New toy: 4.0 OHV supercharged

[monsterchuck]

Hello, new guy here. Came looking for help and info on a new project I just got a hold of. While out cutting wood one day at one of my dads friends-friends house, we were in his pole-barn and I spotted a motor in the corner with a pretty looking little blower bolted on top. I walked over, looked at it, talked about it, and long story short, I'm the proud owner of a 4.0 liter OHV supercharged. It's not a SOHC, but an OHV. One of the paper tags on it, dated June 6th, 1996, says "Owner: FoMoCo". I'm probably going to tear it apart and check everything out, but I think I have an experimental/mule engine on my hands here. I have yet to decide what specific truck it's going in, (definitly manual trans and 4x4) but I'm looking. I'm probably going to me mostly asking about tuning and such here. I work as a tech at a Ford dealer, so the nuts and bolts part will be easy for me. So I thought I'd warn you guys, I'm going to drag myself through a pit of despair on this one, and I'm going to put all of it here.

 

[Downey]

sweeet take some pictures of the damn thing so we can see it

 

[monsterchuck]

I'm working on it, trust me. Still a little exited about it

 

[monsterchuck]

Alright, I have a block part number I cannot quite identify. It's 90TM-6015-AB. According to every decoder I can find, the first digit should be a letter, not a number. But every part on this thing, the oil pan, oil filter adapter, heads, freaking everything with a legible part number starts with that same prefix, 90TM. If I just assume the first two are the year, 1990, that would make sense, I guess, being that the second digit is to indicate the year within the decade of the first digit. After that, T is for light truck, M is for Performance/SVO, 6015 is the base part number for the block, and AB is whatever. So am I safe in assuming what I have here is not your every day 4.0?

 

[Will]

Alright, I have a block part number I cannot quite identify. It's 90TM-6015-AB. According to every decoder I can find, the first digit should be a letter, not a number. But every part on this thing, the oil pan, oil filter adapter, heads, freaking everything with a legible part number starts with that same prefix, 90TM. If I just assume the first two are the year, 1990, that would make sense, I guess, being that the second digit is to indicate the year within the decade of the first digit. After that, T is for light truck, M is for Performance/SVO, 6015 is the base part number for the block, and AB is whatever. So am I safe in assuming what I have here is not your every day 4.0?

You're seeing the casting number, not the part number. This is from the tech library here:

BLOCKS
There have been three blocks used for the 4.0L. Each one is unique in some way, so none of them can be interchanged.

1990-’94
The first 4.0L block was a 90TM-AB casting. It had six bolt holes on the passenger side and 10 bolt holes on the driver’s side. The dipstick hole measured about 0.380˝ in diameter.

1995-’96
The original block was changed in ’95. The new 95TM-AB casting had two more bolt holes on the passenger side and two more on the driver’s side for a total of eight on the right and 12 on the left (see photos above). The dipstick hole remained the same at 0.380˝.

1997-2000
The block was redesigned again in ’97 to reduce noise, vibration and harshness (NVH). Both of the pan rails on the 97TM-AA casting were wider and there were two more gussets added between the pan rail and the horizontal rib that’s right above it on the passenger side. The dipstick hole on this block was enlarged to about 0.435˝, too.

 

[Downey]

sounds like some cool stuff but idk what to tell you about the part numbers. i want to see pics might help tell what it is if someone knows what it is. are you sure its not a 3.8 out of a super coupe

 

[monsterchuck]

Well, I've been scouring the internet, including here, for the past few days looking for info. I found the tech article Will is talking about, under the rebuilding section. Never thought to look there(my own ignorance), but anyway, yes I am very sure that it is a 4.0, not a 3.8. If I can ever get a functional camera, I'll get some pics, but this motor is way too small to be a 3.8. It has an M-62 that appears to be the same as used on the series 1 3800 supercharged Buick engines. In the rebuilding article, I didn't see anything about the actual indentification number, or anything I can use to trace this engines origins. I found some other numbers on the other side of the block, but I don't know where I'd look to decode them, or if they even mean anything. One of the numbers, on the left-hand side of the block, towards the bellhousing, is "24F91", and I'm guessing this is a date of manufacture, February 24th, 1991, which would coincide with the rebuilding articles explanation of casting numbers. The other is a series of numbers arranged in a circle, "178911112345". I have no idea if that means anything or not. Is there any other ID number on this block I could look for? I appreciate the help.

 

[Fx4wannabe01]

Hello, new guy here. Came looking for help and info on a new project I just got a hold of. While out cutting wood one day at one of my dads friends-friends house, we were in his pole-barn and I spotted a motor in the corner with a pretty looking little blower bolted on top. I walked over, looked at it, talked about it, and long story short, I'm the proud owner of a 4.0 liter OHV supercharged. It's not a SOHC, but an OHV. One of the paper tags on it, dated June 6th, 1996, says "Owner: FoMoCo". I'm probably going to tear it apart and check everything out, but I think I have an experimental/mule engine on my hands here. I have yet to decide what specific truck it's going in, (definitly manual trans and 4x4) but I'm looking. I'm probably going to me mostly asking about tuning and such here. I work as a tech at a Ford dealer, so the nuts and bolts part will be easy for me. So I thought I'd warn you guys, I'm going to drag myself through a pit of despair on this one, and I'm going to put all of it here.

