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Originally Posted by dayna240sx
I blew mine at 65K miles. WAY too much boost and not enough fuel. Oh well it now has an S5 jspec engine in.
anyway, about that car... This makes me put up the red flag "Hardly driven in the last 5 years." Rotarys DO NOT like to sit.
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I bought my 87 TII used at nearly 90k miles, ~140kkm, stock with no modifications, an OEM air filter. I used it a few months commuting to a job, then I prepared for rally through the mountains and canyons. I tossed the OEM turbo wheels to a friend, added light wheels and Parada ZR-spec, junked the OEM air filter for a "screen and gauze" performance filter, premium oil (not yet synthetic), punched a hole through the pre-cat, and blended with my driving style, exceeded a 400hp FD rx-7 in the rally except in the straights.
Next, I removed all catalytics for a downpipe, and dual N1 exhaust. It was beautiful except for factory-set fuel cut-of at overboost. At this time I was ignorant of what "octane" really meant. I continued using trash 87 octane sold to the unweary in this California USA racketeered fuel market.
Within a few weeks, I borrowed a friend's fuel-cut-defenser, an operational amplifier device which slopes off the signal voltage from intake manifold pressure sensor, so the fuel management would not see actual boost, hence prevent annoying fuel cut-off -- yes, it lies to the ECU fuel calculations. This is a bad thing....
On a beautiful cool evening, using Shell 87, sporting 250hp and an amazing ability to jump from 90mph to 130mph in a pedal tap, I popped the rotor closest to my toes, and I coasted to a fuel station. Begin US$5000 woes.
Another few weeks later, I wanted to learn more about this rotary besides documentation and animated models. I pulled a 70k-mile normally-aspirated 13B from a carcass at a junkyard. This, without equipment for intake, throttle, water, oil, and exhaust, it is a short-block costing US$100. An ideal learning toy. The engine was easily hoisted by the arms of a friend and me, and fit comfortably into the trunk of my 2001 B5 Passat 2.8l 5V with barely a suspension depression. Without the oil pan, the bottom of the engine is flat, so it remained secured through city driving to his home where I pressure-washed it with water, and completely disassembled it.
I discoveered the ultimate failure of the engine. The water seals on one rotor assembly which are sandwiched between the clad layers of rotor housing and middle and end housings, were failing near the combustion portion of the rotor path. This was causing burned water coolant mix to build mineral debris. The debris scored mating surfaces leading to minor oil leaks into the chamber and caking more mineral deposit on the rotor faces. One rotor had black crispy char packed a 1cm deep on each of its three rotor faces. I scraped that away too.
The parts are clean, no interior part failed, except the seals. I did not see any indication of services or rebuild within the engine. The engine could have been re-assembled and used as is. Externally, however, the oil metering lines had been melted, about 5cm from the block and restricted by the tubing shrinkage. The second rotor was barely showing signs of extra wear from not getting it's perimeter lubrication where the apex seals scrape along the inner raceway of the aluminum housing. This is an amazing engine and vastly superior to an arm/wrist/piston/valve/spring/cam-complication in most ways that I care about.
--edit--
Adding that the FD rx-7 driver is respectably skilled with 15 years extra sport driving experience. He's a good fellow.
--edit 11/21/2003--
I favor blaming the water seals, but I also think some cause of detonation began hammering those seals. The rotor was so encrusted it could have remained aflame through each cycle. But from this view, I have trouble reasoning what first began failing and causing the filth. What do you think? No oil changes, only filling, the sludge clogged oil lines, coated the rotors, and higher wear and heat accelerated effects. I'm really not sure. All hard seals, e.g. apex, were in fair condition. Other evidence I forgot to mention: that lower water-seal area was building heavy stacks of blue-green mineral salts inside the water jacket. I think the operator also suffered from combusion gasses blasting into the coolant. Whatever, it was used for hundreds of hours as it worsened -- operator error.
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"Look at me, I'm trendy." A 240sx with an sr20 is not going to be that fast. Hopefully you have a lot of money otherwise I wouldnt do it.
