Hmm well since my engine is shot im still trying to find what i want.I ve look a lot 355 kit that was ok but im not thrilled yet.

I always loved the torque of a big v8,so i ve maybe decide to buy a 383 instead of a 355 just for the torque curve .The car will see track 1 or 2 times a year just to have some fun with friends and will be a fun summer driver.I also dont want to shift over the 6k mark(if possible).The car also see less then 6000miles a year.

I choose a kit that doesnt have forged component (except rods)because my goal is around 375whp and a lot of torque .

Basic spec:
-Eagle cast steel crank
-6" i beam forged rod
-Keith Black HyperEutectic piston 11:1 with Speed Pro Plasma-Moly
-Clevite bearing(main and rod)
-Comp pro magnum 1.6 with cm612 springs


-What size of injector do i need?
-Do i need to change my stock fuel pump(brand new by the way)?
-Cam choices:
I ve seen 224/230 @0.50" with .536"/.544" lift ,this cam give about 400ish flywheel hp so minus 15% drivetrain lost this would give 340ish whp.
-So what cam do i need to reach my goal?

Thank you

 

Injector sizing depends on the HP the engine will produce. Generally people on this site agree with a loss thru the powertrain of around 40 to 50 hp. A manual looses less than an automatic. So if you're trying to get 375 at the wheels, then the engine has to make around 425HP. If you prefer a larger "fudge" factor use your 15%. I've seen magazines use as much as 20%.

The accepted injector sizing formula is
flow rate = (HP x BSFC)/(#of injectors x 0.8)

Shown here: http://www.chevyhiperformance.com/te.../photo_01.html


Where BSFC for a standard efficiency engine is 0.5 and the 0.8 is the duty cycle rating of 80%.

In your case, plugging in 425HP yields a flow rate of about 33Lb/hr. If the size you calculate is not available, go to the next size up.

Once you have the desired HP of the engine pinned down, go to the HP calculator and plug in the specs of the parts you wish to use and it will tell you what HP the parts you picked will produce.

2 notes regarding what you are trying to do. One, the specs of the cam you listed as far as lift is concerned is usually listed for a "base" rocker ratio. I've always seen that lift listed with a 1.5 rocker ratio. You need to double check that as you said you want to use a 1.6 RR. This would change the lift numbers you listed to 0.572/0.580 (if that were the case). This will have a bearing on the engine HP calcs as well as the springs you want to use.

2nd, you did not say anything about head changes. Either porting the existing heads or purchasing new heads. IMHO not changing these in anyway will be the stumbling block to you achieving your goal. However, the engine calculator will tell you that. But you will need such numbers as valve size, cumbustion chamber volume as well as other specs. The HP calculator is available at automotive retailers as a disc for the computer.

One last thing. Why not use better pistons and crank? Sure it costs more but what if you decide to up the horse power in the distant future? You might then have to go back into the bottom end. If you spend the extra cash up front, you will assure yourself that you won't have to redo the bottom end no matter what you choose later.