Oval Track 253/257 Solid Roller Cam for Chevrolet Small Block

MECHANICAL ROLLER-1/4 - 3/8. 331-355 Limited LM, 2bbl & 390 4 bbl carbs

SKU
12-855-9
$374.98

SBC - 1955-57 models have an oiling groove in the rear journal. The listed part numbered cams will not fit these models, so if you require a camshaft with the oiling groove, please call us at 1-800-999-0853 or click here to contact us, and we will assist you with placing an order.

Grind Number: 281TKR-6
Engine Family: Chevrolet 262-400 c.i. 8 Cylinder (1958-1998)
RPM Operating Range: 3,000-7,200
Cam Type: Solid Roller
Lifter Style: Solid Roller
Camshaft Series: Oval Track Xtreme TK
Camshaft Gear Attachment: 3-Bolt
Usage: Circle Track
Valve Springs Required: Yes
Camshaft Material: Billet Steel
California Proposition 65: WARNING: Cancer and Reproductive Harm P65Warnings.ca.gov
Advertised Intake Duration: 281
Advertised Exhaust Duration: 285
Intake Duration at .050 Inch Lift: 253
Exhaust Duration at .050 Inch Lift: 257
Intake Valve Lift: 0.645
Exhaust Valve Lift: 0.645
Lobe Separation: 106
Assembly Lubricant Included: No
Valve Timing @ 0.02 Lift:
Exhaust Close ATDC: 22
Exhaust Open BBDC: 55
spec-card-valve-timing
Intake Open BTDC: 21
Intake Close ABDC: 52
Note Description
14Requires upgraded gear, thrust button & wear plate
46Must use bronze tip fuel pump pushrod when using high pressure or high volume pump
Component Part Number
Break-In Lube: 159
Distributor Gears: 12200  /   412
Lifter Kit: 818-16
Rev Kit: 4000
Steel Retainers: 731-16  /   733-16
Timing Set: 3100KT
Valve Locks: 611-16
Valve Seals: 503-16
Valve Springs: 26089-16  /   26099-16