snub disphenoid

Earlier tonight I went full throttle, while one of my friends was following me from behind. He said that he first saw a small flame, then a LARGE flame come out of the exhaust, then the car started smoking like crazy. I also noticed a sudden drop-off in performance, and the oil pressure gauge quickly dropped to 0, so I cruised easily to the nearest exit and shut off the engine ASAP. We popped the hood and there was a fair amount of oil spattered around, and it looked like there had been a jet of oil that came up and shot on to the bottom of the hood. There looks to be a screw that came off of the top of the engine (on the rear iron, near the transmission). I'm fairly sure that the rear iron didn't crack and that something simply backed out and caused a major oil leak. The engine seemed fine and it drove normally, except for the smoke and lack of oil pressure (which was not coming from the exhaust, but from under the car). I don't think there was a catastrophic engine failure or anything like that (the car drove fine and normally until I pulled off the highway), but it does seem that something went wrong in the oiling system.

The car in question is an '83 GSL with an S5 TII engine, I believe 12A intermediate housings, large street port, 3mm seals, T04 turbo and an archaic Haltech F3. I was boosting around 14psi on a pig rich map, and I'm not sure if that's enough boost to crack the rear iron.

I'll be sure to take pictures of what I think may be the culprit, but I'll go back tomorrow, fill 'er up with oil and see where the oil leaks from when I start the car up. Any help is greatly appreciated. I got this car not but 2 days ago and I'm already loving the first gen. more than I have any other RX-7, so any help I can get to get this brute up and running again would be greatly appreciated.

SparkienSuggah

...put the bolt back in and see if it helps?

driving with no oil pressure is a big no no.

snub disphenoid

I drove to get off the freeway IMMEDIATELY. I got off and turned the car off ASAP. I'm not sure if there's supposed to be a bolt, or if this is even where the oil was coming from. I definitely can't find the bolt, wherever it is.

Dr_Jeff

bummer

got the car two days ago & you already tore it up.

tisk, tisk, tisk.

inuissus_cendi

front mount oil cooler or beehive?

Directfreak

iTrader: (2)

Ditto. Damn shame.
If you ran the car with no oil pressure at all - You're likely
going to need a rebuild. If not now, then soon.
Hopefully it won't be torn up inside, and you'll be able to save some parts.

NEVER Drive a Rotary with No Oil Pressure - not even for a little bit.

And cracking the rear plate is very possible, especially if you were in a
high gear under full throttle.

snub disphenoid

What would cause the rear plate to crack? Was 14psi just too much? The car had a big front mount, the boost never creeped, and the previous owner said 14 was the normal boost level he ran the car at since the engine got broken in...

snub disphenoid

Also, if the rear iron cracked, wouldn't the oil have gotten everywhere? The oil just shot on to one spot on the hood, not really all over the place...I'm definitely not ruling out the possibility of the engine being totally blown (although the car never made any abnormal noises or anything of the sort). The car was running with 0 oil pressure for less than a minute, and most of that was in neutral. I'll fill it with oil, check where the leak is, and get back to you guys.

snub disphenoid

Oh yeah, the rear plate's cracked. I might take pictures of it, might not. It's cracked at the top of the engine, at a point close to the clutch slave cylinder. Strangely, it looks like there's a plate there to seal the rear iron.

What can cause the rear plate to crack? Too much boost? Too much stress? I was running 13-14psi, the car was tuned very conservatively (AFRs in the 8s and 9s), the boost didn't creep,the intercooler wasn't heatsoaked, water temps were notmal, the car had a full tank of gas, tons of fuel (1000s and 1600s). I seriously don't know what would make it crack so soon. The previous owner said it was running like a champ and for two days there, it was. Oh well, rebuild time, hopefully I can find someone who will do a really good job.

steve84GS TII

I take it by your description that only the rotors are S5 TII?
It impossible to run 12A irons on a TII engine since the water grooves were changed in 86.My guess would be your running GSL-SE rotor housings with 12A irons and S5 TII rotors....?

