97 Vortec 5.7L Rebuild?

[REDBOWTIE]

I was wanting to rebuild my motor. I was thinking of putting on the fastburn heads, vortec aluminum intake, keith black flat-top pistons, a little bit bigger cam, but not sure how big I can run in my motor since it is ran by a computer any thoughts on that would be appreciated. Also some kind of new timing chain not sure which one yet. Not sure if I will need some fuel pressure up grades or not looking for some help on that as well. Anything you guys could think of to help me out would be greatly appreciated. Thanks

[383 silverado]

if this is 97 vortec isn't any after market intakes to work with the stock tb, comp cams recommended their xr258hr/ 08-500-8 for my 97 vortec 350, the stock pistons are -12cc for a cr of 9.4-1 with 64cc heads,cloyes makes a single roller hd timing chain ,gmpp also makes the part # is 12371043. as for fuel pressure go get the fast flash tuner you can add 5,10,15 % more fuel and add 10 % or takeaway 10 % timing

http://fuelairspark.com/Products/details/programmer/over.asp

you an also reprogram the stock pcm for the new cam with it ( fast flash tuner )

[REDBOWTIE]

Hey thanks 383, will I need bigger fuel injectors? I know that the stock injectors are 19lbs/hr or will those be enough for what I want to do?

[REDBOWTIE]

Hey 383, What setting did you set your fast flash programmer at for the cam that you have in your egine. Setting A, B, C. thanks alot.

[Busted Knuckles]

Can't swap injectors on the Vortec intake, or so I've been told a couple of hundred times. Flat top pistons with cleaned up vortec heads, zero decked block and an LT-4 stock cam got me 19mpg in a '99 Suburban. It has plenty of power from idle to about 4500.

[REDBOWTIE]

How come you are not able to put different injectors in? What is the reason?

[REDBOWTIE]

i was wanting to put in 36lb/hr injectors. I wonder why you can swap out injectors?

[98GreenMachine]

i was wanting to put in 36lb/hr injectors. I wonder why you can swap out injectors?

You can, but you would need a marine intake to do so. The stock intake doesn't allow for larger injectors. I asked the same question here:
http://fullsizechevy.com/forums/showthread.php?t=269129

[383 silverado]

i was wanting to put in 36lb/hr injectors. I wonder why you can swap out injectors?


here's a picture why you can not change them. you would need fuel rails to change them

http://www.theautoshop.net/VortecMPFI.htm

[98GreenMachine]

here's a picture why you can not change them. you would need fuel rails to change them

http://www.theautoshop.net/VortecMPFI.htm

:LOL: I always laugh at that price, $456 after shipping :whatever:

[REDBOWTIE]

Is there anything else i can do, besides getting an marine intake? Is there some kind of EFI system that well help me exceed 400hp and still use the stock 19lb injectors.

[383 silverado]

Is there anything else i can do, besides getting an marine intake? Is there some kind of EFI system that well help me exceed 400hp and still use the stock 19lb injectors.


are you serious about making these mod's ?



The gm MPFI is better than the stock poppets. These Multec 2 injectors can be ran at 100 psi of rail pressure continually. This theoretically makes the 19 pph injectors flow 28.9 #/hr of fuel flow. You would need and adustable fuel pressure regulator to run the elevated fuel pressure. The gm MPFI conversion spider is said to allready have an adjustable FPR installed as part of the MPFI spider. There is supposed to be a Torx adjustment screw to raise or lower the fuel pressure. I dont know how high or how low the fuel pressure can be adjusted from the stock psi. To get complete fuel pressure control, you need to elimintae the stock FPR and install an adjustable FPR that is installed i the return line of the Vortec fuel system. Thats how some guys were able to get 100 psi of fuel pressure.

the stock CSFI and MPFI spider run at 60psi stock and at that fuel pressure they flow 22.3#/hr, but are rated at 19 #/hr at the industry standard test pressre or 43.5 psi.

westers garage saying that they have a set up that will support 440 hp

http://westersgarage.eidnet.org/injectors.htm