99 4.0 ohv into a 91/ 4.0 ohv

[shadetreeranger]

will a 99 4.0 ohv work in a 91/ 4.0 ohv

hi
im new here . just bought a 91 explorer with a bad 4.0 ohv engine and was wondering if a 99 4.0 ohv engine will hook in it without any problems?
thanks charlie

 

[shadetreeranger]

well if anyone is inerested the 99 engine went in and started today. had to change the plenum,fuel rail,injectors,exhaust manifolds to do away with EGR,engine mounts,alternator mount. you have to leave the thick spacer on the 99.the 99 crank has 8 bolts for the flywheel,91 only has 6. also there is no low oil sensor on the 99.
have a Merry Christmas and a Happy New Year
charlie

 

[N2FORD]

I am very interested, please keep me in mind (pm if you want to) with any mods or tricks required to doing this. I am wanting to do the same thing. Mine is a 5 speed so I will have to find a 8 hole flywheel for a clutch. Could you have kept the exhaust manifolds and used the 99 y pipe? Thick spacer, not sure what you are talking about? TIA

 

[RiverRat]

I'm interested too. I'm sure a lot of members would like to know exactly how you did the swap.

 

[Doug904]

I'm interested too. I'm sure a lot of members would like to know exactly how you did the swap.

Well, being that it is a OHV to OHV swap it's pretty straight foward like before mentioned but there are a few differences that can confuse a simple guy.

1) The intake studs in the fuel rail are longer because the plastic intake is thicker the the aluminum one, this really doesn't matter except for the front stud, you have to put the nut on the stud before you put the throttle cable bracket back on.

2) The CMP drive and/or sensor. All 95-00 will have this and use it,the 91-94 4.0's either won't have it OR you will have a different style. If you older truck doesn't have it then I wouldn't even take it off the block, it doesnt hurt anything sitting there.

3) All of the sensors, and don't forget the crank sensor in all of this. The temp sensors in the front of the intake must be swapped as well and finally all of the wiring harness from the vehicle it is going in must be used. Like before mentioned their won't be a low oil level sensor on a 98 and newer 4.0 so you'll either have to swap pans or not worry about it and let the wire hang, or tie it up out of the way. I think I would know before the oil level got low enough to trip this light anyway so I wouldn't worry with it.

4) The Exhaust manifolds must be used from the older Explorer but there too they bolt right up. On a 98 and newer there will be exhaust studs that must be removed from the heads, they won't work in the early model exhaust manifolds.

5) Upper intake and possibly fuel rail if your using a 98up returnless system. You can use the new injectors, don't remove them but the rail itself must be changed. Also the 96-up OHV's have a plastic spacer plate below the fuel rail and you must reuse this plate between the lower intake and fuel rail or the injectors will bind up and you'll get an vacuum leak because of the difference in height.

6) Finally the flywheel on a 98up are 8 bolts, you can use the new style flywheel on the old style transmissions no matter whether it's an auto or manual. Now if you have a C4 behind it that's a whole different ball game but I doubt anyone else has ran into this problem, if you do I have a special made flywheel lying around .

That's all I can think of right off hand but it's a very straight foward swap. It's the same basic long block just the heads are different. The exhaust ports on the 98up's will be smaller then your old ones but dont worry with that on a stock setup.

One important thing to remember is you can go late model to early model but you can't go early model to late. The reason being is the number of engine mount bolts on the side of the blocks. They used new castings for new bolt locations every couple of years and it's very specific on that. The way this goes is pretty much...

91-94 used one bolt setup
95-97 another
98-00 the final

You can use the 98-00 on any year model but the 95-97 can only go back, not foward.

Thanks, Doug904

 

[shadetreeranger]

Bravo
Very well put Doug904, i not very good at writing things like that better telling in person.
thanks for the write up.
charlie

 

[Doug904]

Bravo
Very well put Doug904, i not very good at writing things like that better telling in person.
thanks for the write up.
charlie

Yeah, sorry I didn't see your post earlier but I've done PLENTY of these swaps and I hate to see people gettting the wrong idea about it.

Later, Doug.

 

[N2FORD]

Thanks to Doug904, it is the things that he mentioned in a very well written post that clears most of my questions. It is the little things that turn into BIG WOOOP when you are trying to do this over a weekend. It is not a bolt in and fire it up, minor changes have to be made. I like to plan ahead for a project like this.

 

[shadetreeranger]

been 2 weeks since i put the engine in it seems to run great.

 

[NOTAJP]

Doug904, Hopefully you can chime in and let up know if I have the correct information:

When transplanting a 95+ engine or even just the heads into a 91-94 chassis, a custom burned chip is required due to the fast burn heads.

There are suttle differences in the engines. I would prefer to keep the alloy lower intake for porting reasons. I'll be doing almost the same swap in the next few months with a lot of performance additions to my 96 block.

 

[N2FORD]

Picking my 2000 Ranger (10k) motor up Wednesday for my 91 X. Any and all info will be helpful. Thanks already to Doug904 for his info.

