I know I know,
GO WITH THE LSx motor. I really had planned to do that. 2 things made me decide to go with the 5.0 Ford.

1. I just landed a low low mileage drivetrain out of a 92 mustang for next to nothing VS the 3 grand or so for the LSx drivetrain. So right out of the box, I am 2800 bucks ahead before I even start. That is a good amount for power, suspension or brake upgrades.

2. As the previous owner of around a dozen mustangs, including 5 different 5.0s I have a lot more experience with the motor. I know it is less power than the chevy and all, but with some tweaking you can get really good power out of them, and they are TOUGH. I saw a 90 Mustang GT once that had been stolen, and the Douche Nozzle that stole it actually poured sand into the crank case. Trying to destroy it. Thing still started and ran like a champ. I am well aware of the horsepower advantage of the Chevy engine, but with a cam and twisted wedge heads I am reasonably sure I can push it close to 300 ponies. Thats a lot for a car that came with about 100. And in a car this light it will still be a real performer.

So that being said, I have a few questions and would like some guidance.

Currently my RX7 is an automatic. I am torn as to swap it to a manual or leave it auto. The mustang drive train is automatic, but I know I can get a mustang 5 speed for a few hundred dollars. My fear has more to do with adding clutch pedals and messing with the RX7 wiring harness... Any thoughts? I have never had an auto in a sports car before. I always thought of it as herecy to have a performance car with an auto. However, as I get a bit older, and have a wife who might like to drive it once in a while and hates sticks, I am tempted to leave it automatic...

I am tempted to upgrade brakes as I go, and possibly change the lug pattern to something I can get some better wheels for... Any suggestions there?

The rotory in the car runs, but poorly. NO power at all. Rough idle. It was carbon locked, and I was able to break it loose. But I suspect apex failure or a really messed up carb. Should I part the motor out or attempt to sell it as a unit?

And finally, any of you who know about doing this, or have done it yourself, any tips? Any lessons you have learned that could save me grief? Anything you wish you would have done differently?

One really cool thing is that it is old enough to be exempt from emissions requirements so I can ditch the cats and the air pump.

 

A stock Mustang GT 5.0 can make around 400 hp with the stock roller cam with just heads, roller rockers an intake and a carburetor. The 5.0 is a great choice. The 5.0 weighs close to the same as the LS engine once you go with aluminum heads and trim unneeded stuff (smog pump, P/S, etc...).

I would do an automatic were I doing this swap. A full manual shift auto will rock your world as long as you use the right torque converter. all the control of a stick and all the benefits of an automatic. Even your wife can drive this kind of "auto" since no clutch peddle is involved.

 

Personally I like the sound of the ford motor over the chevy LS... Sounds waaay meaner. But that is just my opinion. And with the plethora of aftermarket parts you should be able to put down WAY more than 300hp with that motor.

If you consider the 5spd swap, there are several "how to's" on here about doing a 5spd swap and you should be able to follow them fairly closely only interchanging applicable items.

As for the motor, it would be much simpler to compression test it and then sell it as is with the compression numbers. Search this board for writeups on how to do this with the motor out of the car. You can look through the exhaust ports with a flashlight as you turn the engine to see if you can see a broken apex seal. Also, just turning the motor by hand if you hear three even "chugs" from each hole that is a good sign. OR if the "chugs" are uneven that of course is usually indicative of a bad seal.

Good luck with the build!

 

Hey, bud.
Doing a 5.0 in my '87 GXL also.
Just wanted to say hi and let you know I'd be glad to be of any help I can.
Not that I have all the answers by any means, but here to help.

Cheers.
Phill
'87 GXL
-rotary
+5.0 / T5
Not Fired Quite yet, but in place

 

I appreciate it. Hopefully I can learn from your experience. Hope you don't mind my sponging off of your experience.

 

cant wait to see vids and pics, thats what i want

 

pm'd