In any case,if your running 12A iron housings(particularly the rear iron).....then 14psi is WAYYYY too much boost without doweling,studs or other preventetive measures to help out the rear plate.
Mazda was aware of an inheirent weakness in the rear iron and improved the design on S5 and S5 engines.Many people have cracked rear irons on S4 TII engines,and I can imagine that the N/A 12A and 13B engines have even weaker rear irons,since they were never intended to run boost.........

Said it before,and Ill say it again......being different is fine........but boosting N/A engines is costly and heartbreaking.....

snub disphenoid

Well gee, now I feel like a dumbass for not doing enough research on the engine. Time to rebuild the engine...right this time.

Hyper4mance2k

iTrader: (40)

I'm guessing you blew a oil control seal.

steve84GS TII

Nope,oil control seals keep oil inside the rotors and out of the combustion chamber...he blew oil into the engine bay.....external blowage!

Im still kinda wondering what kind of engine you have...is it a 12A or 13B...... or some kinda hybrid 13B or what? You mentioned a S5 TII,but with 12A parts,which doesnt jive.

If you rebuild the engine yourself....or at least tear it down yourself....then try to determine exactly what components you have so you can mod appropriately.If you are infact running 12A irons,but you have a 13B engine....then jsut skip all the expensive mods and just get a S5 TII engine.Itll have all the best turbo upgrades made to it from the factory.Its much easier than trying to get an N/A or hybrid built engine to stay together.I run 14psi, all-day-every-day, for 3 years on my S5 TII Mazdatrix built engine....30K miles and no issues whatsoever.

If you have a 12A and wanna keep it 12A for originality,then youll HAVE to do some doweling,studs,ect to keep it happy.
Dont waste your time with hybrid 13B engines made from various other engines.If your cool with 13B power,just get a whole J-spec S5TII and never look back....

trochoid

iTrader: (6)

I was at KCIR a couple of summers ago when a fellow with an S4 TII engine in his RX2/3, cracked a rear iron. The track was shut down for nearly an hour cleaning up the mess he made.

I have to agree with Steve84 on this one. Sounds like an SE motor, with 12a end irons, or perhaps even a late 70's 13b 4-port with an S5 intake. If you really do have a 12a center iron, where are your primay injectors? The 12a has no provisions for them.

I would even question the S5 rotors. If the previous owner couldn't provide documentaion to show that the rotors were machined to 3mm, then I would assume they are pre 86 rotors and high compression ones at that.

Sorry to hear that you popped it, but as they say, 'Practice makes perfect". Unfortunately, it is also expensive. Good luck with the next one.

snub disphenoid

Well, I might just take it apart, get rid of the parts and build the **** out of a new 13BT/RE.

steve84GS TII

Thats the best route.
S5 TII engines are everywhere since Japan had TII engines in EVERY 2nd gen made.The send them here in hoards and can be had for cheap and are often in good shape.Even if they are blown,you still usually only need to replace one housing and rotor.If your current engine does have S5 internals,then your halfway there.In addition to the stronger rear iron,the S5 TII block also has bigger ports than the older engines,which makes porting a simpler affair.

snub disphenoid

I just got some info from the previous owner, still waiting on word from the guy who built the engine. He said that only the intermediate housing was from a 12A, the front and end plates were 13B, the rotor housings have 13B stamped on them, and the engine has "the lowest compression rotors". I don't know what that means, but I'm probably just going to plunk down the cash for an S5 shortblock, dowel pin it, run 12 psi and call it a day.

trochoid

iTrader: (6)

Running an S5 block, you shouldn't need the dowel pinning for 14 psi. If you plan on getting extreme later with your boost, or a huge turbo, it would be a good safety margin.

Btw, could you post some detailed pics of your setup? I'm curious how the intake and injectors are setup. A pic of the 13B logo on the housing might give us a clue of which era of housing you have. Include the spark plug holes.

steve84GS TII

Alright then.
With the 12A intermediate plate,youve got to have either SE end plates and rotor housings or 70's style 13B end plates and/or rotor housings.The postions of the water grooves in pre-86 housings would dictate it.Theres little, to no chance you have any TII parts in that engine,except the rotors/E-shaft.

