1998-2000 short block going in a 1991 ranger

[Kirby N.]

Hey guys- I got a good deal on a NOS Motorcraft rebuilt 1998-2000 OHV short block. I would like to build it for my 1991 ranger and put it in to replace the old tired 4.0 OHV. Unfortunately, I am pretty not smart about this stuff. Wondering if some of you can help me. I am not looking to make it more powerful or trick it out. I really just want a reliable good for another 300k miles engine.

I think I need different heads than I have in my current ranger- and different pushrods. Can anyone tell me which heads and pushrods would be good ones to put in?

Will everything else off my old engine bolt on? Anything else I need to buy? I am assuming ill need new gaskets and such for valve cover, oil pan, oil filter extension thingy.

 

[Kirby N.]

This article has some good information: Ford 4.0L V6 Engine

It looks like my flywheel won't work. That is fine, I am already running a SOHC clutch, I can change to an 8 bolt flywheel.

It also says I will need to use a later dipstick because the hole is bigger- should be able to source one of those easily.

Here is the part that concerns me about using a later engine in the aerostars which are designed for the early engines:

Rebuilders should not install an engine with the 95TM heads and deep-dish pistons in a ’95 or ’96 Aerostar. All of these engines had the same compression ratio whether they came with the original heads with the open chambers or the newer ones with the heart-shaped chambers, so they would seem to be interchangeable, but the computer calibration that was used for the old-style heads with the open chambers will not work with the newer heads with the fast-burn chambers. In fact, “It will burn the engine down in a few thousand miles,” according to a Ford engineer who worked on this engine program. Ford continued to use the early heads on the ’95 and ‘96 Aerostar because they still came with the early calibration, so rebuilders must do the same.

That is a little concerning. Any thoughts on this? I am not running any catalytic converter on my engine- but it sounds like there is something off with the mixture calibrations for the earlier engine?

 

[RangerX]

I am not looking to make it more powerful or trick it out. I really just want a reliable good for another 300k miles engine.

I’m no expert, far from it for sure, but I would think leaving it bone stock would be the sure way to get 300,000 miles.

 

[Kirby N.]

yeah that is what I want to do!

 

[410Fortune]

My BII ran a 93 PCM and a 95tm head engine for 12 years, daily driven, I even towed a 20' bayliner from CO to CA and back, all this with 33's and a A4LD!!!!!!!!!!!...........never an issue


You SHOULD BE FINE I have put many later model ohv's into the earlier trucks and never had one burn up
The 98 Engine should have 98tm heads.....not a concern like the 95tm heads were
At least that is my understanding.

You are already running sohc clutch so thats easy, the 98+ OHV has a 8 bolt crank so you just need a sohc flywheel

Use the dipstick designed for the later model engine = no problem there

Now you could also consider a OBD2 conversion, keep the plastic upper intake and all the OBD2 goodies, you will get better performance and MPG
There is "some" wiring involved and you have to add a obd2 port to the dash

 

[Kirby N.]

Ok, that makes me feel better.

You have mentioned converting to OBD2 before, Jaimie. I think I would rather keep it OBD1 (if it isn't going to burn the engine down). But I am always excited to talk about it and learn more from you about it. I have always respected your brain when it comes to stuff like this.

What are the goodies and what is involved in the wiring?