Northstar V8 swap questions (those that done it please chime in) (Page 1/4)
countachmike DEC 20, 10:50 AM
First let me introduce myself, name is Mike and I live in the Houston area (35 miles west of it and in a small town) and secondly thank you Cliff for having such a site with a great deal of information for the fiero)

I have a 85 Fiero with a countach body on it, this is my dream car and I want to make it fast.
This is my 5th "fiero" and the first with a rebody . Currently has a v6 (with a carb) s10 motor and doesn't run and the manual stock fiero trans.

I watched several videos of fieros with the northstar v8 in them and from my reading on here this engine will bolt directly to the fiero manual trans with no adapter plate needed.

My questions are
1. What year or years northstar are people using?
2. Are you using the original ecu from that engine in place of the fiero ecu?
3. Is there a wiring kit out there for the northstar? I read from one member there is a wiring "kit" but after searching I can't find it
4. Using the stock trans I should be able to retain the original axles?
Any advice would be appreciated , I will buy the engine soon as I know which one to get (I think "vin 9" is the correct one ?
Soon as I know this information i will create a construction thread from beginning to end and document it on here and with videos so others that wish to do the same can. I want to add to the community here and it's nice to be here.
Thunderstruck GT DEC 20, 11:40 AM
Do your homework on all the issues Northstars have.

If you are still interested in using a Northstar I strongly suggest ARP head studs, head gaskets, checking the heads for cracks & trueness and re-sealing the block prior to installation.

I've had the pleasure of doing this to Northstars with as low as 38,000 miles.

[This message has been edited by Thunderstruck GT (edited 12-20-2015).]

Lambo nut DEC 20, 12:27 PM
You might try getting a hold of motoracer838. His name is Joe. He had a Northstar in a Fiero a while back along with the Caddi trans I believe.
Judging by your user name, you might have interest in something else he was in to.

Kevin
dobey DEC 20, 12:42 PM

quote
Originally posted by countachmike:
1. What year or years northstar are people using?
2. Are you using the original ecu from that engine in place of the fiero ecu?
3. Is there a wiring kit out there for the northstar? I read from one member there is a wiring "kit" but after searching I can't find it
4. Using the stock trans I should be able to retain the original axles?



1) Most all years have been used. Early engines had a particular issue with the block material at a couple of the head bolts, that would cause the bolts to loosen and coolant leaking. A TSB was issued for how to repair this with a timesert. Later model engines had the manufacturing defect resolved. If you get an earlier block, make sure this has been fixed. Even with ARP bolts, it will still be an issue if the proper repair wasn't done.

2) Depending on the year of the engine, and what features you want, various options for an ECU are possible, from the GM 7730 ECM, LS1 ECM, the ECM that came with the engine, or aftermarket. THe stock Fiero ECU cannot be used.

3) I don't know of any wiring kits for the Fiero, for a Northstar. It is not difficult to mate the Fiero harness and the Northstar harness together, to work properly in a Fiero though.

4) If you are referring to using a stock Fiero manual transmission, yes the axles will be the same length, as long as you don't alter the position of the transmission. If you are referring to the automatic, the Fiero auto shouldn't be mated to a Northstar, as it's quite weak. The 4t80 that comes with the Northstar can be used instead, but you will need different axles, IIRC.

There are plenty of Northstar swaps on the forum, so just search and do your research, and you should be fine.
Thunderstruck GT DEC 20, 12:53 PM

quote
Originally posted by dobey:


1) Most all years have been used. Early engines had a particular issue with the block material at a couple of the head bolts, that would cause the bolts to loosen and coolant leaking. A TSB was issued for how to repair this with a timesert. Later model engines had the manufacturing defect resolved. If you get an earlier block, make sure this has been fixed. Even with ARP bolts, it will still be an issue if the proper repair wasn't done.

2) Depending on the year of the engine, and what features you want, various options for an ECU are possible, from the GM 7730 ECM, LS1 ECM, the ECM that came with the engine, or aftermarket. THe stock Fiero ECU cannot be used.

3) I don't know of any wiring kits for the Fiero, for a Northstar. It is not difficult to mate the Fiero harness and the Northstar harness together, to work properly in a Fiero though.

4) If you are referring to using a stock Fiero manual transmission, yes the axles will be the same length, as long as you don't alter the position of the transmission. If you are referring to the automatic, the Fiero auto shouldn't be mated to a Northstar, as it's quite weak. The 4t80 that comes with the Northstar can be used instead, but you will need different axles, IIRC.

There are plenty of Northstar swaps on the forum, so just search and do your research, and you should be fine.




quote
Originally posted by Thunderstruck GT:

Do your homework on all the issues Northstars have.

If you are still interested in using a Northstar I strongly suggest ARP head studs, head gaskets, checking the heads for cracks & trueness and re-sealing the block prior to installation.

I've had the pleasure of doing this to Northstars with as low as 38,000 miles.




No bolts.... STUDS

Bolts should never be used in aluminum engine blocks. Another GM "F"up. And GM only "improved" of the poor design, not fixed it.

Waaaay to many people with Fieros put waaaay too much faith in a design that even Cadillac dealers hate and I still don't know why.

There are much better choices out there but to each their own. As for me, I like to build something and enjoy it. Not build it and constantly work on it or repair it.

