400 SBC TBI conversion in my COE hotrod project

[kscarguy]

I am attempting something very new to me. Swapping my hotrod truck to TBI Fuel injection. This is not something I have any experience with.

To begin, the vehicle is a 1941 Ford COE car hauler hot rod. The engine is a new 406 SBC, with slightly dished pistons, stock heads, longer rods, fresh cam (not too big, told by mfr. that it would work with the TBI). The trans is a 700R4, the cruise control is1970's Chrysler (not installed yet), the wiring harness is mostly from a 82 Chevy truck and it has dual aluminum fuel tanks . The plan is to swap the truck over to TBI. It currently gets 12 mpg on the highway running about 2300 RPM @70 mph on a Quadrajet carb.

So far: I have collected 90% of the parts I need.

Intake - Aluminum TBI intake from 1987 350. Center four holes elongated, manifold bead blasted and clean.
Throttle body - 1987 stock from 350=
Wiring harness - 1987 Chevy truck. Pulled apart and labeled.
Sensors - all sensors plugged into harness, weld bung for O2 sensor to be put into exhaust header.
Brackets - correct throttle cable/TV cable bracket, Cruise diaphragm/module from 1990 Chevy truck with linkage
Fuel system - both hard lines on engine and flexible stainless fuel lines to body from 1990 350 engine, fuel tank valve for switching between tanks
ECM - xxxx747 truck computer

Installing the manifold, brackets and even wiring the system do not scare me. What scares me is getting a decent working fuel system and programming the computer to work with the 400 SBC engine.

I am considering using the fuel pumps from a 2000 Chevy 3500 truck (without the pressure regulator on the pump) and putting an in-line regulator in the line. I do not know for sure what pressure the 2000 pumps put out. I think it is 45 psi. I was told that I should increase the pressure from 12 to 15 for the 400 engine. I could swap in stock pumps from 1987, but I am afraid they will be too low on the pressure.

I also am confused on the Adjustable Internal Fuel Pressure Regulator available for the Throttle body. I have no idea what this does. Will this allow me to increase fuel pressure?

If anyone has any advice on what I should do to make this swap work, please do not hesitate to share.
Thanks!

[Six_Shooter]

The internally adjustable fuel pressure regulator is just that, it allows the stock regulator that is located in the TBI injector pod to be adjustable. Yes, this will allow pressure changes, such as your proposed increase to 15 PSIG.

As far as the throttle body itself goes, you may find that the 350 TB is a little restrictive, depending on the actual RPM range you plan to run the engine in. If the revs are mostly under about 4500 then it should be fine, though I can see a need to change the injectors to larger ones needed regardless.

I would skip trying to use a factory pump (I say that even though I LOVE to use off the shelf OEM parts), and just go for a frame mount Walbro, or similar. This will keep the fitment easy, and no need for extra regulators, even though you shouldn't really need any extra regulators with the OEM pump you have thought about using. The FPR (Fuel Pressure Regulator) in the throttle body will take care of that.

As far as tuning goes, yes it seems daunting at first and it IS a steep learning curve, but it is a fun one. I will strongly suggest getting equipment that will allow you to emulate the EEPROM, for real time tuning, such as the moates.net Ostrich 2.0, or AutoProm. This will speed up both tuning time and learning, because you can see the changes effects as they are made.
Starting with a stock 350 bin, that is matched to your trans will be a great start and should allow you to start the engine and get driving around, though it won't be ideal, you shouldn't notice any real issues. 350 to 406 is only about a 16% increase in displacement, and shouldn't really effect initial driving sessions to get the tune squared away, just don't go beating on it until you feel the fueling and spark tuning is close.

The biggest effect on how an engine runs seems to be from the cam, mostly, I'm not negating other parts here, but the cam has a huge influence on how the vacuum is developed in the intake. I've tuned large duration cams, and it can be challenging, but is doable. If the .050 to .050 duration is less than about 210 degrees, I have found that most stock bins will run on them, while not ideal, they will start and run, without too much difficulty. The problem comes in when the intake pressure, or rather vacuum is less than about 15 in/hg (>50 kpa), at idle. A stock bin will think the engine is under load and start to pour fuel in, which will only make the situation worse.

Your saving grace here is that you currently have the engine running, so you can do some checks before hand to see if there will be any issues, such as the aformentioned intake pressure checks.

Just read up on tuning techniques and threads that people have created that document their tuning journeys and you will get an idea of what needs to be done. It makes a WHOLE LOT MORE sense once you actually start doing it yourself though. ;)

[kscarguy]

This is a built as a low RPM engine for street driving in a heavy truck. The cam is a Crane H-260-2. The Summit web site says it is not computer compatible, but the Crane rep said it was, because it was in the 400. I put a vacuum gauge on my engine and I had very strong manifold vacuum. If I remember correctly it was above 15 and I think it approached 18 in/hg at idle.

