BLUE THUNDER 3.60” CANTED VALVE CYLINDER HEAD
75cc CHAMBER • SMALL BLOCK FORD • YATES-STYLE RACING DESIGN
PROFESSIONAL-GRADE FORD RACING CYLINDER HEAD
Offered here is ONE Blue Thunder 3.60” Canted Valve Cylinder Head featuring the 75cc combustion chamber, supplied as a bare racing cylinder head as shown in the photographs.
Designed around the proven Yates-style intake and exhaust port architecture, the Blue Thunder 3.60 was developed for serious naturally aspirated Small Block Ford competition engines where airflow capability must be accompanied by casting strength, machining flexibility, reliable valvetrain geometry, and long-term serviceability.
This is not a fully assembled or ready-to-run cylinder head. It is a professional racing casting intended for final preparation by a qualified engine builder or machine shop.
Valve guides, valves, springs, retainers, locks, rocker arms, and other valvetrain components are not included unless specifically stated otherwise.
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AT-A-GLANCE SPECIFICATIONS
Quantity: ONE cylinder head
Combustion Chamber: 75cc
Configuration: Bare racing cylinder head
Material: Alcoa A356 aluminum
Heat Treatment: Certified T6
Port Layout: Standard Yates-style intake and exhaust locations
Maximum Finished Intake Port Height: 3.60” from head gasket surface
Intake Valve: 2.180”–2.200”
Exhaust Valve: 1.625”
Deck Thickness: Greater than 0.650”
Raised Intake Spring Pad: Approximately 0.1500”
Spark Plug: 14 mm, 3/4” reach, peanut-style
Valve Guides: Not included
Valve Seats: Interlocking intake and exhaust seats standard
Intake Bolt Patterns: Straight-in and angled
Thread Protection: More than 30 solid TIME-SERT® inserts per head, plus solid stainless steel exhaust flange inserts
Compatible applications include Ford 302 Windsor, 351 Windsor, 351 Cleveland racing blocks, Boss 302 combinations, and racing applications utilizing standard Yates intake and exhaust port locations.
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A SERIOUS FOUNDATION FOR A SERIOUS FORD ENGINE
There is an important distinction between a racing cylinder head designed primarily around an impressive specification sheet and one designed around the needs of the engine builder who must machine, assemble, race, service, and eventually rebuild it.
The Blue Thunder 3.60 was developed with the latter in mind.
Substantial material is retained in critical areas so the engine builder has room to establish the final port configuration, valve job, combustion requirements, spring installed height, and other dimensions appropriate for the specific engine combination.
Instead of forcing every engine into the same finished configuration, Blue Thunder provides the foundation and allows the builder to determine the final combination.
That philosophy is reflected throughout this casting, from its thick deck and generous port walls to its raised intake spring pads, dual intake bolt patterns, interlocking valve seats, and extensive use of solid threaded inserts.
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THE BLUE THUNDER CASTING EXPERIENCED RACERS MAY RECOGNIZE
Experienced Ford racers and engine builders may have encountered this cylinder head before carrying different identification or engraving.
For sufficiently large production orders, Blue Thunder has supplied these racing castings to manufacturers, racing organizations, and engine builders without Blue Thunder identification on the end of the casting when requested. This permits the purchasing organization to apply identification appropriate to its own racing program or product line.
The cylinder heads being offered here are from the remaining inventory of this newest Blue Thunder production run and carry the BLUE THUNDER engraving on the end.
Consequently, builders familiar with this design may recognize the underlying casting even if they have previously seen versions carrying different identification.
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YATES-STYLE PORT ARCHITECTURE
The 3.60 incorporates the established Yates-style intake and exhaust port locations long associated with high-performance Small Block Ford racing combinations.
The design can be used with:
* Ford 302 Windsor
* Ford 351 Windsor
* Ford 351 Cleveland racing blocks
* Boss 302 combinations
* Other appropriate combinations using standard Yates intake and exhaust port locations
Potential competition applications include Sportsman Drag Racing, Sprint Car competition, Circle Track Racing, Road Racing, Marine Competition, and custom naturally aspirated racing engines.
Proper component compatibility and final configuration must always be established by the engine builder.
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PORT DEVELOPMENT AND AIRFLOW POTENTIAL
Blue Thunder supplies the 3.60 as a professional racing casting rather than a universally finished cylinder head.
After completion of the required valve job, many applications require only appropriate bowl blending and port cleanup, while more specialized combinations can take advantage of the substantial material provided for additional hand or CNC development.
The intake ports permit a maximum finished port height of approximately 3.60 inches measured from the cylinder head gasket surface.
Generous port wall thickness allows the builder to tailor the finished configuration around displacement, induction system, camshaft profile, operating RPM, intended valve lift, and the specific demands of the engine.
When professionally prepared and developed, Blue Thunder 3.60 cylinder heads have demonstrated more than 400 CFM intake airflow and approximately 273 CFM exhaust airflow on a certified SuperFlow SF-1020 flow bench.
