99 and newer 4.0 SOHC swap in a 98 Explorer?

[shelbygt]

I am having reservations about putting $300.00 or more into replacing the head gasket on a 193k mile motor. Not to mention the job will take several days to complete. If I can get a lower mileage motor for a few hundred bucks more, I want to weigh that option. So I would like to be armed with the facts of what I can directly swap into my 98 without changing computers and mechanical parts.
Thanks...
Dave

 

[vroomzoomboom]

you would want to reuse all your sensors and harnesses from your 98 motor to the new one. you would also have to swap your 98 intake to the newer motor.

and most important this thread

http://www.explorerforum.com/forums/showthread.php?t=244560

before seeing this thread, i had no clue how to pull a SOHC. since then, i have done two of them.

 

[2000StreetRod]

Vis?

Replacing the head involves retiming the camshaft. It's a pretty significant job but so is replacing the engine.

Does your 1998 SOHC have the variable intake system? It was incorporated in 1997 and some 1998 models but eliminated in 1999 and later models. If so, then you would have to reuse your 1998 intake system to utilize a later engine. I believe that if you went with a newer long block and reused everything else from your 1998 you could use any Explorer, Ranger or Mustang SOHC 4.0 V6 engine.

 

[shelbygt]

Thanks for the link... great info!
How do I know if it has variable timing? Given all the work involved, it seems doing just the head gasket is as bad if not worse than swapping the engine entirely. I have no problem doing the work, just hate to sink good money in a motor that has already outlived it's intended lifespan. This motor design makes me wish I had found an Explorer with a 5.0 or even a later 4.6 :-(
Thanks for all the help!!

 

[2000StreetRod]

VIS actuator

The photo below shows the VIS vacuum motor and control rod between the two main chambers of the upper intake manifold and aft of the IAC valve.

The rod rotates a lever that changes the volume of the intake runners.

Each of the early Explorer engines has some undesirable trait. The OHV V6 has low power and a tendency to crack heads or blow head gaskets. The SOHC has short lived timing chains/guides/tensioners. I believe the V8 has poor head and exhaust manifold flow. None of the stock engines perform well above 6,000 rpm but then I doubt Ford intended for their 4,000 pound basic box to be sold as a performance vehicle.

 

[shelbygt]

Yeah... well said, most engines have their weak points, but on the bright side, they are still making these motors, so the support for them from Ford will continue. If the motor was garbage, they would have dropped it long ago. After doing some calling around, the cheapest I could find a used motor was 850.00. Most are over a grand. So I am going to just repair this one. I do have the VIS on the intake. But I guess doesn't matter now...lol
Thanks for the info!
Dave