I've been reading around the internet trying to figure out what size injectors I should get for my new motor. I've been reading a bunch of articles and trying to fill in calculators. I still have no idea of what size to go with.

Heres the setup:
Forged 383 LT1 8.5:1, fresh rebuilt heads, crane 224/234 .518 .539 and 8#s of boost.

I have no idea what power thats going to make (to fill in the calculators) or what fuel pressure to run. I have a walboro 255 in tank and the stock FPR. Any suggestions?

-Pete-

 

I run 65# Motrons from Racetronix. We run similiar setups, except I run more boost and have 9.5:1 compression. I haven't been able to do any WOT runs yet to see what the injector duty cycle is, but I'm confident they will be ok. What are your HP goals? Are you going to do anything else to the fuel system? If you don't have enough volume it won't matter how big your injectors are.

 

At 8# if you dont have crazy flowing heads I dont think you will need a ton of fuel. I am going to run deka 60# injectors with @ 14 psi on a 357/ported heads/baby cam

 

I'm not sure what kind of power that setup could make. Considering what the old motor put out with being a 350, stock cam, stock heads, and 180,000 miles I figure the new motor would put out 450 to 500 hp and around 550 tq. Does that sound right? I've never built anything this high performance before and I have nothing to base a decision for injectors off of, or fuel pressure for that matter. I'm going to talk to my engine builder, but I wanted to consult some LT1 experts first since my machine shop mostly builds marine big blocks. Thanks in advance.

-Pete-

 

I think the tune will set the injectors to work with the motor to make it run the best. I would say 42+ would be a good idea and if you go bigger maybe with plans of more hp later the tune will keep it in order and a retune after mods will set them straight again. Watch the Accel brands as i have read issues with them.

 

Mototron/Siemen 60 pders will work for your combo and give you some room to grow later. They are the biggest injector you can buy without going to LOWZ injectors and a versafueler. Excellent spray pattern for good driveability.

 

You can go RC 72lbs in high Z as well but be prepared to shell out close to 1K. I'd stick w/ Siemens Deka's 60's as they're plenty big.

 

(42lb - 60lb) +1

I'm running a 396 w/stock heads at 6lbs at the moment and 42lb/hr bosch green tops get the job done just fine at stock fuel pressure.

 

Get the 60# and be done with it. As was said, this will give you some flexibility in the future.

Rich

 

I really appreciate the help guys. I'll go for a set of 60# Should the walboro 255 and stock FPR be enough for now?

-Pete-

 

I 'think' with your setup one will get you there. I would be careful and mindful of everything though. I have seen people make 600 on stock rails with 1 pump, and others swear they needed them way sooner.

I am hoping to do the same with my setup.