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Old 06-13-14, 08:21 AM
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motor swap

How hard is it to replace my seized motor with a good one? How long will it take and what should I look for while doing it? I got a 79 sa22c and im putting an 85 gsl 12a rotary in it!?
Old 06-13-14, 12:21 PM
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the best answer you will get is ... it depends.

who's doing the work?
how much experience do they have?
do they have basic tools and a means to physically get the engine out?
do you have a shop manual?

for an inexperienced, first-timer, it shouldn't take more than an honest-to-goodness weekend - i figure take your time unplug, label, drain and CLEAN the bay.

for someone with experience, it can all be done in a day.
Old 06-13-14, 01:13 PM
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Originally Posted by diabolical1
the best answer you will get is ... it depends.

who's doing the work?
how much experience do they have?
do they have basic tools and a means to physically get the engine out?
do you have a shop manual?

for an inexperienced, first-timer, it shouldn't take more than an honest-to-goodness weekend - i figure take your time unplug, label, drain and CLEAN the bay.

for someone with experience, it can all be done in a day.
OK well I'm doing it my self I've really never pulled a motor but I do got the basic tools. I'm trying to just have the motor running so I can get this new job
Old 06-13-14, 09:34 PM
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How hard and how long would it take to replace the back end of a 79 sa22c with an 85 gsl? So I can have rear disk brakes!? I got all weekend to get the car running first then upgrades ? I have the main parts the big parts already they came out of the 85 gsl I even have the tranny too
Old 06-13-14, 09:42 PM
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An easy install but you need to flare the main brake hard line since thread pitch has changed in 81. Also, you need the ebrake cable from the gsl.
Old 06-15-14, 07:48 PM
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So I got the motor pulled apart and about to pull it out when I started to ask my self how does the vacuum lines hook up to the carb when I got bother motors they was already off...
Old 06-16-14, 03:20 PM
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Since the donor engine is a 1985 and the original is a 1979, you need to use the emissions/vacuum lines (ofter referred to as the rats nest) from the 1979. It's a little late now, but the best way to take the emissions off is as a unit by removing the intake manifold, carb, and emission as one piece. There are 4 bolts and two nuts that hold the intake manifold onto the engine. There are also a couple of bolts that hold the rats nest to the top of the engine. by removing these, you can take it off as a unit.

If you have already torn in to this and need to know where everything goes, download the Factory Service Manual Foxed.ca - Mazda RX-7 Manuals . There are pictures that show where everything goes. Another good reference are detailed engine pictures.

You will need the use the flywheel/clutch from the 1985 engine but the trans from the 1979. The 1979 has a different shifter location. The rule is that you have to use the flywheel that corresponds to the rotating assembley of your engine. A good reference is MadzdaTrix. This is because the weight of the rotating assembly is different between 1979 and 1985.

Last edited by KansasCityREPU; 06-16-14 at 03:22 PM.
Old 06-16-14, 05:43 PM
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Originally Posted by KansasCityREPU
Since the donor engine is a 1985 and the original is a 1979, you need to use the emissions/vacuum lines (ofter referred to as the rats nest) from the 1979. It's a little late now, but the best way to take the emissions off is as a unit by removing the intake manifold, carb, and emission as one piece. There are 4 bolts and two nuts that hold the intake manifold onto the engine. There are also a couple of bolts that hold the rats nest to the top of the engine. by removing these, you can take it off as a unit.

If you have already torn in to this and need to know where everything goes, download the Factory Service Manual Foxed.ca - Mazda RX-7 Manuals . There are pictures that show where everything goes. Another good reference are detailed engine pictures.

