Beehive valve springs
 

Since I mostly avoided the rocks and stone age discussion on head studs and what ignition system is the best, I thought I'd show I'm doing to bring some of this stuff into the current millennium.

I've been hounding my suppliers and perusing catalogs for valve springs for quite awhile now. Well, my nascar valve spring supplier came through and came up with some springs that I'm going to try on my own 3.3 twin turbo build.

The valve springs weigh 44.6 grams vs the stock spring's 60.6 grams. Seat pressure is 83 lbs and over the nose pressure is about 225 lbs.
Since the steel retainers are quite a bit smaller, they weigh 14.9grams with the 5/16" locks vs 21.9grams for the stock Porsche retainers with 9mm locks. Titanium retainers are also available and weigh 5.8grams if one chooses to go that route (without locks). Since we quit using titanium retainers in higher division nascar racing years ago because of wear issues, I stuck with what I know, steel.

These are off the shelf retainers, locks and spring cups. (Full disclosure, the guides are 993 guides, 8mm but honed to .311" for 5/16" valves)

Saving each gram from the valvetrain allows a 35-40 rpm higher redline. (But reduction in valve spring weight itself counts for only half since the bottom half is touching the cylinder head)

7 grams off of the retainers and locks, 8 grams off of the spring.

The Ferrea 50.5mm intake valve reduced the weight by another 15 grams.


http://forums.pelicanparts.com/uploa...1615510566.jpg
http://forums.pelicanparts.com/uploa...1615510589.jpg
http://forums.pelicanparts.com/uploa...1615510611.jpg
http://forums.pelicanparts.com/uploa...1615510633.jpghttp://forums.pelicanparts.com/uploa...1615512143.jpg

Now those are cool!

So roughly an additional 500 rpm cushion for your set-up?

Likely even higher for smaller valve engines.

Well done!

Hello, What do the springs bind at? What is your installed height? Thanks David

Yup, ~500 rpm higher, not counting the valve.

30 grams = ~1000 rpm, including the lighter weight valve.

how do you hone an 8mm guide to .311?

Bind is 0.950", installed height is 1.640". PLENTY of room for a big cam.

Sorry, 0.313", not .311. Stems are 0.311"

dannobee,
Nice information. How did you arrive at the each gram adding 35-40RPM?
I was thinking about this a while back relative to rocker arm weight.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/1083710-rockers-other-thoughts.html

I know one of the other advantages of beehive springs has to do with harmonics. Do you have any information on how the springs you selected behave relative to harmonics?

john

Are the springs an interference fit? Or do the springs not allow for that on account of their shape? I'm not implying they should be interference fit. Just curious how they fit together since i've seen a new-to-market set of springs provided by another member that is of the non-interference type.

Regarding the weight of the valve being 15g lighter... is that compared to Porsche factory valves?

These beehives are anti-resonance, so no natural frequency, or so high that it's not relevant.

https://www.enginebuildermag.com/2007/01/understanding-high-performance-valvetrain-technology/

Some people claim a 10 gram reduction can increase redline 700 rpm. I was never that optimistic. Rocker arm weight reduction is great, too, but remember the ratio, so weight on the cam end doesn't make as big of a difference. But the Pauter rockers do look great. Pricey though.

Stock 3.3 turbo 49mm intake valve
http://forums.pelicanparts.com/uploa...1615592760.jpg

Ferrea 50.5mm 5/16" stem intake valve
http://forums.pelicanparts.com/uploa...1615592781.jpg

What is the seat pressure at 1.640" and over the nose pressure @1.050" (.100" from bind)

What lift at the valve are you looking to run with this spring?

I was looking into this...I could of done it but I decided to stick with conventional wisdom.
I actually had some heads (customers engine) made by a well known builder and spec-ed out the valves and springs they were using. The machine work was way rougher than I expected and they had way way too much spring pressure.

That's what I found, too. Since GM uses beehives on factory LS engines, aftermarket is geared toward those, which have much higher installed heights and way more spring pressure than we need.

These take drop-in, off the shelf parts, without machining the heads for bigger or deeper spring pockets.

We also worked on a set of heads that used huge, "NASCAR" valves and springs. By that I assumed they were referring to type/style.
It all looks like it would function but we struggled with the 220# seat pressure w/no spring perch or shims. When I confronted the previous builder his response was " we build high performance engines that need the additional pressures". When we measured the springs at .500" lift, the pressure maxed our tester at over 450#.
Our experience points us at numbers closer to 260# so we discussed it with the end user and built this set of heads with Aasco springs set @ 36mm and sent him away with a smile.
The heads also got our VentiPort technology which allows small intake ports to produce great mid-range with exceptional top end performance.
The engine is a 2.8SS (66x98mm) club racer. He's using one of our 9 bolt, 66mm cranks and GT3 Pankl Ti rods with hopes of making reliable power to 8K.

Like I said in the original post, seat pressure is 83 lbs @ installed height of 1.640".
Over the nose is 225 lbs @ 0.540" valve lift.

Henry, could the ‘low pressure’ beehive springs in this post offer advantages in a Porsche air cooled 6 over dual springs ?

I don't know. I hope so.
I am not an engineer, so I'm good with following up on some of the cool innovations.
These kinds of developments require intense trials, so I hope someone is interested in the research.

I've been using Randy's springs since the 80's and they work well. Could someone develop a better spring (by general standards) is a question to be answered.

That’s called a Chicago 2.8 around here 66x98 makes 3 liter engine

Your are correct...I misspoke. 66x98mm is indeed 3.0