How many engine rebuilds?
 

I was discussing with someone recently the idea of tracking this car. They claim to have raced against RX7 most of their life, and always noted that the engines had to be rebuilt often.
So I ask you, those who race your 8's often (around 5 times a year or more, road or drag) how often have you needed an engine rebuild. If at all.
Also mention if your engine had any Forced Induction, the discussion had a lot to do with that as well. Thank you

Before you start listening to crap like that, go to http://www.diasio.com/ and look under D962R and scroll down to the section "THE ENGINE" and read for yourself about longevity for racing applications.

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Wasn't listening to anyone. I want some testimonials to rebuttal with.

Tracking this car is fine and it will handle track days and autocross better than most piston engines. The only thing I would recommend is to run premix. Which I recommend for longevity even street driving.

City driving is what really shortens the life of this engine. It was born to go to the track.

I've been to multiple track days, HPDE's, and autocross events and my engine has seen no adverse affects from it. I'm N/A.

you will find your car will perform better after you track it, than before. Same goes if you dyno tune it. It clears out the carbon.

aka, italian tune up.

Tuning. Is. Everything.

The quality of the rebuild will determine the longevity of the engine. Most amature road racers will go 2 yrs between rebuilds. I believe Speedsource Grand-Am cars only get rebuilt at the end of the season. I don't remember hearing of them having a engine related problem.

Speedsource rebuilds their GT motors every 50-60 hrs at race trim. The RX8's raced in the ST class were lucky to get 20 hrs at race trim.

Jeff hit it on the head though, the tune is everything.

I am not sure about the renesis, but the 12a's and 13b's do not need to be rebuilt often at all for racing. I don't know who told you that but it is false. I have raced rx7 and know many others who do. Every three seasons is what I see, far longer than the piston race engines go. Compression will drop consistently, but it will go. Renesis should be no different IF you get the right guys to build it. Mazda tolerances are too large in the renesis, once you fix that you are good to go. FI I have no idea, I had a 3rd gen that blew several times.

Perhaps.
As I am fond of noting, the engine I am using currently was built entirely from junk and parts that no "reputable" engine builder would use (hopefully) in a customer rebuild.
None of the seals have proper clearance and are all reused stuff from several different motors.
It is also the strongest motor I have ever had.

how did you blow the near new one you put in a year or so ago ?

MM broke a coolant line and overheated. No Mechanical failure internaly. Lost an outer rotor housing o-ring.
I my self have done the 1/4 mile about 5 times and HPDE 1,2,3 and no issues. This engine has about 50,000 miles on it.

^ What he said. I learned just how hot a Renesis can get before it comes apart - 260°F.
Even then, it took a while.

The other motor that I just took apart ingested something. I don't know what, but it was really hard. Gouged everything in sight.
All the seals were perfectly intact, though.

I've been tracking the snot out of mine for two years. NA. Probably 12+ track days a year, plus three or four autocrosses. 32,000 miles on the clock. Heading to Summit FATT this Friday to flog it some more.

Total number of engine rebuilds: ZERO

Total number I expect between now and RX-9 (in 2011? please!): ZERO

Needs a rebuild? Nope. Recent compression test showed good, and I was running away from a lower-mile identical RX-8 at VIR a couple of weeks ago.

There is little reason a properly driven (read: driven hard) non-FI Mazda Wankel won't last for a long time when properly cared for. These things love to rev, and the harder you rev, the longer they go. I've got a front-running Spec RX-7 that I started racing with 130,000 on it, and stopped when it got smashed ten years later at 147,000 miles. The engine is still fine, it will go in when the one that came with the replacement chassis dies (probably in another ten years).

^HPDE's really won't do that much harm to the engine. Try tracking it at Pro race speeds 12x a year plus have rental clients use and abuse the car for at least 10 HPDE 3-4 weekends. They tend to pop really quick. Coolant seals mostly from the ones I've been around.

Coolant seals generally only pop when the engine has been overheated. Are you guys getting local overheating from the RENESIS side exhaust ports, or do you just need bigger radiators? ;)


And OP isn't considering pro racing, just tracking. :)

Can't speak about racing, but here's my two cents:

56k miles on my car so far. Three seasons of National-level autocross and ProSolo competition (25-30 events per year, usually with a co-driver), plus roughly 2500 track miles over the last couple of years (instructor level driver on R comps). My engine runs just fine, but I'm guessing transmission #2 will become transmission #3 some time next season. ;)

Oh no, I understood what the OP was asking, that's why I said HPDE's won't really hurt anything.

As for our engines popping, we have had our fair share of overheating issues but also, side seal failure was a big one. Our cars all had 4" Ron Davis radiators with dual fans and modded water pumps, track temps were around 180 most of the time. During HPDE's they would hit 210 occasionally...only the off chance we had a bad driver would the overheat and pop.