It very well could be an experimental/mule......same sorta thing has been reported about the new "Boss" 6.2L test mules. TONS of pics of them and on the valley pan tray, it even says "the boss is back" molded/embossed into it. Would be interesting to find out about this engine you've got.

 

[Will]

This is a 4.0 from a '91 Ranger. There's not much more to know about your engine. I'm not sure exactly what you are trying to discover. There was a kit, made by BBK that added the same supercharger you are seeing. I believe BBK claimed 220hp and 300ft#. This may be what you have, though maybe someone else made one, or it was fabbed by someone. The only other kit I know about was a centrifugal blower made by Vortech.

 

[monsterchuck]

Well, Will, it does look fairly similar to the pictures/video's I pulled up of the BBK unit, but I see several differences. My setup has a dedicated supercharger belt drive, the BBK unit looked to be using one serpentine belt. Also, the tube that the throttle body bolts to comes around 180° on mine, and only 120° or so on the BBK. Even further, the wiring harnesses are not set up like I'd expect them to be. There are the connectors for hooking the engine harness to the main harness, but there are two connectors with about 4-5 feet of extra length to them, labeled "left" and "right" coming out of the back of where the injector harnesses are. At any rate, you are likely right that this is a completely fabbed-up unit, but one of the old paper tags(from an auction, I can only assume) on it says that the engine was, at one time at least, owned by FoMoCo in it's supercharged form. The main reason I want to know if there is anything special about this engine is I'm going to have to tune it eventually, and I need to know if there is anything special about the internals. I didn't get a PCM to work with, and I will probably end up having to change wiring harnesses. Granted, it's much easier if it's just a basic 4.0 OHV, that some race-shop put a supercharger on, but suddenly the cool factor starts dropping off if it's not a Ford experimental mule engine. Now, if I wanted a fast as all get-out Ranger, I'd be messing with one of my 460s, not a little 4.0 V6. Cool factor is kind of important here. I'm not looking for speed, I have a supercharged Fiero to take care of that. I could tear the whole engine down, measure, check, and gauge everything, but if I can get some definitive info as to what it is(appears to be just a basic 4.0), it will save me a lot of time and money.

 

[Dweano]

That would make my year finding that, possibly life

 

[monsterchuck]

Oh, your not kidding. I was jumping up and down for most of the day. Now I just need to find a patient worthy of a transplant.

 

[Angie]

Nice find, however i have to question your knowledge and fact finding when you made this comment then want to know about 90TM blocks....

"I work as a tech at a Ford dealer,"

Somehow I have to say that of all the people in here you should be able to get your hands on ALL information about ford motors from where you work... if we in here were only that lucky.... still a nice score thou.... and what I would do is find a truck that already has a blown up 4.0 in it to drop that motor into.. for it should make life easier ... and find a older one that matches that motor... OBD1 vrs. obd2.... but you should know this being a "ford tech"

 

[monsterchuck]

Well, you are right in that I am a Ford tech. I have nothing to do with our parts department. I did ask them though, to see what I could find. The 90TM number didn't even show up in their computer system. I even had them look for the part number to a 4.0 of that year range of 90-94, and they gave me a completely different part number. I asked if there were any other forms of engine ID I could give them, but they basically told me that they have no means of identifying this engines origins. I looked for different placed for ID numbers through my account at FMCdealer.com, but the only engine ID locations it shows is the sticker on the core support, and it says there is a tag on the engine, but I can't find one. As a tech, I don't have access to the parts sections, or any other sections for that matter other than diagnosis and repair through the PTS site and OASIS. I can look at any repair manual I want back through 1991, but that doesn't tell me interchanges, identification, ect. Also, I mostly work on the newer stuff. 90% of what comes in is 2000 and up. We're primarily a heavy truck dealer, and the smallest trucks that regularly come around are F-150s. We do get Rangers, Escapes, some cars, ect, so I rarely see anything that gives me much experience in the Ranger department. That's why I came here. I sought assistance from those more experienced than I, in hopes that I may also lend some of my experience to them. Now, I don't claim to be any kind of super-certified-in-everything-master tech. In fact, I think I'm quite the dumbass, and have much learning to do. Some of you here seem to be on-board with what I am doing here, and some seem to be showing distaste, even light hostility for me claiming to be a "ford tech". If I'm not welcome here, please inform me, I'll pack up and leave.

 

[Downey]

still no pics of this motor come on man im dieing here to see this motor