You will need the use the flywheel/clutch from the 1985 engine but the trans from the 1979. The 1979 has a different shifter location. The rule is that you have to use the flywheel that corresponds to the rotating assembley of your engine. A good reference is MadzdaTrix. This is because the weight of the rotating assembly is different between 1979 and 1985.
So can I use the 79 tranny or should I use the 85 tranny
Old 06-16-14, 06:48 PM
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You'll want to use the 1979 trans, otherwise you'll either have to shorten the trans linkage and tailshaft of the 1985 or cut a hole in the trans tunnel. If you cut the hole, the shifter will hit the rear of the center console. The easiest solution is to keep the 1979 trans if it's good. The 1984/1985 is about 5 inches longer.
Old 06-16-14, 07:12 PM
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Originally Posted by KansasCityREPU
You'll want to use the 1979 trans, otherwise you'll either have to shorten the trans linkage and tailshaft of the 1985 or cut a hole in the trans tunnel. If you cut the hole, the shifter will hit the rear of the center console. The easiest solution is to keep the 1979 trans if it's good. The 1984/1985 is about 5 inches longer.
Ku well the 79 trans is rebuilt and still strong! Now let's me ask this how about fuel lines how r they hosed to the motor?
Old 06-17-14, 10:07 PM
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Originally Posted by elhartd
Ku well the 79 trans is rebuilt and still strong! Now let's me ask this how about fuel lines how r they hosed to the motor?
There is a supply and a return.

You really need to download the Factory Service Manual. They don't have the 1979 posted, but the 1980 is really close to what you have.

page 4:1 of this document shows the fuel line connections at the carb.

http://www.foxed.ca/rx7manual/manual..._Inlet_Exh.pdf
Old 06-23-14, 01:37 PM
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Do I need to use the fuel cut off valve? I have swapped out new lines and new fuel filter and pump!
Old 06-23-14, 02:01 PM
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why would you disable/remove it?
Old 06-23-14, 02:07 PM
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Originally Posted by diabolical1
why would you disable/remove it?
There has been sugar in the lines so I'm putting 3/8 lines in and a new pump! What does it do?
Old 06-23-14, 03:22 PM
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if you're referring to what i think you are, then it's there to offer some protection in case you're unfortunate enough to get the car belly up.

are you speaking of this? https://www.rx7club.com/1st-generati...fuel-cut-valve[s]-w-pics-896479/
Old 06-26-14, 02:45 PM
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Originally Posted by KansasCityREPU
Since the donor engine is a 1985 and the original is a 1979, you need to use the emissions/vacuum lines (ofter referred to as the rats nest) from the 1979. It's a little late now, but the best way to take the emissions off is as a unit by removing the intake manifold, carb, and emission as one piece. There are 4 bolts and two nuts that hold the intake manifold onto the engine. There are also a couple of bolts that hold the rats nest to the top of the engine. by removing these, you can take it off as a unit.

If you have already torn in to this and need to know where everything goes, download the Factory Service Manual Foxed.ca - Mazda RX-7 Manuals . There are pictures that show where everything goes. Another good reference are detailed engine pictures.

You will need the use the flywheel/clutch from the 1985 engine but the trans from the 1979. The 1979 has a different shifter location. The rule is that you have to use the flywheel that corresponds to the rotating assembley of your engine. A good reference is MadzdaTrix. This is because the weight of the rotating assembly is different between 1979 and 1985.
Is there any other way to figure out how to hose up the rats nest?
Old 06-28-14, 10:59 AM
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So I have both of the rats nests off the 85 gsl motor and the 79 motor. witch one should I use ? The 85 gal rats nest is more put together and the 79 is tore apart! If I should use the 79 rats nest how does it hook up?

motor swap-forumrunner_20140628_095406.jpg
Old 08-23-14, 08:39 AM
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Alright everyone I'm almost done with my car! This be my new problems!.. I have the 85 rx7 motor in the 79 body ! I also have the 79 wiring harrness and I'm wondering how I hook up the wiring to the 85 motor? And how too hook up the gas line, choke and the other line like so!?

Attachment 541025

Well also what the **** is up with this ?

Attachment 541026

Well I am ganna hook the gas lines up to carb and ganna try to start it ! Are there any way to drive the car around without the rats nest?
Old 08-23-14, 08:41 AM
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Originally Posted by elhartd
Alright everyone I'm almost done with my car! This be my new problems!.. I have the 85 rx7 motor in the 79 body ! I also have the 79 wiring harrness and I'm wondering how I hook up the wiring to the 85 motor? And how too hook up the gas line, choke and the other line like so!?

Well also what the **** is up with this ?

Well I am ganna hook the gas lines up to carb and ganna try to start it ! Are there any way to drive the car around without the rats nest?
Here are the pics


motor swap-forumrunner_20140823_074042.jpg



motor swap-forumrunner_20140823_074031.jpg
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