Has anyone else tried OEM Twin Cam Beehive Springs on an Evo?

OK, I'm a cheap *** and I don't care admitting it. Actually, I am not. I don't mind paying for quality when it is necessary or the best investment but, at the same time, I don't like seeing things go to waste, especially when they are perfectly adequate or better than I already used.

I picked up a 'takeoff' set of OEM H-D Twin Cam Beehive Springs for the later 7 mm valves for nothing more than a courtesy payment, P/N: 18245-02. These are used by Twin Cam Big Twins from at least 2004 upwards until today's 110 ci CVO engines, including the Screamin' Eagle XL 883 to 1200 Stage 1 Conversion Kit.

I have a feeling these are going to enter into Evo riders armoury of so cheap upgrades that it is dumb not to just do it, as folks are already swopping them out as new and Ebaying them.

Stock, the engines run 7mm valve stems, so the neither the new (nor old) OEM top collars or new keepers fit, however, I was able to pick up a set of collars that suited the old keepers out of 'the box' at a local autoshop. No idea what they came out of. I just re-used the old collars at the bottom.

They fit very nicely. I think the old collars are thicker than the new, built-in seal ones. Beehive springs have, of course, various advantages over the straight and dual springs (1984 - 2002) and are kinder on the valvetrain. Strength wise they are pretty much the same as the old stock dual springs at 140 to 310 lbs which suits my mild tune (less weight, means less pressure required to do same job, equals less slam, and better wear).

The only thing I'd like to do is find some cheap alt. titanium tops.

Now, the interesting thing is, especially for those of us using 1.7* rocker arms, apparently HD claims the stock beehive springs will accommodate .569" lift with no issues. I've read other folks (Head Quarters) hinting at up to .640". The SE Sportsters are using them at .540" (E cams).
.660" seems to be their limit.

Used to spending $100 anytime I open my wallet, I was a little shock to discover that they only cost $5 ea new though. However, the reviews look good.
Seems like a no brainer. Am I missing anything?

I've tried a fit up but not a final assembly to measure them up for interference but I cannot see any problems.

Thanks. Hope this turns out to be useful for others.

 

Excuse me talking to myself again ... but this is what folks are saying.
Only very slight downside I can see is a loose fit on the lower collars but it's still within "normal".

.030" should add 10 to 15 lbs pressure depending on who you believe.

I need to weigh my valves.

 

How much does this cost as compared to springs, stock or upgrade, that are made for an Evo's?

 

In my case, $6 dollars versus, say, $100 to 130 + for a set of Kibblewhite or S&S Beehive Springs. More for Manley. I'd say OEM sets are being thrown out by shops as they're upgrading, so I would ask your local. Hardly worth Ebaying.

$20 new if I had bought new from H-D.

Kibblewhite wanted $35 for just a set of top collars, but I had a root around in a friend's shop and found a set for free. Although, there is a guy I think making his own Titanium retainers on Ebay for $30. About £20 for Colony aluminum alloy ones. I think mine are out of a Volvo or Porsche because that's what my friend works on.

I had been looking out for a set of springs with a little more lift for a while but I think
almost all of the "performance" ones - certainly the ones held in stock in dealers - were far to over engineered (too strong, too much lift) in order to justify the expense. You know, it is like the same problem with cams where everyone want to go for the biggest ones because they must be better.

Had I know what I know now, before I started the work I have done, I think I would have gone down the route of doing a 7mm valve conversion too. Replaced the old valves and guides not with 5/16" ones, but with 7 mm ones, and used these springs and fittings. It's the same spring and exactly what these guys are doing (no recommendation, I don't know their work at all).

I didn't know H-D had gone down a size until now.

Longevity, just like performance, is all about losing weight too. Any lightening of the valvetrain is good idea.

