Fuel system

[383Formula]

I'm looking to upgrade injectors and fuel pump on my 383. I was wondering who makes the best injectors and fuel pump, and what size injectors to run?

[Kevin - Blown 95 TA]

How much power do you make?

You might consider Ford 30# injectors and a Walbro 225 aftermarket pump can give you a bit more flow. Depends on how much power you make and if you have any power adders. You need to provide some info for people to help you.

[Injuneer]

To get you in the ballpark on injector size, multiply your flywheel HP by 0.07.....

example: 450 flywheelHP x 0.07 = 31.5#/HR

That assumes a good (efficient) tune, and a duty cycle of 85% or less. To allow for future power increases, add 10-20% to the HP.....

example: 450HP X 1.20 = 540HP
540HP X 0.07 = 37.8#/HR

That's for normally aspirated engines. For a forced induction motor or a nitrous motor, you are going to want to use a different multiplier, depending on how you add the fuel for the boost or nitrous.

I've seen a few problems popping up with the Walbro pumps. My preference is Bosch. I run a pair of 205LPH Bosch pumps, good for up to 1,000HP. They work well with my 78# injectors...

[383Formula]

I am not sure on how much power my new motor will have. Its a 383 stroker, with ported/ polished heads and intake manifold, true duals, and a custom grind cam: .672 in. .672 ex. 26? 27? @50 106LSA

[fastTa]

I am not sure on how much power my new motor will have. Its a 383 stroker, with ported/ polished heads and intake manifold, true duals, and a custom grind cam: .672 in. .672 ex. 26? 27? @50 106LSA

Wow, that is a pretty healthy cam.

Is this a LT1 motor? Are you going to use an aftermarket engine management setup?

Would you mind sharing some more details?

[Kevin - Blown 95 TA]

106 LSA

[fastTa]

106 LSA

Yeah, I take it this ain't no street car.

[383Formula]

This is a lt1 motor and the computer is being reprogrammed, and as for this being a street car, it will be, but mostly on the weekends. I'll still take it to the strip too.

[fastTa]

This is a lt1 motor and the computer is being reprogrammed, and as for this being a street car, it will be, but mostly on the weekends. I'll still take it to the strip too.

Do you have any more details on the motor? Which heads are you using? Valve sizes? Crank? Rods? Flow numbers? What type of headers? Transmission? Intake manifold? Dry sump? Any nitrous?...................

You are going to find it very disappointing trying to use the stock PCM with that cam. That camshaft is going to need close to 7,500 RPM if not more to make good power. The tables are hard limited to 7,000 RPM. That doesn't mean you will not be able to spin the motor past 7k, but you will just not be able to tune over 7k. That isn't good with a cam that size.

I'm just assuming that is a solid roller cam given the relatively high amount of lift in comparison to the duration. You are going to need at least a 4500 stall to get that thing moving. More like 5000 to get a decent launch at the track. You are also going to have to run manual brakes or a vacuum pump in order to have brakes.

I agree with Fred that Bosch makes a very good pump, but it is going to really depend on how much HP you really make at the crank, the fuel pressure you will see at the rail, the actual discharge pressure of the pump, and the flow capacity of your fuel system, and whether or not you want to use an in-line pump or stick with an in-tank.

Just assuming you are going to make 625 HP at the crank(could be much higher), a BSFC of 0.50(may be slightly higher for your application), keeping your IDC at a safe 70%, and assuming a pressure of 47 at the rail, I come up with 53.69 lb/hr.

Of course that flow rate expectation will all depend on your actual BSFC, crank HP, and pressure at the rail.

[383Formula]

I am using an Eagle forged crankshaft, forged Eagle H-beam rods, and forged SRP dome pistons; which will be running close to 13:1 compression ratio. I am using my stock heads but are being worked over, I am not sure what size valves are being used. All the vavletrain components are from Comp Cams. The cam is a solid roller. I won't know a whole lot about the heads until my car is done. The intake manifold is being ported and polished also. I'm running Pacesetter long tube ceramic coated headers, with 2 1/2 inch exhaust. True duals with no cats. This is a 6 speed manual transmission, and I don't plan on running any boost. My goal was to hit over 500 RWHP being N.A. My motor and intake manifold are going to be painted chevy orange, with tall polished aluminum valve covers. I'll have all the informatin when I get my car back as far as head work, and parts. I plan on getting it dynoed,to the wheels, when I get it back too.

