3500 (LX9) swap into a Fiero

[flimbob]

Quite the write up. I'm trying to do some research for a fellow employee who wants to swap a 3400 into a 1985 Fiero 2.8L. Only thing that concerns me is the motor mount holes, did GM change the mounting hole locations from 85 to 1999?

No change in mounting holes. The 85 mount needs just a little taken off to fit correctly.

[natebee]

Quite the write up. I'm trying to do some research for a fellow employee who wants to swap a 3400 into a 1985 Fiero 2.8L. Only thing that concerns me is the motor mount holes, did GM change the mounting hole locations from 85 to 1999?

[02dohc]

hey i'm in the process of doing a 3500 swap into my 4 speed 85 gt. i'm also installing a getrag 5 speed tranny. im mocking up a true dual exhaust system for it and still having the trunk. im running 2.5" exhaust. and a cross flow dynomax muffler with dual inlets and dual outlets. i did flip the exhaust manifolds to the opposite sides of the egine so the one that comes straight down is visual when looking at the engine in the car. thats just the way im doing my exhaust for thought if you needed some.

[flimbob]

As Spring approaches, I've started looking at what's needed to complete my swap. Engine and trans are on a spare cradle. Returnless fuel pump mod needs to be completed as well as the exhaust. Harness is 85% done. I realized after reading several posts of 3400 swaps on Pennocks that I have the wrong alternator. It is the 2 pin type which was originally used on the 2006 Uplander. Looks like a trip to the pick-n-pull is in order.

[flimbob]

ever get the swap finished?

Have the engine/trans on a cradle, waiting for it to get warmer.

[ericjon262]

ever get the swap finished?

[86FieroSEv6]

Which is why some swappers will sacrifice the "trunk" to make room for a good exhaust system.

[flimbob]

It has been just too hot to work on my swap. All I could do was just sit in the house while most of July and August creeped by. I'm about to get geared back up to finish the swap. I've seen a couple of ideas for exhaust designs on 3400s over at Pennock's Forum. I'd like to have the exhaust finalized and my harness wrapped up fairly soon. I received my chip from Ben and am looking forward to finishing this project.

[flimbob]

Got the thermostat neck tapped. Is it common for there to be no gasket between the thermostat neck and the manifold? Mine didn't have any type of gasket, just aluminum to aluminum. Sensor looks like it was made to be there. Finished up some small stuff, i.e., modify/mount the 440t4 dipstick tube and mount the coil-pack. Will pick up my modified a/c flex hose tomorrow. Had them install a pressure sensor in the high pressure side. Looking at what can be done to low mount the alternator. Don't want to have to notch the decklid if I don't have to. Just about ready to start looking at the exhaust system. Many of the 3800 swaps over at Pennocks use a similiar design where the cat is mounted horizontally and parallel with the engine. They then use a Flowmaster or similiar muffler that is constructed like a fiero/firebird type.

[flimbob]

Don't forget that they are referring to pipe thread sizes for the taps in this case. 3/8 pipe thread is of a larger diameter than 3/8 common thread.

Thanks! I looked it up. 37/64 drill bit for 3/18 - 18 NPT.

[86FieroSEv6]

Don't forget that they are referring to pipe thread sizes for the taps in this case. 3/8 pipe thread is of a larger diameter than 3/8 common thread.

[flimbob]

I received the 12mm-6fp adapter to adapt my 96 3100 3 pin CTS for use with the LX9. I'm really concerned with this approach because the CTS will only thread into the adapter a little more than one thread. It also has a very small area that water actually touches the CTS. I do not see turning the CTS down to fit where the original CTS fits is a viable option. I am also uncomfortable with drilling and tapping the the LIM as it seems you could inadvertently get metal shavings in the water chamber I did read where some have indicated drilling and tapping the thermostat neck. I have removed my thermostat neck and it does indeed seem like a good place to mount the CTS. I have searched the forum to find the right drill and tap size but seem to get conflicting answers. Can someone please chime in with the correct drill and tap size? I can't believe the drill is 7/16 and the tap is 3/8. That would make the hole bigger than the tap. Should it be 1/4 for drill and 3/8 for tap?

[flimbob]

For the 7730, your A/C on input comes to the ECM through the pressure switches from the A/C switch in the climate control panel. A/C clutch request goes from the ECM to the A/C clutch relay. If you have the fans control outputs from the ECM wired correctly, they will light when A/C request is made.

Thanks for the info! I've got a spare Fiero flex hose on it's way to me. Really don't want to tear down my DD until I'm completely ready to do the swap. Once it arrives, I'll get the custom hose made. I'm thinking of putting the cut-off switch in the custom hose as it would be closer to the ECU and I wouldn't have to snake a new wire to the front of the car. Any thoughts on this? Also, I have successfully obtained a 94-95 smog ( EGR ) tube for the reversion from 2000+ to digital EGR. The digital EGR is now all installed. One step closer to "S" day.

[86FieroSEv6]

For the 7730, your A/C on input comes to the ECM through the pressure switches from the A/C switch in the climate control panel. A/C clutch request goes from the ECM to the A/C clutch relay. If you have the fans control outputs from the ECM wired correctly, they will light when A/C request is made.

Joseph,

Do you have pictures and/or part numbers for the cutoff switch you used? I believe I picked up a cutoff switch that was on a mid to late 90's pontiac. It was mounted in a small tube which was I believe was headed to the condensor. I can provide a picture of it if that helps. What kind of price did Amazon charge for your modified hose? Also, I was under the impression that the 7730 controlled the fan. Am I missing something here?

I haven't installed it yet but I have it along with a new dryer which was pretty reasonably priced. I don't remember what Amazon charged for the hose mod, I know it was less than $80 and less than what it should have been since welding aluminum was involved. I have not wired my A/C system yet so I'm not sure what exactly can be eliminated, or what exactly the 730 will do regarding the A/C.

https://www.ackits.com/pc/57807MD/conversionitems/Low+-+High+pressure+Cut-off+Switch