A few questions about rotarys...
 

Hi everyone! I am from New Zealand and love the forum - there seems to be lots of useful information around. I am currently contemplating trading my Evo VII for a 1996 RX7. I've never had a rotary before and know nothing about them so was hoping you guys could give me some advice.

The rx7 I am looking at is pretty nice with 411 KW at the wheels. The current owner bought it off the guy that built the engine, and told me that as soon as he bought it he had to spend 10k on the engine. He said this was because the old owner didnt set a boost limit, and the current owner blew a vacuum hose causing it to freeboost and roll the apex seals. He also said the engine was never "dowelled" which he has since done and also replaced the seals with indestructable apex seals.

One of my main questions is what does 'dowelling' the engine mean? And does his story sound plausible or is it BS in your opinions..

Any help would be appreciated!

P.S. here is the link to the car.

http://www.trademe.co.nz/Browse/List...x?id=231114760

Dowelling is adding additional dowel pins to the engine past the factory 4 pins. This prevents the engine from flexing under high loads. Take a look at the factory service manual (see the FAQ for download) in the engine assembly section. It shows a diagram of the dowel pins securing the housings to the irons.

There is no such thing as an indestructible apex seal. Like a head gasket/piston ring, the apex seals will always break of something stupid happens.

If the description of that car is correct, a GT35R is way too small of a turbo for a "monster bridgeport". The porting is being wasted and you're just going to get poor fuel mileage for no good reason.

Learn more.
 

It would be very beneficial to find someone who works on rotary motors to show you exactly how they work. I have recently got into rotary engines and have learned a ton just by looking at opened up motors and having someone show me how the thing works. Luckily I have a background in cars with v8's and i4's so it's easy to understand, but from what I have learned these motors are pretty solid if built right, but if they don't get the proper cooling and lubrication (oil through the crank) things can really suck. Just things to consider before buying someone elses disaster.

Thanks for the replies.

Aaron the thing I am most concerned about is what he may have changed since he got the car, as the initial owner had it perfect. Is the GT35r turbo too small? I found a site with the cars old specs and see that it used to have a Master Power T61 turbo..would this turbo be more suited to the bridgeport? I just want to make sure that he isn't claiming it has as much power as it previously had, if he has gone and changed things like the turbo etc.

Here is a link to the cars specs when it belonged to the first owner

http://www.performancecar.co.nz/arti...zpc-137?page=2

Thanks :)

IMO i dont think id start my rotary quest with a fully build FD... especially a $27,000 FD... but whatever floats your boat.

A T-61 is a bigger (and laggier, non-ball-bearing) turbo than the GT35. 411KW = 551 RWHP, which is going to be well beyond the range of a GT35. It may be possible with the T-61, but I don't know for sure. The single turbo section would be a good place to get specifics on various aftermarket turbos. There's a useful compressor size chart here too: http://www.fc3spro.com/TECH/TURBO/tmodels.html.

Why not?:rolleyes:

Thanks for the reply Rocket

Because there is no manual for how to maintain a highly modified FD. You'll also need to spend more time and money maintaining it because higher power = more frequent broken parts. It also sounds like this particular car has a lot of stuff bolted on but very little intelligence in the method (no boost limit = amateurish stupidity). So if I were buying it I'd have to put serious effort into determining what other things are done in a stupid way before it breaks.

Dave

there is no crankshaft buddy.e-shaft

Sorry purp3rotor. Thanks for the correction. I am still used to normal engines and haven't quite figured everything out on rotaries yet. E shaft does essentially the same thing in a rotary as a crankshaft does in a v6, v8, i4, i6 and pretty much every other motor.

interesting!

hmm, today I was told that they can support around 700hp? or do people have different interpretations..Clarification would be great. cheers

This site here says flow capacity of 600hp

http://www.optionimports.com/garrettgt3540r.html