I bought a 1986 2m4 it was a barn find hasn’t ran in 15+ years. She’s got rod knock. Anyone know if a duke out of an 84 can go in an 86 I assume some modifications will have to be made im pretty new to Fiero’s.
I bought a 1986 2m4 it was a barn find hasn’t ran in 15+ years. She’s got rod knock. Anyone know if a duke out of an 84 can go in an 86 I assume some modifications will have to be made im pretty new to Fiero’s.
Just change the sensors from the 84 to the 86 stuff, like everything good off of the 86 has to go in the 84 engine, probably swap intakes and exhaust as well, are you going to be pulling from the top or dropping the subframe? you can do either but only on the i4 will it properly fit out of the top with the deck lid removed
Just change the sensors from the 84 to the 86 stuff, like everything good off of the 86 has to go in the 84 engine, probably swap intakes and exhaust as well, are you going to be pulling from the top or dropping the subframe? you can do either but only on the i4 will it properly fit out of the top with the deck lid removed
There is a LOT more to it than that..... Different wiring harness... Different ignition system... Different computer...
But! If you just use the long block from the 84, and swap the ignition system and wiring harness, intake and FI unit, it should be pretty easy.
There is a LOT more to it than that..... Different wiring harness... Different ignition system... Different computer...
But! If you just use the long block from the 84, and swap the ignition system and wiring harness, intake and FI unit, it should be pretty easy.
hence the everything off the 86 onto the 85 engine. I'm putting a 86 long block into an 84 currently so I'm actually dealing with these issues just like the g-swap honda I finished up a few weeks ago, I mean if he really wanted to he could go get a random fwd iron duke and throw the parts on and put it in
I bought a 1986 2m4 it was a barn find hasn’t ran in 15+ years. She’s got rod knock. Anyone know if a duke out of an 84 can go in an 86 I assume some modifications will have to be made im pretty new to Fiero’s.
To be fair, there isn't a whole lot of difference between those years (unless we're being nit-picky).
BUT, so long as you use *everything* from the 1986, the long block from the 1984 will work JUST fine. You should use nothing at all from the 84, other than the engine itself. Meaning, literally strip it down to just the bare block and use the brackets, sensors, everything from the 1986.
The only thing that I think bums me out a little bit though, is that the 1986 has some slight advancements that the 84 engine doesn't have. The most pronounced improvement is the use of a roller cam in mid-1985+. Ideally, if you can find a 1985-1986 engine to replace the one you have, is probably your best bet.
Are the intakes interchangeable, and if they are not, do the two engines use the same TPI unit?
And, if the intakes and TPI issues require putting the 86 head on the 84 block, are the heads interchangeable?
At some point, one the cylinder head bolt holes were moved slightly and the intake ports were reconfigured, but I am unclear when that happened.
Does anyone have info about these potential wrinkles?
can 2nd TA's statement of the pre 87 intakes all interchanging as I have an 84 intake with a 85 tbi and 85 Block with 86 head apparently the builder liked Legos lol as for the heads its apparently late 1986 models that come with a 87 engine that have the different head
can 2nd TA's statement of the pre 87 intakes all interchanging as I have an 84 intake with a 85 tbi and 85 Block with 86 head apparently the builder liked Legos lol as for the heads its apparently late 1986 models that come with a 87 engine that have the different head
Yeah, in the 1987 model year, the Duke changed entirely. Cyl head is different, and even the block is totally different. They eliminated the hole for the distributor, and added two new holes for the crank sensor. There are also THREE larger diameter bolt holes in the front of the engine where the belt tensioner mounts. This replaced the normal 4-bolt (smaller bolts) block-off plate that had the timing hole for the crank pulley on it.
The 87 engine is a better design as they went to DIS ignition, a better intake design, and a newer TBI unit. It went from like 92hp to 110hp if I remember correctly. The 88 engine also improved slightly too with an internal oil filter that gets removed from within the oil pan (meaning you don't get oil all over the block), and a new balance shaft which smooths out the motor as well. I'd imagine this would probably also reduce a little bit of power because of more rotating mass, but they rated it the same.
