2nd Gen SOHC swap in a 91'

[turboexplorer]

I have searched for a thread with someone doing this swap but I haven't found anything. My little brother has a 91' and we are thinking of trying for the SOHC 2nd Gen engine in there. Engine mounts and things are easy enough to fab up. Things I am worried about would be more along the lines of A/C lines being able to connect. Computer and harness of course would have to be done. All easy enough with a donor 2nd gen truck. Curious on the forum thoughts about it! ?

 

[Spdrcer34]

The SOHC can be run off the 1st Gen OBD-I OHV Computer...

Ryan

 

[damarble]

I was going to do this but wasn't excited about making the motor play with the old wiring so just went with another OHV.

The back of the A/C compressors are the same so your lines will bolt up.

 

[turboexplorer]

I was going to do this but wasn't excited about making the motor play with the old wiring so just went with another OHV.

The back of the A/C compressors are the same so your lines will bolt up.

Nice good to know. Need to get the two trucks together so we can do some more quick comparing.

 

[snoranger]

The back of the A/C compressors are the same so your lines will bolt up.

Yes the lines will bolt up, but the compressor isnt in the same location. Also, the SOHC lines are routed different. Your best bet is to try to use the SOHC AC lines. I dont know if they will work with the first gen AC box, my SOHC swap is on a 95.

I know Brett (thats his screen name on here) did a SOHC swap into a first gen, but he doesnt have the AC hooked up. He had to cut up the the HVAC box alot to fit the motor in. we talked about cutting the firewall and grafting in the genII heater box. That would be the best way to go.

We both are running SOHC engines on OHV computers. I've got about 6000 miles on mine, with no problems. But be warned, Its alot of wiring you need to cut and splice. If your not comfortable with a soldering iron and heatshrink, dont try it.

 

[turboexplorer]

Yeah wiring isn't a problem at all. That's easy enough to figure out. I'm surprised though that the OHV computer will run the SOHC. But that's cool a few less thing to swap and try to get to fit. And my bro will need A/C for sure. We live in southern Utah and its 107 right now. Gets hotter to supposed to be 111* on Monday. So A/C is a must. but if the same fittings hook up I may be able to have some longer A/C lines fabbed up.

 

[2000StreetRod]

knock sensor & VIS support

There is a knock sensor on the SOHC V6 because of the higher compression ratio. Also, the 1997 & some 1998 SOHC V6s have a variable intake system. I doubt that the OHV V6 PCM supports either of these capabilities. Also, the OBD-II diagnostic capabilities are superior to the OBD-I. I think that you would have an easier swap and a better system using the SOHC V6 PCM and engine wiring harness. A 1997 or 1998 PCM would avoid the PATS issues. What transmission does the 1991 have? There will be control issues if you have an automatic.

 

[snoranger]

There is a knock sensor on the SOHC V6 because of the higher compression ratio. Also, the 1997 & some 1998 SOHC V6s have a variable intake system. I doubt that the OHV V6 PCM supports either of these capabilities.

Your right Dale, the OHV comp wont support these. Mid-grade gas (89 octane) and an '01 engine (no variable intake) were my simple fixes for those problems.

Also, the OBD-II diagnostic capabilities are superior to the OBD-I. I think that you would have an easier swap and a better system using the SOHC V6 PCM and engine wiring harness.

I'll agree with better system, but I cant agree with easier swap.

TurboEx- Your best bet is to use the engine, trans, wiring, and comp from one donor vehicle. The only reason I did it was to see if I could get it too work, now its my daily driver! Now that I have it running good, its time to start collecting parts for a cummins 4bt swap.

 

[snoranger]

Take a look at this thread:

http://www.explorerforum.com/forums/showthread.php?t=159001

 

[turboexplorer]

TurboEx- Your best bet is to use the engine, trans, wiring, and comp from one donor vehicle.

I agree. That's the plan we would run the tranny that is with the SOHC we wouldn't use the 91' trans. And I would swap the computer because of the OBDll. Tells you SO much more. We want to run the Auto trans and that's why we would swap the computers and everything.