Actual airflow will vary according to valve configuration, valve job, port development, test pressure, equipment, and final preparation.
The significance of this casting extends beyond peak airflow numbers. Racetrack performance also depends upon accurate machining, stable valve seats, correct valvetrain geometry, structural rigidity, reliable fastener retention, and the ability of the cylinder head to remain serviceable throughout repeated racing cycles.
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75cc COMBUSTION CHAMBER
This listing is specifically for the 75cc combustion chamber version of the Blue Thunder 3.60 cylinder head.
The 3.60 design has been produced in both 50cc and 75cc configurations, allowing the engine builder to select a chamber appropriate to the intended compression ratio and engine combination.
Please confirm that the 75cc chamber is correct for your application before purchasing.
The cylinder head is designed around commonly available racing valve dimensions:
Intake: 2.180” to 2.200”
Exhaust: 1.625”
Using established racing valve dimensions provides considerably greater component flexibility than a proprietary valve package and allows builders to select valve material, stem configuration, weight, and manufacturer according to the requirements of the engine.
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IMPORTANT: 0.1500” RAISED INTAKE SPRING PADS
One feature of the Blue Thunder 3.60 that must be considered during valvetrain planning is the intake spring pad height.
The intake spring pads are intentionally approximately 0.1500 inch taller than a conventional configuration.
This additional material was incorporated for high-RPM racing combinations where aggressive camshaft profiles, substantial valve lift, specialized springs and retainers, and carefully established installed heights may be required.
The feature was developed by Blue Thunder in conjunction with a major engine-building and racing team to provide additional flexibility when configuring demanding naturally aspirated racing valvetrains.
The additional 0.1500-inch height should therefore be considered before purchasing valves, springs, retainers, locks, rocker arms, pushrods, or other related valvetrain components.
For applications requiring a more conventional installed height, a qualified engine builder or machine shop can machine the intake spring pads to the required dimension.
Providing additional material gives the professional engine builder options. Material can be removed when necessary; material absent from the original casting cannot easily be added.
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PRACTICAL 3.60 VALVETRAIN GEOMETRY
The Blue Thunder 3.60 differs from the 4.30-style Small Block Ford cylinder head in an important practical respect:
The 3.60 does not require the specialized one-piece rocker stand associated with the 4.30-style design.
This gives builders greater flexibility in selecting established racing valvetrain systems without introducing an unnecessary proprietary component into the build.
Appropriate racing valvetrain components are available from established manufacturers such as T&D Machine Products, Jesel Valvetrain Innovation, and other professional racing suppliers.
As with any competition cylinder head, final rocker geometry, pushrod length, spring configuration, valve length, and related dimensions must be established for the individual engine.
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DUAL INTAKE MANIFOLD BOLT PATTERNS
The intake flange is machined with both straight-in and angled intake manifold bolt patterns.
This provides compatibility with a broader range of Yates-style intake manifold configurations and gives the builder additional flexibility when developing or updating an induction system.
For racers who may later change manifolds or alter an engine combination, having both mounting arrangements already incorporated into the cylinder head can eliminate an unnecessary limitation.
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MORE THAN 30 SOLID THREADED INSERTS
A professional racing engine may be assembled and disassembled many times throughout its service life.
For this reason, Blue Thunder does not depend solely upon threads cut directly into the aluminum casting at numerous critical locations.
Each 3.60 cylinder head incorporates more than thirty solid TIME-SERT® threaded inserts.
TIME-SERT® inserts are precision-machined solid bushings rather than spiral-wound wire inserts. Once installed, they become an integral part of the threaded location and provide excellent fastener engagement, load distribution, resistance to thread damage, and serviceability during repeated engine maintenance.
The TIME-SERT® system represents an investment of more than $100 per cylinder head in the inserts alone.
It is the type of feature that may not dominate a flow-bench advertisement, but becomes increasingly valuable to the engine builder over the working life of the cylinder head.
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SOLID STAINLESS STEEL EXHAUST INSERTS
The exhaust flange presents a particularly demanding environment because its fasteners are exposed to high temperature, repeated thermal cycling, vibration, moisture, and corrosion.
For this reason, the exhaust mounting locations utilize solid stainless steel threaded inserts.
Stainless steel provides excellent corrosion resistance while helping preserve the integrity of the exhaust mounting threads through repeated installation and removal.
These inserts are permanent structural features incorporated into the cylinder head, not wire-type repair inserts added after manufacture.
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EXTRA-THICK DECK
The Blue Thunder 3.60 features a deck surface greater than 0.650 inch thick.
A substantial deck provides rigidity in an area subjected to significant mechanical and thermal loads while also preserving valuable material for future machining.
For a racing engine expected to be inspected, refreshed, or rebuilt over its operating life, having additional deck material available for subsequent resurfacing or other required machining can be extremely valuable.
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INTERLOCKING VALVE SEATS
Blue Thunder equips the 3.60 with interlocking intake and exhaust valve seats as standard equipment.