[This message has been edited by Thunderstruck GT (edited 12-20-2015).]

dobey DEC 20, 01:04 PM

quote
Originally posted by Thunderstruck GT:
No bolts.... STUDS

Bolts should never be used in aluminum engine blocks. Another GM "F"up. And GM only "improved" of the poor design, not fixed it.

Waaaay to many people with Fieros put waaaay too much faith in a design that even Cadillac dealers hate and I still don't know why.

There are much better choices out there but to each their own. As for me, I like to build something and enjoy it. Not build it and constantly work on it or repair it.




Quit with your incessant whining about the Northstar already. It's really exhausting, and you are not providing any helpful information to anyone, by going into every N* thread on the forum and complaining about the head bolt issue (which had nothing at all to do with the fact that it was using bolts instead of studs, but was a manufacturing defect in the block itself).

I guess you better get rid of your Fiero then. GM dealers hate them too. And as the saying goes, "if you want to learn how to be a mechanic, buy a Fiero."
Thunderstruck GT DEC 20, 01:39 PM

quote
Originally posted by dobey:
Quit with your incessant whining about the Northstar already. It's really exhausting, and you are not providing any helpful information to anyone, by going into every N* thread on the forum and complaining about the head bolt issue (which had nothing at all to do with the fact that it was using bolts instead of studs, but was a manufacturing defect in the block itself).

I guess you better get rid of your Fiero then. GM dealers hate them too. And as the saying goes, "if you want to learn how to be a mechanic, buy a Fiero."



Truth obviously hurts and by advising people to the facts that the Northstar is a very unreliable money pit, I am be "helpful". Hell, the 2.8-V6 is a better platform.

And if you ever want to put your mechanical skills against mine, bring your cash.

[This message has been edited by Thunderstruck GT (edited 12-20-2015).]

Thunderstruck GT DEC 20, 01:50 PM
I'll tell you what.....

I have stated facts of what makes the Northstar a poor chioce. Other than the horsepower over the 2.8L, what makes them so good???
cptsnoopy DEC 20, 02:53 PM
Hi Mike,

I'll give it a go...
1) I believe the majority have been 95-99 but earlier and later years have been used (mine is a 1999 4.0L N* (Olds Aurora) with vin 9 intake cams and chrfab springs/retainers (new rpm redline 8,500)
2) I'm using the Holley Dominator EFI ecu. Works well for me. I have not tried other ecu's but I suspect the LS1 ecu that Shelby was using with my motor would have been even better.
3) I bought the Dominator through chrfab.com and Allen had a wiring harness for the N* made to the lengths that I needed for my install. It was very helpful.
4) I decided to use the stock 5speed manual transmission. In my car (originally an 88 4cyl coupe) it was an Isuzu. While it is the least desirable it is holding up well so far. Stock axles are fine as long as the trans is in its stock location. Some minor adjustments might be ok but I left it alone and modified my passenger side strut tower to fit the engine. In an 85, that might not be necessary.

I think most are aware of the head bolt issues and there are plenty of threads detailing the repairs required. You can decide whether or not your interested in dealing with it. I was lucky that I ended up with new in crate engine and won't (shouldn't) see any issues for years into the future.

Good luck on whatever you decide to do. I think most agree that the N* sounds better and is a quality power plant but that the 3800SC is cheaper and easier to install with more power available with mods.

I personally love how my car drives with my baby N*.

Charlie
Will DEC 20, 03:49 PM
This is the only thing you've said in this thread that approaches being a fact:


quote
Originally posted by Thunderstruck GT:

No bolts.... STUDS

Bolts should never be used in aluminum engine blocks.



FACT: GM has built millions of aluminum block LS engines with head bolts.

FACT: Steel inserts in a Northstar block result in a permanent fix.

FACT: For the MY 2005 GM eliminated the head bolt thread problem by changing the Northstar head bolt thread pitch from 11x1.5 to 11x2.0, matching the LS engines.

The rest of what you've said is opinion... and lousy opinion at that.


quote
Originally posted by countachmike:

My questions are
1. What year or years northstar are people using?



The most commonly used engines are '93-'99. The most difficult are '00-'04. The most rarely used are '05+
I have not heard of a VVT RWD Northstar being used in a Fiero. Yet.

2. Are you using the original ecu from that engine in place of the fiero ecu?

It's possible to use the original ECU in a swap application, but that gets harder when using a manual transmission vice the Caddy automatic.
Other options for '93-'99 engines include the OBDI 7730 computer and the OBDII Shelby Series 1 computer. I'm using the Shelby computer
The '00-'04 engines use a unique trigger wheel. There are no other factory computers that operate that engine.
The '05+ Northstars use the 58x trigger wheel that is now common to GM engines across the product line. Many many aftermarket computers can use this wheel.

All epochs of engines can be run with aftermarket computers. See www.chrfab.com for some of the options.

3. Is there a wiring kit out there for the northstar? I read from one member there is a wiring "kit" but after searching I can't find it

No, but it's not hard. If your Countache kit is stretched, a Fiero based wiring kit wouldn't work well anyway.

4. Using the stock trans I should be able to retain the original axles?

Stock Fiero trans? Yes, you can use the original axles.

Any advice would be appreciated , I will buy the engine soon as I know which one to get (I think "vin 9" is the correct one ?

VIN 9 is the L37 engine, which is the high horsepower front wheel drive option.