12A Engine Problems after Rollover?

[tdw6974]

Looking at a 12A Engine to replace our rapping/knocking http://Forums.ImprovedTouring.com/it/frown.gif current engine. Am looking at one that was in a car that was rolled and ended upside down. What can I check/look at to make sure the engine is ok. I suspect the Rotary probably is pretty rugged but what should I check? Pull pan? At best any used engine can have problems as could any rebuilt engine. Thanks for any advice/help. Tom Weaver Truck Driver ailing ITA #63

[theenico]

About the only thing you can do (you won't be able to see anything with the pan off), short of disassembly/inspection, is to check the compression in the rotor housings. The further the numbers are away from each other the more likely it is that there is something wrong. If you don't have a way of checking the compression, then the age old method of crossing your fingers and hoping for the best is the next step http://Forums.ImprovedTouring.com/it/smile.gif
Another option is to use the engine as a core and have someone rebuild it. Tony Rivera redid one of ours for about $1500.

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Nico
KCRaceware (816) 257-7305
[email protected]

[Quickshoe]

Most of the 12a's that made it to the junkyard out this way ended up there because of an overheated motor.

Finding a 12A rx7 with a good body is bad news. Finding a rx7 with a totalled body most likely leads to a good motor. Must have been running when it was rolled/crashed.

[lateapex911]

Yup.....I'll second that...the best engine I've gotten out of a "pre-owned" car was the one pulled out of a car that was a little too intimate with a big oak tree....

Rapping ? Knocking?? Sounds like a stationary gear has become un stationary!

Been there, done that....



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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[Hotshoe]

I have bought and sold a few motors and the best way to tell if one is good in a junk yard situation is to pull the thermal reactor ( exhaust manifold for you piston guys ) and turn the engine slowly by hand to where you can see the apex seal in the exhaust port.
Take a plastic tipped object ( I use a windshield installation knife ) and check to see if the seal will push in. I have seen these stuck before and have loosened them with some WD40.
I also check the top of the rotor housings for any sign of oil leaking (bad O ring seal between housings)
I have had a 95% success rate using this method.

Rick Thompson

[Weaver7]

Nico,Tony Rivera will do rebuilds? That doesn't sound like a bad price at all. Do you have a number that I can contact him at? Also what happens if the stationary gear goes can you just replace that and call it good or is a full blown rebiuld in order.

[Quickshoe]

I've never had a stationary gear come loose. But it appears to be common enough to have remedies available to prevent it. As well as it being an inspection item during teardown/rebuild.

I would imagaine having a gear walk out would wipe out the side housing. Probably too much so to have it machined. Can't be good for the rotor sides either.

Just a guess.

[lateapex911]

A good guess.... and after machining those side housings, isn't the gas nitrading compromised???

Modifications do exist for stationary gears that "walk", but as I recall, they suggest it isn't really needed for engines that don't turn 9K. I think a groove is machined in the rotor and a clip holds the gear in place.

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]