twisted7

iTrader: (3)

Well, i was on my way home tonight from work. Just another normal day of landscaping. I decided i would let my car warm up for a minute or two since it is a little cold out and it doesnt like the cold weather very much.

I hop in the car and take off for home. I wait until i read my safe gaurd of 82 C to actually get into boost. It works out well that its right around the time i get onto the highway. So i boost to 12lbs and get onto the highway, i see a cloud of smoke behind me after i get the throttle.

I didnt really think much of it since i just had the car tuned and everything, just some excess oil burning off. The car is acting fine still and has power. About 20 minutes later as i approach a stop light after getting off the highway, my RPM's drop about 200rpms. I had to sit at the light for about 3 minutes. I turned the car off just in case something did happen, it wasnt going to be terrible.

I pull into an advanced auto parts store and coast in, I look under the hood and find that one of my vaccum caps had busted open, and i was out a quart low on oil. I replace the cap and a few others that looked like they might be on there way out and add the oil. I start up the car and its still doing the same thing.

I hear some scraping noises coming from my engine at first i thought maybe i blew a seal into the turbos. But than eliminated that since the sound wasnt coming from the turbos themselves. It was the engine.

I take the car to defined autoworks and we do a compression check and all is good on the front rotor 95 95 95....but the second was 80 22 22 roughly.

So it appears i have a fractured seal and it is now time for a rebuild. I guess i get that streetport and scalloping done now. lol

Thanks for your time, Jake

G's 3rd Gen

iTrader: (11)

how many miles? did you creep or spike?

twisted7

iTrader: (3)

Just .84bar thats it. no creep or spike. Im guessing it was due to either poor lubrication or the cold weather and rapid warming. or both.

This is on a reman engine with 43,000 miles on it. roughly 2.5 years.

adam c

iTrader: (2)

I feel your pain . My car is in the shop being rebuilt now. Hope to have it back next week.

spandy

iTrader: (1)

Hey look at it this way, now you can build it to suite your needs.

A blown motor isn't always a bad thing. I about cried a year ago when mine blew as I knew it was going to take a while to get it back on the road with my busy schedule. I'm just a few weeks away now, and I'm going to be putting down a good amount more ponies with a few extra touches. I was happy with the previous setup, but I'm going to enjoy the new setup even more.

Not to mention since it's been so long, it will be like the first time I drive it all over again....I still remember pitching a tent the first time I boosted it , and now I get to do it all over again.

Mister Destiny

iTrader: (1)

I have to totally agree. Blowing your engine- as unfortunate as it is- is a good reason to do things that you always wanted to, like streetporting it. It really is better the second time around. And third. And fourth. And fifth...

twisted7

iTrader: (3)

thanks guys. Ya blowing your engine is good and bad but it all depends on how the engine blows. Im just glad mine is a very minor thing and i probably will not need a new housing or rotor.

Im just stuck on whether i really want to build the engine or if i just want a streetport and few other things.

Otherwise it would be 3mm ceramic seals and new housings and new rotors, along with a semi p port and streetport with a 500r.

ahhh to have lots of money.

Jason

iTrader: (5)

If you cracked apex seals then you had some detonation which is usually from lack of fuel. You need to figure out what caused that or it could happen to your new motor.

twisted7

iTrader: (3)

jason, my fuel never went above 54 percent. and afrs were fine.

theorie

iTrader: (31)

bummer. same story for me only mine was an original motor (not rebuilt) with only 32k miles on it. haha

hey maybe you can get a new body kit while the motor is out? (please!!!)

skir2222

Ahhh, my reman died around the same amount of miles. Due to oil starvation though.

Jason

iTrader: (5)

Duty cycle doesnt mean much. Were you monitoring A/F at the time it went? Seals just dont break for no reason. Only way to break a seal is lack of fuel or timing issue.

twisted7

iTrader: (3)

haha whats the matter you dont like my body kit now???? lol its all good i have a cwest just sitting in the garage needing paint. I figured i will now take this opportunity to make my car even better. redo a lot of wiring and make it cleaner.

I had one omp line that wasnt putting out oil and went unnoticed for awhile but than had it fixed. Couldnt this of caused it to crack as well?

Jason

iTrader: (5)

Lack of oil will compress the side seals but very unlikey to crack an apex seal. If lack of oil was an issue you would have noticed that a while ago. Since you had the line replaced that wouldnt have been the cause of the problem. You would need to open the motor to really tell what the problem was, but if its cracked apex seals the odds were the car ran lean.

twisted7

iTrader: (3)

thats really odd. I had it dyno tuned and everything. I watched the Afr's while he was tuning the car and everything seemed fine. Guess we will see what happens when i get it torn apart.

