Kurgan

Well, not exactly. I have the famous 13bt weak rear housing oil leak... too much power without reinforcements in my old block. The hollow dowel on the rear driver's side of the block is seeping oil.

Not quite sure what I'm gonna do now, but I have a few optons...

I could:

• Pull the engine and replace the rear housing fixing it for now, but it may happen again
• Send my engine off to have it rebuilt
• Pull the engine and rebuild it myself
• Go crazy with a 20B

Right now, I'm thinking that I'll pull it and rebuild it myself. I want to go 3 rotor, and I will in the future, but this is just bad timing... unless I can find a 3 rotor for < $3000 with the turbos and accessories, I'm not gonna do it now.

I'm not too bumbed, I know the rest of the engine is still fine, but I want to freshen it up while its out... something I'd thought about doing any how. The engine still idles fine, holds perfect vacuum, revs perfectly and has power...

Just thought I'd keep you guys informed.

I'm coining a new term:
The Nick Effect - If something can go wrong, it will... multiple times.

I hate murphy...

Kurgan

The red is where the oil is seeping out, only while the engine is on.

E6KT2

Isn't your engine a rebuild?

Kurgan

Yes, but it was rebuilt about 3 year ago by some guy. I really don't know how well he did the porting on my housings... thats the main reason that I want to rip the SOB apart and see whats inside. Now that I somewhat know what they should look like, I'll be able to see how much power this thing can actually make. I'm leaning more and more to rebuilding the engine myself and putting extra pins in the weak area.

Plus, with the engine out, its a perfect time to paint the engine bay

photoresistor

iTrader: (5)

*chanting tone*

20B 20B 20B 20B 20B 20B 20B 20B 20B 20B 20B 20B

tesla042

That's dangerously close to where the oil filter neck leaks when the o-rings go.. It's a long shot, but are you sure that's not where your leak is?

-Tesla

HWO

It's not a famous 13BT weak rear housing oil leak, looks to me like the famous "i pinged and instead of blowing an apex seal i blew the rear plate instead"

I think you've detonated without knowing about it.

Kurgan

I disagree.

I wasn't even driving the car hard at all... I hadn't boosted it over a week, just driving back and forth to work. Then, all of a sudden, pool of oil in the garage.

Also, my engine has been running SO rich, I don't think its even possible to detonate... I'm at about 11:1 AFR, closer to 11.6:1 at 7500 rpm and 15psi. i guess a misfire could have hosed it up... but I dunno.

It doesn't make since to me. This is usually the result of detonation, but there is no way that I had detonation... unless I just hit a lean spot in normal driving, but I doubt it...

And yes, it is a famous weak spot. HWO, I know you know what you are talking about, but I've heard about this weak spot on the GTR block for years... seen plenty of this happening... how can you say its not a weak spot? thank god for the weak spot, cuz if it was detonation (it might have been, but I have NO clue when it would have happened), I would have blown the rear rotor...

RarestRX

Yo,


Well, the title of this thread only holds true for turbo rotaries. *wink*

They may go "Pop!", but the NA rotary goes "Hummmmmmmmmm". *grin*

Just don't want any potential RX-7 owners out there to get the wrong ideas about rotaries.

Your friend at 8000rpm,


KS
1989 GTUs "The TurboII without the Turbo."

fc3s.org

I would have to say 20B

Mykl

No no no! You got that all wrong, it should be...

"The Turbo II without the headache."

:p

Scott 89t2

I'd say take a look at the oil filter block o-rings. the "weak spot" takes about 400HP to get.

HWO

kurgan - 99% of what you read about rotary turbo's on webpages is total BS, When i first started talking to the likes of Rice Racing and Crispeed i thought they had lost the plot, they were trying to tell me the exact opposite of what everyone else had told me and what i had read everywhere, then i realisde that most people get their "info" from someone who has got their "info" from someone else who was mis informed, so basically it started out along the lines of Joe Bloggs told someone some totally BS info, that person told his mates, who told their mates and it all basically snowballed on from there and we get where we are today with 99% of people trying to tell you total BS which they and the other 99% of people believe to be true, cause they hear it from everyone else.

Now Crispeed reckons 700RWHP and you need extra dowels, so until you are making say 600RWHP (allowing 100HP for this 'weakspot' that the Series 4 13BT block has in it) thats still 600rwhp, thats a lot more HP than you are making right?
So until you are making 600rwhp or more, then the only way you can crack plates is the result of detonation.

You say you are running 11.0:1 then leaner to 11.6:1
frankly i wouldn't call 11.0:1 hell rich, i'd call it in the edge between being safe and loosing a bit of HP due to the added gas and in the making safe HP reigon
all it would have taken was a single engine cycle to occur in which it ran slightly leaner or it sucked in hotter air or whatever and it would have detonated.

The 'results' you have seen for years have been a RESULT of detonation. it's all to do with what is weaker, the apex seals or the area around the top dowel on the plate, whichever is weaker gives and the result is a blown motor. I'd say it's cracked bu not baldy, normally the result of this is oil sprayed everywhere.

I'd say it detonated, but only cracked it very minorly, while the engine was still hot, the expansion process held it all together, but once it cooled down the oil was able to seep out the crack and onto your garage floor.