[fastTa]

I am using an Eagle forged crankshaft, forged Eagle H-beam rods, and forged SRP dome pistons; which will be running close to 13:1 compression ratio. I am using my stock heads but are being worked over, I am not sure what size valves are being used. All the vavletrain components are from Comp Cams. The cam is a solid roller. I won't know a whole lot about the heads until my car is done. The intake manifold is being ported and polished also. I'm running Pacesetter long tube ceramic coated headers, with 2 1/2 inch exhaust. True duals with no cats. This is a 6 speed manual transmission, and I don't plan on running any boost. My goal was to hit over 500 RWHP being N.A. My motor and intake manifold are going to be painted chevy orange, with tall polished aluminum valve covers. I'll have all the informatin when I get my car back as far as head work, and parts. I plan on getting it dynoed,to the wheels, when I get it back too.

LT1 castings, even if fully ported with 2.00'/1.60" valves, and that nasty of a cam are not going to get along.

What are you goals and/or plans with this car?

[Kevin - Blown 95 TA]

I am using an Eagle forged crankshaft BARF, forged Eagle H-beam rods, and forged SRP dome pistons; which will be running close to 13:1 compression ratio RACE GAS. I am using my stock heads OK (not) but are being worked over, I am not sure what size valves are being used Who is in charge of the project?. All the vavletrain components are from Comp Cams. The cam is a solid roller. I won't know a whole lot about the heads until my car is done Who is in charge of the project?. . The intake manifold is being ported and polished also. I'm running Pacesetter long tube ceramic coated headers, with 2 1/2 inch exhaust. True duals with no cats. This is a 6 speed manual transmission, and I don't plan on running any boost. My goal was to hit over 500 RWHP being N.A. My motor and intake manifold are going to be painted chevy orange, with tall polished aluminum valve covers. I'll have all the informatin when I get my car back as far as head work, and parts Who is in charge of the project?. . I plan on getting it dynoed,to the wheels, when I get it back too.

Not trying to rag on you, but you should know this stuff up front. Don't cheap out on the crank on an engine like this. Chinese rods work OK, but their cranks have a worse rep. It will be a dog on the street with that cam.

[Injuneer]

With the duration and overlap on that cam, he might not need race gas at 13:1 CR. His DCR may be low enough to sneak by on good pump gas. But the engine's not going to have any sort of bottom end performance... striclty a track car. Agree.... component selection is marginal in some areas. Totally surprised that it would be using the ported stock heads. I don't think anyone has gone that far over 300cfm on the stockers, and if they do, the cost would probably be greater than the cost of a set of ported AFR's that would be able to make his HP goals. I don't think anyone gets the stockers to flow well at all above 0.600", so the extreme lift on the cam is almost wasted. I was expecting to see a set of the SB2.2 heads on a motor with than cam.

[fastTa]

Believe it or not I learned a few years back that just about all forged steel crankshafts come from the exact same foundry-----overseas, mostly India and not China like the popular rumor. Even some like Callies claim that their cranks are made in USA. Well they are cut in the USA but the forgings come from overseas.

In other words when Eagle, Callies, Lunati, Scat, Cola etc. get their rough forgings they are all the exact same. The difference in the cranks ends up resulting in how each manufacturer cuts the cranks. Now start getting into billet and even higher dollar cranks like the billet Sonny Bryant and that is different.

383 Formula, you really might want to consider a different camshaft. I realize that solid roller number always sound much higher than their hydraulic cousins, but that is still a pretty healthy cam and will likely not work very well with a ported LT1 casting and intake manifold.

BTW do not waste your money on getting the heads or intake manifold "polished". That is an absolute myth. In fact it is a good thing to have the intake runners slightly grooved.

I ran a solid roller cam with FULLY ported LT4 castings. And I think were startingto approach the limit of the LT4 heads. My cam was 258/266 @ .050", .610"/.610", 109.5 LSA. We were able to get 311 CFM out of the LT4 heads, but that required tapering the valve stem boss and modifying the upper and lower cut, increasing the throat cross section and back cutting the 4 angle valves. That made 488 RWHP with a vacuum pump, low tension second rings and a knife-edged crank. There was more in the tune, but the motor broke due to a faulty timing chain before I was finished tuning on it.

I think 500 RWHP is do-able, but I think you are going the wrong direction with that cam and the LT1 castings.