[{"id":347630918,"handle":"best-selling-products","title":"Best Selling Products","updated_at":"2024-12-12T14:33:41-06:00","body_html":null,"published_at":"2016-10-02T12:22:59-05:00","sort_order":"best-selling","template_suffix":null,"disjunctive":true,"rules":[{"column":"title","relation":"contains","condition":"Best Selling"},{"column":"title","relation":"not_contains","condition":"Best Selling"}],"published_scope":"global"},{"id":241321312455,"handle":"black-label-cathedral-heads","updated_at":"2024-12-03T14:05:09-06:00","published_at":"2021-01-11T11:27:46-06:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"Black Label - Cathedral Heads","body_html":""},{"id":404018266325,"handle":"black-label-cylinder-heads","updated_at":"2024-12-04T16:55:10-06:00","published_at":"2022-03-14T10:16:40-05:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"Black Label Cylinder Heads","body_html":"\u003cdiv style=\"text-align: center;\"\u003eLooking for something more specific ?\u003c\/div\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/www.mastmotorsports.com\/collections\/black-label-cathedral-heads\"\u003eCathedral Port Heads\u003c\/a\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/www.mastmotorsports.com\/collections\/black-label-ls3-heads\"\u003eLS3 Heads\u003c\/a\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/www.mastmotorsports.com\/collections\/black-label-ls7-heads\"\u003eLS7 Heads\u003c\/a\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/www.mastmotorsports.com\/collections\/black-label-lt-di-cylinder-heads\"\u003eLT Heads\u003c\/a\u003e\u003c\/div\u003e\n\u003ch5\u003e\u003c\/h5\u003e"},{"id":416547668181,"handle":"ls-cathedral-cylinder-heads","updated_at":"2024-12-04T16:35:19-06:00","published_at":"2023-04-10T17:27:30-05:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"LS Cathedral Cylinder Heads","body_html":""},{"id":401051746517,"handle":"ls-cylinder-head","updated_at":"2024-12-06T10:55:07-06:00","published_at":"2022-01-19T14:28:35-06:00","sort_order":"manual","template_suffix":"","published_scope":"global","title":"LS Cylinder Heads","body_html":""},{"id":170383245409,"handle":"all-cylinder-heads","updated_at":"2024-12-06T10:55:07-06:00","published_at":"2020-09-06T12:55:14-05:00","sort_order":"manual","template_suffix":"collection","published_scope":"global","title":"Products - All Cylinder Heads","body_html":""}]
["4.000\"","Bare","Black Label","cathedral","Cathedral Port","CNC","cylinder heads","Hydraulic","LS","medium bore"]
Skip to content
Cathedral Port 245cc 4.000"(+) Bore - Single Black Label CNC Cylinder Head - Bare
Description
Description
The Mast Motorsports cylinder head product line is completely manufactured from a raw casting to a finished cylinder head in the USA located in Nacogdoches Texas.
Mast refuses to compromise on materials and methods that may jeopardize longevity, performance, and quality. When buying Mast Cylinder heads, you are getting the highest level of quality and performance on the market.
Full Send, no compromises, no shortcuts, ever.
Dimensional Specs
Bore Size: 4.000" (+)
Weight: 28.5 lbs.
Intake Valve Size: 2.165"
Exhaust Valve Size: 1.600"
Valve Stem Diameter: 5/16"
Valve Length: 5.450"
Valve Angle: 11°
Valve Spring Pocket Diameter: 1.65"
Valve Spring Install Height: 1.800"
Head Stud Size: .493"
Valve Guide OD: .502"
Valve Job Type: Newen CNC 5 Angle
Air Flow & Performance Criteria
Intake Max. Flow: 358 CFM @ 0.700"
Exhaust Max. Flow: 245 CFM @ 0.700"
Intake Average Flow: 248 CFM
Exhaust Average Flow: 171 CFM
Intake Seat Material: Ductile Iron
Intake Port Volume: 245cc
Exhaust Port Volume: 106 cc
Standard Chamber Volume: 70cc
Port Type: CNC
Materials
Cylinder Head Material: A356-T6 Aluminum
Intake Valve Seat Material: Ductile Iron
Exhaust Valve Seat Material: Ductile Iron
Rocker Stand Type: Mast Billet
Rocker Arm Type: LS3 1.7 or Aftermarket
Deck Thickness: .750"
Guide Material: Phosphor Bronze
General
Rocker Stand Type: Mast Billet
Rocker Stands Included: Yes
Rocker Stand Dowels Included: Yes
Uses Stock Rocker Bolts: No
Rocker Bolts Included: No
Rocker Arm Type: LS3 1.7 or Aftermarket
Head Bolt QTY: 6 Bolt Style
Valve Cover Rail Height: + ½ inch
Can use OE Valve Cover: Yes
Custom Options Available
Chamber Softening
Custom Chamber Sizing
½ inch head stud clearance
Copper Exhaust & Intake Valve Seats
Read more