Hello,

I have an open thread in the conversions/hybrids page of this forum. I am in the process of retrofitting an 0411 ECU to a GEN IV 72 Big Block Chevy. I am currently waiting on parts. While I wait I would like to build the fuel system on the car. I've upgraded pumps in already fuel injected cars and swapped injections on LSx's running pump gas but what I am looking to do here is a little different. Many of the threads online seem to have conflicting information as to what is do-able and I would like some advice specific to my application.

The engine is a 454 BBC with Iron Oval Port Heads. Will be running a Holley EFI Manifold 300-561. Engine is predicted to make between 500-550HP. I haven't chosen a fuel pump yet, I have a bunch of them in my basement. I will list what I've got an we can choose the best one lol. My goal here is a flex fuel tune... so 93 pump to E85. I know this is going to be different to tune because of the ecu I am using is not for a big block application and I am not looking to complicate things by going too large on the injectors but also looking for a size that will allow me to run E85 safely. I've seen recommendations online from 38lbs to 80lbs. The system is going to be a return style system with an adjustable fuel pressure regulator, so fuel can be pre-set at 43.1 psi and will remain there.

Also, what's a good, affordable source for a set of genuine injectors?

And if anyone knows of a thread where I can get a idea of how to route an out of tank pump correctly for a return style system, I would appreciate you posting the link. The tank was just replaced for a Carb Setup, and I am really trying to avoid having to replace it again for an in-tank pump.

Dan

 

"And if anyone knows of a thread where I can get a idea of how to route an out of tank pump correctly for a return style system, I would appreciate you posting the link."

Dan, take a look on the Aeromotive site, They have layouts for a system you are planning to use.

 

Awesome, Ill check it out! thanks

DG

 

You never said which pumps you have. Also, upping your fuel pressure to 58 PSI will help with injector choice.

 

Injector choice doesnt really care about the engine.

If you've a 550hp engine, you need an injector that will support that, simple as that really.

Although surely it'd be easier to use a standalone ecu rather than trying to retrofit an OEM ecu ?

As for an external pump, as long as it is gravity fed with a good clean uninterupted supply of fuel with enough volume to keep the pump happy, it should be fine

 

Hey guys, I'm really sorry for the delayed response; wife decided to take me on a spontaneous 3 day vacation... but I am back again and ready to get this car rolling.

The only pumps worth mentioning are 2 brand new Walbro GLS392 pumps I have. I also have a Mallory Adjustable fuel pressure regulator, part #4309 which is vacuum actuated. I guess since I have them it would be nice to use them if I can get away with it on E85? Also... would I need to run just one or both? and if so, Inline or side by side?

I am going to venture to say that they only way to accomplish this is with a sump... Any thoughts on a tanksinc?

Dan

 

You'll be topping a single Walbro 255 out at 550 flywheel on E85. Run them both in parallel.

Tanks inc stuff is fine. You don't have to run a sump. You can run in-tank pumps no problem.

 

GOOD TO KNOW! Thanks! I will run them in parallel. Good thing I have 2 of them. I decided against the tanksinc. I am going to sump the tank. It will actually make the plumbing easier. Monday I am going to order a set of injectors. Ill speak with a few different companies and make a decision based on what they say.

Thanks,
Dan