'91 ex budget build, 4.0 or 4.0?

[Centaurious]

The head/combustion chamber got hot enough that the valve seat loosened and did the damage you see.

Did you find the missing piece of valve?

I would spread Jam on that head..... It's Toast!

It is POSSIBLE that the damage to the top of the piston also damaged/bent the connecting rod. I would measure the top of the piston to the top of the block/head surface with the piston all the way up and compare to the other undamaged pistons. I hope someone more experienced in this type of damage will chime in.

Best of luck

 

[natenkiki2004]

Pushrods & rocker arms look normal and acceptable if you want to reuse them. Just be sure to put them back in the right order.

 

[trueblue02]

UPDATE: I have gotten the engine 90% of the way to being able to be pulled, just need to unbolt the transmission, remove one AC line that it in the way, and pull the engine(unbolting motor mounts in the process). the shop crane arrived this weekend haven't had time to set it up since ive been in Oregon but going to set that up and then get the engine out on thursday hopefully.

Been thinking about modifications i can do for power/fuel economy now that the engine is out of the car and was considering headers. the stock ones are pretty rusty and it seems that they are not designed very well for flow. was thinking of getting the $280 hedman headers but people on here say that they do not add power on stock motors and its not worth the install. is this true for all years of the OHV? was hoping to find a 95/96 engine to go into the explorer, would just run off the 91 computer for now but i would have more potential for future gains by going to a 95 computer and wiring harness.

anybody have any experience with headers on a 95? i dont care if the install is tough, since the engine is coming out should be easier than in any other situation. have also, heard that a dynomax muffler from jegs will up power output, the muffler on this truck was replaced with a (quiet) flowmaster a few years ago.

 

[jd4242]

Not power or mpg gain on any ohv with headers unless other supporting mods are done like cam,head work and exhaust. .look at pacesetter, they are better but know the black paint is just shipping paint..they need to be coated..personally I would go with the jet hot coated pacesetters..nice headers and coating..they are not hard to install, personally they are easier than stock..

 

[mr cribb]

My butt-o-meter liked the headers I had in my last rig. It was 2 wheel drive with a 5 speed.

I seemed to find the power much more responsive.
Headers only:

Significant power increase? No.

Noticeable? Yes.

 

[trueblue02]

UPDATE: Ive got the new engine!

so over this memorial day weekend i finally got the original engine pulled from the ex and sitting in my garage. what a pain in the a$$! took me three evenings in a row to get it all out, what really hung me up was that i didn't know that the starter motor had to be unbolted from the transmission bell housing to let the engine come out. i was having a hell of a time getting it out as i had removed the 8 connecting bolts and the engine and tranny would not budge! after realizing that it was rather quite simple to take the engine out, just slowly working it, had to turn it sideways to fit the fan assembly out.

after that it was time to get the new engine!! so of course my roomate leaves town this weekend, just for the day i had to get the engine out as well, he even got home before i did :/

so because a pickup could not be borrowed on short notice, i had to rent a uHaul box truck. an extra $120 i wish i didn't have to spend. so i load up the uHaul and take the old engine to pick n pull with a couple of buddies. when there we find an Ex that looks to be a pretty good candidate. It had some front end damage which is what probably sent it to the junkyard, but upon inspection of the engine it was in good shape, the only thing that got damaged in the accident was the radiator fins got bent(shame too the radiator was almost brand new, one of the dual cores with a tranny cooler). the engine had clearly been maintained recently, with belts in good shape and a new alternator.

we started in on the removal of this engine and as we worked diligently(well some of us - Kyle slept the whole time) and by the end of the day we were very close, but the yard was closing soon so we rushed just a bit to get the engine out of the vehicle, bending the fan a good bit on the body of the car.

taking it home i see a few things that need work before going back into the car, first off it needs a new fan (gonna go to electric fan once this is running so i dont care if the fan clutch is not so great)

and since the Ex we pulled it from was an auto i will need a new clutch and flywheel. this is where im looking for some guidance. The engine we pulled was likely a 93-94 as it had an EGR system (my 91 did not) and upone looking through clutches i am seeing a division between some. what it looks like to me is that 91-92 had a 1" inner spline diameter, while 93+ had a 1.06" inner spline diameter. am i correct in assuming i should get a 93+ clutch for my new engine? was thinking of this one

http://www.rockauto.com/catalog/moreinfo.php?pk=2390034&cc=1119608&jnid=513&jpid=4 --Exedy from rock auto $149.79
Disc mm 254; Disc in 10; Splines Dia 1-1/16; Splines 23

and this flywheel
http://www.rockauto.com/catalog/moreinfo.php?pk=4695270&cc=1119608&jnid=512&jpid=0 --LUK $37.79

has anybody used an exedy clutch?i have one on my mustang and it has a rather short takeup, which i would like to avoid on this car, however my mustang clutch is cable and rated for much higher power. i have heard that the LUK clutches are light feeling but may not clamp hard enough for towing duties.

 

[jd4242]

Luk is stock replacement. .

 

[jd4242]

Also your gonna need to obviously swap upper intakes and exhaust manufold plus injectors and wiring..especially if its a 94..

 

[trueblue02]

The Luk clutch is only $84 from RockAuto, paying so little for such an integral part of the car seems a little dubious to me, i don't mind paying a bit more for something better than OEM either.

I kept 91's upper intake as well as the fuel injectors, do they have different wiring connectors? using the 91 wiring harness.

