leave-eye

Ok I am having a couple issues here, first off its an 84 gs 12a stock port 180k miles, no history on car (picked it up super cheap from a kid). What I've done so far:

1. Cap, rotor, plugs, wires.

2. seafoam through gas and carb.

3. deleted emissions and rats nest. made a 1/4 block off plate on intake manifold with gasket i made and silicone.

4. put new thermostat coolant flush oil change in motor tranny and diff.

5. built custom header dumped through turbo tubes at the moment.

6. new fuel filter

So problem is, the car starts easily and idles well when warming up, have a slight bog when driving (not to bad probably needs carb rebuilt). Kind of strange my radiator seems to be pressurizing quite high haven't pressure tested but put new 13lb cap on and after driving its starts coming out of cap slightly and overflow starts hissing/sputtering. It doesnt get hot but once up to operating temp it starts to blow white/gray smoke out of only one combustion chamber(rear), and idles very poorly, will die without playing with gas. What I am expecting is internal coolant seals, but what I find strange is the good operation up until operating temp and driving.

Any suggestions would be nice, kind of noob on rotary engine, rebuilt one when I was 17. at 180k I'm thinking hard seals are quite near the end of their lifes which puts me at sort of crossroad. Thinking of a few different options.

1. rebuild/port 12a if housing are in good shape

2. find lowish mileage 13b carbureted to drop in

3. chuck a v8 in there (i know i know)

Let me know what you think of engine please. Thanks!

Crispin38

iTrader: (3)

First, looking at what you stated above, the only thing i can add is run a 16lb radiator cap.
16lbs is what mazdaspeed recommends, read any competition parts catalog and go to the back in the tech tips.

Second, if you're looking for engine options i would go with whats readily available. I run a Extended port 12a, love the power. But i think i would more satisfied with a Large Street ported 13b. More power, and easier to find nice rotor housings and intermediates.

That's my 2 cents.

leave-eye

Still wondering why I'm smoking out of one combustion chamber only, maybe the seals just gave up in the back of the engine. Still it runs fine and doesn't smoke until reaching operating temperature then it runs like crap and starts smoking at any rpm out of rear housing.

trochoid

iTrader: (6)

Not sure what this statement means:

?? 5. built custom header dumped through turbo tubes at the moment. ??

"Still it runs fine and doesn't smoke until reaching operating temperature then it runs like crap and starts smoking at any rpm out of rear housing."

Sounds like you blew a coolant seal in the rear housing. If the exhaust smells like coolant and there's bubbles in the radiator, it's toast.

Personally, I'd opt for a ported 13B.

leave-eye

Custom header flanged to chambered mufflers called turbo tubes.

Anyways I guess that I will tear into the motor to check out the damage maybe ill be able to do a soft seal kit and get a few miles out of it yet. Don't really have funds to get my hands on a 13b unless it was a great deal. I wonder how well the head gasket repair stuff would work on the coolant seals, may have to do a search on it, do that and run it until it blows.

Thanks for the feedback