 

two cam valve guide and valve stem is 7 MM - evo valve guide and valve stem is 5/16 or 8mm the springs are not as good as you might think -- so you have something for another bike you might buy

the small lift Goodson springs fit hyd lifters up to .600 lift @ around 1.850 install height ( evo installed height - not 2 cam IH )

 

You know how it goes, John. It's an H-D. Everything want a hundred dollars spent on it. Or two. I'd spend it if I had it, but everything else wants a hundred dollars too. I know there's better but I think there's a lot of overkill for the mild performance level I am at.

You're suggesting I might be .050" long and therefore losing some pressure, say 20 lbs? You might be right, I'll have to measure the installed height.

I've got two manuals, for late Evo and early TC, and some books, but it's quite difficult to find all the baseline specs (Donny Petersen is the worst for that. For all the repetitive garbage he copy and pastes in his brick sized books they lack baseline figures on which to make judgements. He also gets the stem diameter wrong).

The Evo and the Early TC shared specs and components.

All I can find is,
What is the weight of the OEM 7mm valves and what's the relationship between the valves' weight and the strength of spring? At what saving does lightness start to benefit? I'd say it was their weight not stem sized that mattered.

I'm thinking I'm OK because this one has lighter valves and the lower collar is thicker. I'd be happy around stock weight, with a little bit more travel (need .530").

The book says STD Evo springs are 125 (- 130) lbs on the seat.

 

Let me explain a few basics here! The beehive springs have become popular as part of the development of modern engines to enable them to better meet emissions regulations, both noise and exhaust. One of the problems of engines until recently has been 'parasitic losses', in other words the power wasted around the engine.

Turning to the valve train, the camshaft and springs create parasitic losses. The way the industry has reduced them is to use higher grade materials in the valves, so they can be made lighter, hence require less strong springs. The beehive not only achieves that, but by it's shape and the reduced diameter of the spring collar also contribute to reducing valve-train weight, hence parasitic losses.

So unless you go through your valve train to reduce valve weight etc you may be disappointed. I haven't studied a twincam but I wouldn't be surprised if the rockers are also lighter than an Evo. Our ole dinosaurs may look old, but the MoCo is using modern engineering to design and build 'em!

 

Screamin Eagle Evo heads already use them and have been out for years, the Beehives are in the Ultima Evo engine also.

 

Or not.

Here's your big surprise of the day. Part numbers for the 2014s are 17360-83A and 17375-83A. That dates them back to 1983 and our venerable Evos.

Either they're very cheap, H-D must have overstocked them, or "they ain't broke" yet. In fact, I just looked at the spec for the 120 CVO Screamin Eagle "Race" engine, and it's using them too.

I cannot find the weight for the stock rockers anywhere, but I have bushed roller ones which come in at 295 gm.

At present, I am (approx) 5 gm lighter on the pushrods, 15 gm lighter on the valves, 10 gm on the top collar and the springs are stock @ 125 gm versus 100 gm for the Twin Cam's Beehives.

So that's 45 gm so far. Roller tips are going to have less friction.

What sort of reduction are we looking for before it makes any difference?

For me, rather than the "more cubes (and more dollars)" approach it makes more sense to go lighter weight, less resistance, less impact (= more longevity).

But I don't know if I am wasting my time.

I have two manual and numerous books but it's actually difficult to find stock baseline measurements and tech details. All the emphasis on the web is just on 'spend money'. It seems this is an under discussed area.

Questioning is good ... I just found something called Engine Builder Magazine. It says,
By that theory, you're talking 2,000 rpm more (Good heavens. No, I don't believe it either). And all these components are stronger than stock.

In addition, high lift rocker arms reduce the amount of lifter travel needed to open the valves, reducing friction and inertia of the lifters and pushrods that must be overcome by the valve springs.

You see where I am going with this? Again, I don't know all this because I have not measured but this all according to good theory. Obviously on a H-D you're going to hit another wall somewhere else, sooner or later.

Here's some other interesting quotes
Following up, I found that Crane and Comp make retainers that can vary installed height up 50 or 100 thou.

 

As an aside, someone is thinking of how to improve this with adjustable rockers. Too much legalese for me to understand but there are drawings.

http://www.google.com/patents/US20130263806