Car Craft
Click here to find out more!

Crane Hydraulic Roller Lifters

8,500 RPM!

By , Photography by

Pump Up, or Pump Down?

So how is it that a hydraulic lifter is capable of controlling a heavy stainless steel intake valve at 8,500 rpm? A commonly held belief is that high valvespring pressure at high engine speeds can push the oil out of the lifter, creating pump-down problems, explaining why hydraulic lifters cannot withstand high engine speeds. Knight says this is possible if the lifter suffers from excessive internal clearances that directly affect the lifter's bleed-down rate. Since the Crane lifter maintains such tight clearances, Knight says that lifter pump-down just doesn't happen. As long as the check ball in the lifter is not unseated by some foreign material, Knight says, the lifter will not bleed down. Our engine testing certainly supports that contention.

The other problem area is the exact opposite of lifter pump-down—the dreaded lifter pump-up. In this case, at some rpm point, valvetrain separation occurs due to a loss of control of the valve by the spring, causing a gap to open between the rocker-arm tip and the top of the valve stem. When this occurs, engine oil pressure forces the small piston upward against the snap ring, eliminating the amount of lifter preload. This could be enough to hold the valve open, which would be instantly followed by a dramatic loss of power. Valvetrain separation occurs most often not through the fault of the lifter but rather either poor valvetrain harmonics or by any number of potential problems, such as flexing pushrods, weak valvesprings, heavy valvetrain components, or perhaps a dozen other potential problems. This again reinforces the point of a systems approach to a high-rpm valvetrain. If the springs, retainers, valves, rocker arms, and pushrods are properly matched, valvetrain separation should be an extremely rare occurrence.

The Test

With the Westech 355ci small-block assembled, it was time to start twisting up the rpm. Steve decided that rather than go for it all at once, we would begin at 7,000 rpm and work our way up. The pulls at 7,000, 7,500, and 8,000 all went very well, so there was nothing left to do but yank it to 8,250. The curve looked about as perfect as we could ask for, which just begged Steve to try 8,500. The curve that we've reproduced here is not that run, but probably the fifth or sixth run at this rpm. As you can see, the curve looks as smooth as a baby's butt. Needless to say, we were pretty stoked, which prompted a discussion about what a bad curve would look like. Steve pulled up a curve from a big-block Chevy that, just after 5,700 rpm, begins to fall off rather sharply. When viewed by itself, this curve does not look all that bad, but when you compare it to a subsequent run with upgraded valvesprings, you can see just how much power that big-block left on the table. What is perhaps the most surprising is that better valve control was worth 10 to 12 more horsepower below 4,000 rpm. This means the poor Rat motor was suffering almost from the moment the engine started! Then, look at the improvement at 6,100 rpm where superior valve control is worth 33 hp. In our experience, when an engine gets into valvetrain trouble, each time you run the engine up to max power, the rpm point for peak horsepower continues to fall and very soon the engine simply won't rpm past 5,000 rpm because of this lack of control. So now look back at our multiple 8,500-rpm pulls with the hydraulic roller cam, and it makes it all that much more impressive.

Conclusions

Clearly, Crane's lifters when combined with a professionally designed valvetrain will allow you to spin a little small-block Chevy, Ford, or even a Mopar to unheard-of rpm points and make power up there without the need for massive valvesprings and mechanical roller lifters. By reducing valvespring pressure (compared to a mechanical roller cam), the load on the engine is automatically reduced, which immediately means the parts will last longer. If you've ever read any of the day-to-day accounts from Hot Rod's Drag Week™, then you are no-doubt familiar with the valvetrain carnage that the competitors regularly deal with. The daily reports of broken and mangled valvesprings, rocker arms, and pushrods sounds more like the casualty reports from the D-day invasion of Normandy in WWII. Given our experience with Crane's hydraulic roller lifters, you could make a case for converting a high-horsepower, high-rpm mechanical roller package to a hydraulic roller and then sit back and watch your competitors replace valvesprings and mechanical roller lifters while you drink ice tea in the shade.

VALVESPRING SPECS
PN Spring Dia. Closed Load Open Load Coil Bind Spring Rate
96883-16 1.540 in. 225 lb. at 1.950 in. 570 lb. at 1.300 in 1.130 in. 544 lb./in.

CAM SPECS
Cam Duration at 0.050 Valve Lift (inches) Lobe Separation
Intake 268 0.640 w/ 1.6:1 108
Exhaust 272 0.640 w/ 1.6:1

PARTS LIST
Description PN Source Price
AFR 227 heads 1067 BuyAFR.com $3172.34
AFR offset stud girdle 6208 BuyAFR.com 102.96
Crane cam custom Crane Call
Crane hydraulic roller lifters 11532-16 Summit Racing 696
Crane springs, dual 96883-16 Summit Racing 340.80
Crane valve retainers 99659-16 Summit Racing 355.20
Crane valve locks 99107-1 Summit Racing 48
Crane spring locators 99460-16 Summit Racing 72
Crane alum. rocker arms 11772-16 Summit Racing 456
Crane offset rockers 1.6:1 left 11765L-1 Summit Racing 33.40 (ea.)
Crane offset rockers 1.6:1 right 11765R-1 Summit Racing 33.40 (ea.)
Crane pushrods 95623 Summit Racing 156.80
Edelbrock Super Victor II 2892 Summit Racing 379.97
JE pistons 182012-8 Summit Racing 782.96
Holley 950 Ultra HP carb 0-80805HB Summit Racing 822.97
Milodon oil pan 31065 Summit Racing 359.97
Milodon oil pump 18750 Summit Racing 41.97
Milodon oil pickup 18314 Summit Racing 43.97
Milodon oil pump shaft 23050 Summit Racing 16.97
Edelbrock Super Victor II 2892 Summit Racing 379.97
ATI balancer 917020 Summit Racing 279.80
MSD crank trigger 8615 Summit Racing 255.97
MSD distributor 85501 Summit Racing 259.97
MSD spark plug wires 31223 Summit Racing 84.97
ARP head studs 234-4301 Summit Racing 224.08
ARP crank bolt 134-2501 Summit Racing 23.59
ARP intake bolt 134-2001 Summit Racing 19.90
Fel-Pro head gasket 1010 Summit Racing 38.97
Fel-Pro oil pan gasket 1818 Summit Racing 12.97
Fel-Pro intake gasket 1206 Summit Racing 14.97
Fel-Pro valve cover gasket 1628 Summit Racing 50.97

SOURCES
Holley Performance Products
1801 Russellville Rd.
Bowling Green
KY  42101
270-781-9741
http://www.holley.com
Crane Cams
1830 Holsonback Drive
Daytona Beach
FL  32117
866-388-5120
http://www.cranecams.com/
ATI Performance Products
6747 Whitestone Road
Baltimore
MD  21207
877-298-5039
http://www.atiracing.com
JE Pistons
15312 Connector Lane
Huntington Beach
CA  92649
714-898-9763
http://www.jepistons.com
Edelbrock
2700 California St
Torrance
CA  90503
310-781-2222
http://www.edelbrock.com
Rockett Brand Racing Fuel
Mount Prospect
IL
847-795-8400
http://www.rockettbrand.com
MSD Performance
1350 Pullman Dr., Dock #14
El Paso
TX  79936
915-857-5200
http://www.msdignition.com
Lucas Oil
302 North Sheridan Street
Corona
CA  92880
951-270-0154
http://www.lucasoil.com
Air Flow Research
28611 W. Industry Drive
Valencia
CA  91355
661-257-8124
http://www.airflowresearch.com
Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!
0 comments
Car Craft