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Fairlady Z

Anyone know a rotary engine buff please help

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Cmon Mick i know how to put correct level of oil and also know what 710 stands for. ;D





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OMP lines connected wrong way around?


To the unknowing, a eprotary requires a very small amount of oil, much like a two stroke , to be mixed with the fuel prior to entering the combustion chambers.

When they run a whopping big 51 mm Weber IDA downdraft, on a peripheral port, like my thing, the oil has to be mixed with fuel, prior to going into the tank, ratio of 125 mils to 20 litres of fuel.

Best bit, i use Castor oil, and THAT exhaust smell is so lovely.


A real Homer Simpson - mmmm Donuts moment !!!

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Best bit, i use Castor oil, and THAT exhaust smell is so lovely.


A real Homer Simpson - mmmm Donuts moment !!!


Try Sesame oil.  That should get your juices flowing.  maybe with a dash of peanut oil and a sprinkle of chilli.  MMMmmmmmmm

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Try Sesame oil.  That should get your juices flowing.  maybe with a dash of peanut oil and a sprinkle of chilli.  MMMmmmmmmm

I can see it now,,,,

New tv show,,,,


"Lets Cook a Donk, with Simon and Jason"


Nah the castor oil, or bean oil comes from the same plant that some crazy fat japanese retard tried to poison gas the japanese train system with, it worked.

Hmm, i just cant see " roki doki, retts pouson the people rith asesame oil"  quite working.!!

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hahahaha u guys crack me up. hmmm at least will smell njami from the back.  ;D


nope OMP lines are hooked same way around. to think about it i never check if they correct .


but omp was loosing lot of oil around the gasket. so took it off clean it up and used little bit of rtv or whatever its called on the old gasket as a temp fix. Ordered new gasket also new gasket for water pump (slight leak) and need to replace omp hose clamps not clamping hard enough.


now not sure if the oil leak had anything to do with smoking but seems lot of oil had gone through the exhaust at some stage.  but how and why?


there was another two issues that occurred.

I guess there's no point being smart with you guys as you helped me the most. so i let the secret out


one was mentioned by one of the forum members regarding PCV valve and emission system. saying if not correctly hooked up will smoke. that issue #1.

Most people have ripped out the pollution gear or car modded so no one really knows how it works and what it should look like. 

even though i rerouted 98% of the hoses as per service manual there was a pipe that looked redundant.


Studied few of the emission diagrams between models and that pipe was just a routing pipe to make the system look neater.


At some stage a normal mechanic didn't look at the emission diagrams and randomly placed stuff till he got a reasonable engine operation. 50% of hosing was incorrect or split.


initially i just replaced the split ones. after got my hand on manual realised few things were out.


after resealing OMP to stop the oil leaks, i routed all the emissions as per diagram. While cleaning the engine bay i found a piece of hose with an orifice that was part of the fuel tank. The orifice had a really small hole.


the orifice is highlighted in the manual. so I replaced the hose and fitted the orifice. Now i was 100% sure the emission are hooked correctly. tested some of the solenoids and were operational. another hose was plugged from manifold to the solenoid while it should be open to air and manifold one plugged.


started the car after refitting the rest of the gear on. hit the key started it warmed it up but wouldn't idle just stall.


Played with idle air and mix setting till i got stable idle.


Gave it few revs and was still backfiring and didn't like being revved. still no smoke and almost 1hr running. looked promising just needed to get to higher revs so i can repeat the previous smoking issue.


check the timing and noticed that wast getting any signal from leading coil. What tha??. while trying to figure out why i noticed engine revs changed ran lot smoother and i was getting a flash from the timing light.


re did the mixtures and idle as it was revving lot higher than before. and gave it few revs. it responded like a chain saw. light tap of accelerator and revs will shoot up almost instantly. hmmmm never behaved like this before.


shut the bonnet and took it for a drive. it was almost 9:30Pm and dark but i could still see the street behind me. so increased the revs and still nothing.


Booted it to 6K still nothing. kept giving it hard time and after 10min i started to see small amounts coming out but after 2-3 sec it disappear. drove around for another 10min and mostly clear only few puffs when really hard acceleration. but every time was less and less.


got me thinking its residual still in the exhaust. when booted exhaust gets hot and start burning the oil inside.


went home to check the fluids and plugs. oil lightly seeping from omp lines due to weak clamps. easy fix. coolant leak from water pump gasket . easy fix. oil out of the exhaust pipe nothing. out of the 3 tips 2 were dry and no wet or oily residue. one tip still had slight residue.


pulled the plugs out and they were dry and clean all 4 of them.


looking good. started it again and starts relatively easy. still the tune i believe is out of the whack as i tuned it just by feel and sound. need to get a gas analyzer and set the correct mixture settings.


was very happy. As i was ready to hand out 2k plus for a rebuild. so saved 2k woohoo.


it was too good to be true hence i kept it quiet that night and wanted to test the car during day time as i though maybe the smoking looked less due to being dark.


so tested it yesterday driving around for a while. and only twice it puffed when i hit the rev buzzer. exhaust tips get so hot that u cannot touch them. Driving it normally around 3-4k max rpm . not one puff. exhaust not hot enough.


no significant loss of coolant or oil. no smoke, start easy,.


though was checking the coils while running and removed the high tension lead. it started to spark between high tension ad -+ terminals. looks like insulation is broken down. so will replace both coils and get new leads. clean the disy and hopfully spark will be as good as it can get.


so it wasn't the Oil Control Seal but combination of things.


