So... i have an extra 3100 sitting on the side of my garage... I read somewhere that with the 3400 sfi you could use Stock mounts and the stock 2.8 wiring... is this true? and if it is then i assume that it should be the same for the 3100, (If its not then wiring shouldnt be too bad)

I saw one guy on here was trying to sell his turbo'd 3400 (which i love that car and wish i was closer) but could you use 2.8 wiring?

Thanks before hand

-Daniel

well you could use a stock fiero 2.8l harness and convert it to run the 7730' ecm w/DIS. It would be obd1 as opposed to obd2 which the 3x00 motors came with stock.

So prolly easier just to throw the whole stock setup in? Like with the 96 computer and obd2

I Got my first 84 sport coupe just sitting with no motor and its sad to look at lol.
(well right now its covered in ICE!! )

I just finished a 1999 3100 4T60-E swap for my parents' 87 Fiero last fall. The 3100 I used had a cast aluminum oil pan that the main bearing caps were cross bolted to as well as the usual rather large cast aluminum front cover that contained the water pump. A stock Fiero 2.8 engine mount won't work on this engine without some serious modifications (you might also need to replace the oil pan). I custom made mounts to work with this engine's stock aluminum oil pan and also the 4T60-E transmission which presented more challenges than any other swap I've done thus far (concerning mounting). The cast aluminum oil pan does not give you much room at all, and even less room if you are going to use the stock A/C compressor that comes on the 3100. I was able to make it work and am satisfied with the end result. I did use the 99 OBD2 PCM so I could keep the SFI and 4T60-E; which you can't do if you use the 7730 ECM.

If you don't care about not having SFI and if you aren't running an electronic auto trans, then you can use the 7730 ECM on this engine, no problem. You should be able to modify the stock Fiero 2.8 harness to work with this engine and the 7730 ECM without too much effort.

Here are some pictures from my swap:



















-ryan

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OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

Well heck ya that looks awesome. I want the sfi, you wouldnt happen to have any wiring notes would you? And i plan on using my 4 speed. This one does have the aluminum oil pan though... could i use a 2.8 pan or a 3.4 maybe?

When I installed my 3400 I decided to use the 7730 ecm. This means re-pinning the fiero harness just like described on the 7730 thread. The Fiero harness does not match up to the 3400 (in your case 3100) so some wires will need to be lengthened/ shortened with splices. This is not difficult just somewhat time consuming and requires attention to detail.

You can tune your chip or have someone mail order tune it. I had Sinister Performance ((( http://www.gmtuners.com/ ))) tune mine.
Edit to add: I was happy with the exceptional customer service I received and would recommended him to others.
This time around I bought a moats ostrich emulator & wideband O2 and will be learning to tune my own.

The stock engine mount will work (with a little grinding on the 3100 aluminium oil pan casting) but the dogbone will not. You will need a 4th mount so it helps if you have access to welding capabilities or are very clever and able to bolt something together.

Other than that you need a knock sensor from a 7730 car and 3 wire coolant sensor ( i think the early 90s 4 cyl sunbirds had this).

The rest is the same as any swap: custom exhaust, custom fuel lines, custom coolant lines.

The 3100 would be a great daily driver swap. My 3400 was much stronger than the 2.8 and also achieved better fuel economy (up to 35mpg on some trips). The smaller bore (and less cubes) of the 3100 means it is capable of even more fuel efficiency.

I would bet the 3100 should be faster than the 3.4 camaro block/ fiero top end swap and also more fuel efficient. It would also be a better platform to build up from.

Edit to add: Also, if you leave the alternator in the stock position you will have to cut a notch out of the deck-lid for clearance.

[This message has been edited by LZeppelin513 (edited 02-01-2011).]

quote Originally posted by dhobbs84sc: Well heck ya that looks awesome. I want the sfi, you wouldnt happen to have any wiring notes would you? And i plan on using my 4 speed. This one does have the aluminum oil pan though... could i use a 2.8 pan or a 3.4 maybe?

If your 3100 has the cast aluminum oil pan that has the main bearing cap cross bolts in it, I'm not 100% sure what needs to be done to convert to a stamped steel oil pan since I have never tried it.

Concerning the wiring, I might be able help you there as I already have instructions posted on my website if you were going to use a 98-99 PCM: http://www.gmtuners.com/fil...400_4T60E_wiring.pdf (you can use a 98-99 PCM with your 96 harness if you repin it using these instructions).

If you already have a 96 PCM and harness you would rather use; for a small fee I can custom make you some wiring instructions for that specific computer.

Let me know via PM or email (sp1@gmtuners.com).

-ryan