Basic Operating RPM Range:1,200-5,000 Intake Duration at 050 inch Lift:204
Exhaust Duration at 050 inch Lift:216
Duration at 050 inch Lift:204 int./216 exh.
Advertised Intake Duration:260
Advertised Exhaust Duration:272
Advertised Duration:260 int./272 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.427 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.454 in.
Valve Lift with Factory Rocker Arm Ratio:0.427 int./0.454 exh.
Lobe Separation (degrees):110

Looking back, I also see where I have an email from Harris Performance (tbichips.com) and they said I should run "18 psi fuel pressure", along with a custom chip to "remap the timing and fuel for the engine".

[Six_Shooter]

If that cam works anything like the H-260-2 that I had in my V6, you will have no problems. I ran that engine on stock EPROM(s) for a couple years. Having 18 in/hg is pretty good, you might even be able to improve on that with the EFI. ;)

Fuel pressure isn't really a good way to make up for a lack of injector, but higher pressure can help atomize the fuel better than a lower pressure. Tuning for the actual combination will always produce the best results. You may find a little less fuel pressure works better, or a little more, though most people run their TBIs at no more than about 18 PSIG, unless they have the late 454, which ran a higher pressure from the factory, 30 PSIG IIRC.

[blue68deville]

Sounds like a cool project, I think it will work out great. There is a ton of good info on this board, use the tutorials when you start tuning and it will all make sense.

Forget that you ever heard of the tbi chips guy. He told me that my current setup would never work, and has advised others poorly.

[kscarguy]

OK, already forgotten LOL


I am making some progress. I down-loaded TunerPro RT and also got the ASDU.bin off of the diy-efi site. I put that into the "BINS" folder under my TunerPro files.

However, I am having trouble downloading the $42-1227747-V3.xdf and xds files from this site. They keep coming in as .PHP file extensions. Do they also get stored in the "BINS" folder?

[blue68deville]

Mine downloaded the same way, I'm not sure how to change them but they work anyway as PHP. I just make sure the name I type in matches what the file actually is, it will just have php at the end.
XDF goes in bin definitions folder and ADS in acquisitions (?I think)
The bin's saved on mine in 2 versions, one was a txt file. Make sure you open the .bin and not the .txt, it will do weird stuff.

[EagleMark]

It's your version of Windows... Right click and save file as.

[BLG355]

Forget that you ever heard of the tbi chips guy. He told me that my current setup would never work, and has advised others poorly.

I am proof of this! You are at the correct place if you want tuning or help tuning.

[kscarguy]

I've been reading about EFI all day and now my mind feels like overcooked oatmeal...everything just raises more questions.

Will the hydraulic (non-roller) cam work with the TBI?

Should I swap in a VE table from someone who has done the 400 TBI swap or just work from the 350 table?

Should I swap injectors from the 454 into my 350 throttle body? If yes, what tables will I most likely need to modify to compensate?

Most likely I will buy the APU1 emulator and set up an ECM with the correct socket. After I get it running correctly, I will then burn a new chip and put it into a spare ECM and install that in my truck. Then I can use the first ECM as a tool for doing other/future EFI conversions. OR Is there a better way?

[Hog]

The TBI truck engines were non-roller cams for the most part.

peace
Hog

[kscarguy]

The TBI truck engines were non-roller cams for the most part.

peace
Hog

whew!

[kscarguy]

Some more seriously dumb questions that have probably been asked 1000 times...I read the tutorial and devouring all the information I can find. I'm learning a lot.

I think I know the answer, but my first question is, will it run? If I physically install everything and connect up the stock ECM, will the 400 run? I think the answer is yes. More importantly, will it be drivable? This, I do not know.

My 7747 computer is for a 1990 5.7, automatic. Do I just put it all together and see if it starts? Is there a better method or a better starting place (better BIN)? I ask this because I can't afford to have the truck be unmovable and stuck in the garage since I may have to relocate soon...

[lionelhutz]

It should run at least well enough to move it around.

That cam is just fine for EFI, in fact I'd almost consider it a little on the small side for a 406 engine.

I would use a dual plane carb intake with an adapter plate.

It should work with the newer fuel pump. I have run a high pressure pump meant for port injection just fine. Others have mentioned the same. The advantage with a newer fuel canister is that it has a jet pump to keep the canister full and it won't ever stumble due to the pump sucking air. A frame mounted pump would work OK too but you may need to take measures to ensure no air reaches the pickup. I have used a sump on the bottom of the tank with success.

You could just add 16% to the VE table to begin with, unless you don't have the programming equipment yet.

Your thoughts on the tuning and using a final chip are good. That gives you the ECM to use for tuning another project.

[Fast355]

It should run at least well enough to move it around.

That cam is just fine for EFI, in fact I'd almost consider it a little on the small side for a 406 engine.

I would use a dual plane carb intake with an adapter plate.

It should work with the newer fuel pump. I have run a high pressure pump meant for port injection just fine. Others have mentioned the same. The advantage with a newer fuel canister is that it has a jet pump to keep the canister full and it won't ever stumble due to the pump sucking air. A frame mounted pump would work OK too but you may need to take measures to ensure no air reaches the pickup. I have used a sump on the bottom of the tank with success.

You could just add 16% to the VE table to begin with, unless you don't have the programming equipment yet.

Your thoughts on the tuning and using a final chip are good. That gives you the ECM to use for tuning another project.

I wouldn't add it to the VE, I would adjust the BPWC and BPW vs EGR table.