My 3800sc swap

The engine I'm using is from a 1999 Grand Prix GPZ that I picked up from Langley Discount Auto & Truck Parts for $2,000. The series 2 3800 came with wiring harness,starter,alternator,flex plate,and OBD2 computer.

The car is a 1985 Fiero GT with a Getrag 5 speed.

First thing is to pull the 2.8 out of the car. This is done by dropping it out the back of the car.

The cradle has to be reinforced by boxing in the front cross member. This is done by welding a 1/8" thick flat bar across the under side.

The engine was then installed with a flywheel from westcoastfiero.com to the Getrag 5 speed and set into the cradle. The front engine mount was made first using the trans to position the motor.

I mounted the alternator were the ac would sit first by finding a path for the belt and then how to hold it there. I used a bolt point in the block for one mount and made a vary strong bracket for the other.

Once the alternator was mounted I found the place to mount the belt tensioner and made a mount that would also become the top engine mount.  Do you think your engine has belts and pulleys?

I installed the motor at this point and checked fit. Lots of room with a full inch of hood clearance.

More to come.

With the engine in I made the upper engine mount and boxed it well. A Dickman adjustable dog bone was used with the new mount as well as down below. It is important to tie down the 3800sc vary well. Notice the alt belt tensioner is part of the mount. I did not like the way most people scab this part. also in the pic is the heater hose nipple. I had Orbit Machine make them for me.

Next I cut the lower trunk from the car and painted what was left. I used 1/8" aluminum sheet metal to make the new floor of the trunk. adhesive heat foil on the bottom side after sealing the seams. Then all that was left was to add a heat shield 1/2" bellow the floor were the highest heat source is going to be.

For an exhaust I used a 50 series Flow Master muffler with 2 1/2" mandrel bent pipe. The stock Fiero tips fit with no restriction.

A flex pipe must be used with the series 2 because the exhaust is solid mounted to the manifold on these engines.

Now that the hard stuff is done it's time for the wiring. First the GP harness has to be disassembled completely and all unused parts cut away. 

It's vary important that you get pin out and electrical diagrams for the car the engine came from. With out them you may never drive your car again.

Here are some samples of what they look like.

With the new harness made and installed I ran all the Fiero wiring into the car and hooked it up to the GP harness and computer. I picked up a pre programed computer from Fast Fieros of Dallis Texas. It was well worth it. I had them keep the EGR and gas tank vent sol. working but no second 02 sensor, pass key,or auto programing.

Part 3 coming soon

I found that the 87 2.5 4cyl. throttle cable fits the 3800 throttle bracket and pulley. The cable is 3/4" of an inch too long but I,m going to leave it that way till the clutch is broken in.

The air tube is a trimmed down 3 1/2" polished aluminum tube with a 45 degree bend from Vibrant Performance #2890N and a pair of silicone joiners.

To extend the coolant hose I used a piece of ss under body coolant tube from a wrecked Fiero. 

To hook up the fuel lines I used Russell 5/16" fuel injection fitting #640860 and 3/8" fuel injection fitting #640850. These fittings allow you to connect to Airoquip # 6 braided fuel line. For the fuel filter a stock Fiero fuel filter was used with Earl's fuel filter adapters #991955ERL.

Notice I have kept all required emissions equipment and made sure I have room to add a cat later. This is important if you plan to keep the car for a while. You never know when you'll have to be inspected.

May6 Fired the car up and went for it's first test drive. :) :) :) Even with a limit of 60% on the throttle the car goesss!  You can hear the blower whistling almost all the time. When you shift under spirited throttle the engine lets out a decell bark through the exhaust that sounds like a monza car.

There is still some finishing work to be done but I'm vary happy with the swap.

If you plan on doing this swap you should budget $4,000 for parts and engine. If you are going to hire someone to do the install (maybe not a shop) look for a quote around the $3,000 mark. This should include engine removal, engine bay paint and heat control installation, trunk trim, and assembly of engine to driving condition. Pre existing engine problems not included.

If you have any questions on this swap or parts used feel free to ask.

I'll update on the drivability of the car later, see you on the road.

Well I put 85km on the car yesterday with only one problem. While passing a slow moving truck at 60kmh the tires started spinning. It made for an awkward sideways pass.

I think I'll hold off on any more power mods for now.

Capt Fiero wrote: Blair even with my feelings toward 3800SC swaps, I have to admit that looks wicked and sounds even better. You are going to have to take me for a scream in it. When we setup the track days, you and I are going to have to go at it.

Consider it done.  You can feel the pull of the dark side can you.