1.Leading spark plugs weren't operational. not complete burn = smoke fuel


2.Emission was incorrectly routed causing to suck extra oil out of the engine. (this could have been happening for some time, hence the oil in exhaust ) smoke oil


3. orifice missing from fuel tank possibly causing pressure differences and again possibly sucking extra fuel/oil (speculation but it wouldn't be there if it wasn't needed)


Theory #1.


car was last regod in 05. possibly being diagnosed as OCS and requiring build due to above last owner of 19 years and decided to just decided to upgrade after all that time. inside and outside state was sad and not nice. 


Someone bought it to rebuild it. to preserve the motor they poured oil into it. common practice. to protect the housings and stop stuck seals from occurring.


Maybe decided to let it go and sold it to the person who i bought it off. they may have had it cleaned up and engine started while engine in oil burned out quickly lot of it still remained in exhaust. so while idling and cold no smoke. when exhaust gets hot we get oil burning. 


Theory #2


car had perished vacuum lines and was running badly. Original owner had it checked at some normal mechanic. He "fixed it" by plugging and routing lines just to get it to run good. plug this route that here yep its smooth fixed.  :o


Shortly after it started to smoke and probably diagnosed with Oil control Seal and expensive rebuild. Owner after 19years decided to part way.


who know how many owner after that till i ended up with it. it seemed fine cold but due to extra oil through system accumulated in exhaust it never showed till exhaust gets really hot and starts smoking.


this was the key difference from Oil control seal failure which initially happens on cold start or prolong off period. 5 forums and 3 rotor buffs confirmed.


but when i asked i don't have that i got the opposite. some ummed and hummed while others started talking crap and making stuff up or saying it can happen the other way too.


i refused to believe that cause across 4-5 rotary forums no mention of this anywhere.


car would have idled for hours without smoke. its when gets bit hot.


as not many standard cars around with all pollution gear on it most people didn't come across this problem.


Though the engine is a beast. little 1.1L after 3K just want to go. The more revs the more power you get. She not backing off at all till the little rev buzzer tell u to back off. So smooth. quite fun car highly recommend it. be perfect partner to a 240Z similar size a bit lower in body height more comfort features.


Definitely not my last Rx7 and last rotary. Wouldn't mind a hotted up version S3 Rx7 and want back an  Rx4 Coupe in my collection.


as impressive as Mazda is still nothing beats the Z. but it could be a good investment and very cool drive. so keep an eye out for a lost one selling for nothing. they quite cheap these days.


Tip: look for good interior as its hard to find undamaged dash or trim bits. red interior is worse for wear. browns and blacks seem to be better and more common. but red on red is just right  8) or if you can find silver or white with red. nice combo in my opinion.


now see if i have any bites on my $1 guesses. ;D














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Congratulations on saving all the $$$ on a rebuild.  Oh and thanks for making me look like a fool.  ;)


As you said, most people pull off all the anti-emission gear on the early Rotary Engines, so most Rotary nuts (including me) even most of the 'gurus' haven't encountered issues with the emission control equipment.


Anyway, may you happily rotor on for a long time.

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Dazda don't feel bad. Beginners luck.  ;)


though have researched very hard across 5 forums and talked to at least 4-5 rotary specialist that are willing to talk and not rip you off.


overall pattern emerged that i realised with Rotary owners.


1. Hardly any stock cars around

2. Most owners have no idea they just drive and get someone else to fix it.

3. People that know they really know their stuff but only when things ain't stock and they don't take into account what issues incorrect emissions can cause. Besides one quiet member.


So really no reason to feel bad. understandable. But i did rub it in to some ppl that were giving me the S$^Ts and calling me cheapscate noob via PM. Probably the reason why i got rid of my Rx4 years ago as community wasn't good.

Though there are some really good members out there. SA guys seem to be in force and are willing to help any way possible.


Yeah I hope i get at least 3months out of it than I don't care if it blows up. Still on a lookout for cheap 12A hopefully with symptoms like mine to have as a back up and learn to rebuild it myself. 3.5K for labour is just stupid for a simple motor. once i perfect that than i be set. another notch under my belt. Than  may expand the rotary collection.







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Emmissions crap.

Dont exist on real fast rotaries

Dont exist on a race track!

Niether does the oil metering stuff,

Simple Weber, carb, or throttle body injection.


You then rely on oil addition yourself, and then the things that go wrong are the internal sid and apex seals, and crank seals, along with water seals.


Need a monster port 13b? End plates and housings, matched

Got a set  here,  dismantled !

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yeah yeah i never said this be fast rotary  :D


I was aiming for standard rotary. heaps of modded ones around. I may do another one bit later and have it efi and turbo. but considering removing the air pump and fitting extractors to it. (can be reverted easy) gasket is stuffed so need to look into it anyway.


not a 13B at the moment. looking to find a cheapish 12A. and rebuild it just in case.

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