Explorer EFI swap

[BRONCO69]

Hello all, I'm contemplating doing an Explorer EFI swap on the current motor in my Bronco, however I'd like to get a clear picture of what that entails before I take the initial plunge.

My current motor is a 302, flat tappet, 15426378 firing order, recently rebuilt. No mechanical issues, currently running stock exhaust manifolds, and an Autolite 2100 carb. Heads are stock.302 heads. Running a Saginaw power steering pump with remote reservoir, stock alternator, fixed blade fan.

I found a 1996 Ford Explorer donor vehicle that I can get for cheap. Only thing wrong with it according to the owner is a bad fuel pump. Current mileage is about 200,000. I went and looked at it today and took a photo of the intake (attached below).

So, here come the questions. If any of you know of previous discussions which address these questions (and the conversion process in general), feel free to link to those discussions.

1. Would I need to use the heads from the Explorer motor, or can I bolt the intake from the Explorer directly on my existing heads (and would this be a bad idea)? I believe (based on the year) the Explorer has GT40 heads.

2. I understand I would need to change the front cover out for the crankshaft pickup. Would I need to convert to the serpentine belt setup, and could I adapt my existing Saginaw pump?

3. Does the camshaft need to be changed to change my firing order?

4. What resources are available online for making the ECU wiring harness?

5. What else would I need to purchase to make this work?

6. How would this setup perform on the trail?

7. Is it worth it opening this can of worms?

As far as why I'm thinking of doing this, it is primarily for drivability issues. I've been looking at different EFI options out there for years now, and although this seems to be the cheapest option, it also looks to have a lot of fitment and compatibility concerns.

Any help is greatly appreciated, thanks in advance!

Clint

[904Bronco]

Damn Website dropped me off as I was typing this

It is not really a can of worms, unless you go blindly in without doing your research... Like you are doing.

200K motor, no guarantees on what is inside. The 97 I pulled last June had 130K and it was hurt inside. I pulled a 98 a few years ago with 180K and it was like new inside, it all depends on the maintenance history or lack thereof. Then with most of the various sensors having high miles, replacements probably are needed.

The 96 and into early 97 had GT40 heads, 3 slashes in the castings on the ends , which are hard to see with everything bolted up to them. (Sparkplugs should point in the same direction as your current heads. P-heads 97-01 have 4 slashes in the castings on the end.) Both are good heads, but P-heads have limited choices for exhaust manifolds due to spark plug location.

Heads Direct bolt on? yes they bolt on the same, but one is a flat tappet cam and the other is a roller cam motor. I haven't tried to do it, so refer that question to a machinist?

Bolting EFI upper and lower plenums on your motor, yes. Important to get correct intake gaskets to prevent leaks.
Cam sensor instead of Distributor, Cam sensor has a steel drive gear on it which may not be compatible with you current cam?

Front cover - Explorer Serp setup is the way to go! But... You do need to replace the timing cover, and have the Harmonic balancer from the Explorer rebalanced from 50 oz imbalance to 28 oz imbalance like your motor is now. Or you can buy a new balancer already set up. Must remove the fuel pump drive eccentric from the current motor. Yes, I believe one of the vendors has a bracket to retain your sag pump. More research. Explorers came with metal and plastic fans, typically the plastic fans start cracking with high miles and replacements are still available from Ford. Your may have to modify your fan shroud, position and depth, as the fan needs to sit about halfway in the shroud to work best. Some minor rewiring needed to use the Explorer 4G Alt.

Camshaft - I can't answer that one, I have always used the Factory Explorer cam. Firing order needs to be the same, is my simple answer.

EFI Guy - Garry, is the go to guy. He can rework the harness and reflash the computer. Last harness and ECU I had done was $640, 2-years ago with me striping off all the old loom and tape, cleaning everything up before shipping it to him in CO. He was 3-4 months out on doing that. The harness comes back clean, rewrapped, with every wire and connector labeled. Or, if you are feeling bold, he has posted U-tube videos on how to do this work yourself. I haven't done this yet, but I am giving it some thought. Finally, there was a post on FB where someone was asking about a Ron Francis new harness that works with an explorer motor. It had one of their big assed fuse boxes that you run their wires to and cut to fit. There wasn't much info on it online, but it sounds like they are not stocked, but built as requested.

