ITS 13b rebuild

[ThePartsTrader]

Guys,
I am in the starting process of building an ITS car from a '91 RX-7. I have never offically "road raced" in door to door competition but I have been running SCCA Solo I for two years now and have been Solo II competing for around 8 years.

The car I am starting with has a low compression motor (had 130k + miles on it) that I picked up for nearly nothing. I have been pricing a rebuilt motor for this car. I have been quoted everything from $1800 for a basic rebuild to around $5000 for an "ITS Race" motor.
Is the extra $3200 (difference between cheap and race motor) just going to ceramic apex seals and new side housings?
What else are the pro engine builders doing to justify the price difference? Ceramic seals and new rotor housings can be purchased for around $2800. Is the rest put towards balancing and extra time spent checking the clearance of all the parts?



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B. Carmon Colvin
ThePartsTrader.com
'86 Mazda RX-7

[C. Ludwig]

Do a search in this section. There was a good thread a while back about junkyard motors versus "built" motors. Some seem to feel rotaries get better with a lot of break in. My personal experience is that I haven't had any rotaries run off and hide from my 80k or so mile motor.

Chris

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Chris Ludwig
08 ITS RX7 CenDiv

[ThePartsTrader]

The search function on this website must not be working correctly. A search for "motor" in this section only turned up two threads (unrelated) and "engine", "horsepower" and "junk" turned up nothing.

I did manually scan through the thread titles and came up with a legality discussion about a MazdaTrix motor. But that was the only thread I found close to the subject.

But some other information I have read on the net seems to point to the fact that there really is not a speed secret when it comes to building a n/a rotary motor (when porting is not allowed) and most modifications are just for reliablity.


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B. Carmon Colvin
ThePartsTrader.com
'86 Mazda RX-7

[Quickshoe]

The motors are easy and cheap to build yourself. MUCH easier than a pissed-on engine and cheaper than just about everything but maybe a SBC or a 1600VW

take your time, make sure it's clean, and check clearances.

Spend a small portion of the $3200 on some dyno time with a knowledgeable tuner, a good cooling system, and a good exhaust system.

Very ignorant about the chip availability for a 13B, but money might be better spent there as well.

[Aged racer]

Cormon, let me make a suggestion based on experience. Get someone to build you an engine who knows what they are doing and will let you decide how far to go. I had Stan at SDJ build mine for my 2nd gen many moons ago- I opted to save some money on a few things, but spent extra on durability items like the oil pump, etc.. The core was a boned out, high mileage street engine- excluding the side plates (more later), it cost me a little over two grand, and I have not touched it in 5 years. The side plates wrere too worn to reuse, so that was an extra $500-600. Yours may be OK, but do you feel confident in measuring ??

Anyway, the point is, a pro-build was money well spent. Only had to R&I one time, ran like a freight train, and all I had to do was drive. I like Stan's work, but there are others. Just don't let someone convince you to spend big bucks until you are ready.

Stan's outside of Charlotte, NC, BTW. Has a website under "SDJ Motorsports".

Good luck, and have fun !

[Boswoj]

In my case, I decided to pull out my one-rotor and replace it with a professionally built one. Then I had my old motor sitting there so I could take my time and rebuild it without the pressure of needing to get it back in the car. There is a video tape of the 13b testing and rebuilding process by Bruce Turrentine available that I watched about 20 times before I started so I felt like I had rebuilt one already. I'll let you know how it goes when I plug my homebuilt "spare" into the car when the pro-built motor goes away - maybe that way I can give a good comparison between the two!

Rick