Supra Engine Swap Part I Index: Part II Index: What's new this month? About the swap Repairing the frame Mounting the transmission Mounting the engine/transmission Installing the cab The fuel system Other interesting information Part III Index:

All of the easy parts of this swap are completed. Now I am into the harder detail oriented parts of the swap. Items like the wiring, fuel system, cooling system, air intake, and other smaller items. These details take much more time than such things as mounting the engine.

Cooling system

After much measuring and lots of brainstorming on the problem, I think that I have finally settled on the Toyota Cressida radiator. The Cressida also came with a 5M-GE and the radiator is narrower than the Supra one which runs into the steering box on the truck.

The bottom port is not a problem as it is well past the passenger side of the engine and has plenty of room for the hose. The top driver's side port is definataly not going to be an easy thing to figure out. If the port on the engine and the port on the radiator were to line up, there would only be about a 1/2" gap between the two which is definately not enough to allow for the movement of the engine.

I do not have a Cressida radiator yet, but I am hoping that the ports do not line up perfectly, but rather are offset. This should allow me to fit a hose in there that loops around and will allow for the movement of the engine.

I was working on my Camry the other day and noticed that it has 2 nice 10" electric cooling fans. I will most likely try to find a set of these at the junkyard since they are the exact size that I need to fit them in front of the radiator and will probably be a lot cheaper than buying a set from an automotive store.

The Fuel system

The fuel system is actually quite easy. I will be running a 5/16"steel hydraulic line from the Supra fuel pump up to the engine. I bought some compression fittings for the hydraulic line, which have a 1/4" NPT female thread on them. I also bought some 1/4" NPT male, to a barbed fitting which will attach to the cut off rubber hoses from the engine, and the fuel pump.

I actually went a little overkill, but I do not want the 40PSI fuel pressure to cause me to have a leaky fuel system - especially since the exhaust and the fuel line have to cross over at some point. I will be running the fuel line across to the driver's side of the truck in the "U" shaped crossmember to try to shield it from the heat of the exhaust a little.

The only problem that I can see is that the pickup line from the truck's fuel tank is close to 5/16" in diameter, where the intake line for the pump is around 1/2" in diameter. If the truck does not run well at high RPM, or the fuel pump starts to burn up on a regular basis, I will know what the problem is!

There is a difference in the Supra fuel tanks that may need to be considered when preparing for this swap. 82-83 Supras have an external fuel pump, while 84-86 Supras have a fuel pump in-tank. There are also slight changes in the tank design on the upper passenger side of the tank that prevent the earlier tanks from fitting into the later vehicles. The wiring across all years is the same.

Electrical

The electrical system also still needs to be worked out. At the moment I plan on running it at two seperate electrical systems - one for the accessories, and one for the engine management system. I will have to find a place for the extra fuse boxes - under the hood and in the cab. This will also make the engine electrical system easy to swap to another truck in the future should I want to do so.

I will have to drill a 2" hole somewhere in the firewall to run the fuel injection wires into the cab and to the computer. I have not decided if I will locate this hole on the driver's side of the truck and run the wires on the inside of the truck to the passenger side, or on the passenger side where the hole was located on the Supra.

Oil pan clearances

I am still hunting for the ever elusive 7M-GE oil pan. I am positive from looking at the drawing that the Toyota parts guy gave me that the sump is in the correct position to clear a swaybar - or a crossover steering drag link.

According to all of the guys who have swapped 7Ms into their Supras, the 5M and 7M oil pans are interchangable except for the sump. I would have to relocate the sump and filter, but this is a minor problem compared to the benefits.

What kind of power can be expected from the 5M?

From talking with various sources on the internet, 160HP is not an unreasonable amount of power to be expected from this engine. Most of the modifications are cheap and can be done with parts that I will have to have built anyhow, or can find at a junkyard without much trouble.

The engine in stock form has about 145HP. I have been told by some of the members of SOGI (Supra Owners Group International) that there are a few easy modifications that can net reasonable results.

They claim that a 2-1/2" to 2-3/4" exhaust along with a good free flowing muffler will provide over 10HP alone. Apparenly headers are not worth the money that they cost as the stock manifold already flows rather well.

One of the differences to the engine in '84 that led to higher HP was the intake manifold. Swapping on the later manifold is said to be an easy 5-7HP gain. This manifold can be found on '84 to '86 Supras and can easily be identified by the "D" shape of the inside of the runners rather than the original round shape found on the '82.

Replacing the mechanical fan with electrics is rumored to be a 1-3HP gain.

This is about it as far as the cheap and easy modifications go. I have also been informed that a nice swap would be a 6M-GE engine - which was never imported into the US, but han be purchased from importers for around $600. This engine has a longer stroke, accounting for an extra 0.2 litres - bumping the total to 3.0. When using this engine, you should use the wiring and accessories from an '85 - '86 Supra. You must get the engine with the intake manifold intact as the 5M one will not work.