blew my engine
 

Well sadly my engine blew today. i just purchased the car a week ago and it gave up on me. the guy i bought it from daily drove it and it seem fine. i test drove it and it seemed fine. so today i was warming up my car to take my friend out for a drive. it warmed up to 180ish and the fans turned on. i reved it up and around 7k the engine blew and died. antifreeze was gushing out of the engine. i jacked it up and found the problem. the center intake housing cracked. the crack is right below the spark plugs. its a hairline crack that goes horizontally and is about 3 inches long.

i was shocked at how that happened and that it wasnt the apex seal that died. i havent pulled it out yet. im hoping that the housing just cracked on the outside.

has this happened to anyone? do i have to rebuild the whole engine or do i just buy a center intake housing.

sorry i meant rear rotor housing lol

Post a picture of the damage.

Plates being cracked can be caused by binding of apex seal fragments, rotors, plates & housings trying to occupy the same space at the same time, while not meshing (something was out of place.

I've seen a rotor housing break out a 2" chunk in the load zone.

It sounds like you may have rolled an apex seal & it got smashed so hard into the housing that the housing cracked to reliev the pressure.

How many miles were on the engine? If it isn't locked up do a compression test before you pull it, then you'll know for sure if it's fuber with a 0 - 0 - x psi reading. What was the compression on the engine the last time you tested it?

Sorry it happened, I've been through it myself recently :)

I'll take a picture of it tomorrow. It supposedly had 30k on the motor. It has 3mm apex seals and it was a new shortblock. The engine is locked up now. The compression test were normal. Above 7psi on both rotors

take it to ben /karack, hes the best :) hes over by the orleans

What's the shop called

^ Rotary Evolution

so my car is all prepped up for me to pull the engine tomorrow. unfortunately the engine is seized so i have to pull the tranny out with it.

i should have a picture of the crack tomorrow, sorry for the delay.

im gonna have ben check it out, hopefully its not bad

I'm just going to leave this here... $750 if you come get it.



https://www.rx7club.com/3rd-generation-rx-7-1993-2002-parts-99/koyo-n-flo-steel-motor-mounts-ppf-subframe-3x-fd-trannys-rew-going-ls2-sale-957388/

talk to J.T.P here since you are in Vegas.
he's got a shop in Long Beach and does Formula D.

thats kind of a far drive for me

If I am reading understanding correctly.. from what you wrote in the 1st post... and that you say the motor is now seized..

Sounds like you had a catastrophic engine failure.. where the rotor internally comes off the stationary gear and crashed into the rotor housing.. breaking/cracking the rotor housing..

I have seen an engine that this happend to before. I broke it down (was not easy to do.. had to beat it apart with a serious hammer) all of the internals were destroyed..

The shortblock was all trash..


You where free reving the engine to 7000 rpm?

Why?

i think your right, the side is completely cracked. i was reving it up to burn carbon buildup. i got up to 7k and then boom

so its a lot worse than i thought

this was the crack i was talking about first

but i was way off

wow! ...that sucks! id say you would have been better off with a little carbon build up... more than a rebuild you have there.

you can see the rotor through the crack! thats crazy.

needs a rotor and a housing for sure ..but may have damaged the adjacent housings and even the crankshaft

yeah its pretty bad, i think i have get a new block

wow thats screwed

Can't imagine why anyone would do this. It betrays a serious lack of mechanical sympathy.

I guess it is the sort of thing that would seem cool in a video game.

dude, that blows

arent you supposed to redline it once a week for carbon buildup??

Not free-revving...

Yikes!!!

I guess I called it..

Your complete shortblock is most likely junk now..

Cant imagine what that sounded like...... and surely you went higher than 7,000 rpm and im willing to bet you held it there too....


Start looking for another engine, atleast a complete shortblock..

The engine I had that had this failure lost the rotor on the other side and took out the exhaust manifold, turbo, and LIM...

i only got to 7k and it was for a brief second. it wasnt a loud boom. it sounded normal till 7k and then it just started to clunk and died instantly. there was no explosion. there was black smoke coming out of the exhaust right when it happened. i have a video of it because i was wondering if it was going to back fire or not. and it didnt backfire. i wasnt reving it like crazy either.

so your supposed to redline while your driving then, expensive lesson learned. i tried to do it just like this video.


http://www.youtube.com/watch?v=bYpx9...eature=related

Wow! That if a grade-A catastrophic failure if ever there was one.

So there's a video you say...

yeah, i have one, ill upload it when i can.

I agree with what you are saying but from firsthand experience I will say that shouldn't cause this kind of failure. When I had my first Rx-7 (I was 19), a nonturbo FC, I used to do that all the time. I must have launched it at 7k a dozen times (had a puck clutch and lightweight flywheel) and it never caused any engine problems ever. Sure it eventually broke the mounts, the diff, and the tranny, but it never did a damn thing to the motor. And FD internals are better suited for high rpm than 86-88 rotating assembly.

