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-   -   Oil in exhaust port (https://www.rx7club.com/new-member-rx-7-technical-256/oil-exhaust-port-932722/)

cab91089 11-30-10 06:38 PM

Oil in exhaust port
 
I looked into my exhaust ports on my 87 n/a engine and seen a little oil in the second rotor housing port. Someone who came to buy my old 13b today who rebuilds them and drag races rotaries told me that the oil seal is most likely blown on that housing. If this is true I'm planning on either selling my Rx-7 and engine or having it rebuilt and street ported. Is the oil seal blown on that housing?

jjcobm 12-01-10 01:03 AM

Yes, the oil control rings are worn out. I still drive my 150k engine daily with bad oil seals (I have seen worse to the point the car smokes 24/7) If it still runs and doesn't smoke when driven, it doesn't mean it's completely blown, they just wear out... Every rotary owner has a bad oil control ring story to tell.

cab91089 12-01-10 12:42 PM

The problem with this engine is that it's already out of the car and the kid I bought it from claimed it was rebuilt. He is going to be in serious trouble for selling me a blown engine. On the other hand I am seriously thinking of rebuilding the engine and getting some kind of porting done now or just selling the 7 :/

jjcobm 12-01-10 02:14 PM

well in that case i would be mad. you can tell if the oil seals are bad by rotating the engine, the oil will seep pass them and you get more oil in the exhaust port.

cab91089 12-02-10 03:03 PM

Believe me I am pissed off. Thanks for the help, I'm going to try that out a little later today.

cab91089 12-11-10 10:17 AM

Haven't moved the shaft yet, I didn't tighten the e shaft pulley bolt enough and I don't want to damage anything internally.

cab91089 04-26-11 08:50 PM

Been a long time since I posted here but the seal is definitely worn. Engine is going in really soon, hopefully it doesnt smoke when I drive it.

Zero10 04-27-11 08:35 AM

You are installing the engine with a known bad oil seal?

Aga 04-27-11 11:48 AM

i would just use that as an excuse to rebuild the engine :)

cab91089 04-28-11 02:13 PM

Yeah I am installing it with a known bad oil seal. I was told by the person I bought the engine from it will smoke at start up for a few minutes and then stop so it will be drivable. This is only temporary until the end of summer, then I am pulling the engine back out, rebuilding it w/ bridge port and doing the 6 port turbo conversion.

Aaron Cake 04-30-11 10:33 AM

Wait...this is a freshly built engine? Has it been run at all? If it is fresh of the stand, there should be oil in the exhaust ports as the lube was needed when assembling the engine. If it's fresh, it will be dripping oil from all of it's orifi for a while until it is started.

GTU_FAN 04-30-11 01:05 PM


Originally Posted by Aaron Cake (Post 10597902)
Wait...this is a freshly built engine? Has it been run at all? If it is fresh of the stand, there should be oil in the exhaust ports as the lube was needed when assembling the engine. If it's fresh, it will be dripping oil from all of it's orifi for a while until it is started.

Yeah +1 on this... a freshly built engine won't seal completely until its broken in. I wouldn't freak out on your engine builder just yet..,

cab91089 04-30-11 01:41 PM

No it isnt freshly rebuilt. The guy said he rebuilt it himself about 1,000 miles ago and it was already out of the car because he was parting out his rx-7's because he was getting out of rotaries because he just found out he was going to be a dad. He was pretty sketchy about some questions but I let it go until I had someone buy my engine that originally came out of my project 7. He builds rotaries for drag racing so I had him take a look at things that concerned me with the engine and oil being in the exhaust port was one. He looked at it and told me it is my oil control seal if I remember correctly. I bought the engine for $400 and I have plans to rebuild it in a few months anyway plus the guy I bought it off of gave me $100 plus a bunch of parts after I told him the deal so I cant complain too much. I know I should have looked into it more but I figured I could trust the guy but never again.

GTU_FAN 04-30-11 02:15 PM

Well maybe he was cheap about the rebuild and just reused the oil control rings? I've seen guys do that, and if the motor was built for racing you don't know how it was broken in during those 1,000 miles. You'll find out sooner or later when you take it apart. $400 doesn't sound like a total rip off, even if it isn't all new seals it's better then buying a garbage engine out of a junkyard for $150 that doesn't have any resusable seals.

Red_Rotor 04-30-11 07:57 PM

b/s if its n/a 400 aint worth it. i baught an s5 long block with 30k on the rebuild at 91psi no leaks for 250

cab91089 04-30-11 10:03 PM

He could have been cheap and rebuilt the engine with used oil seals but either way he said there were no problems and that to me is a problem. The person who I bought my engine off of did not tell me the oil seal was worn it was a guy who came to buy my spare engine that was blown. He is the one who rebuilds them for drag use and he looked at my engine and told me. It is N/A and it even if it is blown it was worth it to me. An s5 or s4 block with a recent rebuild for $250 is pure luck or someone being extremely nice. Blown engines usually go for around that price. A stock rebuilt engine usually costs around $1,200 easily. I am not that worried about my engine being blown like I was at first. I have since started working and can afford to rebuild the engine and do all the mods and upgrades I planned.

cab91089 07-19-11 10:10 AM

Got my s5 vert engine out yesterday from my parts car, took the exhaust manifold off to put my RB header on and the manifold was filled with oil and it dripped from the 1st rotor housing exhaust port. Blown oil control ring??? The previous owner of the s5 vert parts car I pulled the engine from (who actually is a member on this forum) said he put the oil in the engine to stop it from being carbon locked. The car sat since 03' and it showed with the amount of rat shit and leaves all over the car and engine bay. Im also not too sure how he got oil into the combustion chamber other then dumping it in through the spark plug holes since I can tell no manifolds were taken off since the car was brand new.


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