DarkLikePoe

Heh, only on an RX7 forum.

Sorry to hear, man. I hope you are able to diagnose the problem! When I had to rebuild mine, it was the second rebuild on record at 150K miles. It was a compressed side seal, presumably from a lack of oil. After checking all supporting systems, it was determined that the engine was just tired, and that I just needed to monitor the rebuild carefully.

NTIMD8

iTrader: (1)

Do you have a wide band in the car? A big drop in temps can result in leaner A/F ratios and therefore detonation.

GtoRx7

iTrader: (5)

When a full factory FD Rx-7 with 255 hp and 85,000 miles blows up, is that a factory lack of fuel as well? My point being that on its best day a factory FD with only 210rwhp will last 85-90k. If you increase the HP past this point, the life of the engine will decrease. Its a nature of all things, more power- less life. This engine laid down much more power than stock, and lived 45,000 miles, on a Re-man which I think most know are not the best built in the first place. I say the engine did its job, and did it well, even with lack of lube (which from what I have seen, compresses the apex seal springs, and fatigues the apex seal itself.)

Sgtblue

iTrader: (16)

All cars have "consumables"......brake pads, clutches, turbos, even belts and hoses. But only on an FD does the engine seem to be similarly "consumable".

Jason

iTrader: (5)

Makes no sense considering the factory computer isnt controlling the fuel and timing anymore. When compression on an engine goes from 100 down to 22 on two of the faces that tells me something major happened that wasent just a tired engine on its last leg. If its compressed springs then thats one thing, but if it cracked seals then it was something else.

FDWarrior

iTrader: (6)

I always had the understanding rotaries ran strong untill they blew up. I think it makes sense, your just driving along and then a tired motor gives to the stress of boost and use. It happens all the time piston or rotary. Nothing lasts forever.
O and what do you mean that the factory computer dosent controll the fuel and timing. GtoRX7 was saying that a FD just rolled of the showroom floor can expect a life-span of 80,000 miles or so all stock. If you start building power you decrease life span. A top fuel dragster gets rebuilt after every 1/4 mile pass, the same principles of stress are applied to any motor; 8000 whp or 300 whp it dosent matter every thing breaks someday. I have one more question. You said if compression goes from 100 to 22 somthing major happened, so if I get a cracked seal from just old age and use my compression would go from 100 to 80 or somthing higher than 22? A break is a break it dosent matter how it happened.

Jason

iTrader: (5)

This car was not running the factory computer. I have opened a couple hundred motors to know what causes cracked seals. I dont call a reman with 45k miles on it that old and the apex seals wouldnt be that worn to crack on their own. He was only running 12 lbs of boost.

As I recall this guy was only running a power fc for a few months and had the car tuned 2 months ago, so its not like he has been pushing it very long.

I want to add that it could be a few things that are wrong with his motor. I have not opened it so Im just going off what he said.

Bob_760

I have an idea... Why don't you guys listen to Jason, unlike you guys he's not just making up random theories, he acctually knows what he's talking about... Contrary to popular belief rotaries do not just randomly blow up for no reason just because they are rotaries... For that matter no engines just randomly blow up, if the reason they die is exessive wear due to age then that's a reason, but no motor should experience enough wear to die of old age at 40k miles, if it did there was another problem. If this motor had say 40psi compression on all 6 faces after a few hundred thousand miles, that would be a tired motor. This motor cracked an apex seal, that's not a wear thing. From the sounds of things he did not have full time wideband monitoring so the fact that it had fine AFRs on the dyno means nothing on the road especially since it was cold. It could easily have run lean due to the weather.

Trjackson

Honestly, if I had to guess it wasn't the tune or lack of lubrication. My money says it the combination of the cold weather we had last week here in ohio and the shitty stock intake and the shitty correction factor the PFC has. The car was tuned in warm weather, the powerFC in my eyes does not handle correction factors very well. I mean there was a 40 degees drop between the day the car was tuned and last week. The stock manifold, may have not been the culprit, but it certainly wasn't helping it. Why do you think it is alway the rear housing that lets go?

Jackson

GtoRx7

iTrader: (5)

I have an idea too, lets review pictures of all the factory 13b twin turbo engines that blew with full factory computers, and very well maintained. How many do you think have just "even low compression" meaning a basic rebuild with new seals would be in order? Last time I checked, every factory FD I have rebuilt had a completely destroyed rotor housing and rotor, due to a apex seal shattering. Unlike a piston engine, the apex seal gets slapped back and forth every time the rotor goes through all 4 cycles, and is exposed directly to the flame front. If its turbocharged, then this slap is much much harder, and the flame front much much hotter. Eventually the fatigue sets in, and the seal dies. Most rotaries run hard to the very end.