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Registered
Join Date: Mar 2019
Posts: 1,600
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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. ![]() ![]() ![]() ![]() ![]() |
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Racer
Join Date: Oct 2010
Location: Franklin, TN
Posts: 5,885
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Now those are cool!
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Scott Winders PCA GT3 #3 2021 & 2022 PCA GT3 National Champion 2021 & 2022 PCA West Coast Series GT3 Champion |
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Functionista
Join Date: Jul 2011
Location: CO
Posts: 7,717
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So roughly an additional 500 rpm cushion for your set-up?
Likely even higher for smaller valve engines. Well done!
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Jeff 74 911, #3 I do not disbelieve in anything. I start from the premise that everything is true until proved false. Everything is possible. |
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David Gouk Race Engines
Join Date: Dec 2009
Posts: 186
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Hello, What do the springs bind at? What is your installed height? Thanks David
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Registered
Join Date: Mar 2019
Posts: 1,600
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Yup, ~500 rpm higher, not counting the valve.
30 grams = ~1000 rpm, including the lighter weight valve. |
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abit off center
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how do you hone an 8mm guide to .311?
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______________________ Craig G2Performance Twinplug, head work, case savers, rockers arms, etc. |
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Join Date: Mar 2019
Posts: 1,600
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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" |
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Registered
Join Date: Feb 2004
Location: denver
Posts: 1,143
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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. Rockers and other thoughts 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 |
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Schleprock
Join Date: Sep 2000
Location: Frankfort IL USA
Posts: 16,639
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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.
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Kevin L '86 Carrera "Larry" |
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Registered
Join Date: Jul 2005
Location: Cleveland, OH
Posts: 1,367
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Regarding the weight of the valve being 15g lighter... is that compared to Porsche factory valves?
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Registered
Join Date: Mar 2019
Posts: 1,600
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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 ![]() Ferrea 50.5mm 5/16" stem intake valve ![]() |
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David Gouk Race Engines
Join Date: Dec 2009
Posts: 186
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Quote:
What lift at the valve are you looking to run with this spring? |
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Puny Bird
Join Date: Nov 2002
Location: Port Hope (near Toronto) On, Canada
Posts: 4,566
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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.
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'74 Porsche 914, 3.0/6 '72 Porsche 914, 1.7, wife's summer DD '67 Bug, 2600cc T4,'67 Bus, 2.0 T1 Not putting miles on your car is like not having sex with your girlfriend, so she'll be more desirable to her next boyfriend. |
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Join Date: Mar 2019
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Quote:
These take drop-in, off the shelf parts, without machining the heads for bigger or deeper spring pockets. |
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Try not, Do or Do not
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Quote:
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.
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Henry Schmidt SUPERTEC PERFORMANCE Ph: 760-728-3062 Email: supertec1@earthlink.net |
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Registered
Join Date: Mar 2019
Posts: 1,600
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Quote:
Over the nose is 225 lbs @ 0.540" valve lift. |
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Registered
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Henry, could the ‘low pressure’ beehive springs in this post offer advantages in a Porsche air cooled 6 over dual springs ?
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Try not, Do or Do not
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Quote:
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.
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Henry Schmidt SUPERTEC PERFORMANCE Ph: 760-728-3062 Email: supertec1@earthlink.net |
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Registered
Join Date: Aug 2010
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Quote:
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Try not, Do or Do not
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Your are correct...I misspoke. 66x98mm is indeed 3.0
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Henry Schmidt SUPERTEC PERFORMANCE Ph: 760-728-3062 Email: supertec1@earthlink.net |
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