I need some info on a second v-8 swap I have started and did not get one response from the Fiero v-8 forum. With the many members of this group I hope some one has some info. The questions: As I mentioned earlier I am starting my second Fiero v-8 swap. My first
was an '84 and the second is a '87. Since there are some differences I
know I have to change some things and I hope some of you have
experienced these differences and can provide some advice:

1. COMPUTER: I removed the computer from the '84. Can I also remove it
form the '87, or does it handle some functions that would require it to
be retained?

2. MOTOR & TRANSAXLE MOUNTS: I used solid motor/trans mounts in the '84
and want a softer ride in the '87. Has anyone used rubber mounts in
their swap? If so I would appreciate to hear how it worked and any
other details.

3. AIR CONDITIONING: I removed the A/C in the '84, but with the '87 I
plan on retaining it. Will the hoses reach the compressor? I suspect
they will not. If not, what is the method of solving this problem you
used?

4. RADIATOR: I did not replace the radiator on the '84 and it tended
to run hot at times. I want to avoid any problems with the '87 so I am
planning on installing a larger radiator on the '87. I would be
interested in hearing what those of you who have replaced the radiator
used.

5. TACHOMETER & SPEEDOMETER: On the '84 I converted the tach ( 8000 RPM
) and speedometer ( 200 MPH )to work with the v-8. I suspect I can use
the same process with the tach, but I am not sure. In place of the
stock items I used a .00339 uf capacitor for the tach and 7.3728 MHz
crystal in the speedometer.( Thanks to Archie I saved a lot of time as
he provided the rating for the capacitor.) Will the same ratings work
for the '87?

Well thats about it. I think most of the other parts of the swap will
be the same or comparable. I would appreciate hearing from any of you
about these items.

BRIAN

1. You need to keep the computer. It will process fuel level, water trmp, oil pressure, fan and vehical speed sensor.

2. You can use the rubber transaxle mounts with an LN1 type motor but a solid mount will be used on the front end, anything else is custom hard mounts.

3. The hoses will reach you have to remove the frame rail tie down, and support it another way.

4. You can buy a 4 core radiator from V-8 ARCHIE, it is a no modification drop in radiator.

5. the speedo can be modified like your 84 and the tach will have to be modified for an 8 cylinder, archie can do this as well.

Good luck on your upcoming swap.

1) I never was totally clear about the computer, but I think Coyote's right. I'm running a carb and still have the ECM. I think it's needed if you're retaining the factory gauges.

2) Unless you can engineer a better front (passenger side) rubber engine mount, you have to use the solid mount. You can retain the rubber cradles bushings if this is not going to see a lot of high performance usage.

3) Seems like V8 Archie has a special little adaptor kit to allow use of the A/C. It can be done.

4) I have a bigger radiator, but it was already installed when I bought the car, so don't know much about it. I can take some pics and email them if you want. My setup needed a little modification to fit.

5) Don't know anything about the speedo mod, but you can swap in a Fiero GT 120 mph one if you want. All you need to do to modify the tach is to replace the capacitor with the correct one for a V8. The Big Fiero Book says to use a 0.0064 uF capacitor. I don't know who is right, V8 Archie or my book???

Are you doing this by yourself or with an archie kit? I don't get it?

Thanks for the replies. It sure helps with input for others. Some clarification may be in order first.

I am doing the entire swap myself. A friend and myself built the parts needed to do the swap using the Zumalt approach without the extension on the water pump drive.

1.All of the gauges worked on my '84 conversion without the computer. What is different about the '87? I have looked at the '87 wiring diagram and the ECM shows only "A/C on in" and "A/C comp. contr. rly." It looks like these are inputs for the fuel injection. Nothing shows about gauges. I know the headlights use there own dedicated ECM so that should not be a problem.

2.I will not be using the fuel pump since I will be using carbs.

3.I have the 120 MPH speedometer now since the Fiero is a GT. Apparently the values of the tach capacitor vary depending if you are converting a 4 or 6 cylinder engine. The rating used on the '84 worked perfectly. I was hoping someone would know when to use which ratings. I think the speedometer crystal change is dependent on the top MHP used.

4.I would sure like to see a picture of the radiator upgrade. Maybe some will recogize the radiator.

5. I am gladto hear I will not have to lengthen the A/c hoses.

Any additional ideas or comments are appreciated.
Brian

As far as I know you will still need the fuel pump but with a pressure limiter in the line for carb applications. If I'm wrong ley me know as I'm setting up to do a 350 conversion into my 87 coupe and according to Archie you still use the fuel pump. By Zumalt do you mean you are cutting the drivers side axle and using a longer passenger side axle to keep the entire engine in the engine compartment?

I can tell you about the computer.

If it was an 87 4 cyl with cruise then the cruise unit is run by the ECM. Coolant fan control is also in this ECM. You however will need to install a coolant temp sensor in the block the same as the V6 or older 4 cyl uses to run the fan.

The VSS signal goes to the speedometer where it is divided by 2 then fed to the ECM. The only dash device controlled by the ECM is the SE light.

Frankly I think solid mounting is a very bad method to install any motor. It creates a number of problems not the least of with it a huge amount of vibration.

There are rubber and/or pollyurethane motor mounts that will work on a V8 fiero. They aren't used in most Fiero installs because no one has bothered to research it properly. There are at least a couple of methods to prevent breaking the mounts and properly contolling torque movment of the motor/tranny set, but again no-one's taken the time......