Suparslinc

yes that is exactly what happens on this forum and it pisses me off, too. People just love to have their "own" opinions on topics they have no business even posting on. they just regurgitate someone elses post and half the time its not even true. I get quoted sometimes and I KNOW I'm full of ****. Well, anyways since I'm completely off topic I'll shut up now.

Kurgan

HWO, well said. What you said before came across, at least to me, as being spewed out without thought. But, as I said, I knew you know what you are talking about... and I wanted to hear what you REALLY meant. Thanks for clarifying. Like I said, I don't think it was detonation... but what the hell else could it have been? Right, there isn't much else So, as I take time to collect my thoughts and decide what I'm going to do, things start to make a bit more sense...

Let me ask you this... the detonation was obviously not 100% fatal, as my car still runs fine. Do you think that the internals of the rear rotor and the rest of the engine, sans the rear iron, are fine? I have spoken with 1 VERY good engine builder, and he seems to think that the rest of the motor is fine... but what have you seen in cases like this? Anyone else, feel free to chime in.

I listen to what Crispeed says with open ears... he knows a LOT. He knows nearly infinitely more than I do, and I TOTALLY respect his input, but I feel that I'd rather be on the safe side and put extra dowels in WELL before 700 bhp. But, this argument is worthless... what the hell would it hurt to put the reinforcements in? Right, nothing. But, what might happen next time is not cracking the rear iron or the hollow dowel, it might mean apex seal death... so, there are tradeoffs, I know... Arguing over when to pin your motor is like arguing over when to use 2mm vs. 3mm seals... people will do as they please.

Like I said, NEED MORE INPUT! Start posting guys...

And HWO, thanks for your insight, I really do appreciate your contributions (make more ).

Kurgan

This is a total possibility... I'll know soon

Kurgan

Good call there. Been there, done that. Its not the culprit. Thats what we thought... but unfortunately, its not the case. When I use a mirror, I can very clearly see it seeping out of inbetween the rear iron and the rear rotor housing, exactly where I've highlighted in this picture :



p.s. This is a pic that I swiped from Vosko's thread about his engine, its not my engine, just purely for demonstration purposes.

Mykl

The only way you'll know that everything else is good, for sure, is to tear it down, buy a set of micrometers, and measure everything.

I'm not sure how likely it is that you damaged something else, but if you keep driving it then I'd think that the chances that you're going to break it worse than it is is pretty high. But I think you realize this already.

HWO

Peter is more clued up on this particular area than i am - you see he hasn't told me all he knows YET :P

He has had engines detonate with the factory 3 piece 2 mm seals crack the end plate, sent the apex seals away for crack testing and had nothing wrong with them.

My Theory on weather you crack the plate or the seal goes something like this. If you actually detonate, that is uncontrolled combustion when ignition is supposed to occur you either crack the seal or the plate which one i am not sure, on the other hand if you pre ignite - that is the spark plug has retained enough heat from the last spark that it operates like a glow plug in a diesel engine, and when you get enough compression in the compression phase it ignites the mixture, the result is either a seal or an end plate, the opposite of what cracked when it actually detonated. thats just some random thoughts i had a few hours ago, it may be true it may not, but there has to be a reason why you can still crack end plates with detonation with stock seals.

HWO

Maybe Obei Wan Kanobe fired a photon torpedo at R2D2 when he was being a bad egg and it bounced of luke's light sabre and impacted with the dowel area of your rear plate as you sped past.....................

t_mak@mail.plymouth.edu

My NA rotary pops, not motor, but a huge backfire

BOOSTD 7

I wish I could remember the URL of the pics of my broken housing. When mine did this, it cracked the rear housing and oil came shooting out. When I tore the engine down, the apex seals were just fine. But it was obvious that it had gotten VERY hot inside the engine. The corner seal springs had lost all their tension and were flat as a pancake. The engine still ran fine, but it wouldn't have ran for to much longer.

The bitch of it is, right when it blew it ran like it had never ran before. I ran next to a mid-11 second car and walked on him probably 20 cars from 30 - 120mph. Then pop, no audible sign of detonation, just pop. EGT's and A/F's were all looking fine throughout the run, nothing on the datalogging that would indicate a problem.

Kurgan

Right now, I'm blaming 0 degrees split timing. You're running a Wolf, right? When mine did this, I had it set to 0 degrees because for some reason, it gets better mileage set to that (it doesn't make since, but I get an extra 5 mpg like this). It suppose to be good for more power, but that's not why I was running it like that.

I won't be messing with 0 degrees split timing for a while, at least until I am confident in my own tuning abilities...

And HWO, the Star Wars theory is pretty good. But, Photon Torpedoes are from the future (Star Trek), and Star War happened "Long long ago, in a galaxy far, far away"... So, the enterprise would have had to travel back in time several millenium, givem Obi Wan a photon torpedo, he would have fired the torpedo and it would have had to entered a time altering wormhole to enter present time... then the likelihood of it hitting my car in the area of "The famous 13bt weak spot" is not very good... so I doubt that is the case

Suparslinc, what the hell are you talking about?

vosko

iTrader: (4)

i feel honored

jizzajuice

You want turbo ALSO on the 20B?? Hot Dang! The 20B already has incredible power, add a turbo to that and you'll likely blow your pants off if you drop the throttle. ^_^

Peace,
AJ ^_^