Sandecker

I was disappointed to read that the scc project RX7 blew its first engine and is about to lose the second one, from an update in the latest sport compact car issue. I was impressed with the thrashing that car was taking in the build-up, and all the effort to prevent engine detonation. The car had around 60k miles originally when they started, and had even been crashed about half-way thru the build-up. With one little paragraph in the scc update, over 2-years of effort and expense seems to have shattered enthusiasts confidence in a reliable 300hp+ RX7.

If anyone has more specifics, pls post. And a few posts from those with modified original engines would be nice too. Long live the RX7!

Flybye

Is this article in the current SCC?

Johnny

No there is just a burlb about it being rebuilt at SRMotorsports..thus the assumption it blew another engine...I guess which is possible, but I'm sure there is a explanation for it.

SleepR1

That's just life with trying build UP a sports car motor. The factory 13B REW motor is NOT overbuilt like a Honda Civic I-4 of Porsche 911 flat-6. The truth of the matter is, the rotary is a delicate motor despite fewer moving parts than its piston motor counterpart. IMHO, if rotaries were so stout, they'd been by accepted F1 motor engineers a long time ago. Fact is, F1 motors which wind out to 18,000 rpm are all boingers!

The problem with trying to maintain a 300+ hp 13B REW is rooted in designed-in tolerances. The factory had designed-in wear tolerances to withstand daily use for 100,000 or so miles.

Once you start dikking around with boost pressures and fuel, you're applying much more stress on the moving parts inside the 13B REW, than what the Mazda engineer intended. As we all know, the bigger the bang, the bigger the horsepower numbers. There's nothing magic about that. In order to produce a big "bang" inside the combustion chamber, you turn up the boost pressure, add more fuel, and increase the combustion's explosive force by 1.5 times what the factory intended the motor to withstand. Yeah, you get the horsepower numbers, but you also decrease the lifespan of the motor!

What's funny is why everyone's so shocked that the SCC Project Rx7 is going on its 3rd motor. I'm not. It's par for the course.

It's the Law of Conservation of Matter. You can't make big horsepower and expect that factory motor to last 100,000 miles too!

Flybye

I certainly hope there IS a good explanation for it. Especially since this REALLY should have been called "Project M2"

maxpesce

From The SSC website:

>>The third generation RX-7 is the best sports car ever made. It's absolutely brilliant in every measure of performance. And then it blows up.
Sure, we could blame ourselves, like we did the last time it blew up. That time, we foolishly drove it on the track with less than half a tank of gas and experienced the penultimate "snap, crackle, silence" of fuel slosh.
This time, we forgot to keep an eye on the temp gauge and fell prey to a slow coolant leak. The car still runs brilliantly, but the telltale whiff of burning antifreeze in the exhaust says we'll be replacing the engine soon.
This time, SR Motorsports will go through our rotary and try to prevent another encore. They will also guide us through some cryogenic treating procedures for the transmission in anticipation of more power. When it's up and running again, the stock turbos will be replaced with either JDM '99 RX-7 turbos or perhaps just a big single. The simple plug-and-drive A'pexi PowerFC engine management is also in the works<<

At least they admit the Blow-Ups were their own fault.

Flybye

It's truly sad because they only thing really weak about it are seals. The water seal and the apex seals are the first ones to always go. I really don't see why anyone has bothered to truly make a bullet proof version of these seals. I mean, it's been over 20 years since turbo rotaries have been in existence.

maxpesce

F-1 motors are all boingers because the RULES say they HAVE TO BE!
The current F-1 rules limit engines to 3.0L V-10s ONLY.
also F-1 motors get rebuilt after every 10-20 hours of use Thats equal to about 1500 miles
a 400hp 13b is producing as much HP/L as a 900hp (Race Trim) F-1 Mill
400hp/1.3L = 307hp/L
900hp/3.0L = 300hp/L

Sandecker

I guess what bothers me and probably many others is that this RX7 was really a model for what I wanted to do with my own car, so it was a bit of a let-down, although yes I'm not surprised. It won't stop me from continuing thou, i'll just always carry a little more anxiety - the thought of having to spend $000's to rebuild, just to get the car you had before, when that money could have gone to other upgrades...

SleepR1

I've read that there are 3-mm ceramic coated apex seals available. Now if we could address that prone-to-failing O-ring...

