What differences (if any) are there in an 86 2.8 and an 87 2.8?
My recently acquired 87 GT needs a long block and my 86 SE is willing to donate. What problems could arise?
thanks!

The only thing that jumps to mind is the different routing of the heater hose. The 86 has a hose that goes directly to the water pump. On the 87 this hose is routed to the passenger side coolant pipe.

Check that hose routing, it may or may not be the same. IIRC, there is a chance that if you got a late production 87 2.8, that it is internally balanced, which is normal for all 88's. the heater hose also only changed in 88.
IF there is a counterweight on the flywheel/flexplate on your 87, then it is the same as the 86, and you should have no issue.

oil pan & timing cover

So should I put the 87 timing cover, oil pan and 87 water pump on the 86 longblock?

If the accesory brackets (Alt/AC) that bolt to the COVER will still bolt on, I'd leave it alone. water pump the same ?

I stripped and painted my 86 intake, got it mounted on my 87 only to realize that the vacuum port for the brake booster was way smaller...

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-Brian

My 87 GT Poly Suspension Upgrade (all pics) thread https://www.fiero.nl/forum/Forum2/HTML/094633.html

There's no need to change the pan, timing cover or oil pan. Just remove the pipe nipple on the 86 water pump and the pipe plug on the 87 and swap places with them. I have an 87 engine in my 85 and the only thing that was changed was the pipe nipple. The engine wasn't internally balanced. It used the same flywheel as the 85. One of the benefits you're losing is that the 87 engine had slightly better oiling. If your 86 is a 4-speed, the engine harnesses are a little different. The 86 didn't have provisions for the backup light switch built into the transmission, so there is no connector plug coming off at the VSS connector.

I put an 86 5sp engine in an 87. My engine harness had the connector for the backup lights. I believe the the 87 intake manifold had Fiero engraved, while the earlier ones had a decal with Fiero.

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Jim
86 SE 355 Body Kit w/3.1 Auto (Sold)
87 T-Top Coupe 2.8/5 Speed new project

To clarify, yes, the 86 5-speed harness are identical to the 87's and has the pigtail for the backup lights. The 86 4-speed is the one that doesn't have the provisions for the transmission switch, so if using an 86 4-speed engine harness, you would have no backup lights.

I goofed, my 86 2.8 engine came out of a 4sp car and had the pigtail. I put the engine in a 5sp 87.
Jim

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Jim
86 SE 355 Body Kit w/3.1 Auto (Sold)
87 T-Top Coupe 2.8/5 Speed new project

I am only using the 86 longblock because I have it in my parts car and the 87 sounds like a can of rocks LOL

quote Originally posted by bowrapennocks: I goofed, my 86 2.8 engine came out of a 4sp car and had the pigtail. I put the engine in a 5sp 87. Jim

The 86 GT 4-speed I just sold didn't have the backup light pigtail at the transmission. Guess some of them did and some didn't.

Iroc, if you're just using the longblock, then you'll be using the 87 engine harness. No problem with the wiring in that case.

Thanks for everyone's help. I will just use the 86 longblock with 87 everything else. Unless I can find a cheap 3.4 in 2 weeks. I'd much rather have a little upgrade.

quote Originally posted by tjm4fun: the heater hose also only changed in 88.

WRONG! I have an 87 4cyl and 2 87 6cyls.ALL have the rerouted heater hose. It's no big deal though the water pumps are the same except for the nipple. If you buy a new water pump (I would) it will probably come plugged but will include the nipple to add for using on the 86. Since you are putting it in the 87 you shouldn't need to change it.

The timing cover and oil pan are different but it doesn't matter which you use as long as you use both from the same year. (I prefer the 87 set)

'87's with a serpentine belt have a water pump that runs opposite to '86 and down 2.8's in S10's. Fiero's don't have that set-up do they? My '85 doesn't.

[This message has been edited by raysr11 (edited 07-14-2009).]