thought it was a 2.8 when purchased, but its a 3.4!
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thought it was a 2.8 when purchased, but its a 3.4!
howdy all, awsome site/forum here. well i'm a new fiero owner, just picked up a 86 gt for next to nothing as it had a bad engine knock/tick, which turned out to be a rod bearing. interesting part is that as i tore this engine apart and started measuring things to order parts, i found out its not a 2.8, but a 3.4. had the red 'fiero' upper intake plunum and everything so i never even asked. anyways my question is when a 3.4 has been put in place of a 2.8, where does the 2.8 end and the 3.4 begin? i know every conversion can be done differently, but typically speaking, would the computer and harness be fom the 2.8 still? what would need to be changed to put a 3.4 in place of the 2.8....would the intake have to be changed (ths one had the red 2.8 upper part at least)... would injectors ahve been changed, or would the 2.8 ones work? the cam had 4 failed lobed and that metal debris got into all bearings. luckily crank and pistons still in good shape, so i'm putting in all new bearings, a hone with new rings, new cam and lifters. i've ordered all that based on 3.4 an by size so thats all fine, but what led me down this question is the oil pressure sensor was broken off, so that got me asking wether i'd order the stock 2.8 fiero oil pressure sensor or order one from a 3.4? (or they might be the same). my guess would be the block, crank, pistons and rods, and heads would all be 3.4, then intake and everything else 2.8....i'm a heavy duty mechanic by trade so automotive/gas type intake systems not really my field of expertise. anybody who's savy with that stuff or has done a 3.4 conversion, i'd really appreciate a little advice or whatver insight anybody could throw at me. thanks to all and cheers for now.
Re: thought it was a 2.8 when purchased, but its a 3.4!
The 3.4 was made for the Camaro and Firebird from 1993-1997 I believe. It uses a nearly identical block to the 2.8l, and is a fairly common replacement. I wouldn't call it an engine swap, more of a replacement. Most owners use the 3.4 long block, with the 2.8l intake/exhaust manifolds and everything else is therefore the same. I believe the only thing needed for the replacement is to drill and/or tap a bolt or two for the starter.
So basically, you did right by ordering the internal parts for a 3.4. From the oil pan to the heads it is a 3.4. The intake manifolds/fuel system/computer/wiring/exhaust is all 2.8l.
The oil pressure sender is probably the same between the two, but I'd order a 2.8l one to be sure the wiring connector is the same. I believe most any one you'll find will be a typical 0-5v sender with the same thread, so it's just a matter of wiring differences.
I hope this helps, I'm not extremely versed on these. The 3.4 basically adds like 20hp over the 2.8l IIRC.
So basically, you did right by ordering the internal parts for a 3.4. From the oil pan to the heads it is a 3.4. The intake manifolds/fuel system/computer/wiring/exhaust is all 2.8l.
The oil pressure sender is probably the same between the two, but I'd order a 2.8l one to be sure the wiring connector is the same. I believe most any one you'll find will be a typical 0-5v sender with the same thread, so it's just a matter of wiring differences.
I hope this helps, I'm not extremely versed on these. The 3.4 basically adds like 20hp over the 2.8l IIRC.
88GT 3.4 DOHC Turbo
Gooch wrote:Way to go douche. You are like a one-man, fiero-destroying machine.
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Re: thought it was a 2.8 when purchased, but its a 3.4!
The 3.4 vs. 2.8 is like the 350 vs 305 comparison in the SBC world. The 3.4 will make significantly more torque, but only a little bit more power because of the restriction imposed by the Fiero intake manifold and iron heads.
You'll have to look up the part numbers of the injectors you have. Sometimes they're changed, sometimes not.
Are you going with an overbore?
The oil pressure sensor should be the Fiero unit. I don't think there were any external differences in that part of the block.
If the engine was already installed in your car, then the modification for starter mounting has obviously been done.
If you wanted to, you could convert from distributor to DIS ignition and use the Camaro intake manifold, which will free up a few ponies, but won't look stock.
You'll have to look up the part numbers of the injectors you have. Sometimes they're changed, sometimes not.
Are you going with an overbore?
The oil pressure sensor should be the Fiero unit. I don't think there were any external differences in that part of the block.
If the engine was already installed in your car, then the modification for starter mounting has obviously been done.
If you wanted to, you could convert from distributor to DIS ignition and use the Camaro intake manifold, which will free up a few ponies, but won't look stock.