Either one of those rear plates is going to be substantially less robust than a TII plate,more-so when compared to the S5-S6 housings.Thats why you popped.Even with a low static compression ratio,you were pushing 14psi of positive manifold pressure through ported intakes,into an engine mechanially desiged for atmospheric induction(N/A).Your actual running compression ratio was high,too high for the engine to withstand,despite the small compression decrease the S4 TII rotors provided.

I agree with trocoid,and I have personal experience to back it.You dont need dowling on a S5 engine if your staying at or below 14psi.Ive got 30K miles on my S5 block at 14psi to confirm that....

Turbo II-FB

no you dont need dowel pinning. If you are running som,thing alonmg the lines around 600 hp and up or mabe 500 you need pinning

trochoid

iTrader: (6)

I asked for the pics because because no usdm 12a center plate has provisions for injectors. I'm not familiar with the jdm 12a turbos, but my guess is they do have the injector ports. If one of the Aussie mates are reading this, perhaps they could comfirm, one way or the other.

This is why I said in an earlier post that you probably have 12a end plates and an SE center iron. A pic would show exactly which intake is on the engine and where the injectors are located. The S5 intake is not a bolt on to the SE engine. There are a few modifications that need to made for the ports and mounting bolts to line up. I'm not up on the Haltech's and when each series was produced, but I suspect that the 3 is a pretty old one and that leads me to believe that your engine is probably an SE or an early 13b version.

If you are going to the expense of sourceing and rebuilding an S5 motor, I suggest you look into a later model Haltech or other brand of stand alone. The Haltech may have been the problem in the first place. With the afr's you were running, the engine should not have popped, unless there is a problem with the Haltech or you were running too low of an octane, or there are other ignition issues. (misfires, wrong plugs, old plugs/wires, etc.)

I think pinning is recommended above 400 hp and or above 16-18 psi of boost. Don't quote me as gospel on this though.

snub disphenoid

Alright guys, I really appreciate all of the advice. I'll snap some pictures tomorrow when I get the car towed.

The Haltech F3 is pretty old. It's a fuel only computer and it's only adjustable every 1000RPM. The car is currently running a distributor ignition setup (which may have caused some problems, I'm not sure). Since I'm going to be using a rebuilt S5 TII shortblock, I'll definitely be changing the EMS setup. I may use the F3 for the break-in period when the car will be operating without boost, but after that I am most definitely switching to either a Wolf 3D or a Haltech E6X.

The plugs could have been the wrong plugs, the ignition could have been too crappy, the car could have misfired, etc. I'm not too sure what happened, but I'm going to go ahead and put down the money to make sure it doesn't happen again. I'm going to run 13-14psi daily and I'm shooting for anything above 300rwhp. I'm not sure which Garret T4 turbo I have, the compressor housing looks larger than the T04B I have on my FC, and the only spec I have on it is that the exhaust housing has I believe a 1.06 A/R. By next year, if the car is running well, I was considering installing meth/water injection, installing a PT67 and jacking the boost up to 17psi on pump gas, 21 or so on race gas. That might be simply too much power for the transmission/rear end.

steve84GS TII

No doubt.
A smoothcase trans will not last long and the rearend will only hold for a while,depending on how you drive.The stock 1st gen rearend will hold 300hp for a long long time if you dont abuse it too often.But when you get around 400hp,its time to start looking at Ford 8.8" or better......

snub disphenoid

I think the engine may be all 13B parts, but what 13B parts I don't know exactly. The center iron has two injectors in it, and the rotor housings are obviously 13B. Here's a few pictures from the long tow "home."

steve84GS TII

Ah,so you might actually have some TII parts in there.It all depends on if the center iron is GSL-SE or FC.After you pull the engine,provide some more pics and we can narrow it down....

The "crack" in the first pic is just a sheet metal cover over the flywheel.Nothing detrimental.
Do I see a Fram filter!?........Also,Im not liking the way your oil looks.....................