This is the first article in a series where I do an EFI swap on an old classic car, namely a 1961 Ford Thunderbird.
When I say EFI swap, I mean swapping in a 5.0 (302) fuel injected engine from a ford car from the years 1986 to 1993, into the engine bay of a 1961 ford thunderbird that originally had a 390 FE sitting there.
Below is the car I’m talking about. Yes, it’s green, the paint code is actually from a 1977 Renault of some kind(I don’t remember the model it came from).
Why do the EFI swap?
First, this is a custom car from way back, not an original by any means, although with some work, a pro would be able to get it in original shape. In the spirit of a customizer I wanted to have a driveline in the car that was both pleasant on the highway, and economical as well. I wanted a car that was easy to start and was overall dependable.
Don’t get me wrong, you can get most of that with a 390 also, but this car had a shot 390 FE engine and a likewise shot “Cruise O Matic” automatic transmission. So the choice was easy. These parts have now been sold off to finance parts of the EFI build.
What is needed for the EFI Swap?
There are actually multiple routes to take when doing this project. You can source most parts from a complete donor vehicle like the 1986 to 1993 mustangs.
You can take a trip to local junkyard to find what you need, or you can buy most of these stuff as aftermarket parts. If you go aftermarket, it will most certainly be a much more expensive build, but it might be simpler to do because a lot of thinking have been done for you already.
In this project I’m doing a little of both. As this is a budget build, I will try to keep the cost as low as possible by getting as many good deals as possible, this means it will take time, but I’m in no hurry.
I use the local forums or ebay to find most parts, you can get some really great deals on ebay in my experience.
Here is a preliminary list of what parts I needed to get hold of to complete the efi swap.
- Engine
- Auto Transmission
- Engine Wiring harness
- EEC (Engine computer)
- New flexplate (50oz)
- Engine mounts to fit where the 390 mounted
- Fuel system parts, hi-pressure pump, fuel lines, fuel cell etc.
Engine
This is of course one of the most important items in the efi swap. The most favorable ones are the mustang HO engines from the years 1986 to 1993. Other non-HO ones will work also with some minor changes.
Keep in mind that truck engines from trucks and van’s where speed density engines, which is not bad, but if you want to do upgrades, MASS AIR (MAF) is a must.
If you choose to take the cheap route, like I did. Then get everything related to the efi setup from the donor car. If the computer and wiring harness is in good shape, take it with you, as this will save you a lot of bucks down the road.
I ended up getting an engine from a 1988 Van, not sure which one, as the engine was already out of the car. As I’m on a budget, this was ideal for me, even though it is a speed density engine. I got it very cheap, so that helps a lot.
Transmission
It took some time to choose a transmission for the project. There were quite a few options to choose between, which made me think really hard for a while. You can use many different transmissions, like the c4 and c6, which is the old style, or you can opt for a more modern transmission, like the AOD, AOD-E or the 4R70W.
AOD transmissions are expensive, and in standard factory condition, they are not that strong. The 4R70W is a stronger built transmission from the start, and it is waaaay cheaper than the AOD. That is why I bought a 4R70W from a 99 Ford explorer to use in this project.
Engine wiring harness
The engine I bought had the speed density harness on it, and that harness was in a relatively bad shape. It had many connections that was specific to the van, and in general a real mess. As I am going mass air, I opted to buy a harness from a local guy who already had it fitted for this type of swap, he had even marked each wire by function, talk about easy.
EEC Engine Computer
The computer that came with the engine was a speed density computer, so that was out of the question. As I wanted to go with mass air, I needed a MAF computer. There are many computers to choose from, but the most popular ones are the A9L for manual cars, and the A9P for the automatic cars.
Since I’m running with a 4R70W and not an AOD transmission, I did not need the computer to control the transmissions, so I chose the A9L as the guy who sold the wiring harness had one laying around. If you choose to run with a manual transmission, a C4 or a C6 this is the EEC for you. With an AOD you need the A9P.
Flexplate
Usually you get a flexplate with the engine when you buy one, but this engine missed that. So I needed a new one. The one needed here is a 50oz 164 tooth flexplate, like this one on Summit: BMM-50238.
Fuel System
This is a really important subject because the injected engine does need both a high pressure line from the tank to the engine, and a low pressure line as a return to the tank.
The high pressure line needs to be fed by a high pressure electrical pump. This pump needs to be able to push 35-40 psi. You also need to make sure you use fuel lines and hoses that are rated for that level of pressure. The pump I’m using is the one that came of the van, so it should suffice.
Fuel Cell
I will use a fuel cell mounted in the trunk. The fuel cell is a 15 gallon aluminum from ProComp. It is sumped and has a fuel sending unit integrated. The fuel cell will be mounted so that I don’t need to cut anything in the trunk.
The reason I go the fuel cell route is that my tank is leaking and in addition needs a new fuel sending unit. This would cost me about $400 if I bought replacements. The fuel cell costs me about $190 bucks. On my budget that is a no brainer. In addition I get a fuel tank that is more equipped for the EFI system, with fitting for a return line already incorporated.
The trunk of the Thunderbird is quite wide, so I will still have a good deal of trunk space left for luggage and other stuff.
On important thing to know when using a fuel cell in the trunk, is that you need to seal the trunk from the coupe. I’m sealing the rear firewall and the sides if the trunk with steel plates to ensure the safety and legality of this system.
Engine mounts
This is where I’m at now, and I have not decided on which mounts to use. I will come back with more info on this when I have researched this a bit more. The concern here is to fit a 302 in a engine bay designed for the 390. I have never done this before, so it should be exciting.
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That’s it for the intro to the project, I will post articles on each subject in the conversion these next months as I finish them. My plan is to have the efi swap finished and car road legal before July 4 2012.