Help! I am about to embark on something I've never tried before - rebuilding a rotary engine. The phrase "mechanically declined" would best describe my current ability, although I can change a tire and my oil.

The situation: I run PRO-7 in the International Conferenece of Sports Car Clubs (ICSCCC). This class is limited to 1st Gen RX-7s. The rules require all engines to be stock, with a stock intake manifold and carb and a stock exhaust manifold. Porting or other mods are not allowed, although the engine can be blueprinted and balanced. Also carbon seals are permitted.

My goal is to build a bullet-proof engine, maybe not the highest horsepower, but one that will last a couple of seasons (about 4/5 race weekends per year). I have so many questions but here are a few to start:

1. What tools do you recommend as absolutely essential to the rebuild? Any recommendations on an engine stand?

2. Is there a specific tech manual that is recommended?

3. Are there videos or DVDs that review an engine rebuild?

4. There are a number of rebuild kits out there, from stock to racing. I need one that fits the parameters of the rules - any recommendations?

5. This question is very broad - but is there a "good" way of doing the job? I don't mean speed tricks (legal or not) but a methodological way of dismantling and rebuilding the engine?

6. How will I know whether a part (the few there are) is still reusable?

7. Any other advice . . . for example - other threads or comemnts that have been posted.

I know this covers a lot of area but I'm looking forward to teh challenge.

Thanks in advance for all your help!!

 

I rebuilt my engine about 2 years ago. It is still running strong.

1: Besides normal hand tools (sockets, wrenches, etc.) You will need a high quality set measuring tools to check specs on parts (see list below). I made my own engine adapter that fits to a standard v8 type of engine stand out of a piece of 3" angle iron.

2: The factory service manual for your year car should have a really good illistrated directions.

3: Atkins Rotary sells a 13b rebuild video. It will help you quite a bit. Well worth the money.

4: I bought my kit partially from Mazdamotorsports and the rest from Atkins Rotary. I think Mazdamotorsports will have the carbon seals you need.

5: Label everything and keep your workspace very clean. Get the Atkins rebuild video, the guy does a great job showing you step by step.

6: You will have to measure everything, the FSM will give you the acceptable specs, thus the necessity of the measuring tools (see #1)

7: Take your time and be prepared to spend 2x as much time as you think it should take. And be prepared to spend hours cleaning your old parts. I probably spent 40 hours breaking down and cleaning two engines to get enough good parts to build one good one. Assembly with the video took me only about 3 hours.


I got my measuring tools from ToolParadise.com
(this was some time ago.. I am sure prices have changed)

 

Hi - I also race an Rx-7 in Conference, although I am in EIP / Group 5. There are several guys who build their own in your neck of the woods I believe. I believe Bert Dilley builds his own and is usually a very friendly guy willing to help. Scott and Mark Hanken have also built their own in the past I believe and are both really nice guys who are usually willing to share just about any info they have. Lots of pro's building them around too, if you want a reliable motor from someone who knows the tricks. The 13b assembly tape available through Atkins is handy, but I don't buy anything from them for customer service reasons. Mazda Motorsports should have most of what you need and if you are registered as a racer their prices are a big help!

 

This thread https://www.rx7club.com/pineapple-racing-171/engine-building-thoughts-575631/ will answer questions you don't even know you have yet. Should be mandatory reading for anyone considering a rebuild. Check it out.

 

I still have a season or two left on my motor but am considering doing it myself for both the experience and challenge. Atkins, Pineapple (still in business?) and Jeff Clark could all do an excellent job but I'm trying to save some $$$ as a way to budget for tires, entry fees and the like!

One question though: is there a specific kit you would recommend - such as Racing Beat or Mazdatrix - or is one available through MazdaSpeed?

Thanks for your time - see you in Group 5 next year!

 

Thanks on the thread!!!

 

After my sealed 13B race motor suddenly started detonating with 17 hours (1600 miles) on it, I'm thinking the same way. (The hell with the seal: guys I race with won't care). But, I'd like to have a local rebuild shop close by for advice/questions/help. Since I'm out of youse guys' loop, I wouldn't know where the closest one would be. Anyone got a suggestion?

Thanks.

Ted
Shoe String Racing

 

Start with your timing. If that is set correctly, then you might want to try running some Seafoam through the gas tank (1 can to 1/8 tank of gas). With my Sterling carb, I run pretty rich which can cause excessive carbon buildup. I was also experiencing some high end ignition breakup/detonation which the Seafoam cleared up for me within a few minutes. I've always used this product every couple of months or so, and have always felt a huge improvement afterwards. Its definitely worth a shot for the 8 bucks it will cost you. Good luck...