The interlocking configuration is intended to promote secure seat retention in the demanding thermal environment of a competition cylinder head.
For specialized engine programs requiring cylinder heads without the intake valve seats installed, a limited quantity may be available from overstock inventory.
Please contact us before purchasing if this configuration is required. Approximately three additional business days may be necessary to locate, pull, and prepare these heads for shipment.
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BARE CYLINDER HEAD – FINAL MACHINING REQUIRED
This listing is for ONE bare 75cc Blue Thunder 3.60 cylinder head.
Valve guides are NOT included.
Guides are available separately through our other eBay listings.
Supplying the head without valve guides gives professional engine builders the ability to select the appropriate guide configuration and establish the final valve-to-guide clearances and honing dimensions for the intended valves and operating conditions.
The cylinder head must receive the appropriate valve job, final machining, cleaning, inspection, component selection, setup, and assembly before being placed into service.
This component is intended for preparation by an experienced racing engine builder or qualified machine shop.
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BUILD THE ENTIRE ENGINE TO THE SAME STANDARD
A cylinder head capable of supporting a serious racing engine deserves components selected to the same standard.
The cost difference between an adequate racing component and an exceptional one can be relatively small compared with the total investment represented by the completed engine.
Valve springs, valves, retainers, locks, pushrods, rocker arms, lifters, fasteners, head gaskets, timing components, and oiling-system components all become part of the same mechanical system.
A single compromised component can place considerably more expensive components at risk.
For that reason, component selection should be based upon engineering suitability, dimensional accuracy, material quality, reliability, and compatibility with the complete engine combination rather than price alone.
The goal of a properly developed racing engine is not simply horsepower.
It is reliable, repeatable horsepower.
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COMPLETE TECHNICAL INFORMATION
CONSTRUCTION
* Alcoa A356 aluminum casting
* Certified T6 heat treatment
* Stainless steel shot-blast finish
* Precision-machined surfaces
COMBUSTION CHAMBER
* Listing configuration: 75cc
* Blue Thunder has produced both 50cc and 75cc versions
PORT CONFIGURATION
* Standard Yates-style intake and exhaust locations
* Maximum finished intake port height approximately 3.60” from head gasket surface
* Substantial material available for professional hand or CNC port development
AIRFLOW POTENTIAL
* More than 400 CFM intake when professionally developed
* Approximately 273 CFM exhaust when professionally developed
* Testing performed on a certified SuperFlow SF-1020 flow bench
* Final results depend upon preparation and test configuration
VALVES
* Intake: 2.180”–2.200”
* Exhaust: 1.625”
SPRING PADS
* Intake spring pads approximately 0.1500” taller than conventional configurations
* Can be machined to the required installed-height configuration
DECK
* Greater than 0.650” thick
SPARK PLUG
* 14 mm
* 3/4” reach
* Peanut-style
VALVETRAIN
* Yates-style racing geometry
* Does not require the one-piece rocker stand associated with the 4.30-style Small Block Ford head
THREADED INSERTS
* More than 30 solid TIME-SERT® threaded inserts per cylinder head
* Solid stainless steel threaded inserts at exhaust flange locations
VALVE SEATS
* Interlocking intake and exhaust valve seats standard
* Limited heads without intake seats may be available by request
INTAKE MANIFOLD MOUNTING
* Straight-in intake manifold bolt pattern
* Angled intake manifold bolt pattern
* Compatible with numerous appropriate Yates-style intake manifolds
ENGINE APPLICATIONS
* Ford 302 Windsor
* Ford 351 Windsor
* Ford 351 Cleveland racing blocks
* Boss 302
* Appropriate combinations utilizing standard Yates intake and exhaust port locations
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INTENDED FOR EXPERIENCED ENGINE BUILDERS
The Blue Thunder 3.60 is not intended to be an inexpensive mass-market replacement cylinder head or an out-of-the-box street replacement.
It is a professional racing component designed to give the engine builder a high-quality foundation from which to develop the finished cylinder head.
Its value comes from the combination of features engineered into the casting: substantial port material, airflow development potential, thick deck construction, raised intake spring pads, interlocking valve seats, extensive solid threaded inserts, dual intake mounting patterns, practical valvetrain geometry, and the ability to tailor the finished cylinder head to the engine.
For the experienced Ford engine builder, those details matter.
They matter during machining.
They matter during assembly.
They matter at the racetrack.
And they matter when the engine returns to the shop for inspection and freshening.
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BLUE THUNDER
For decades, Blue Thunder has manufactured Ford performance components for racers and engine builders who recognize that the quality of a finished racing engine begins with the quality of its foundation.
The 3.60 Canted Valve Cylinder Head continues that philosophy by giving the builder the material, engineering features, and flexibility required to develop a serious naturally aspirated Small Block Ford racing combination.
Professional racing engineering. Serious Small Block Ford capability. Built on the Blue Thunder foundation.