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rebuild or replace?

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Old 02-02-09, 02:37 PM
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Exclamation rebuild or replace?

hey
i have an 87 base model rx7 (13B engine)
it has the N/A engine and im not sure if i should rebuild or replace the engine
the guy i bought it from said "the radiator blew" and when i drained the oil from the oil pan there was old oil and a lot of water from the cooling system in it.
the same mixture was in the radiator as well when i drained it.(oil and water)
i think it had been sitting like that for about a year
i'm wondering if it would be worth it to pull the engine and rebuild it with a rebuild kit or if i should just start shopping for a replacement engine.
thanks in advance
Old 02-02-09, 09:10 PM
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I would look for a used motor to replace it. Tear the old one down and see what you might salvage.
Old 02-02-09, 09:17 PM
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a replacment engine could be hit or miss. at least with a rebuild you know the condition of the engine
Old 02-02-09, 09:22 PM
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do you think that the engine(rotors, irons, and housings) will be salvageable?
Old 02-02-09, 11:40 PM
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I would think a lot of the internals would be badly rusted. As I understood your post the engine oil and water filled the combustion chamber. Tear it down and see what you have. There is a great rebuild video posted in the group buy area. It's very interesting even if you don't want to rebuild your motor yourself.
Old 02-03-09, 02:08 AM
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You probably won't know for sure until you crack open the engine. Coolant in the oil is usually caused from a front freeze plug popping or a coolant seal within the oil pan perimeter. Oil in the coolant, usually from a cracked housing or iron due to overheating.

You can look inside the exhaust ports and get some clues to condition. You may see rust, carbon, an engine steamed cleaned from coolant or heat damage. If you can borrow a boroscope, you can get a better look.
Old 02-03-09, 02:24 AM
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You'll find out once you crack the engine and as long as the water jackets aren't damaged by rust, you can save a lot of parts or rebuild it.
Old 02-03-09, 04:36 AM
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how to test if my engine should be rebuilt?
Old 02-03-09, 04:38 AM
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my fd runs normally,looking somewhere could do the test.........then
Old 02-03-09, 05:19 AM
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Normally, one does or has a compression test done. You can do a basic one yourself or find a Mazda dealer that uses the rotary specific compression tester. The following link is to the online FSMs. Download the FSM for your model year and start reading.

http://www.wankel.net/~krwright/cars/rx7/manuals.html
Old 02-03-09, 01:21 PM
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this is ridiculous
so i was getting started on removing the engine and i take off the radiator hose and one bolt and the metal just cracks off
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