TK7

iTrader: (6)

Well, I blew my first engine last night. The car was able to get my girlfriend and I home, no tow trucks.

I bought a compression tester this morning and gave it a shot. Front rotor has 3 equal pulses and I saw a peak of about 115. But my back rotor measures nothing at all. The needle never even twitches.

I know it's done but my question is, is no compression at all common in failures?

Mr rx-7 tt

iTrader: (5)

Yes. Now it's a matter of how much damage was done in the rear rotor chamber.

Vortes

Its common when you blow an apex seal. Since you said you drove home on it, it probably made everything much worse than if you shut it down right when it happened. Your rear iron, rear rotor housing, rear rotor, and probably center iron may all be toast, but your front rotor housing and front iron should be fine.

Should check out your turbos also

adam c

iTrader: (2)

And you blew it because???

Possibly 2 seals gone in the rear. I friend of mine drove 130 miles with a broken seal on each rotor. Couldn't shut it down because it would not start again. Had to idle at 2K. Getting gas was tricky. I pumped while he kept the idle up. Must have gotten about 8 mpg on that tank.

MazdaSpeedDan

iTrader: (4)

Haha, sounds like my 1st gen....couldnt take foot off gas or it would die. 350 mile road trip in that sucked.

Tem120

iTrader: (5)

but why did it happeN?

TK7

iTrader: (6)

boost spike. EBC recorded 16.4 psi. i had it set for about 11. I havent looked yet but im guessing one of my fancy atutozone nipples probably failed, making the ebc not open the wastegate. PFC recorded 100% injector duty cycle was in the heat of the moment racing a friends WS6 and didnt react quickly/appropriately enough.

to be honest, i think i kinda started to feel like it was invincible. Ive done a lot of no-no's to it and with it over the years and its been bulletproof. I had a false sense of security.

I also was almost out of gas and was afraid to shut it off! haha. Im proud of it for getting us home safely.



on a related note, I may attempt to rebuild her on my own. Is it pretty likely all the rear parts are toast because i had to drive it home? ive been out of the forum loop for some time, where should i look for rotors and housings?

dgeesaman

iTrader: (7)

That'll do it. Those parts store vacuum nipples don't just fail, they fail much faster than I ever expected.

David

Japan2LA

iTrader: (256)

Rear rotor housing and rotor will be no good..

Sideplates might be ok..

Turbo/turbos will need to be inspected.

RotaryEvolution

iTrader: (30)

yeah, in all honesty i haven't really found too many reliable sources for vacuum nipples that work. a silicone hose with a plug in it or wrapped to another port in a "U" works better than those things.

TK7

iTrader: (6)

can i use any rotors and housings i can find for 13b? or do they have to be a cetain kind and new?


also, i got into boost to climb a hill on the way back after the boom, and it spooled and sounded fine. how will i know if they're broken? just visual inspection?

RotaryEvolution

iTrader: (30)

has to be rotors out of a '89-91 turbo TII, cosmo, or FD.

housings from the '89-91 turbo II will also work but the coolant passage needs to be plugged, the chrome on the turbo II housings also isn't quite as durable as the S6 FD housings.

djseven

iTrader: (56)

To elaborate on Karack's post:

While the chrome on the s6/Rew housings is better, it is still often easier to find a s5 NA or S5 TII housing used in better condition than a used S6/REW housing. The REW housings are usually cracked around the spark plug holes and show more striation wear above the trailing spark plug hole which will hurt compression some. Just find the best s5 or S6 housing you can find and you are good to go. If you go with the S5 NA you will need to swap the exhaust sleeve out of your damaged housing.

TK7

iTrader: (6)

im torn between doing it myself as a project or driving the shortblock down to rotary resurrection in TN

RotaryEvolution

iTrader: (30)

if you do i would probably recommend sourcing the replacement faulty parts yourself.

djseven

iTrader: (56)

Send it to Kevin at RotaryResurrection. I just got off the phone with him and he is picking up 2 sets of ALS seals from me. Took me a while to convince him to use them but he is now offering them to customers. Best steel seal on the market. I spent over 3 years learning under Kevin before I started building on my own. Cant beat how fast Kevin gets his customers engines done and the man has built well over 500 rotaries over the last decade.

jetlude

iTrader: (9)

What about rotor housings from a S4 NA 13B? Other than the exhaust sleeves and lack of knock sensor hole can these replace a FD housing?

RotaryEvolution

iTrader: (30)

the chrome is weaker yet in the series 4 and very difficult to find them with real good condition chrome surfaces on.

there is also a spark plug gap difference in the series 4 USDM housings versus anything in the later series. you CAN run them but you CANNOT mix and match them with later series housings, ie when using different housings you have to use them both from a series 4, series 5 and up can be mixed up.

TK7

iTrader: (6)

interesting you mentioned that, cause i just emailed him today about bringing some ALS seals with me!