Hello everyone, first off I love this forum so much great information so far. I recently picked up a 1986 Fiero GT and from all the stories from the PO I am the third owner. It needs some love but the car is solid and it really moves. A week after purchasing this vehicle the PO tells me that the engine was swapped out in 2012 and at that point the 2.8L was no longer being re-manufactued and that the engine is either a 3.1L or 3.4L. Well here I am working on the engine and cleaning and I've spent about and hour under the car looking for any markings on the engine that might help me identify it and I am out of ideas. So here I am asking for the experts help on identifying the engine. Under the engine on the rear of the engine I find the Markings 820R 22 and on the front of the engine 820L 19 these are the markings I can find under the engine without taking anything off. As for the top end it looks like stock Fiero intake but I saw that these can be mounted to several different engines. Any help would be appreciated.
------------------ 1986 Fiero GT with a rebuilt Jasper Engine.
If it was the typical Camarobird 3.4 (which is the favored source for 3.4s to transplant), it would have an F, inside a rectangle, cast into the sides of the block.
There should be a boss, cast into the side of the block, just above the pan rail, on the "trunk side" of the block. If it has that boss (which should have a threaded hole, but may or may not also be drilled for a crank sensor) it's at least an 88 block. Also, a 3.4 will likely have a plug in the top of the block, just above the timing cover, designed for a cam sensor. Don't think any 3.1s used a cam sensor.
I asked my engine builder if they could bore the 2.8 out to a 3.4. He told me he could bore possibly to a 3.1, but couldn't take it further. I know he bored my 2.8, but I don't know how far out he took it. I told him not to go wild with it and keep it so it would pass CA smog bullcrap. He guaranteed me it would. Too bad his guy screwed up my rear crankshaft seal. The engine runs fine, otherwise, much better than it did before. I can't wait to get this thing back on the road for real.
The 3.4 will have an angle where the Fiero starter is mounted and the F as Raydsr indicates. The 3.1 will have a flat surface where the starter mounts. I believe my 3.1 Lumina APV engine also has a crankshaft sensor in the trunk side of the block as does my 3.4.
According to Aerodonsmic (RIP) the 2.8 can be bored and stroked to a 3.1 and the same with a 3.1 to bring it near a 3.4.
Z, the 3.4 Pushrod block from the Camaro/Firebird should have x-shaped raised webbing on the block for strengthening (see picture below.) Also, it should have starter mounting holes on both sides of the block (one side was original and the Fiero location side is drilled into the block by the engine swapper.
Thank you everyone! I was able to find 2.8L stamped on the block just above where the oil filter is located. I now have a block "code" as well. I am not sure what help that will be in the future but at least I have the information now. My numbers exactly match what PhatMax shows in his pictures. Thanks again! with this information I was able to put the correct filter and oil in the car. I also replaced the belts on the car as I noticed they were at the end of the adjustment slide and I figured while I was under there I would take care of it before the weather in NY gets any worse.
