1984 corvette x-fire intake porting? or upgrade

grumpyvette · Sep 17, 2008

IF your thinking you can port the stock intake and heads......Ive got some advice gained thru experiance

don,t get the idea Im against the x-fire system,design, it has potential,Im just against throwing money down a rat hole!
sellecting the aftermarket crossram bases matched to a correctly matched cam, better heads and a low restriction exhaust with decent headers can make a huge improvement.
but the stock intake, heads and cam are KILLING your potential power

http://www.technovelocity.com/chevyhack ... olish.html

SHORT ANSWER! STOP BEATING A LONG DEAD HORSE!!

Ive been playing at the hp wars for years,your stock heads,intake, displacement and compression ratio and cam are killing performance. the cross fire intake is the worst offender as it only flow about 170cfm-190cfm
swapping to a EDELBROCK SY1 OR OFFY CROSSRAM INTAKE with CUSTOM LID removes that resriction
THE EXTREMELY RESTRICTIVE STOCK INTAKE

custom lid SY1

compare the ports, the SY1 flows about 270cfm

<b>"A MODIFED EDELBROCK SY1 WITH CUSTOM TOP MATCHED TO 190CC AFR HEADS CRANE 114142 CAM -- AND add a 383 high compression engine kit"

b>
BTW Ill save you the math, youll need to get the 10:1 cpr flat top piston 383 kit for the street, and the 74cc combustion chambers AFR 190cc HEADS with L98 spark plug angles if you intend to run high test gas you find everywhere (some is lousy quality) and get the head gasket as close to .018-.022 as you can for correct quench
fyi DD-2000 and EA pro both guess at OVER a 115 hp improvement at the rear wheels, having done this type mod in the past Im reasonably sure thats UNDERESTIMATED for those listed changes

383 rebuild kit $1000
http://www.strokerkits.com/383.htm]http://www.strokerkits.com/383.htm
crane cam/lifters $150
AFR heads $1200 http://www.flatlanderracing.com/cyl...//www.flatlanderracing.com/cylhead_index.html
SY1 with custom lid $500-$600
DOING YOUR OWN WORK>>>>>PRICELESS! :thumbs: :thumbs:

offy

Part numbers are 5893 base,
http://store.summitracing.com/partdetail.asp?autofilter=1&part=OFY-5893&N=700+400429+115&autoview=sku

5903 for the dual-four top,
http://store.summitracing.com/partdetail.asp?part=OFY-5903

5902 for the linkage.

http://store.summitracing.com/partdetail.asp?part=OFY-5902

both SUMMIT AND JEGS CAN GET IT FOR YOU

MORE USEFUL INFO

http://www.swko.net/~lionsden/crossfire.htm

http://www.swko.net/~lionsden/crossfire1.htm

unless your rich or hopelessly masochistic get a SY1 or OFFY BASE

the sy1 flows close to 270cfm out of the box, a cfi flows 170-190cfm (DEPENDS ON WHICH PORT (STOCK) and theres not enought room to port without cutting/welding (EXPENSIVE AND TIME CONSUMEING AND EASILY SCREWED UP)

these are the STOCK CFI INTAKE RUNNERS,

you can extensively port them and its a big improvement over stock.............but they are still EXTREMELY RESTRICTIVE, and its not a huge help, if your looking to make significant hp

THEY WILL NOT SUPPORT A LARGE INCREASE IN HP WITHOUT MASSIVE CUTTING AND REWELDING WORK,WHICH COSTS FAR MORE AND WORK FAR LESS EFFECTIVELY THAN AN SY1 SWAP WITH A CUSTOM LID

this is the port work necessary to get them to flow even as pittifly as a TPI
for those guys that suggest swapping to a LT1-4 and MPFI on your 1984 crossfire...
just so your not confused, or under the wrong impression, the offanhauser intake base significantly out flows even a ported LT4 intake,doesn,t require re-plumbing the coolant flow like on the LT4 intake,(remember the LT1 and LT4 have no place to install a radiator hose or distributor in stock form),the offy, will function with minimal rewireing,and has a wider effective power band ONCE ITS CORRECTLY MODIFIED with the correct dual TB top or if you just use the dual 4 barrel top plate and a couple 650cfm carbs like many guys use, plus if its correctly done the engine appears to remain stock too the average casual inspection as you can still use the stock air cleaner assembly with the custom TB top, but the windshield wiper motor needs to be replaced with a smaller version for clearance issues

OFFY BELOW

grumpyvette · Sep 18, 2008

http://www.swko.net/~lionsden/crossfire.htm

viewtopic.php?f=32&t=640

more info

1984 corvette x-fire intake porting? or upgrade

grumpyvette

Administrator

grumpyvette

Administrator