I'm starting to put together my plans for my next project vehicle. I have a late 50's VW bug that I plan to make an entire tube chassis for using an RX-7 IRS along with engine and tranny. My only concern is that the RX-7 motor will run hot. Since I will have the motor mounted up front, and all the radiator and cooling fans in the back I'm concerned that it may overheat. Has anyone heard that the RX-7 runs really hot? I'd love to use the T2 turbo motor from an early 90s RX-7, can anyone reccomend a different year that may run cooler? Would I be better off doing a NA motor for this application? Thanks.

BTW, of course it'll be bagged and lay flat on the ground too

-Aaron

 

Contact Xenon7. He had two rx7's and did ALOT of work on them.

 

I think blxmjx used to have one also? I could be mistaken though.

 

you're right...he owned one and knows rex's pretty well...

 

Sorry, I've never had the pleasure of doing the rotary to vw swap. I had a friend that did it though, he had the engine mounted midship and it was a 13B streetport. Cooling is definitely critical in a rotary engine and yes they do need substantial cooling.

Here is a site that may be able to help you out. They've been around for a really long time and sell parts for the rotary into a vw swap.

Powerhouse Engineering

 

Aaron, sounds like a fun project, my first suggestion is do
some research on the 12A (4bbl) and 13B(EFI) rotary engines and chassis components so you know exactly what your are getting into. These 2 motors are very different animals in terms of ignition, fuel, EGR systems, and performance. Esp. the Turbo II’s.

Mazdatrix out of California could make it real easy to obtain parts like headers and other misc. items you may need to complete the install. I assume you are looking at used parts through a junk yard. I would consider get a good shop manual and get a compression testing kit to verify each motor you find.

VERY IMPORTANT, the apex seals. This is the failure of most early rotarys and will put a damper on your whole project. I would find an engine that can be proven to start, like still in the engine bay. Check for rotor housing leaks and make sure the oil pumping system is working properly. Also look at the 2-plugs in each rotor housing for color.

If you do decide to go with either the 12A or 13B it is important to keep them from overheating. Get an over sized radiator and some electric fans an you’ll be fine.

Best of luck- hit me up in PM if you have specifics.

 

I didn't know RX7 engines to VW bugs were so popular...do they just drop right in or something?

I personally found the mechanics of the RX7 engine too confusing.

 

Actually, this sounds like a great project. Cooling will be a challenge for exactly the reasons you specify.

From what I understand from a friend who builds race rotaries, 1979-1984 Rx-7 motors (12A) are less subject to overheating, but still require a lot of cooling. Later (13B) engines, normally aspirated or turbocharged will require more significant cooling.

Still, in HP per unit displacement, rotary motors are some of the most efficient around. Too bad they didn't catch on...