SOHC broken timing chain questions, OHV swap reasonable?

[Mbrooks420]

My wife's uncle recently purchased a 97 sohc with 120k. He had a first gen he loved, and I told him he had to get the V8. Of course, he goes out and buys the second Ex he looks at. Its a SOHC, and of course has the death rattle. Don't know if the private owner had shown it warm, but it rattled since day one. Instead of calling asking what the death rattle was, he adds marvel mystery oil and drives it. Any idea's where this is going? Well, within a week it quits running.

He said he got on it a bit and it quit. He said he thought he broke a chain "or something" He was thinking that it only had a front chain, and it could be done by pulling the rad. He didn't like hearing the motor came out and was probably going to be a real PITA.

So the main question, I found in my searching here the SOHC is an interference motor. If the chain did break are the valves bent for sure? He said the oil was full of sludge so the stock motor is prob in poor shape.

Is a OHV swap much more involved than swapping motors, and computer(s)?
Would it be tougher than yanking and repairing the failed SOHC in there? Sorry it was so long, but I could use some help. I assume I will be getting roped into fixing this.

 

[vroomzoomboom]

i just went through this. if the chain drops, the valves will make sweet love to the pistons. no not fun. changing to a ohv, you would almost have to replace everything, trains, wire harness, motor mounts, basically from the firewall forward. however, if you have some skills, you can rip a sohc out in about 6-8 hours. here is a very good like that i used, and all things considered, it went well.

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

 

[Mbrooks420]

Boo. Wish I could wash my hands of this. Looks like yanking the scrap engine, getting a junker SOHC and then replacing the defective stuff inside and reinstalling.

 

[Mbrooks420]

Bump, anyone else have other words of wisdom before I break the bad news?

 

[Moto Mel]

Boo. Wish I could wash my hands of this. Looks like yanking the scrap engine, getting a junker SOHC and then replacing the defective stuff inside and reinstalling.

To save some time and aggravation I would go to the nearest pick-n-pull and use the metal block plate from a 4.6 or 5.0 against the 4.0 SOHC., I know that the 4.6 bolt pattern is the same as the 3.8. the trans will almost certainly be able to take the difference in power as long as it is not abused too much. You will need the engine wiring harness and the cpu for the power plant that you select.

 

[Mbrooks420]

What aggravation would a 4.6 or 5.0 block plate save me?

 

[MrQ]

I told him he had to get the V8.

I think this is what he was referencing.

 

[Glen4X4]

I remember when searching to do the opposite to replace my OHV in my 96 to SOHC and read that it was pretty much bolt in and that I could use my OHV computer for it except fer some wire on the SOHC so that being said I think that the OHV is possible with little changes being made.

 

[Mbrooks420]

I don't see how the same computer could work. The motors would have to have different shift points, fuel trims, and such.

 

[Moto Mel]

What aggravation would a 4.6 or 5.0 block plate save me?

The block plate is the metal piece that goes between the engine and trans and is a lot lighter to carry around to match up engine and trans bolt patterns. If you know for certain that the engine will fit up to the trans, you won't need the block plate. If you don't know and find out that there is a mismatch when you have every thing ready to go in you will be very disappointed to say the least.

Mel

 

[Mbrooks420]

Ahh, I get it. No v8 will bolt up to the v6 transmission. The v6 trans doesn't hold up to v6 power, so a v8 would destroy it. Was interested in a an SOHC v6 to OHV v6 swap.

 

[2000StreetRod]

Find out what's broken

Before I would buy another engine and swap it out I would try to find out what's broken. It could be only that the chain has slipped and the timing is so far off the engine will no longer run. You may not have any bent valves or damaged pistons. It seems like so many people are too anxious to replace things these days without first determining what's broken.

I would pull the spark plugs and the valve covers and carefully turn the engine over by hand a few degrees and see if the cams still rotate. If they do then I would check the timing to see if one or both cams are out of time. If both are out then the lower crank to jacksaft chain has slipped. Do not rotate the crankshaft counterclockwise because the chain can slip more in that direction. Do not force the crankshaft clockwise against any obstruction because it could be a piston striking a valve.

 

[Glen4X4]

I'm searchin for the thread I read about it so you can see. If you have access to getting the Engine computer from the same year I'd just use it to ensure an easier swap.

 

[renegadepig]

just a side note on my attempt at a 4.0 sohc to 4.0 ohv swap in a 98. I had everything together and was ready for a start andran into PATS issues right off the bat...O.K so I go the library and look for the mitchells wiring diagrams for both the X's and find that the wiring from the ECU is diffrent in the body controls between the 2 X's so basically to make the swap work, I would have to taken the wiring harness out of the OHV X and retrofitted it into the SOHC X which would have been an incredible amount of work...
All I wanted was to use the better body from the SOHC X with the bad timing chain and good trans and the good OHV motor out of the other X with the bad trans and rattier body... Oh well, I am going to just put all the stuff back into the OHV X and move on. I agree W/ 2000 street as to checking the SOHC motor first but the motor was in very poor shape in the one I had.
Dave

 

[Glen4X4]

Mbrooks, did you ever do the swap or did you just stick with the SOHC?

 

[Mbrooks420]

Not sure what was done (it was my wife's uncles truck, not mine) he never called for more info, or asked for help. He had found a replacement, and he's now driving it, so he must have swapped in another SOHC or repaired the one that was in there.

 

[Glen4X4]

Alright, thanks

 

[Moto Mel]

Ahh, I get it. No v8 will bolt up to the v6 transmission. The v6 trans doesn't hold up to v6 power, so a v8 would destroy it. Was interested in a an SOHC v6 to OHV v6 swap.

I know it's an old thread but I want to make something clear to the readers here.

I am running a trans that originally came out of a 3.8 L. Cougar in my '94 Lincoln Mark VIII, 4.6 V8 DOHC. It FITS perfectly, I've been running it for more than 3 years now with no problems. My suggestion was for getting rid of the front/rear cam chain design engines and using an engine that has fewer problems. A V8. If you doubt what I say you may come to my home and read the numbers on my trans and then check it out. I'll even take you for a short ride.

 

[Mbrooks420]

What you are running in your 94 Lincoln isn't anything like an obdII 4x4 1997 Second Gen X.If I wanted a major swap in I would have done the 5.0 4r70w swap. I just figured if I could swap the SOHC for the OHV with just the motor and computer it would be worth it.

 

[2000StreetRod]

Mk VIII trans

Your Lincoln MK VIII came with the 4R70W transmission. In 1994 Mercury Cougar switched from the AOD transmission to the 4R70W for the 3.8L V6. The 3.8L V6 was produced in the Essex plant and the 4.0L V6 was produced in the Cologne plant. The blocks are different. All of the Explorer V6 engines (OHV and SOHC) use the Cologne block. The Explorer V8s use the 4R70W transmission. That's why you can't bolt an Explorer V6 transmission to an Explorer V8 engine.