Tim Benton

iTrader: (1)

well looking at the blurb, its seems like both engine losses were the cause of the Shiv's lack of attention. Running the car on empty, then it runs out and starves it for fuel, easily avoided, fill the damn thing up when the light comes on. Engine 1 - stupid owner mistake, nothing to do with the engines reliability other than it shows what can happen to a rotary without any fuel....duh. Current engine, coolant loss at the track. Well another thing Shiv might have been able to avoid. Was it a leaking hose? loose clamp? Going around the track extra hard trying to get your best time of the day while your chasing down your friend in the NSX in front of you. Again, we all know losing coolant is bad and can cause you to lose your engine if it loses enough and the heat builds up, especially at the track. Again, not something the average FD will really ever see is track use. So the fact Shiv was on the track, with a coolant leak, would surely cause the engine to fail (water seal wise). Every day car with a coolant leak, chances are you can catch it soon enough if your observant enough to look at your gauges every once in a while. I had the hose that goes from the AST get cut in half buy my ecc. shaft pulley and dump coolant, I smelled it, pulled over and let it cool down. That was 2 years ago, and I've been making over 300 to the wheels for the past 3 plus years. Am I lucky, nah, I think the stories you hear about seeing the temp guage rising and people pull over and it still loses its water seals mean that driver didnt notice it soon enough so just be more attentative if you have an FD. You really have to lose alot of water for it to over heat.
Tim Benton
no offense to Shiv but both engine failures were more to do wth him than the engine themselves

Tim Benton

iTrader: (1)

Also keep in mind that the stock temp guage doesn't start to movc until its almost to hot to save the engine by letting it cool down, turning on the heater etc. most all new cars have the water temp gauge like ours in that they sit rather still until its pretty dam hot to be making it go up.

Tim Benton

SleepR1

Well, that's a shame. Track use is what the Mazda engineers had in mind with FDs, especially the R1/R2 models! When I say track, know that I mean road racing circuit, NOT the drag strip!

SleepR1

Lost all my radiator's coolant at Mid Ohio '99 coming out of the "Key Hole". How did that happen? The radiator hose was expanding under pressure and touched one of the spinning pulley bolts. As I was accelerating on to Mid Ohio's back straight, there was a loud "boom!" I thought I had a tire blow-out. Then it happened...the temp gauge shot to "H", and stayed there.

Here's the amazing thing...I limped the car all the way back to the paddock (1.25 miles), and did not shut the motor off after parking it...(I dunno--in the confusion, and hysteria, I forgot to shut the motor off??). I eventually did, of course, but it was a few minutes after I parked it.

Well that was 32,000 miles ago. Last dyno figure was 269 rear-wheel horsepower (Kenny Brown's Dyno Jet chassis dyno, '00).

I'll need to replace the turbos this year, but the motor still seems to pulling strong at 92,000 miles. Dodged a bullet, I guess!

KZ1

so they blew a few engines because they are unfamiliar with rotaries. wow, no suprise, infact the 13B is a very strong engine. Rotaries are known for their durability and ability to withstand a beating. Only probablem is that they are senstive to some differnt things than boingers when you through turbos on them. **** man, you know how many rotaries are involved in SCC racing, a lot.

I haev 65k miles on my engine, it runs like new. luckily the owner bnefore me was a freak about cars too. I have all the records from the day it was bought, and I run 13lbs of boost for almost a year, and plan to run 15 in next 2 weeks. I have never had anythign on the car breakdown. only normal wear items. Haven't spend a penny unexpectibly or on repeairs. Just maintenance items maintenace items, power items, them more maintenace items.

Tim McCreary

Ceramics are by no means the solution to the problem. I have read post after post, but the truth is that if you ping bad due to the same problems with standard apex seals, you are going to break the ceramic ones also. I read a post on another website about 2 years ago where a very knowledgeable person was all for ceramic 3mm seals. He spent thousands of dollars and rebuilt his engine. This was no amateur, he has built several performance engines before and was what I would consider an expert. First time on the dyno, a vacuum line popped off, and that was all she wrote. I think he was using Ianetti (unsure of spelling or name) apex seals. After all this, he realized that if he would have spent the money on preventing lean conditions, the apex seals did not matter. I think his quote was that he could have rebuilt his engine about 5 times over for the money he spent on the ceramic 3mm seals.

Now of course, they apex seals are stronger and will work better at high boost, but if you hit a lean condition and start pinging for any reason, kiss your money goodby.

Tim

newRX7fan

iTrader: (1)

<well looking at the blurb, its seems like both engine losses were the cause of the Shiv's lack of attention. Running the car on empty, then it runs out and starves it for fuel, easily avoided, fill the damn thing up when the light comes on.>

Long before the light comes on, he said 'less than half a tank'. And I'm not sure why he had a problem there, I've done that many times. Just let off the gas when it happens. And it is annoying (and easy to forget), having to fill up after every track session. But yeah, Shiv's fault.

Sandecker-
Same here, the SCC build-up was part of the reason I bought my car. Also seeing it come up behind me on a track like I was riding a bicycle. Great looking car, 300+rwhp, can be reliable if you're careful and smart. Well, 2 out of 3 as they say.