 

[jd4242]

If its a 94 they the wiring is different. .they use sequential injection instead of batch injection that the 91 uses..should be same injectors tho..i just normally dont separate the injectors,fuel rail and wiring from the lower so swap it all as one unit

 

[trueblue02]

UPDATE: ordered a new clutch and it came today, it's looking great and the new flywheel is really clean. Upon researching this job more I realize that I will have to replace the slave cylinder as well :/ ordering that in the morning.

One thing I noticed that is different between the two engines is where the starter mounts to the transmission. On the 91 there was a backing plate of sorts, that kept dues from getting in the bell housing. Im not seeing a plate like that on this engine, is it necessary? Does anybody know Wlehat it's technical name is? Having trouble finding info online

 

[mr cribb]

I think that's a starter shim or a dust shield.

If it ain't all boogered up I would just swap it over.

 

[trueblue02]

UPDATE: New engine is in!!

Sorry for not updating in a while but its finals week and ive been on a real crunch to get this project done before my lease ends on the 14th

I put on the clutch and flywheel, found a backing plate for them at the junkyard that fit with a little bit of hammering, and started work on putting the engine back in. ###### what a pain. getting the engine and transmission to line up was an effort in patience and took quite a few late nights staying up till 1-2 working on it. when i finally torqued that last bolt down it felt like 4.0 liters of weight had been lifted from my shoulders

after that i managed to get the starter on and the headers done today, and took the fan off. had to remove the entire water pump to get the fan off due to the way we had removed it, then pick up a few bolts at the hardware store for the new fan blade. Something that was mildly concerning was that the water pump and thermostat were gunked up with what looked like coolant(the orange kind) and dirt. thinking of filling the system with water then flushing it after a few days.

now im putting the accessories back on and just about to run to oriellies for oil and tranny fluid. What kind of fluid do you guys run? ive got a quart of redline D4 ATF (mercon V replacement) from when i changed the fluid on my 'stang, thinking of just going with that so i can get the most life out of the tranny before its untimely death (hopefully not till next year lol).

has anybody who has done an engine swap before have any tips for starting it? i should be able to start cranking tomorrow night if i get all the parts (need a gasket and fuel line fitting)

 

[mr cribb]

My favorite mix of fluid is ford spec dextron, and a quart of Lucas trans fix. I think it comes down to 2qts of dex and 1 qt Lucas. I think it is 2.25 qts total.

The way I filled mine, and this IS the easiest way.

1) remove 3 shifter bolts (t25 torx I think) and fill plug 1 1/8 inch or large crescent wrench.
2) place drain pan under the plug area.
3) fill with Lucas first, the rest with dextron.
4) stop when fluid runs out of the fill plug into the drain pan.

Reinstall fill plug and shifter.

Be sure shifter is in neutral before you remove it, otherwise it is a royal beeoch to reinstall the shifter.

 

[xplorernewb]

just saw this thread and honestly i had no idea there was that much of a difference in motors, so i have to ask if you dont mind, is there a difference between the 91 and the 93 4.0? i have a 93 ex with a 91 motor and found out that some of the pulleys were different, so now im curious what else is different.

 

[mr cribb]

just saw this thread and honestly i had no idea there was that much of a difference in motors, so i have to ask if you dont mind, is there a difference between the 91 and the 93 4.0? i have a 93 ex with a 91 motor and found out that some of the pulleys were different, so now im curious what else is different.

The early 93 has two oxygen sensors, and possibly egr depending on month of build. 91 and 92 model engine has one oxygen sensor. Late 93 and 94 has two oxygen sensors, egr, and dpfe sensor.

 

[trueblue02]

just saw this thread and honestly i had no idea there was that much of a difference in motors, so i have to ask if you dont mind, is there a difference between the 91 and the 93 4.0? i have a 93 ex with a 91 motor and found out that some of the pulleys were different, so now im curious what else is different.

I found it easier to go 93 into 91 because i kept the 91 wiring. the belt looping and tensioner are also different i believe

 

[xplorernewb]

The early 93 has two oxygen sensors, and possibly egr depending on month of build. 91 and 92 model engine has one oxygen sensor. Late 93 and 94 has two oxygen sensors, egr, and dpfe sensor.

oh i see. so what would it take to swap a 91 into a 93? im even more curious now to find out if who ever installed this engine did it completely. possibly pick up a 93 and revert it back to original. although the 95 conversion seems it could be a little more fun. the current engine has always ran kinda lopey, like it has a cam in it but not sure if thats due to age or not, or if it has something to do with the A/F mix because as far as i know, its stock

 

[trueblue02]

FINAL UPDATE: All finished!!

i got the exploder running a few days before my lease ended, after a couple of parts runs and three days straight of car work. with everything bolted together and all the intake and wiring done i crossed my fingers and gave it a crank.

Started on the first try!! then quickly stalled :/ a couple more attempts and it was purrring like a sickly kitten, almost sounded cammed. I was able to drive around town a bit like this to test everything out, and i had not problems besides the rough idle and occasional stall. went to a shop that did smog to schedule an appointment and they told me to check for vacuum leaks, and it turns out i was missing a PCV valve. replaced that and i was good to go!!

My Ex doing some explorations of campus http://imgur.com/a/v7zSX and engine pic minus intake

its been running great for the past 1000 miles, went up to Yosemite National Park (about 450 miles round trip from my home) last weekend and it did great in the altitude, and fit all 5 of us with our gear no issue, and had plenty of clearance for the dirt road leading to the campsite (about 5 miles of potholed, rutted and washed out road descending 1500 ft or so)

overall im loving the car, and getting way better mileage than i could in my mustang (21 mpg in Yosemite). bonus waterfall pic! www.imgur.com/zuMDbkl

 

[xplorernewb]

or would i just have to swap computers? maybe a dumb question