Survival Blue Thunder Tech Info

Blue Thunder Cobra Jet style aluminum cylinder head
Still the best street/strip Ford big block cylinder head on the market today.

Appearing similar to stock heads from the outside, this lightweight cylinder head
is a bolt on replacement for production CJ and SCJ iron heads. Blue Thunder
heads flow like ported heads - - much better than stock. Usable with minor bowl
and port clean up, they do not require CNC porting. Flow potential with minor
clean up exceeds 380 cfm at .700” lift and peaks around 400 cfm at .900” lift.

Blue Thunder cylinder heads are cast at aircraft foundries using Alcoa A356
aluminum with a certified T-6 heat treat. Stainless steel shot blast finish, and
machined surfaces provide an attractive finish. All heads are pressure checked to
60 psi. Extra thick deck surfaces for structural integrity, and future cutting.
Standard bolt hole locations on ends of heads permit easy accessory mounting.
A .250” thick port wall for porting if so desired. Includes easily opened heat riser.
Uses 14mm 3/4” reach 5/8” peanut style spark plug.

Valve cover rail is raised .300” for additional valve train clearance, which allows
production valve covers to clear many aftermarket valve train components.
Production type intake manifold can be used with these heads. A variety of 3
different exhaust ports are offered - - standard height Ford, raised Ford, and raised
Chevy exhaust. The Chevy exhaust version is currently available - - the Ford
versions are currently being redesigned and should return to the markeplace later
in 2006 (with a little luck). Combustion volume is 78cc or 100cc as machined.

Uses standard 429 CJ valve train geometry, and components. Longer valves will
allow higher lift cams. May use stock pistons and valve reliefs. Valve sizes can
range from 2.20”-2.25” intake/1.88” exhaust or 2.30” intake/ 1.80” exhaust. Uses
standard 429 CJ valve train geometry, and components. Longer valves will allow
higher lift cams.

Includes Time Serts at all critical fastener locations - - a threaded solid steel
bushing (not a spiral wire) to keep bolts from stripping out of the aluminum.
Hardened head bolt seats (to keep the head of the bolt from distorting the
aluminum while fastening. Interlocking leaded chrome-moly steel intake, and HI 3
steel exhaust seats. Manganese-silicon-aluminum bronze guide undersized .
0015”, for honing. All guides and seats are thermally pressed using liquid
nitrogen to preclude metal displacement during installation. Accessories include
required grade 8 bolts for raised exhaust applications and 10 hardened blanchard
ground flat washers.

Sample flow data courtesy of Blue Thunder
Intake with minor bowl and valve job
Lift        Flow (in cfm @ 28")
.100          77
.200        155
.300        223
.400        285
.500        340
.600        363
.700        380
.800        389
.900        397

Chevy exhaust port 255 cfm with similar prep, 320 cfm potential