Parts - Fuel tank to in tank pump or external pump. (I don't recommend the 2nd option) You will need to run a pressure line and return line... A number of EFI fittings needed, some sort of EFI filter, usually an Explorer filter. A new Areo fuel tank from the last Mass buy was about $600 that you could mount the Factory Explorer fuel pump assembly into. Wiring to the pump as well there are a number of other things: lines you use for the fuel, clips to hold them in place, Accel pedal mods, add more grounds, different heater hoses because of the cooling tubes on the top of the motor, Mods to Coil bracket to clear the hood, you might need a 1" body lift, etc.

Hope this gets you started... I am on my 5th conversion so let me know if you have something specific you need answered. Doug

[pippinmader]

What Doug says and:

• The different firing order of the two engines will confuse the engine and make one bank go lean and the other bank go rich, you are best off to swap to a 351w cam or go with the whole explorer engine.

• IMO, doing an external fuel pump is OK as long as you use a low pressure pump and accumulator to feed it.

• I would definitely consider using the whole explorer engine.

[BRONCO69]

Thanks all for the detailed responses. From what I have researched so far, if I want to put Explorer EFI on my existing block, it will involve pretty much tearing down my motor down to a short block, and building up from there, with the following considerations:

• Camshaft definitely needs to be changed out for a 13726548 firing order. Whether I would need to convert to roller cam vs. staying with flat tappet is still up in the air. I need to do more research on this
• I should use the GT40 headers from the Explorer motor, and not try to use my existing headers. Given the mileage on the Explorer motor, a head rebuild would be in order (about $300-400). Besides, the GT40 heads will give improved power in the higher RPM bands.
• The factory Explorer EGR spacer will need to be changed out to a Mustang EGR spacer or equivalent due to it facing the wrong direction.
• Need to talk with the EFI Guy (Garry) about whether or not I need to reflash the ECU.
• Need to re-work the wiring loom from the Explorer.
• Modify my Aero fuel tank to accept an in-tank pump. Also need to run a fuel return line (supply line is already hard-lined for EFI).
• Need to research how to run the throttle cable.
• Currently running a 2” body lift, so hood clearance shouldn’t be an issue.
• Classicbroncos.com has a great write-up on changing out the front dress at http://classicbroncos.com/tech/explo...elt-conversion. A few things are needed to make the swap.
  • The Saginaw PS pump would need a conversion bracket (Wild Horses #2029) to fit.
  • Need to convert to the 4G alternator (something I’ve wanted to do anyhow).
  • Radiator hoses would need to be addressed with either a reverse-flow radiator, or a cross-over tube (Wild Horses #5047) for the lower hose, and cobble something together for the upper hose.
  • Fan shroud would need to be extended due to the increased fan to radiator clearance.
  • Need to convert the 50oz harmonic balancer to 28oz. Can use Wild Horses #2502 custom crank pulley to bolt to my existing harmonic balancer.

If my budget was not an issue, I would re-use the existing Explorer motor after a fresh rebuild. Given the miles on the Explorer motor, and the fact that my existing block is just now broken in from the last rebuild, I would really like to use the existing block. From what I can see, the only outstanding item I see is identifying the appropriate cam to use, as well as potentially new pushrods.

Anyone see anything I’ve overlooked?