I had to have my engine rebuilt due to a water seal failure- I'm blaming it on a prior owner not changing the coolant regularly. Or maybe as JimLab might say, Mars was in Aquarius and Jupiter was rising with a waning Moon, which also causes o-ring failure in 3rd-gens.

solo1seven

Hi,

I've also been using the SCC project RX7 as a guide for my upgrades, and it was disappointing to see that they have gone through two engines albeit it was their own fault. So it still seems true, if the rotary is kept cool and fed enough fuel, it will last. So what do we do about the fuel issue, has anyone baffled their fuel tank? Rotaries consume fuel fast on the track and keeping it over a half in a lapping session isn't always an option.

In the issues of SCC I have, I do not recall any mention of what boost level they were running, I remember them saying that they were overworking the turbos on hot days and still overheating at high altitudes and warm temperatures. Hopefully my Koyo will work better than the fluidyne and slightly lower boost will reduce turbo and underhood temperatures preventing the overheating issue. Anyone remember boost?

jimlab

No, no, no. When the Moon is in the Seventh House
and Jupiter aligns with Mars...

artowar2

I have been subscribing to SCC for the last few years. The only reason I've kept the subscription is because they keep promising new articles on Shiv's Project RX-7 car. It's been too long since they had a real article in the series, and a blurb that SR will be rebuilding the engine doesn't cut it*. At this rate, FDs will be selling in Hemmings Motor News before SCC publishes a substantive update in the series. And after last month's articles on tuner Cavaliers and Sunfires I've had it. When this year's subscription is up, I am dumping the SCC subscription.

* What they should do is some kind of "autopsy" article on the dead motor. Let's see the gruesome photos of destroyed parts and an analysis of what the hell caused it. In other words, show people some bad examples that they can learn from...

Devilish

I just wish Shiv would quit dickin' around with that 2.5RS. Who would spend that much bank on a car (custom gears from Australia?) when you can get the same set up via a WRX for much less. Not to mention the STI version coming next year.

As for project 7, I don't think the cooling system was good enough for a lot of track use. He should've chucked the AC condenser, ran a bigger radiator than the Mazda Comp. (Fluidyne or Koyo), & ran bigger oil coolers. Yes, the car has the dual R1/R2 coolers, but the CWR ones would be better. Or the new kit Jason sells. Finally, who knows what pressure radiator cap he had. If it was the 1.3, that easily could've popped an o-ring.

I wonder if Ray is doing the engine for free?

Sidestick

iTrader: (1)

13psi

Coulthard Fan

I dunno about this whole thing. Shiv almost sounded like he was making excuses for the car, not the other way around. Sometimes **** just happens at the track - nothing you can do about it with these cars - and I doubt Shiv acted like the little old lady who wore her brakes down halfway through the ROTORS. I know he has a temp guage and I'm sure he was checking it, but for whatever reason it blew the o-rings. I bet that with as much track time as he gets you all would be likely to make a mistake or the engine would just go for no reason. Same **** happens to the Viper & C5 guys who track their cars all the time. (Except their motors are $+20G's)

As for the fuel starvation... I don't know why he never addressed this. He's racing with slicks and he never did anything about this??? Sure, most people just run with at least 1/2 a tank but that just seems half *** to me if you get considerable track time on really sticky tires. Also, I wasn't aware that this could lead to more than just crappy lap times, meaning I didn't know fuel starvation would pop the motor... but I guess that makes sense. (The ECU doesn't take any measures here?)

Scott

shiv

Here's the deal with the project car. The first motor popped before we even began doing anything with it. Simply knocked twice while doing baseline testing at Willow Springs. It was running less than

shiv

Here's the deal with the project car. The first motor popped before we even began doing anything with it when the engine was essentially stock. Simply knocked twice while doing baseline testing at Streets of Willow. It was running less than half a tank of gas at the time and fuel sloshed and pinged on the tight left-hand uphill turn (Turn 3, I think). Stock tires, BTW. That was all it took for it to loose an apex seal. Soon after, in went a re-manufactured motor from Mazda Corp a la extended warranty.

The second failure was not induced by anything out of the ordinary. Never ran hot. Didn't ping. Just started loosing water after tens of thousands of miles. For another year, the car was still driven (although not hard) on a regular basis. The add coolant light would go on every now and then. Eventually, it got to the point at which it went on every time the car was started. Then it got to the point where the car wouldn't start easily. And that's when I drove it to SR Motorsports for some serious work.

Instead of using another re-man motor, Ray completely built a new one. Checking tolerances all along the way. New gaskets, seals, housings, etc,. In addition, proper engine management will be fitted (big injectors, Power FC) for max. safety/performance. After driving a few FC-equipped cars, I'm confident it's a big step up from the remapped-ECU options currently available. Also doing a big KKK single turbo kit which is bound to improve performance significantly while reducing much of the exhaust backpressure-induced thermals stresses that I think led to the previous engine's demise. The AC system has also been removed. There will be some additional cooling system work as well. All in an effort to keep this sucker together for the long haul. It's been a pleasure working with Ray on project.

Along with a completely rebuilt transmission and a few other upgrades, the car should be pretty impressive and hopeful more reliable and a lot more powerful.

Cheers,
shiv