Anybody here using them? If so what does the rest of the valve train look like, particularly what kind of specs is your cam and what type of lifters are you using?
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Chris,
Dan Jones will be the man with the straight dope regarding the beehive springs, he has them installed on his new motor, in conjunction with a hydraulic roller cam.
GM has installed them in the new Z06 'Vette, also with a hydraulic roller cam. The idea is to accomplish resistace to valve float with the mechanical dampening properties of the beehive spring, instead of resorting to excessive spring pressures which would lead to accelerated valve train wear.
Your friend on the DTBB, George
Dan Jones will be the man with the straight dope regarding the beehive springs, he has them installed on his new motor, in conjunction with a hydraulic roller cam.
GM has installed them in the new Z06 'Vette, also with a hydraulic roller cam. The idea is to accomplish resistace to valve float with the mechanical dampening properties of the beehive spring, instead of resorting to excessive spring pressures which would lead to accelerated valve train wear.
Your friend on the DTBB, George
> Anybody here using them? If so what does the rest of the valve train look
> like, particularly what kind of specs is your cam and what type of lifters
> are you using?
I'm running the largest of the Comp Cams beehive springs:
P/N 26120
beehive valve springs
OD 1.095/1.445"" (top/bottom)
ID 0.650/1.00" (top/bottom)
Seat Load 155 @ 1.880"
Open Load 377 @ 1.280"
Coil Bind @ 1.230"
Rate 370 lbs/in
Titanium retainers P/N 794
These springs were originally designed for BBC hydraulic roller cam
applications. The BBC has similar size valves and rocker arms ratios as the
351C. The beehive springs take a little nickle-sized titanium retainer that
drops a fair bit of mass off the top of the spring. I'm also running a custom
Crane hydraulic roller cam. The cam was originally spec'd using a pair of
Comp Cam lobes but Comp could not grind the lobes on a standard steel core
(they use a reduced base circle austempered iron cam core) so I matched the
lobes to the closest Crane lobes. Crane's 351C hydraulic roller cam cores
are standard base circle 8620 steel cam cores. The specs for my cam were
chosen to peak at 6500-6600 RPM with acceptable street manners in my
engine (407 cubic inches, C302B heads, independent runner EFI, etc.).
Crane's equivalent lobes are HR-238/365 on the intake and an HR-242/372 for
the exhaust. With the rockers I'm using, the specs work out to:
238/242 degress duration @ 0.050" lift (300/304 advertised)
0.621"/0.595" lift (with 1.7:1/1.6:1 ratio rockers)
I'm also using the Crane link bar hydraulic roller lifters and matching steel
distributor gear. Crane's recommended spring with both of those lobes is
P/N 99890-16
131 lbs seat (1.900 installed height)
390 lbs open (1.290")
0.630 max lift (0.060" clearance)
428 lbs/in
but on David Vizard's recommendation, I went with the Comp beehives mentioned
above. Springs and related valve train components are really important when
it comes to hydraulic roller cams, especially in engines with big heavy valves
and large rocker arm ratios. Compared to say a solid flat tappet cam of
similar specs with the same spring pressure, a hydraulic roller will typically
float the valves at a lower RPM and will be limited to the maximum spring
pressures (before collapsing the lifter). GM developed the beehive springs
for the LS-series SBC engines. The beehive shape results in a lighter spring,
a much lighter retainer and no need for a separate damper (the various parts
of the spring resonate at different frequencies so there's no single RPM
where the whole spring goes into resonance). Comp Cams (and others) have a
line of beehive springs now. Originally these springs were replacement springs
for the GM LS1 but Comp has recently introduced a larger diameter version
for BBC applications (P/N 26120 mentioned above).
Vizard related the results from a magazine article he had just finished
comparing BBC hydraulic and solid flat tappet cams. He said the new spring
amd lifter technology can now make hydraulic cams as good or better than
equivalent solid cams (even with the lash optimized on the solid cams) for
most applications. As I understand it, Vizard's tests were performed on a
BBC with flat tappet hydraulic and solid cams but there were other tests with
a 5.0L Ford and hydraulic roller cams. He claimed a substantial RPM increase
with the 26120 Comp springs when used on the BBC hydraulic cams. He said the
hydraulics matched the solids at the top RPM, even when the lash was optimized
on the solids and, in some cases, made a bit more power at lower RPM. I spoke
with another engine builder and know of a couple others who have also tested
these springs and they were all favorably impressed, reporting 300 to 1200
more RPM on hydraulic roller applications. Vizard recommended the Crane link
bar retrofit lifters. He said recent testing had revealed the big problem
with OEM hydraulic roller lifters was a side force bending mode that binds up
the internal metering mechanism. The Crane lifters are much stiffer than the
OEM Ford lifters and worth a bunch of RPM. The downside is they are over $400
a set versus maybe $130 for a set of Ford lifters. I'm actually using the Ford
Motorsport version of the Crane lifters as they were a few dollars cheaper
from Summit than the same lifters in a Crane box. BTW, Vizard's article gives
some good guidelines on when to pick what type of cam and lifters.