Something was up with this motor.

Sounds like the guy was trying to shoot fire out of the exhaust... who knows what other abuse the poor car endured during his brief ownership

alright I don't get why some people are bashing this Guy. he just bought the car, he thought he was doing something right by revving the motor (killing the carbon. Why does everyone assume this guy was hooning his car?

anyway sucks to hear about the motor blowing! Atleast now you can research and figure out where you want to go with the car.

that's not a crack, that's a fault line! good look with it man!

THANK YOU, i appreciate that.

yeah, i think the motor wasnt built right, as i started taking it apart, there were a bunch of plugged up vacuum ports and unconnected boost lines. there was also a huge hole in the air pump, 1 1/2 inch by 1/2 inch. i found pieces of the apex seal inside the exhaust manifold

It seems like something could have been up with the dowel pins or tension bolts or something. Lots of rotaries tach to 6000-7000rpm before launching in a drag race, without special internal modifications.

I agree, reving to 7k while not in gear should not cause that.

You say you let the car sit there and get to temp, then you revved it and it popped?

Im guessing you would have had some nice high intake temps rite there!! redlining a heat soaked rotary is not the smartest thing to do.

+3 on there had to be someting wrong with the motor to begin with, free rev to 7k won't blow a rotary in proper operating condition. Think how high the stresses are in a 500+hp rotary at 7k and full load.. compared to free revving? Also like Arghx said there are many draggers out there that launch at high rpms regularly... I launch mine at 5k all the time in autox with no issues other than clutch wear...

it wasnt heat soaked. the water temp was at 180. and i didnt even get to redline

i never launched the car or clutch kicked it. didnt have the chance. the previous owner said he tracked it. i did floor the car in second and third gear and shifted at 7.5k. i didnt have any problems there except the shifting

Heat soaked is basically when your other engine bay components heat up due to engine bay heat..
Your telling me your intercooler had air passing through it so it was not "heatsoaked"/ at engine bay temp??
your intakes were breathing cool fresh air? not air that has heated up in the engine bay from idling to 180degrees??

Your engine compartment had no air passing through it. Your intercooler would have been the same temp or close to the temp of your engine bay, hence heat soaked.:scratch:

Engine bay temps could well be higher then water temps...

You´re kidding, right?

http://www.streetfire.net/video/13b-...-rpm_9899.htm#

By your reasoning, these guys should have rotor sticked in their head:lol:

This is catastrophic failure, even detonation - which would hardly occur without load couldn´t do this. I would have serious discusion with previous owner:bottom:

looks like a broken e-shaft IMO, which is a rare oddity occurrence.

anyways, if i do ever see this motor i will take pictures for reference. i doubt there will be much as far as usable parts from that engine though.

free revving a rotary isn't cause for something like this so just bury that stupid argument.

wasn't a broken e-shaft but close enough, can only guess a tooth fractured on the front stationary gear which caused a catastrophic chain of events. the engine did have 3mm apex seals, solid corners and oil modifications done to the eccentric shaft. of which i have no clue if any of it is what caused the failure but this is the most gnarly teardown i have seen to date.


https://img593.imageshack.us/img593/5471/dsc00331a.jpg


and

BOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOM!

https://img98.imageshack.us/img98/3513/dsc00332tx.jpg

unfortunately obviously 2/3 of the motor is now scrap and nothing to pinpoint as the root cause aside from bad luck.

the rotating mass of the flywheel is what caused the extensiveness of the damage. the flywheel woodruff key was half sheared but managed to hold on enough to cause all the damage without letting go.

https://img808.imageshack.us/img808/7760/dsc00335a.jpg

looks like the roads around here, an abrupt lane shift...

Holy crap lol...it almost polished the gear teeth smooth

Gonna be hard to buff that out :P

If that had happend to me I'd still be running in circles flapping my arms and crying like a little girl

well after getting the car together and to my shop i found that it was idling like a bridgeported motor on my streetported engine. :scratch: so i checked a few things and the map sensor was reading 0 in FCedit so i checked the map sensor and it had a check valve in line to the map sensor instead of a filter..

supposedly this was not changed and i am going to assume that it could have been the cause of the failed engine which wasn't all that old.

moral of the story i suppose is do not put a check valve in line to your map sensor, even if it makes your car sound like a mock bridge port. :)

the map sensor would read boost ok but not release the pressure, i don't really see how it was drivable but i can't find any real reason why the engine failed in the first place aside from the modified eccentric shaft oiling holes for the stat bearings.

Talk about bad beginners luck!

i'm more curious to know what it sounded like when that thing let go! heh