Isuzu SUV Forum banner
1 - 7 of 7 Posts

·
Registered
1994 Isuzu Trooper
Joined
·
6 Posts
Discussion Starter · #1 ·
Hey Folks,

I know this question has been put out there plenty of times, but I'm having trouble finding a clear answer.

I have a 94 Trooper with SOHC that's on its way out. the local salvage yard has a 94 Trooper with a DOHC with decent mileage. I've read everything from "it drops right in" to "the wiring is all different and the injectors use a different impedance". So, can anybody clarify exactly what I'm getting to if I go this route? I also included a pic of a few parts I threw at it last week!
Font Material property Auto part Circle Fashion accessory
 

·
Registered
Joined
·
4,816 Posts
Here's some info from a 19-yr-old post at the 4x4wire.com Isuzu forum:

Yes, you can use a early model DOHC, but you will have to use
the intake system from the SOHC engine.
That is what I have in my '95.. it's a DOHC with a SOHC intake
and it runs great. It's 190hp vs. 175 SOHC engine and it has
the low end torque that the DOHC doesn't normally have.

You will also have to use the ignition system, wiring harness,
and exhaust manifolds from your SOHC. The EGR is in a different place on the DOHC, so to mate it up with the SOHC, you have to use the SOHC exhaust manifolds.

You'll use the airbox and throttle cable from your existing
SOHC also.

Other than that, everything pretty much lines right up and
goes in without a hitch.




 

·
Registered
1994 Isuzu Trooper
Joined
·
6 Posts
Discussion Starter · #3 ·
Here's some info from a 19-yr-old post at the 4x4wire.com Isuzu forum:

Yes, you can use a early model DOHC, but you will have to use
the intake system from the SOHC engine.
That is what I have in my '95.. it's a DOHC with a SOHC intake
and it runs great. It's 190hp vs. 175 SOHC engine and it has
the low end torque that the DOHC doesn't normally have.

You will also have to use the ignition system, wiring harness,
and exhaust manifolds from your SOHC. The EGR is in a different place on the DOHC, so to mate it up with the SOHC, you have to use the SOHC exhaust manifolds.

You'll use the airbox and throttle cable from your existing
SOHC also.

Other than that, everything pretty much lines right up and
goes in without a hitch.


That's Awesome, Ed! Thanks very much. This is exactly what I wanted to hear.
 

·
Registered
Joined
·
252 Posts
grab heads, valve covers, timing covers, everything in the heads. you'll need a new DOHC timing belt and new DOHC spark plug wires, new head bolts. Have a repudible shop go over the heads to resurface, check the valves, and the hydraulic lash adjusters to see if you need to replace any.

Everything else should be fine. Air from SOHC mix chamber upward will bolt on. Headers will bolt on. SOHC ECU should be fine.

You'll need to time the heads before you time the belt. they have marks on each gear. I found taping a nail to the edge of the head helped line the marks up.
 

·
Registered
Joined
·
4,816 Posts
I just remembered something, this would be a great time to remove the restrictors in the exhaust head pipes. They can be cut/chiseled/ground out, whatever tools you have available. You'll make better low-end torque with the restrictions gone.

See below thread for details on the mod:

 

·
Registered
Joined
·
150 Posts
Ed Mc…. I just completed my sohc/dohc swap a week ago, and I love it. Still breaking it in. DOHC parts needed : cam covers , valve covers, spark plug wires, camshaft seal holders.
The timing belts are different. All the sensors are retained with the sohc harness. Butgrab as much stuff as you can with the dohc engine. . SupaTroopa is correct on the head bolts , 8 per head + 2 smaller ones. Order new ones , they are cheap. Lots of us have completed this , so you have a knowledge base. Eric
 
  • Like
Reactions: SupATro.0pA

·
Registered
Joined
·
3 Posts
Ed Mc…. I just completed my sohc/dohc swap a week ago, and I love it. Still breaking it in. DOHC parts needed : cam covers , valve covers, spark plug wires, camshaft seal holders.
The timing belts are different. All the sensors are retained with the sohc harness. Butgrab as much stuff as you can with the dohc engine. . SupaTroopa is correct on the head bolts , 8 per head + 2 smaller ones. Order new ones , they are cheap. Lots of us have completed this , so you have a knowledge base. Eric
Was this just to swap dohc HEADS onto a sohc block? Or was it to do a full dohc engine swap into a original sohc engine bay?
 
1 - 7 of 7 Posts
Top