Vizard also recommended Crane's new "Quick-Lift" roller rockers. Roller
lifters come off the seat slower than flat tappet lifters and these rockers
have a geometry that yields a little larger ratio near the seat to compensate.
The part number for 351C/460 applications is 27750-16. As this is the same
part number as the old Crane gold seris rockers, it wasn't clear to me if
Crane had redesigned the lifter or just re-labeled them. Plus my cam was
spec'd for a shorter exhaust ratio, so I stuck with my stainless steel Crower
roller rockers.
In addition to the 26120 BBC roller springs, Comp lists a couple other
beehives:
P/N 26918
Gen III LS1/LS6 valve spring
single beehive, no damper
max recommeded lift 0.625" (elsewhere they state 0.600")
OD 1.065"/1.290"
ID 0.660/0.885"
Seat Load 130 @ 1.800"
Open Load 318 @ 1.200"
Open Load 333 @ 1.150"
Coil Bind @ 1.085"
Rate 313 lbs/in
Titanium retainers P/N 772
P/N 26595
Pro Pac single beehive ovate for Winston Cup flat tappet restrictor plates
OD 1.185"/1.589"
ID 0.731/0.850"
Seat Load 150 @ 2.000"
Open Load 370 @ 1.250"
Coil Bind @ 1.110"
Rate 293 lbs/in
Titanium retainers p/n 785
Isky also has a beehive for hydraulic rollers up to 0.625" lift. BTW, don't
confuse beehive springs with conicals. Conicals were designed to fit into
stock head SBC's without requiring machining.
For an example of what is possible with hydraulic roller cams these days, a
friend of mine turned 8800 RPM without valve float on a dynojet recently.
His 347 cube 5.0L stroker made around 550 RWHP from 7500 to 8500 RPM. Marc
used the Ford Motorsport version of the Crane hydraulic roller lifters,
titanium intake valves (stainless exhaust), titanium retainers, an Anderson
Ford Motorsport hydraulic roller cam of 0.697" lift and some monster valve
springs.
Dan Jones
> like, particularly what kind of specs is your cam and what type of lifters
> are you using?
I'm running the largest of the Comp Cams beehive springs:
P/N 26120
beehive valve springs
OD 1.095/1.445"" (top/bottom)
ID 0.650/1.00" (top/bottom)
Seat Load 155 @ 1.880"
Open Load 377 @ 1.280"
Coil Bind @ 1.230"
Rate 370 lbs/in
Titanium retainers P/N 794
These springs were originally designed for BBC hydraulic roller cam
applications. The BBC has similar size valves and rocker arms ratios as the
351C. The beehive springs take a little nickle-sized titanium retainer that
drops a fair bit of mass off the top of the spring. I'm also running a custom
Crane hydraulic roller cam. The cam was originally spec'd using a pair of
Comp Cam lobes but Comp could not grind the lobes on a standard steel core
(they use a reduced base circle austempered iron cam core) so I matched the
lobes to the closest Crane lobes. Crane's 351C hydraulic roller cam cores
are standard base circle 8620 steel cam cores. The specs for my cam were
chosen to peak at 6500-6600 RPM with acceptable street manners in my
engine (407 cubic inches, C302B heads, independent runner EFI, etc.).
Crane's equivalent lobes are HR-238/365 on the intake and an HR-242/372 for
the exhaust. With the rockers I'm using, the specs work out to:
238/242 degress duration @ 0.050" lift (300/304 advertised)
0.621"/0.595" lift (with 1.7:1/1.6:1 ratio rockers)
I'm also using the Crane link bar hydraulic roller lifters and matching steel
distributor gear. Crane's recommended spring with both of those lobes is
P/N 99890-16
131 lbs seat (1.900 installed height)
390 lbs open (1.290")
0.630 max lift (0.060" clearance)
428 lbs/in
but on David Vizard's recommendation, I went with the Comp beehives mentioned
above. Springs and related valve train components are really important when
it comes to hydraulic roller cams, especially in engines with big heavy valves
and large rocker arm ratios. Compared to say a solid flat tappet cam of
similar specs with the same spring pressure, a hydraulic roller will typically
float the valves at a lower RPM and will be limited to the maximum spring
pressures (before collapsing the lifter). GM developed the beehive springs
for the LS-series SBC engines. The beehive shape results in a lighter spring,
a much lighter retainer and no need for a separate damper (the various parts
of the spring resonate at different frequencies so there's no single RPM
where the whole spring goes into resonance). Comp Cams (and others) have a
line of beehive springs now. Originally these springs were replacement springs
for the GM LS1 but Comp has recently introduced a larger diameter version
for BBC applications (P/N 26120 mentioned above).
