figures, don’t forget a lot of springs made for our application will cover lift ranges .580” to .640” the pressure variance in .060” for an installed height can be up to 40lb this can take a seat pressure from 180lb to 220lb which is getting up there a bit for street. If you look at David’s spring graph you will see the spring pressures go stellar when he nears .025” .
In most heads for a decent street engine I would aim for 180lb on the seat, full lift pressure would be whatever the spring makes, if it’s a Comp double with damper set at 180lb@ 1.860” that would be around 429lb for .600” lift, If it’s a Kibblewhite ovate beehive set at 180lb @1.860” it would be around 361lb for .600” lift, the beehive has less inertia that the double so can run a lower full lift pressure.

3,   I would be more worried about the spring on the exhaust than the inlet, that’s the one that crashes if the engine goes well over the limiter, remember the inlet valve chases the piston, the piston chases the exhaust valve,,you don’t want it to catch up.

Springs used by Harley in their performance applications are all very good quality springs whether they are beehive or multiples, they can be used with confidence in any application Harley refers them to.
One thing to keep in mind is when you use multiples in stock heads there can be spring retainer to rocker box clearance issues, so beehives fit in a lot easier, it’s no problem to grind clearance when the engine is apart. In the rocker boxes supplied with SE heads the box is relieved for the springs.
As for what is the best spring??  Any good spring that suits an application is the right spring, in 8mm heads I use Kibblewhite beehives and Comp Cams dual with dampers or Comp duals, in 7mm its Kibblewhite, Comp or AV&V, in 6mm it’s all AV&V.

Cheers.

When I mentioned stock springs/heads and redline in my head I was thinking stage 1 bike, first thing a lot do is change exhaust and intake along with a tune flashed in that could well have the redline at 6500 and wring it's neck, no power but they will spin up there.

Yep I understand on the loosing force over time, seen that often when rebuilding cat diesels, I understand starting with a known component, your reputation is on the line, I would do the same.