SC Engine Compatibility

IAMBJC

Registered User
Good Evening everybody,

I have a 1989 SC with a blown engine. A friend of mine has a 1991 SC with a blown tranny. He is going to give me his 1991 for the engine (I want the 89 instead of the 91). My question is if there is anything I need to worry about when swapping out my 89 engine for the 91 engine, and if it is even possible to replace my 89 engine with his 91 engine.

I have never done this before so ANY and ALL information you can provide would be GREATLY appreciated.

1) Is it possible to replace the 1989 engine with the 1991 engine?
2) What is different between the two if anything?
3) Is there anything in particular I need to be careful about when doing this?
4) Are the sensors, computers, etc., the same or do I need to pirate from one engine/car to the other?

Please send me e-mail if you don't mind answering my questions. My e-mail is IAMBJC@Hotmail.com

Thank you for your time.
 
Swap

I did the same swap 6 years ago and this is what I remember:

You'll need to use the engine harness from the '89 because the '91 harness main plug is different and there may be no connector/wiring for the PFE sensor for the EGR valve.

If both have the same trans, no problem though you might want to replace the pilot bearing for the M5R2, if applicable and you'll have to pull the bearing if the donor engine is from a manual car and yours is an auto. (Don't ask how I figured that one out!).

The '91 may not have an EGR valve, if not, use the one from the '89. Be careful not to break the tube! Get a new piece of silicone hose for the EGR tube to PFE connection (don't get it from Ford!)

Replace your motor mounts as it won't get any easier than at this time. Same goes for the plugs, heater hoses....

Other than that, just take your time, keeps parts and fasteners organized and perhaps take some reference photos or video if you have the equipment before you take yours out.

You should be able to do it over a weekend w/o any rush, good luck!
 
Last edited:
Good tip with the motor mounts.
Might also be a good time to examine the power steering line that runs under the engine between the frame to see if the engine has worn a flat spot on it. (If it has, good time to replace it.)
How many miles on the '91?
 
Engine Compatibility

Thanks, guys, for the tips. As I said before, (although I'm no idiot when it comes to working on cars) I've never done anything remotely close to an engine swap so your tips are WAAAAYY greatly appreciated. As far as the 91 goes, I have no idea how many miles are on it. I will be towing it home this weekend. Once I switch out the engines I'll be parting the rest out (with the possible exception of the interior, may want to swap that out as well with my 89's) so keep your eyes peeled if you are interested in anything.

All I know at the present time is that it is a 91, good engine, blown tranny, medium to dark blue with leather interior (not sure what color the interior is but I believe it is blue as well).

I have a couple other questions, though.

1) I read some time ago on this site that the blowers on the 89 and 91 are different (although I can't remember how--output or boost or something). Is this true? If so, will I need to replace the intake manifold and blower on the 91's donor engine with my 89's to keep the 89's computer happy or is it a non-issue?

2) My 89 is silver with red cloth interior and red NASCAR trim (like a pace car). I bought it used from another dude and don't know much about the history of it. Is this some sort of special edition car, rare, or anything like that? Or, was it probably done by the previous owner? It's very tastefully done and I really like the way it looks but I'm just curious as I have not seen any other SC on this or any other site that has that kind of trim. The red pinstriping is toward the bottom near the ground effects and the red NASCAR text is just in front of the rear wheels. Once I'm done with the car I'll post pics (AND, of course, become a member of this club).

Thanks again (MILLIONS) for your help. Anybody else care to chime in with additional pointers? EVERY tip and piece of help is GREATLY appreciated.

I will HOPEFULLY begin this project this weekend. THANK GOD for you guys out there! If I run into any snafus I'll be looking for ya!
 
Last edited:
The blowers are the same. The blower change occured for the 1994 model.

One thing you might want to consider is also changing the rear main seal while the motor is out. The intake manifold is the same for all SC's, new blower or old.

There is a myth out there about the new blower requiring a different manifold. I think this might stem from a misprint in an old Superford Magazine; they had an article on the SC and were making the point that the new style blower does require a different inlet adapter (the elbow from the throttle body to the back of the blower) Unfortunately they printed a picture of the lower intake manifold next to the quote on the blower inlet.

FYI the 1989 also had a slightly different cam profile. It might make more power, but I doubt it would make enough of a difference to really feel. Definitely not worth tearing into a running engine to change it.
 
Back
Top