Vizard related the results from a magazine article he had just finished
comparing BBC hydraulic and solid flat tappet cams. He said the new spring
amd lifter technology can now make hydraulic cams as good or better than
equivalent solid cams (even with the lash optimized on the solid cams) for
most applications. As I understand it, Vizard's tests were performed on a
BBC with flat tappet hydraulic and solid cams but there were other tests with
a 5.0L Ford and hydraulic roller cams. He claimed a substantial RPM increase
with the 26120 Comp springs when used on the BBC hydraulic cams. He said the
hydraulics matched the solids at the top RPM, even when the lash was optimized
on the solids and, in some cases, made a bit more power at lower RPM. I spoke
with another engine builder and know of a couple others who have also tested
these springs and they were all favorably impressed, reporting 300 to 1200
more RPM on hydraulic roller applications. Vizard recommended the Crane link
bar retrofit lifters. He said recent testing had revealed the big problem
with OEM hydraulic roller lifters was a side force bending mode that binds up
the internal metering mechanism. The Crane lifters are much stiffer than the
OEM Ford lifters and worth a bunch of RPM. The downside is they are over $400
a set versus maybe $130 for a set of Ford lifters. I'm actually using the Ford
Motorsport version of the Crane lifters as they were a few dollars cheaper
from Summit than the same lifters in a Crane box. BTW, Vizard's article gives
some good guidelines on when to pick what type of cam and lifters.
Vizard also recommended Crane's new "Quick-Lift" roller rockers. Roller
lifters come off the seat slower than flat tappet lifters and these rockers
have a geometry that yields a little larger ratio near the seat to compensate.
The part number for 351C/460 applications is 27750-16. As this is the same
part number as the old Crane gold seris rockers, it wasn't clear to me if
Crane had redesigned the lifter or just re-labeled them. Plus my cam was
spec'd for a shorter exhaust ratio, so I stuck with my stainless steel Crower
roller rockers.
In addition to the 26120 BBC roller springs, Comp lists a couple other
beehives:
P/N 26918
Gen III LS1/LS6 valve spring
single beehive, no damper
max recommeded lift 0.625" (elsewhere they state 0.600")
OD 1.065"/1.290"
ID 0.660/0.885"
Seat Load 130 @ 1.800"
Open Load 318 @ 1.200"
Open Load 333 @ 1.150"
Coil Bind @ 1.085"
Rate 313 lbs/in
Titanium retainers P/N 772
P/N 26595
Pro Pac single beehive ovate for Winston Cup flat tappet restrictor plates
OD 1.185"/1.589"
ID 0.731/0.850"
Seat Load 150 @ 2.000"
Open Load 370 @ 1.250"
Coil Bind @ 1.110"
Rate 293 lbs/in
Titanium retainers p/n 785
Isky also has a beehive for hydraulic rollers up to 0.625" lift. BTW, don't
confuse beehive springs with conicals. Conicals were designed to fit into
stock head SBC's without requiring machining.
For an example of what is possible with hydraulic roller cams these days, a
friend of mine turned 8800 RPM without valve float on a dynojet recently.
His 347 cube 5.0L stroker made around 550 RWHP from 7500 to 8500 RPM. Marc
used the Ford Motorsport version of the Crane hydraulic roller lifters,
titanium intake valves (stainless exhaust), titanium retainers, an Anderson
Ford Motorsport hydraulic roller cam of 0.697" lift and some monster valve
springs.
Dan Jones
Wow,
8800rpm - I always thought you'd have to go overhead cams to get that high.
Is that motor easy to drive on the street?
8800rpm - I always thought you'd have to go overhead cams to get that high.
Is that motor easy to drive on the street?
> 8800rpm - I always thought you'd have to go overhead cams to get that high.
Plain old iron 351C's with cast cranks were turning 9500+ RPM in Pro Stock
back in the 1970's.
> Is that motor easy to drive on the street?
No. It's strictly a race engine. Marc still runs mass air fuel injection
which doesn't like the massive cam overlap at all. It surges at low and mid
range RPM but it's a drag race only vehicle.
Dan Jones
Plain old iron 351C's with cast cranks were turning 9500+ RPM in Pro Stock
back in the 1970's.
> Is that motor easy to drive on the street?
No. It's strictly a race engine. Marc still runs mass air fuel injection
which doesn't like the massive cam overlap at all. It surges at low and mid
range RPM but it's a drag race only vehicle.
Dan Jones
heh, heh, heh. I like it.
Dan
Dan