47lb injectors with Holley Terminator X

[OldZeuski]

Hello all,

Quick build list:
306 w/ flat top pistons
gt40 heads, 1.6 rockers
N41 cam
Trick flow track heat intake, 70MM TB
running a Holley terminator X

I expect less than 300 wheel with this setup, but I do plan on running it till the cam rolls over and I am worried 24lb injectors will be well over 85% duty cycle on stock presure.

Ford performance sells 24 and 47 lb injectors with ev1 adapters, and nothing in between. All the 30's I can find are either remanufactured or they're twice as expensive as Fords 47's.

Has anyone ran too big of an injector without issue using a holley? I don't want any drivability issues.

Or, am I safe with 24's?

 

[RAU03MACH]

to big of an injector, you will wash the rings
flood out

 

[RAU03MACH]

even 24 can Couse problems your heads would need to be set up and then tuned

 

[ttocs]

I am not the motor expert but I thought the cobra still had room to grow with the 24s. You have a few more cubic inches and a bigger cam but I don't think your that far ahead to outgrow the 24s at the moment.

 

[RAU03MACH]

i am barely at 24
but i have the aluminum heads ported out
and a tubular intake with a b303 cam its close to the limit
thats another reason im going 5.8

 

[95opal]

Hello all,

Quick build list:
306 w/ flat top pistons
gt40 heads, 1.6 rockers
N41 cam
Trick flow track heat intake, 70MM TB
running a Holley terminator X

I expect less than 300 wheel with this setup, but I do plan on running it till the cam rolls over and I am worried 24lb injectors will be well over 85% duty cycle on stock presure.

Ford performance sells 24 and 47 lb injectors with ev1 adapters, and nothing in between. All the 30's I can find are either remanufactured or they're twice as expensive as Fords 47's.

Has anyone ran too big of an injector without issue using a holley? I don't want any drivability issues.

Or, am I safe with 24's?

If your running a termiX you should be fine. Correct injector info, new fuel table and retune. Not a big deal.

 

[RAU03MACH]

On one of my friends cars his seems to always flood out
Or over fuel
He's done a lot of engine work with all good stuff
The 24s washed his piston rings
We checked the computer the injectors
Just about everything
He finally gave up and ran 19s so much better

 

[OldZeuski]

If you’re running a termiX you should be fine. Correct injector info, new fuel table and retune. Not a big deal.

Safe with 47#?

 

[shovel]

I know it's not exactly apples-apples but Holley Sniper TBI uses four, 100lb injectors and they claim it's suitable for engines as low as 200hp. Four 100lb injectors works out to 50lb/cyl in a V8 and you're eating quite a bit more than 200hp worth of fuel and air.

The variable is TBI injects above the throttle blades at 58psi and wets the manifold so I'm guessing the physics of evaporation and temperature etc are different from port injection at 40psi - that's all above my pay grade.

 

[OldZeuski]

I know it's not exactly apples-apples but Holley Sniper TBI uses four, 100lb injectors and they claim it's suitable for engines as low as 200hp. Four 100lb injectors works out to 50lb/cyl in a V8 and you're eating quite a bit more than 200hp worth of fuel and air.

The variable is TBI injects above the throttle blades at 58psi and wets the manifold so I'm guessing the physics of evaporation and temperature etc are different from port injection at 40psi - that's all above my pay grade.

Thanks that is helpful to know.