 

[410Fortune]

Good thread I would have gone this route if I could keep a V6 transmission together long enough to wear out a OHV....

 

[NOTAJP]

Good thread I would have gone this route if I could keep a V6 transmission together long enough to wear out a OHV....

Did you ever consider the 700R4 swap?

 

[410Fortune]

Yes I did, and for MANY it would be an excellent choice, but for me, if you are going to spend that much $$$ mine as well replace the engine too....
There seems to be ALOT of stuff going on under there with the 700R4 conversion as well, all the adapters, and the amount of space required, plus the new stsarter , shifter linkage, and the $$$ involved mine as well put in a 5.0L and AODE or 4R70W.
PLus Brett was just begging me to buy one of his 5.0L drivetrains (right Brett?)

I would also have to look at doing a SOHC with a 5 speed conversion if I wasnt to use my BII for towing the boat still.....

 

[bates]

Doug904, Hopefully you can chime in and let up know if I have the correct information:

When transplanting a 95+ engine or even just the heads into a 91-94 chassis, a custom burned chip is required due to the fast burn heads.

There are suttle differences in the engines. I would prefer to keep the alloy lower intake for porting reasons. I'll be doing almost the same swap in the next few months with a lot of performance additions to my 96 block.

Doug can you confirm? If the engine is out of a 95 aerostar, can I grab the chip from it? And where would I find it? kickpanel?

 

[Rhett]

Doug can you confirm? If the engine is out of a 95 aerostar, can I grab the chip from it? And where would I find it? kickpanel?

When I get home tonight I am going to check my info I have regarding OHV engines and the changes of the head design. Wasn't 1995 the last year of the Aerostar? If so, your donor 4.0 would be OBD-I/EEC-IV and would have the old-style heads. It's computer would be set up for that burn, too.

 

[bates]

ok thanks!

 

[Rhett]

ok thanks!

Sorry about the delay bates. I finally found the info re: 4.0 OHV head castings. I also have block info, piston info, crank info, and more broken down by years. I think some of that was covered by Doug and others above though..

HEADS
There have been three distinctly different heads with five different casting numbers installed on the 4.0L since 1990. The combustion chamber was changed in 95 and the exhaust ports were revised in 98.

1990-94 All and 95-96 Aerostar
The original 90TM casting had an oval-shaped chamber that was slightly bigger in diameter on the intake side. It was replaced in 93 by the 93TM-AA casting that was exactly the same. These heads can be identified by the letter "T" located on the top of the right rear/left front exhaust port.

1995-97 Ranger, Explorer and 97 Aerostar
The 95TM-AD casting that came out in 95 had the heart-shaped, fast-burn chambers that shrouded the intake valves. It was replaced by the 97TM casting in 97, but it was the same, so they can be used interchangeably. These castings were used on the Ranger and Explorer from 95 through 97 and on the Aerostar in 97. They can be identified by the letter "U" that is located on the top of the right rear/left front exhaust port.

1998-2000
Ford introduced another new head in 98. The exhaust ports on the 98TM-AD were much narrower than they were on the earlier castings; they measured 1.40 across the port compared to 1.70 on the 95TM/97TM castings. According to the engineers I have talked to, the smaller ports increased the velocity of the exhaust gasses so they carried more heat down to the catalytic converter. This helped the converter "light off" sooner, so it did a better job of reducing emissions during the critical start-up and driveaway phase of the EPA emissions test. With that in mind, it's probably not a good idea to swap these heads back and forth with any of the earlier castings.


All of these heads have the letter "A" cast into the head right above the right rear/left front exhaust port.

That?s the story on all the castings and the major components. Most of the differences are specific to given years or applications or both, so they can?t be consolidated or interchanged. The only exceptions are the rods that can be used in matched sets, no matter when they were made, the 90TM cranks with the notches that can be interchanged with the 90TM/96TM cranks with the long keyway as long as the matching crank gear is used, and the various cam consolidations that are open for discussion.

 

[bates]

5) Upper intake and possibly fuel rail if your using a 98up returnless system. You can use the new injectors, don't remove them but the rail itself must be changed. Also the 96-up OHV's have a plastic spacer plate below the fuel rail and you must reuse this plate between the lower intake and fuel rail or the injectors will bind up and you'll get an vacuum leak because of the difference in height.

Don't take this the wrong way doug, but I love you. This post helped me so much, I was worried about my new motor until I remembered this post. Just wanted a little clarification on this part. My motor is all brand new so I want to use as many new parts as possible. I can use the new injectors in the old fuel rail? just as long as I change the front stud, and put the spacer in under the fuel rail? Thanks in advance

Rhett thanks for the casting info!

 

[stumpy150]

hey guys im new here but i have a 95 explorer with the 4.0 ohv engine to just blew up (overheated blew a head the blew the engine) i fiend told me that a 4.0 engine out of a 97 expoler would work what would i have to do to out it in ? any help would be appretated. would it matter if it was an SOVH or OHV?