[904Bronco]

Thanks all for the detailed responses. From what I have researched so far, if I want to put Explorer EFI on my existing block, it will involve pretty much tearing down my motor down to a short block, and building up from there, with the following considerations:

• Camshaft definitely needs to be changed out for a 13726548 firing order. Whether I would need to convert to roller cam vs. staying with flat tappet is still up in the air. I need to do more research on this
• I should use the GT40 headers from the Explorer motor, and not try to use my existing headers. Given the mileage on the Explorer motor, a head rebuild would be in order (about $300-400). Besides, the GT40 heads will give improved power in the higher RPM bands.
• The factory Explorer EGR spacer will need to be changed out to a Mustang EGR spacer or equivalent due to it facing the wrong direction.
• Need to talk with the EFI Guy (Garry) about whether or not I need to reflash the ECU.
• Need to re-work the wiring loom from the Explorer.
• Modify my Aero fuel tank to accept an in-tank pump. Also need to run a fuel return line (supply line is already hard-lined for EFI).
• Need to research how to run the throttle cable.
• Currently running a 2” body lift, so hood clearance shouldn’t be an issue.
• Classicbroncos.com has a great write-up on changing out the front dress at http://classicbroncos.com/tech/explo...elt-conversion. A few things are needed to make the swap.
  • The Saginaw PS pump would need a conversion bracket (Wild Horses #2029) to fit.
  • Need to convert to the 4G alternator (something I’ve wanted to do anyhow).
  • Radiator hoses would need to be addressed with either a reverse-flow radiator, or a cross-over tube (Wild Horses #5047) for the lower hose, and cobble something together for the upper hose.
  • Fan shroud would need to be extended due to the increased fan to radiator clearance.
  • Need to convert the 50oz harmonic balancer to 28oz. Can use Wild Horses #2502 custom crank pulley to bolt to my existing harmonic balancer.

If my budget was not an issue, I would re-use the existing Explorer motor after a fresh rebuild. Given the miles on the Explorer motor, and the fact that my existing block is just now broken in from the last rebuild, I would really like to use the existing block. From what I can see, the only outstanding item I see is identifying the appropriate cam to use, as well as potentially new pushrods.

Anyone see anything I’ve overlooked?

- GT40 Explorer steel headers are restrictive, given bends and crimping. They will work. Aftermarket headers and cast iron manifolds should bolt right up.

EGR - are you keeping that? Yes, you can switch to Mustang spacer or if you delete EGR then you can install a block off plate. Would also have to plug Exhaust gas source at lower plenum. 96 year still incorporates Mustang based plugs/connectors so there is interchangeability. So this also gives you the opportunity to use Mustang accel cable and mounting bracket if you use Mustang EGR spacer. Will also have to make mods to Explorer TB, with Mustang TB parts, if you go this way.

- Yes must reflash ECU

- Keep factory Rad, use #5047 pipe, reuse Factory Bronco lower hose to attach by cutting a portion off each end. Summit racing Continental (formerly Goodyear) upper Bronco hose #CEL 60710. Put it on backwards, tirm to fit for clearance. Cut, install 1.5 coupler so you can rotate ends for best fit. See Pic, only hose that works this way.

[B-Rad]

Did you end up buying it? I saw that one listed also but the post says deleted by author now

[BRONCO69]

Did you end up buying it? I saw that one listed also but the post says deleted by author now

Yup, I bought it! Previous owner had it parked outside under a pine tree for the last two years with the windows cracked. The inside is a moldy, spider web infested mess, but the engine is good to go. I'll be posting pictures here of my progress on removing the motor and tranny as I work on it over the next couple of weeks.

Also, after more research, I've decided I am going to pull the Explorer motor as a whole and rebuild it. Once ready, I'll swap out my flat tappet for the Explorer motor. The more I think about it, I would rather have the roller motor it was made for instead of my old flat tappet. My current motor is a fresh rebuild, so I should be able to recoup some costs from its sale.

For now, the Explorer is in my garage sitting next to the Bronco with the hood removed. I'll be posting my progress on the engine removal over the coming weeks. Wish me luck!

[pippinmader]

You are going to love it!

[B-Rad]

I seriously considered it but never called. 100-ish miles away. Hope it all works out!

[904Bronco]

My suggestion... Pull the Engine wiring harness, ECU, and tranny harness and send it to Garry. You will get it back in 3-4 months and it is one less thing you will have to wait on.

[B-Rad]

Is yours 4x4?

[Action]

any chance i can see more pics of your front bumper....mainly the winch area?....Thanks