Byron Ward wrote:

Hi Paul,

I just bought an '84 RX-7 at auction for $60 :) It was in an accident so
it was driving before it got to the impound yard, and I managed to
break the ignition and start it (no key) so I know it runs. 126,000
miles. This is the 12A engine, right? 

I think so. I am not sure. Look on top of the rotor housing just above
the top spark plug. Either 12A will be there or 13B.

Is it suitable for a one-rotor
conversion? I need 70 hp minimum, preferably 80 hp. 

You will need to wind it to 7000 RPM or so and port it.

Also it would need to be light (under 200 lbs I think). 

You need to pay close attention to the weight of the accessories. 
Particularly the PSRU. You might also look into getting the front
and rear housings chemically machined or acid dipped. Also if it
is a manual transmission you will need an auto tx flex plate. Think about
hand proping it to start it. I don't know of anybody that has done that yet.
EFI would help.

You mentioned to me before that I might
get 70-80 hp turbocharged and direct drive. Do you think this is possible
with this engine? 

Yes but I don't think you can get a low compression rotor for a 12A
so only modest turbo boost like 5 psi would be advisable. I think you would
have trouble getting 70 HP at only 3000 RPM with only a 5 psi boost.

Would it be better to leave the carb, or switch to EFI?

EFI by all means. The stock four barrel would be unsuitable for
a one rotor. 

Also is there anything else I can do to check the condition of the engine
without pulling it? 

Best thing is take out one of the spark plugs from each rotor.
Get a low cost compression tester and take out the schrader valve.
Check for uniform pressure pulses at least four or five in a row from
each rotor as you turn the engine over with the starter. One pulse per rotor
per rev of course. The needle should bounce up to the same 60 or 100 psi
as the engine rotates. If you get a weak bounce every now and then you
have one or more stuck or bad seals.

Also do you know if anyone makes replacement sheet
metal for this car? It was hit in the rear wheel and I would like to put a
new rear axle on it and drive it for a while but underneath the car is
pretty rusted and there is nothing left to attach the rear suspension to.

Thanks,

Byron

Usually what they do is cut the car in half and weld on  a good rear half from
the junk yard. It takes a lot of work and lots of tools are required
to do this. The car is not worth that amount of labor probably.
I would save the engine, engine accessories and fuel pump from 
the tank and junk the rest. Don't forget the instrument panel.
Perry has a stock RX7 instrument panel in his airplane.

You could also look for an RX7 with a good body but bad engine and
swap parts if this engine is good. BTW don't forget to check for
a thermostat in this engine.
 
Paul Lamar
 
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