[s-cars] New 5 cylinder vs. AAN

[manuelsanchez at starpower.net]

I had a couple of RX7's back in the day. The apex seal problem had a remedy called "The ATF Treatment". I used this treatment several times with good success. You pour a small amount of ATF fluid into the engine (it was easier to do on the carbureted engines than the EFI's but still doable) and you bumped the engine around with the starter to get it all distributed, then let the ATF detergents work their magic (usually overnight was enough). Now it was best to wait until evening to restart the car because the ensuing plume of smoke is only rivaled by the cooling towers at some large power plants. It was quite the spectacle. After a little bit of idling you'd go out and give it the eye-talian tune up and everything would be back to normal.

As it was explained to me, at the tip of each lobe of the spinning triangular piece of metal is an apex seal. The seal (a hard substance of unobtanium I think) sits in that groove but it moves up and down slightly to make contact with the side of the rotor housing (i.e. cylinder). It is pushed against the side by a small leaf like spring. Combustion crud would build up and bind the spring, thus not allowing for a good seal against the rotor housing and the result is no compression. The ATF detergents dissolved the crud allowing the spring to do its thing.

There were many stories of guys going to junk yards and buying complete "ruined" engines for a song, applying the ATF Treatment, then having a perfectly good runner.

I still miss the RX7's, they may have been the most fun car I've ever owned so far. Sure they had their quirks, but they only had 3 major moving parts, and when they spun, they were super smooth. That plus a live rear axle in the early cars I had and they were oversteering beasts which demanded a lot of your attention. I used to say it was a video game come to life.

Manny
95.5 urS6 Avant

Past Wankels:
'80 RX-7 (with a 13B engine swap)
'85 RX-7 GSLSE



>Message: 2
>Date: Fri, 15 Oct 2010 09:22:37 -0400
>From: Peter Schulz <pcschulz at comcast.net>
>Subject: Re: [s-cars] New 5 cylinder vs. AAN
>To: Jared Robinson <chapel976 at gmail.com>
>Cc: Mark Strangways <MarkS1234 at spamarrest.com>,	S-CAR list
>	<s-car-list at audifans.com>, JC <jc at j2c3.com>
>Message-ID: <3DC2E858-A63B-49AC-BDA8-E9DA5D5BAEB9 at comcast.net>
>Content-Type: text/plain;	charset=us-ascii
>
>Better for what?
>What's your goal?
>
>rotories are not the best design when either torque nor low fuel consumption are desirable.
>
>As Herr Myers has pointed out, the rotorie's achile's heel are the seals.
>
>-
>On Oct 15, 2010, at 8:48 AM, Jared Robinson wrote:
>
>> and this is why rotaries are better than reciprocating engines :D
>> 
>> On Fri, Oct 15, 2010 at 6:46 AM, John Cody Forbes <cody at 5000tq.com> wrote:
>> 
>>> Yeah it's all down to piston acceleration and crank offsets.
>>> 
>
>
>
>-Peter Schulz
>Chelmsford Ma, USA
>http://www.naaclub.org/
>
>1995.5 S6 Avant Emerald/Ecru
>1995.5 S6 Avant Silver/Platinum
>1991 90Q 20v Q Red
>1991 90Q 20v Indigo
>1991 CQ silver  (eS2 recipient) 
>
>