AmericanPie said:Soon I'll be doing a mostly stock rebuild of the original 327/300 from my '65 Impala, using a mild (216/228 @ .050" dur., .454"/.480" lift) hydraulic Crane cam. I've been advised that Crane springs tend to be too strong for street use and will probably wear the cam prematurely. Is this true, and if so what would be a good choice in quality springs for this engine? This will be basically a street cruiser, w/ power peak of about 5500 rpm. Thanks!
ASSUMING ALL VALVE SPRINGS FROM ANY SOURCE are too strong, too weak or anything else is absurd ! keep in mind the LAST THING any manufacture wants is customers having problems with their products , so they go to great lengths to insure durability and trouble free operation, thus they try to suggest the best possible matching components.
most suppliers have dozens if not hundreds of different valve springs to choose from and most valve spring load rates change to some degree depending on the installed height and cam lift used.
from your limited description of the cam I think your referring to this cam I'll link too, as you can see it listed the proper springs , as PART # 99848 and installed height at 1.70 inches and load rate is certainly not excessively high as listed at 114 lb seat and 318lb open btw Ive run that cam and the slightly milder crane 114132 in my corvettes 383 in the past and I think youll find the slightly milder crane cam #114132 a better match
(especially if you use 1.6:1 ratio rockers as it has better low and mid rpm torque and gives up very little peak power)
in your particular application so I'll post a link at the bottom
THE CRANE HYDRAULIC FLAT TAPPET CAM THAT I THINK YOU ARE REFERRING TOO
AND TAKE THE TIME TOO
,read this link
OBVIOUSLY YOULL WANT THE CORRECT VALVE SPRINGS
the reduced diameter of beehive valve springs usually eliminates the rocker too retainer clearance issue
BEEHIVE SPRINGS GIVE A GOOD DEAL MORE ROCKER TO RETAINER CLEARANCE
http://www.compcams.com/Products/CC-'Valve Springs By Usage'-0.aspx
keep in mind all roller rockers do not have identical dimensions, crower offers .050 off set trunion designs ans the designs dimensions do differ slightly between manufacturers
it only takes a few seconds running a new engine for an improperly installed cam , lifters and valve train, during the break-in process to generate teaspoons of metallic trash that ,once in the engine oil flow ,rapidly destroys bearings if the clearances ,spring load rates or valve train geometry is wrong
even roller cams can wipe out lobes if the valve train components, are not matched correctly, or the spring load rates are not correct, or valve train lubrication, geometry is not set up correctly
CRANE, ISKY,ERSON, CROWER, or most any other cam manufacturer will supply you with the correct MATCHING valve springs and the IDEAL height installed specs, if you ask and pay for them
The following recommendations are from Erson Cams. If you have questions, you can reach their tech department at 800-641-7920.
ALL MAJOR CAM MANUFACTURERS TECH DEPARTMENTS WILL SUPPLY THIS INFO IF ASKED
Hydraulic Flat Tappet Camshaft: 110 lbs Seat pressure/250-280 lbs open pressure
Solid Flat Tappet Camshaft: 130 lbs Seat Pressure/300-325 lbs open pressure
Hydraulic Roller Camshaft: 130-140 lbs Seat Pressure/300- 355 lbs open pressure
Solid Roller Camshaft: (Minimum Safe Pressures DEPEND ON SEVERAL FACTORS)
Up to .600 valve lift: 200-235 lbs Seat Pressure/600 lbs open pressure
Over .600 valve lift: 250-280 lbs Seat pressure /100 lbs pressure for every .100 of valve lift
theres also direct sources
Proform Pushrod Length Checkers 66789 SBC 3/8" rocker studs
Proform Pushrod Length Checkers 66790 SBC 7/16" rocker studs
Proform Pushrod Length Checkers 66806 BBC 7/16" rocker studs
heres a bit of useful related push rod length info (POSTED HERE) youll want to select the correct set or SETS for your shop
Big Block Chevy, Standard Length Big Block Intake 3/8" / .080" 8.275"
295-7941-8 Big Block Chevy, Standard Length Big Block Exhaust 3/8" / .080" 9.250"
295-7969-8 Big Block Chevy, Standard Big Block +.100" Long Intake 3/8" / .080" 8.375"
295-7979-8 Big Block Chevy, Standard Big Block +.100" Long Exhaust 3/8" / .080" 9.350"
295-7951-8 Big Block Chevy, Standard Length Big Block Tall Deck Intake 3/8" / .080" 8.675"
295-7961-8 Big Block Chevy, Standard Length Big Block Tall Deck Exhaust 3/8" / .080" 9.650"
295-7800 V8 396-454 Retro Fit Pushrod Set, Intake & Exhaust, 1965-Present
3/8" / .080"
3/8" / .080" 7.725 Int.
295-7913-16 Small Block Chevy, Standard Length Small Block Chevy 3/8" / .080" 7.800"
295-7984-16 Small Block Chevy, +.100" Long 3/8" / .080" 7.900"
295-7934-16 Big Block Ford, Standard Length Ford `72-'78 429-460 3/8" / .080" 8.550"
295-7951-16 Big Block Ford, Standard Length Ford `69-'71 429-460 3/8" / .080" 8.675"
295-7582-16 Oldsmobile, Std Length 455 5/16" 9.550"
http://www.psisprings.com/index.php?opt ... &Itemid=34
http://www.cranecams.com/bulletins_list ... catagory=4
http://www.compcams.com/Products/CC-%27 ... %27-0.aspx
RELATED INFO YOU SHOULD READ THRU
]THE CRANE HYDRAULIC FLAT TAPPET CAM THAT I THINK IS A MUCH BETTER MATCH TOO THE APPLICATION GIVEN THE LIMITED INFO AVAILABLE
Id also point out that youll want to lubricate any valve you install in a valve guide and verify the valve train clearances very carefully, and use the correct valve springs and add the correct valve seals installed
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